Up to date heavy-duty equipment cabs come equipped with full color, touch screen displays showing a variety of gages and indicator icons. OEMs are shifting technology from the traditional instrument panels with a plastic frame and housing and several gages and indicator lights to easy to use and interpret display screens that are helping to increase equipment productivity. Like all technologies, there are many factors that drive change.

Dial gages have many components to make them work; overlays, needles, stepper motors, etc.  These components and the subsequent labor required to assemble have driven up the cost for traditional dial gages. Meanwhile, the cost of a good resolution, full color LCD display has come down in price. Displays have relatively few components and generally require less labor to assemble than a series of dial gages, making them an attractive alternative to traditional dial gage clusters.  

To customize a dial gage, several components usually need to be modified, which typically results in an additional cost for customization and production support.  A single base part number display screen is freely programmable and can be customized with software to show many gages or icons on screen. Having more than one screen, allows more information to be made available to the operator.

And, the display can be customized to show details only when the operator needs it or requests it.  For example, the DEF tank level on a diesel engine doesn’t need to display its level on a continuous basis. However, if the fluid level is low, the operator should be alerted and the gage showing the level of the fluid in the tank can appear on the screen.  This “instant on” capability of virtual gages allows a vast number of possible of gages and indictor icons to be shown.

With dial gages, when an operator preferred to view the data in a specified language, a new dial gage overlay was used. But, now with digital displays, the language and the units for the gages and indicators can also be more easily customized.

Original equipment manufacturers can customize the screens, gages, logos and colors for certain OEMs. And, this is managed in the display’s software. So, there is only the need for one part number for the hardware, only one part number needs to be inventoried, maintained and procured. This helps OEMs manage the indirect costs of handling multiple variants of similar parts, while still providing a custom look and feel to their customers.

As the shift towards freely programmable displays continues, more OEMs will adopt screens, in place of dial gages. Not only will this help drive down costs and increase operator productivity, but it will also offer OEMs the ability to add value to their customers through custom virtual dashboards. In order to help OEMs, respond to this shift in technology, Parker has launched new line of PHD displays designed for mobile equipment that offer up to date features, capabilities and ease of programming at a competitive price point.

Visit www.parker.com/phd to learn more.

Article contributed by Kirk Lola, product manager, Electronic Controls Division, Parker Hannifin Corporation.

Related articles:

How OEMs Capture Global Market Share with Multiple Language Support

Advantages of Displays in Mobile Machinery

Easy to Use Display Programming Tools Help Drive Value for Machinery OEMs

Since the advent of mechanized agriculture, agriculture machinery is an indispensable part of how the world is fed.  Powered machinery has long replaced the work of manual labor and working animals like oxen, horses and mules.  

Parker engineers have been trusted partners to develop innovative solutions in agriculture equipment. By understanding OEM goals, needs and expectations Parker delivers value by improving the bottom line and increasing machine performance. Parker’s Global Mobile Systems (GMS) team works directly with OEM customers to solve complex problems which lead to breakthroughs that make the world smarter, safer and more efficient.

With dedicated resources strategically located around the world, applying a broad array of technologies, Parker brings motion control systems to a new level. Parker has the ability to optimize systems through whole-vehicle integration elevates them as the global industry leader in intelligent motion control for mobile equipment. The process begins with gaining a prioritized understanding of your specific goals, needs and expectations. The final result is exceptional value in areas that bring bottom-line revenue and help you compete.

As farmers demand uniform seed depth at faster planting speeds and a higher level of precision from their equipment, it is increasingly necessary to apply force efficiently and precisely to ground-engaging implements. Parker’s hydraulic downforce system can provide a simple easy to control system to meet the end customer’s needs. 

Hydraulic downforce provides either active or passive force to maintain the ground contact a ground engaging implement to maintain a seed-specific depth. The Parker system approach uses a single solenoid control for up and downforce and a two hose solution for fluid conveyance.  

Parker’s GMS team provides maximum flexibility in assisting customers to develop their specific downforce solution using proven components. Parker’s team can provide full system support from development, testing and implementation, to single component support.  

Parker’s GMS team recently partnered with an OEM to help restructure the hydraulics system of their harvester. The OEM had set a goal to significantly improve fuel efficiency, which would would make their product more attractive to end-users. The team saw an opportunity to improve the system efficiency by using variable displacement piston pumps to drive key functions.  

GMS completely restructured the hydraulic system by switching to a variable displacement open circuit solution, using P1 Series pumps with Electronic Displacement Control (EDC) and F12 Series bent-axis piston motors. This compact electronic solution reduced system complexity and increased efficiency; which reduces operational costs over the machine’s lifetime. The new hydraulic system exceeded the fuel consumption goal set by the OEM, saved costs and simplified the hydraulic system by reducing the number of components used.

Parker’s Global Mobile Systems engineering team is focused on helping OEMs optimize machine performance and efficiency as the technology changes the way farmers manage their operations.  

This article was contributed by David Schulte, P.E., senior systems engineer, Parker Hannifin Corporation. 

Related articles:

New Hydraulic System on Sugarcane Harvester Exceeds Performance Goals

Modern Digital Ecosystems Take Mobile Hydraulic Systems to a New Level

Improving Hydraulic Systems for Better Performance and Energy Efficiency

How Can Pneumatic Technology Help Farmers Boost Their Crop Yields? Part 1 of 2

How Can Pneumatic Technology Help Farmers Boost Their Crop Yields? Part 2 of 2

Eco Green Equipment, a tire recycling equipment manufacturer, was looking to meet the stringent demands of the crumb rubber and rubber powder markets. Due to rubber use in artificial turf, playground surfaces, and other applications, crumb rubber and rubber powder are in greater demand with higher quality expectations.

Existing cracker mill technology could produce crumb rubber in reasonable quantities. However, due to their friction ratios, mills could not produce it at a high enough quality or a low enough mesh crumb rubber. As a result, Eco Green wanted to achieve both volume and high quality of crumb rubber in one machine. To fill this gap in the market, Eco Green’s Krumbuster was created.

The following design specs were set for Eco Green Equipment’s Krumbuster:

• Produce up to 4,000 pounds an hour of smaller than 6 mesh crumb rubber

• Produce up to 2,000 pounds of smaller than 30 mesh rubber powder with the same machine and set-up

• Decrease horsepower usage by 20% or more

• Achieve a smaller equipment footprint than traditional mills

• Create a high-performance hydraulic grinding mill that remains highly responsive with:

  • Changes in friction ratios

  • High shock loads

  • Constant changes in pressure and pressure spikes

With Eco Green Equipment collaborating with Parker Hydraulic Pump and Power Systems (HPS) and a Parker distributor, a high-performance, reliable hydraulic system for the Krumbuster was designed. Key hydraulic components for the Krumbuster, included Parker P24 and P6 Gold Cups and T6 Vane Pumps.

These Parker pumps were chosen to complement the hydraulic motor due to their reliability, responsiveness, and ability to handle a high shock load. The Gold Cup pumps were especially critical for this demanding application and the ability to maintain them through authorized repair centers throughout the world.

The results of the Krumbuster’s hydraulic system have revolutionized rubber mill technology. The Krumbuster’s higher production and quality in comparison to traditional mills has been achieved, along with a smaller equipment footprint and less energy consumption.

Parker’s Hydraulic Pump and Power Systems Division has been designing pumps and transmission for over 50 years. The division is the result of the Parker piston pump business's acquisition of Denison Hydraulics and the merger with the Parker Oildyne Division. These two businesses combined have extended Parker's product offering to include the quality compact hydraulic products and systems the division has been pioneering since 1955. To learn more about the products, visit www.parker.com/hps or contact the team. 

Article contributed by Bill Vetters, applications engineer, for Parker Hannifin Corporation's Hydraulic Pump and Power Systems Division.

Related Articles 

Pumps in Hydraulic Systems are Key to Tire Recycling Solution for Mining

High Performance Hydraulic Pumps and Motors Expand Production in Lumber Mill

New Gold Cup Hydrostatic Pump and Motor eConfigurator

5 Benefits of Smart Technology In Extreme Duty Hydrostatic Pumps - Infographic

Hydraulic Pump/Motor Selection Considerations for High-Production Shredding Applications

We think so, because OEMs can reduce the cost of harvesting machines used in agriculture by using Parker's Overcenter Intelligent Flow Control (IFC) architecture.

Closed loop hydraulic systems are commonly utilized for rotary functions. They provide a simple solution without additional valving but can be very expensive when compared to open loop hydraulics. In certain applications, closed loop systems are used, but may be over specified for the application. In these applications, a partial overcenter solution may be worth considering.

In looking at agricultural harvester machines there is an opportunity for OEMs to reduce the costs of harvesting machines using the Parker's Overcenter IFC architecture. There are many potential harvester machines that could benefit from this type of system including;

• Combine harvester – feeder system
• Sugarcane harvester – base cutter system
• Forage harvester – intake system

To see why these machines are an attractive application, think about the typical harvesting duty cycles. Reversing applications are rare and typically do not require full flow. Reversing is also a low duty cycle, sometimes less than 5 percent of the overall duty cycle. Typical operating pressures in normal conditions tend to be low. In some applications, only reaching a continuous pressure rating of the designed components under rare conditions.  

When we design a hydraulic system we typically ask ourselves questions about the functionality of the machine. In terms of pumps, we investigate how pumps can be better utilized. For example, in the event of a function reversal, cleaning functions are typically turned off or idle. Can the flow from these functions be re-directed?

We also investigate what happens when clearing a blockage. We found that the heat rejection requirements are reduced, as the machine comes to a stop to address the blockage. The question then becomes, can flow be diverted from a cooling system momentarily to provide the reversal?

Parker's Overcenter IFC architecture uses our uniquely designed overcenter open loop pump in conjunction with a reversing valve and one additional flow source. This unique design works well in systems that tend to operate in a primary direction most of the time and only need to reverse direction for small isolated duty cycles.

The diagrams below compare a traditional system to Parker's Overcenter IFC system. First, we explore the harvesting duty cycle, a traditional system may consist of a closed loop crop conveyance function and an open loop cleaning function. During a reversal the cleaning function is turned off, while the closed loop changes direction to clear a blockage. 

Traditional System                                                                    Overcenter IFC System

Using the Overcenter IFC system, flow from the cleaning function is diverted to the blocked motor, the flow then returns to tank by driving the crop conveyance pump overcenter. 

Because proportional control is provided by the pump, valves are needed simply to provide direction change, assuming directional control is needed. When designing these systems, pressure drop through a directional valve must be considered. High pressure drop can lead to excess heat and may reduce system performance.

Parker has designed custom low pressure drop manifolds which can be integrated into existing manifolds or mounted as a standalone component. These directional cartridges and manifolds are designed for high flow while maintaining pressure drop. Our target is to be no more parasitic than a charge system.

The R08E3 cartridge provides simple reliable directional flow control at 300 LPM while maintaining pressure drop at or below 3 bar. The R08E3 is also pressure rated to 420 Bar for high pressure systems.

There are three main reasons why the Overcenter IFC is superior. The first is cost: the closed loop systems tend to be more expensive than open loop systems. The second is that the system reduces complexity. There is no longer a need for a charge filter and there is no need for a flushing valve in the system. And, finally the system may provide superior efficiency, it eliminates charge losses, although valve pressure drop should be considered and minimized.

In many applications, we see cost and system simplification advantages to utilizing either the Parker Overcenter IFC concept. While not all systems are applicable, it is probably time to consider the Parker Overcenter IFC system during your next machine architecture redesign.  

The Parker Global Mobile Systems engineering team and Hydraulic Pump and Power Systems Division's application engineering experts are available to assist our customers in designing and implementing new systems to meet your application needs.

This article was contributed by David Schulte, P.E., senior systems engineer, Parker Hannifin Corporation. 

Related content:

Sowing the Seeds and Harvesting Innovation in Agriculture

Split Pump IFC on a Wheel Loader: Simply Smarter

New Compact Design Solves for Typical Check Valve Challenges

Mobile-equipment designers know that in the real world they have to deal with more than level surfaces and two-dimensional access envelopes. Designers at JLG industries in McConnellsburg, Pennsylvania, know that additional obstacles at ceiling level will challenge the platform on their boom lifts. That’s why they created the Model E300AJP electric boom lifts with the exclusive Jib-PLUS boom that provides access up, over, and around obstacles 30 feet above floor. 

Eight 6-V/370-Ahr batteries power the 15,000-pound boom lift through a 48-V DC electrical system. Dual electric traction motors, with automatic spring-applied multiple disc brakes, handle travel. Wheel sensors feed information back to the travel control to ensure that both wheels work independently for improved traction on uneven surfaces or while driving over obstacles.

A permanent-magnet motor drives a highly efficient, internal crescent-gear pump to supply all the hydraulic functions from a three-gallon reservoir. The motor is energized to run the pump only when flow is needed, thus maximizing time between battery charges.

The control console on the 30 x 48 inch operator’s platform incorporates 12-V switches that energize solenoid-actuated, pressure compensated cartridge valves in the operating circuits down at the chassis. A minimum number of controls are used, and they are organized on the console to enhance the operator interface. High-contrast graphics and easy-to-understand symbols make the controls operator- friendly and help to shorten training time.

Reach specifications for the Model E300AJP include 20 feet, six inches horizontally; 13 feet, 1 inch of up-and-over height; and 360° of non-continuous rotation. The articulated jib produces a near-vertical orientation as it swings through a range from 55° downward to 86° upward. A Parker Helac rotary actuator at the base of the jibPLUS adds a 140° arc of side-to-side movement to the jib and platform. Finally, the 500-pound capacity platform is rotated 180° by a second  Helac rotary actuator. In other words, the E300AJP offers truly versatile positioning.

Parker builds both of the Helac rotary actuators installed at the boom’s working end. The Helac L20-15 actuator between the main and jib booms is an integral part of the boom structure — functioning as a mounting bracket, bearing support, and power hinge, as well as the rotational device. The main boom is pinned to the upper hole in the actuator's clevis; the leveling cylinder is pinned to the lower hole. The jib-boom assembly mounts right on the actuator. Its upper mounting bracket is bolted to the large diameter, drilled and-tapped shaft flange. The jib’s lower mounting bracket is attached to the bottom of the actuator by a tie rod that passes through the actuator's shaft bore. (The tie rod functions as a second load path, for added safety.) The straddle orientation of the jib boom not only contributes stability and rigidity but also results in an exceptional 65,000 inch-pounds moment-load capacity (a 2.75:1 design margin). 

The heavy load-carrying ability is largely due to Helac's patented integral journaled bearing design, which eliminates any need for external bearing support. Helac rotary actuators use a sliding-helical-gear operating concept that produces high torque from a compact envelope. (The Model L20 15 is rated for 15,000 inch-pounds at 3,000 psi.) High torque output combines with zero leakage for smooth operation with a solid feel and permits selected positions to be held without drift. For extra safety on the E300AJP. The hydraulic circuit includes an integral, factory installed counterbalance valve in a protected position between the clevises.

This article was contributed by Daniel Morgado, applications engineer, Helac Business Unit, Cylinder Division and was originally published by Hydraulic & Penumatics. 

Related articles:

Lifters Designed with Rotary Actuators Dump Waste More Effectively

New Sealing Solution Extends Service Life of Swivel Joints for Mobile Cranes

Sprayer Steers Clear of the Ordinary

By replacing the previously used steering cylinders with Parker’s sliding spline rotary actuator technology, Huron Manufacturing was able to solve the issues that were inherent with the hydraulic cylinders. By incorporating helical, hydraulic rotary actuators to steer the four tracks on its Easi-Pour Compact 880 slipform paver, Huron Manufacturing was able to provide its customers with a machine that accomplishes what used to require multiple machines. 

The compact Easi-Pour machine can be used for large or small jobs ranging from tight radius curbs, gutters, and sidewalks to surface grade preparation and trimming. 
 

“Our customers are impressed with what this Easi-Pour can do – which is essentially everything. They can buy the less expensive Easi-Pour, yet get the same versatility found in larger slipform pavers ... While it’s rare that a contractor attempts a radius as tight as two feet, this machine can actually turn and hold grade even tighter than that.”

— Murray Serfling, engineering manager at Huron Manufacturing 

Huron Manufacturing replaced the previously used steering cylinders with Paker's Helac sliding spine rotary actuator technology. Hydraulic cylinders offered a turning radius of only 60° - 30° left and 30° right – compared to the 180° of rotation offered by the rotary actuator. The former steering configuration also required multiple mechanical linkage components that needed to be machined and welded together, which is characteristic to this type of design. Parker’s rotary actuator technology offers a cylindrical housing that contains all moving parts safely inside. The rotary actuators not only become the steering unit for all four tracks but provide the support of the load and the hydraulic turning power as well.

Huron Manufacturing also had maintenance and machine performance issues with the steering cylinders from all the pivot pins as well as the pins to keep bearings mounted between caster plates. The machine operators needed to make sure the pins were kept tight, and the bearings had to be greased regularly. The machine wouldn’t operate properly if the pins holding the bearing loosened. With the Parker solution bearings, seals, and torque-generating elements are all completely sealed and lubricated by the hydraulic fluid inside the actuator housing, resulting in low maintenance and zero leakage. The use of mechanical drives – chains and linkages – with the cylinders also limited the vertical and horizontal positioning of the tracks. However, the rotary actuators provide steering feedback through a transducer mounted at the end of each actuator.

The Easi-Pour Compact 880 pours barriers to 42 inches high, paves up to eight feet widths, and handles any tasks that fall in between these specifications. After an accompanying transit mixer pours concrete mixture into its conveyor hopper, the Easi-Pour’s auger moves materials across the machine to a slipform mold that’s located at road level. As the paver travels forward, a hydraulic vibrator helps shape the concrete in a mold, guided by a stringline sensing system also manufactured by Huron. The stringline system automatically ensures perfect steering and grade by incorporating five sensors – two steering, two grade, and one cross-level control. The 880 machine also comes with a grade trimmer with a standard width of 51 inches to trim high spots from the road surface.

Huron’s Easi-Pour matches up well against industry alternatives. In addition to the tighter turning radius, this low-profile machine allows the operator excellent visibility of all the machine’s operations. It features the industry’s largest concrete hopper, yet requires no breakdown for transport. All Easi-Pours feature four-leg stability, and all legs are capable of hydraulically sliding to accommodate essentially any paving configuration. Most importantly, safety, durability, and long life are engineered into every Easi-Pour.

The Easi-Pour Compact 880 is entirely hydraulically operated and does not come with any mechanical drives. Hydraulics in the form of helical, hydraulic rotary actuators are used to operate its four-track steering system. The actuators are rated to 3,000 psi. The four tracks are driven hydraulically through two-speed piston motors – low speed during forming operations, and high speed for travel around the job site.

The track drives are rated to 4,500 psi with a total flow of 49 gallons per minute (GPM). The hydraulic driver trimmer drive uses a closed-circuit piston pump operating at pressure to 4,500 psi, with flow to 36 gpm. The machine’s conveyor and hopper auger are driven by a gear pump with a manual hand valve to regulate speed. The conveyor and hopper’s operating pressure is 2,500 psi, requiring up to 25 GPM flow from the gear pump. Elevation and steering pressures of the machine top out at 2,200 psi, supplied by a pressure compensated, open-circuit pump. 12-V solenoid valves are used to control all the functions performed by the pressure-compensated pump.

The advantages of the actuator technology go far beyond eliminating the cylinder steering. 

“We’ve used Helac actuators for two other machines in the past, including our milling and mining machines for 4-wheel steering and conveyor positioning. The products continue to be durable and reliable and are incredibly easy to design into any of our machines,”

— Murray Serfling, engineering manager at Huron Manufacturing 

Helac actuators improved the overall appearance of the Easi-Pour 880 machine with their clean package that’s compact and doesn’t interfere with other functions. Improved performance of the slipform paver was an additional benefit of the rotary actuator.

The torque output generated by the Parker's Helac L30 Series actuator gave the Easi-Pour machine the power to make much tighter turns than many comparable machines in the industry. The quality of the pour also improved because the height of the drive tracks could be independently controlled without impacting the steer capability. 

The cutaway above shows the initial position of piston and output shaft. Pressurized fluid entering inlet port A displaces the piston; a stationary ring gear causes the piston to rotate clockwise. At right, teeth on the output shaft mesh with those on the ID of the piston, causing the shaft to rotate clockwise relative to the piston. Pressurizing port B returns the piston and shaft to their initial positions.

Operating technology is the key to the benefits of Parker’s hydraulic rotary actuator. Its design affords a unique combination of features not found in other rotary positioning components – high torque and moment loads, high angles of rotation, and compact configurations. Its sliding-spline operating technology is designed to replace multiple components and function as a rotating device, mounting bracket, and bearing, all in one. The design of Parker’s rotary actuators systematically converts linear piston motion into powerful shaft rotation. Each actuator is composed of two moving parts – a central shaft and piston. Helical spline teeth on the shaft engage matching teeth on the piston’s inside diameter. When hydraulic pressure is applied to the piston, it moves axially, while the spline causes the piston and output shaft to rotate simultaneously.

To learn more about Parker’s hydraulic rotary actuators, please visit our website.

This article was contributed by Jessica Howisey, marketing communications manager and Daniel Morgado, applications engineer, Helac Business Unit, Cylinder Division

Lifters Designed with Rotary Actuators Dump Waste More Effectively

Sprayer Steers Clear of the Ordinary

Unique Tilting Coupler Technology Gives Construction Firm Competitive Edge

The safe navigation of ships in challenging marine environments is a testament to the skill of the crew and the performance of the equipment they use. In offshore applications, the ambient environment can become hugely unpredictable, with wildly fluctuating temperature, humidity and vibration. This puts instrumentation and automation equipment under extreme duress, at a time when the performance of such systems is most critical to operators. 

Fortunately, mandatory marine type approval exists to ensure that safety-critical apparatus installed on any classified vessel is fit for the task at hand. The stringent UR-E10 test specification from the International Association of Classification Societies, for example, provides strict criteria for the test requirements for electrical, electronic and programmable equipment intended for control, monitoring, alarm and protection systems for use in ships and other offshore applications.  

At its heart, UR-E10 demonstrates the ability of equipment to function as intended under specified testing conditions - which is a comforting thought in marine and other offshore environments, no doubt, as the waves swell and the weather closes in. 

For equipment suppliers, meeting the requirements of UR-E10 is a result of considered design at every stage of the product development process, with engineers working hard to ensure that equipment meets strict electrical, Electromagnetic Interference (EMI) and environmental performance expectations. For UR-E10, specifically, there are a whole host of multi-point tests covering varied aspects of performance including an external power supply failure test, Electrostatic Discharge (ESD) and surge immunity, dry and damp heat, vibration and flame retardancy, to name but a few. 

Achieving marine certification is, therefore, no mean feat. That’s why here at Parker, we are pleased to announce that the Pro Display 10 human-machine interface has now achieved UR-E10 and also fulfills Electromagnetic Comapatility (EMC) requirements for installations in general power distribution zones providing customers with a space-saving, cost-effective and reliable Human Machine Interface (HMI) solution for marine and other offshore applications.  

As well as guaranteeing performance in the harshest conditions, the Pro Display 10 comes with a full set of functions to support marine crews. The rugged 10-inch display module features multi-touch capability for ease of operation, even in the roughest of seas. The touchscreen interface enables rapid and accurate interaction with the display’s apps, although the platform can also be controlled using remote buttons or a pulse wheel if preferred.  

Furthermore, the use of in-plane switching (IPS) screen technology results in crystal clear images with impressive colour reproduction from wide viewing angles – a particularly important consideration in the highly variable light conditions that may be encountered in marine environments. 

In terms of software development, Pro Display is an app-based platform and provides tools for fast and advanced application development. Parker’s UX Toolkit enables better usability for customer HMI applications, by bringing modern features such as dynamic user interface, fluid UI animations, and easy-to-use and intelligent data management. With Pro Display, marine customers can deploy customized HMI functions such as machine functionality, diagnostics, data monitoring and visualization and work management. 

Moreover, Pro Display 10 can be a central HMI unit in a system or serve as a stand-alone display. A wide variety of communication interfaces supports versatile use within marine applications. For example, four CAN buses and Ethernet support communication for various systems in the application.  Besides the two analog camera interfaces, a number of IP-cameras can also be connected to via Ethernet switch or a WLAN access point. 

The result, then, is a product that performs at the highest levels in the harshest conditions. And that’s what marine crews and offshore operators demand as they combine their skills and experience with cutting-edge technology to ensure safety at sea. 

Learn more about Parker Pro Display HMI solutions.

This article was contributed to by Mikko Konttila, Mobile Hydraulic Systems Division Europe, Electronic Controls Business Unit Parker Hannifin Manufacturing Finland Oy.

Related articles:

How Does a Smart User Interface Improve Machine Efficiency?

Integrated ISOBUS Functions Help Agriculture Sector Plow Ahead

Meeting New Sulphur Limits for Marine Fuel Oil

Today, planters typically drive tractor pressure to high-pressure standby, generating excess heat and reducing fuel efficiency when tractor remotes are used to power fans, compressors and fertilizer pumps. Hydraulic downforce systems can also require high pressure at low flow driving the tractor to maximum pressure. 

Multiple planter systems are typically controlled using the main tractor directional valve. The tractor pump usually operates at max pressure during planting creating: 

• Excess heat 
• Reducing fuel efficiency 

By using a dedicated pressure-compensated pump driven by the tractor’s PTO to power the planter hydraulic downforce system, the tendency for the tractor pump to operate at high-pressure standby is reduced, thereby reducing a major contributor to excess heating and poor fuel consumption. Pump should be low displacement, sized to handle downforce flow needs. Pump also provides supply pressure to operate the Power Beyond pump. 

The pump has a secondary function by providing a pressure source for a proportional pressure control valve which can be intelligently controlled via the tractor power beyond load dense port. 

By intelligently controlling a tractor pump by using the tractors power beyond option, the planter has complete control of the pump providing freedom to design and control the planter as desired. Pressure sensors at the fan and fertilizers functions allow for intelligent electric load sense, removing the need for additional hoses.

By separating the hydraulic downforce from the other planter functions, the tractor and planter power usage is optimized, reducing heat and therefore improving overall efficiency and component life. By controlling the tractor pump directly the planter is free to control the fan, fertilizer, and other accessory functions more intelligently.

Parker's extensive knowledge of the agriculture industry and understanding of the challenges farmers face help to shape integrated products and services that simplify installation and equipment service, reduce noise and drive performance. Doing so enables farmers to improve efficiency, reduce operating costs and comply with industry regulations, so they can focus on their critical role in our society. 

The P1M-28 is a low displacement pump that is ideal for providing only the flow needed for downforce systems at the pressure required.  The P1M Series delivers higher speeds and efficiency that increases machine productivity, reduces costs, and extends pump life in a robust, compact envelope. 

Parker’s EPR series of valves is an ideal valve choice when Intelligently controlling load sense systems for hydraulic devices up to 285 bar (4,000 psi).   

The EPR valve’s market-leading performance features the capability to handle flow rates up to 60 lpm (15 gpm) and can control pressures as high as 285 bar (4,000 psi). For systems with pressures less than 70 bar (1,000 psi), a slip-in style is available, otherwise a threaded screw-in style connection is available for systems with pressure in excess of 70 bar (1,000 psi), making the EPR a versatile addition for numerous applications. 

The Parker Global Mobile Systems engineering team and Hydraulic Pump and Power Systems Division's application engineering experts are available to assist our customers in designing and implementing new systems to meet your application needs.

This article was contributed by David Schulte, P.E., senior systems engineer, Parker Hannifin Corporation.   

Related articles:

Is It Time to Rethink Open Loop Hydraulics in Agriculture Machines?

Sowing the Seeds and Harvesting Innovation in Agriculture

Sprayer Steers Clear of the Ordinary

Defining Our Unique Contribution to the World

Keeping up with the Joneses means big business for Enumclaw Landscape based out of Enumclaw, WA. As a full-service landscape construction company, they provide landscape services to residential, commercial and government customers. Good old-fashioned work ethic and integrity are two key factors in running a successful business for more than 40 years — but David Schodde and his team of experienced professionals have another ace up their sleeve in the PowerTilt Tilting Coupler Attachment.

Enumclaw Landscape purchased a PowerTilt model PT-6 attachment for their mini-excavator. This machine, with PowerTilt installed, can be used to perform a wide variety of landscaping tasks, such as, grading, contouring, ditching, sloping and trenching.

Prior to their purchase of the PowerTilt attachment, the company used a significant amount of manual labor on their landscape construction projects. With the PowerTilt, they received better results on the job site with fewer workers required.

“PowerTilt works awesome! It adds so much versatility to our mini-excavator. I wish I would have had a PowerTilt 40 years ago.”

David Schodde, Owner, Enumclaw Landscape

PowerTilt’s ability to increase the number of tasks a single machine can perform allowed Enumclaw Landscape to better allocate their resources into enhanced profitability.

Landscape construction companies often work in tight quarters. Residential customers have multiple neighbors bordering the job site or other natural obstacles like trees, shrubs or water features that require special attention. Small footprints on the jobsite are imperative. PowerTilt allowed the equipment operator to avoid repositioning the excavator any more than absolutely necessary. The attachment is flexible enough for the driver to reposition it without having to move the equipment. 

Another benefit of the PowerTilt is the ability to tilt a wide bucket and then use the corner of the bucket to dig a trench without having to switch to a narrow trenching bucket. This functionality saves the operator significant time by allowing the rotation of the 48" bucket to then dig a narrow shallow trench to lay conduit or irrigation line. Previously the operator would have had to change to a different bucket.

PowerTilt uses innovative sliding-spline operating technology to convert linear piston motion into powerful shaft rotation. Each actuator is composed of a housing and two moving parts — the central shaft and piston. As hydraulic pressure is applied, the piston is displaced axially, while the helical gearing on the piston outer diameter and the housing’s ring gear causes the simultaneous rotation of the piston. At the same time, piston inner diameter and shall cause the shalt to rotate and tilt the buck. PowerTilt’s end caps, seals and bearings all work in tandem to keep debris and other contaminants out of the inner workings of the actuator, prolonging product life and reducing required maintenance.

"PowerTilt gives us more flexibility with our machine. With PowerTilt installed, we can use our mini-excavator to its fullest potential."

Dave Magstadt, Equipment Operator for Enumclaw Landscape

PowerTilt's versatility allowed it to stay on Enumclaw Landscape's machine almost the whole year-round. the competitive advantage for the company has been to complete jobs faster and more cost-effectively. 

Over a decade of innovation and engineering has gone into making PowerTilt an integral solution for worksite efficiency. It is specifically engineered to work with a variety of attachments to improve a machine's versatility like wide buckets, brush cutters, narrow buckets, hydraulic hammers, rippers and mowers. PowerTilt is available for equipment up to 75,000 pounds in eight sizes with a standard rotation of up to 180 degrees. Each model is engineered for a specific class of machinery and individually customized to fit the machine. Learn more about Parker’s PowerTilt.

This article was contributed by Jessica Howisey, marketing communications manager, Helac Business Unit, Cylinder Division

.

Related articles:

Unique Tilting Coupler Technology Gives Construction Firm Competitive Edge

Lifters Designed with Rotary Actuators Dump Waste More Effectively

Screw-to-Connect Couplings Make Hard Work Easier

The Michigan Street Lift Bridge reopened to vehicular traffic Friday, July 31, 2020, after a yearlong rehabilitation project. The bridge spans the Milwaukee River and is one of many downtown bridges that link Milwaukee, Wisconsin's East Town and Westown neighborhoods. 

The City of Milwaukee’s Department of Public Works oversaw the project, which upgraded, and replaced as needed, the existing structural, hydraulic and mechanical components. The previous lift bridge had a latticework steel deck, which was replaced with concrete decks.

Parker Distributor MFP Automation Engineering was a key subcontractor in this large public works project. MFP Automation Engineering was founded in 1991 and specializes in pneumatics, hydraulic power units, custom manifolds, servo motors, motion control products, electromechanical and much more. Over the past five years or so, MFP has made a name for themselves for their involvement in several movable bridge projects. Their bid for the project was selected over other hydraulic suppliers in part due to their ability to supply a turn key system as part of their bid package.

MFP supplied a custom-built hydraulic power unit, a directional control manifold, four large Parker cylinders, and installed all the associated plumbing. MFP was a valued partner to the large civil engineering firm for the project, and during the process was able to suggest some modifications to the original design.

Hose Products Division supplied the 387TC GlobalCore Hose and 43 Series Fittings that are used on the bridge.  Parker’s 387 GlobalCore hose is a constant working pressure hydraulic hose offering 3,000 PSI in all sizes, ranging from ¼-inch to 2 inches in diameter. With three cover options: Standard, ToughCover, and SuperTough Cover, this light, durable, and easy-to-bend hose meets and exceeds ISO 18752 performance specifications. 

The 387 hose offers low force-to-flex and delivers full SAE-standard pressure at one-half SAE bend radius, resulting in easier handling and installation. 387 hose also offers a 30 percent smaller OD by area compared with SAE-standard spiral hose and is compatible with petroleum-based hydraulic fluids and lubricating oils. 

GlobalCore 387 hose is compatible with Parker’s 43 series fittings in sizes -4 to -20. The fittings feature one-piece construction with chromium-6-free plating, are offered in more than 2,500 configurations and are available around the world.

The Cylinder Division was able to provide critical design insight and engineering assistance for this application, The cylinder required many special design characteristics to meet the stringent safety parameters on this project.

The hydraulic cylinder that is used on the bridge is based off of Parker’s 3HB series product. While this starts as a traditional NFPA product, the 3HB differs in that it does not utilize tie rods. This was extremely beneficial for the project since it eliminated the need for tie rod supports (there would have been several needed) and allowed for MFP’s custom manifold to be affixed to the cylinder body at an optimal location. The lack of tie rods and supports also reduces overall weight and makes maintenance much easier. The standard dual wear band design of the 3HB piston provides excellent bearing surface that will translate to long cylinder life. 

During the installation, MFP’s team utilized the Service Master Easy from the Quick Coupling Division to monitor the different cylinder pressures. The Service Master Easy is a convenient, easy to use, handheld meter that can measure four different pressure transducers simultaneously. The large screen readout allows the user to see if there are pressure drops (or spikes) in the hydraulic system.   

The Service Master Easy is just one product in the division’s SensoControl product line. Being able to effectively monitor equipment systems and diagnose issues before they become problems can help alleviate costly downtime and prevent damage to expensive equipment. Parker SensoControl products gives end users an edge in downtime prevention with a full complement of condition monitoring and diagnostic equipment that is ideal for individual components or entire systems.

Safety and reliability are necessary in a lift bridge, especially for a downtown city location. The Michigan Street Lift Bridge benefits from decades of Parker pump expertise. The Pump & Motor Division supplied the 365 Series gear pump for the project.

The 365 Series is a fixed displacement gear pump which offer high pressure durability due to its cast iron construction, making them ideal for high duty applications. The 395 Series Pump is ideal for critical applications due to the high horsepower and proven durability and efficiency. 

Smooth and reliable acceleration and deceleration control are critical to the safe operation of the bridge. The Hydraulic Valve Division’s D41FC series are installed as the pilot-operated proportional directional control valves to provide dependable, precise closed-loop control over a range of high flow rates. Additionally, the D41VW provides reliable on/off directional control of the system. 

Milwaukee has rapidly changing weather with cold, windy, snowy winters and warm, humid summers. The lift bridge and its components need to withstand a variety of environmental conditions. The digital onboard electronics are situated in a robust metal housing, providing protection against these challenging elements, while also carrying an IP65 designation for the vibrational conditions. 

Parker's distributor partnership with MFP Automation Engineering and many of Parker’s division engineering experts brought the Michigan Street lift bridge to life, and will be part of the city's infrastructure for years to come. 

Related articles:

New Hybrid Actuation System Ideal for Renewable Energy Applications

Hydraulic Cylinders Enable Artistic Architecture at University | Case Study

Today’s off-highway mobile construction equipment is more complex than many would have ever imagined a mere 20 years ago. At the turn of the century, mechanical advancements and machinery upgrades rarely involved electronic controls or computerized enhancements. Yet in today’s world of off-highway equipment, special devices called “gateways” are utilized for security, safety and increased efficiency. These gateways serve as central hubs that allow for secure and reliable interconnections that process data across a wide range of vehicle networks and electronic control units (ECUs). 

Because of the advancing technologies in the off-highway machinery space, it is more important than ever to stay prepared for future changes. As large mobile equipment networks continue to become more complex, the existing communication strategies will result in system bottlenecks down the road. A gateway device, such as the PVSG, solves these challenges by enabling future communication network architectures which allow for multiple network buses and managed communication between networks.

Ideally, such a wireless gateway provides routing support for different CAN network protocols, such as 11 bit CAN, 29 bit CAN and J1939. In order to support a multitude of CAN network protocols, the PVSG was developed with a PC configuration tool that enables OEMs to easily set the routing table without custom applications or detailed software competency - taking the challenge out of the process so OEMs can focus on reliability, efficiency and safety.

This article was contributed by Sharlette Carey, marketing specialist and Curtis Rebizant, marketing manager, Electronic Controls Division.

 

 

 

 

 

 

A common place integrated hydraulic circuits can be found are on mobile applications in the construction, forestry and material handling markets. To meet the essential feature of load controls in these applications, a counterbalance valve is often used.

The basic function of a counterbalance valve is to control a load, by providing a restriction through a differential area. They also help prevent cavitation when controlling an overrunning load. Load control is achieved when enough pressure is present at the work port of the valve to overcome the spring setting. Specifically, when an actuator is pressurized, pressure is developed at the work port. This pressure builds and acts on the differential area until it overcomes the spring setting, shifting the poppet and allowing fluid to pass through to tank.

In addition, there is also a pilot signal (usually the opposite side of the actuator) that connects to the counterbalance valve. This signal enables the valve to shift with much less load pressure. If the load attempts to “run away” (when it moves faster than the pumps can supply flow), the pilot signal is diminished, resulting in the piston to restrict flow to tank thus controlling the load.

An added feature of a counterbalance valve is a built-in thermal relief. Because oil expands under intense heat conditions, actuators of load holding applications sometimes have unintended movement. However, built-in thermal relief allows drops of oil to pass when work port pressures reach the spring setting eliminating unintended movement in load holding applications.

There are many factors to consider in selecting the right counterbalance valve for a specific application. From flow selection, vented or non-vented, to adjustment types and setting selections, there is a lot to consider. However, the pilot ratio is one of the most important features when selecting a counterbalance valve.

Defined, a pilot ratio is the ratio of pilot area to differential area. This means the higher the ratio, the less amount of pressure needed to assist the valve and unseat the poppet. However, a caveat for selecting a higher pilot ratio is less restriction, less control, and less horsepower required.

The decision of pilot ratio is highly dependent on application. For example, the most popular counterbalance valve ratio is 3:1, often used in position-critical applications such as pick and place applications, where control is essential. On the flipside, a 10:1 ratio is common amongst high speed and motor control applications where positioning is not critical, and required horsepower is reduced. At the end of the day, it is important to remember the following:

• Higher pilot ratio = less restriction, less control, and less horsepower required
• Lower pilot ratio = more restriction, more control, and more horsepower required

Other functions a counterbalance valve performs include holding a load, protecting against hose failures, and offering control in critical metering applications. However, it is important to note that counterbalance valves are only needed if the application has varying loads or speeds. If they are fixed, Parker Hydraulic Cartridge System Division’s flow control valves and pilot operated check valves should be used. For example, using a counterbalance valve on outriggers may result in the scenario pictured below. Here, back pressure developed assisting the counterbalance valve through the pilot signal, causing the cylinders on the construction equipment to give out.

As one might realize, picking the right features for a counterbalance valve might seem harder than expected. With Parker’s Hydraulic Cartridge Systems Division’s Application Engineers, finding the right products for a specific application is easy. For more information on Parker’s cartridge valves, and how to select the right counter balance valve, contact us.

Article contributed by Nate Borries, technical sales associate, Parker Hannifin's Hydraulic Cartridge Systems Division

Flow Force is Essential for Proper Cartridge Valve Function

Three Ways to Improve the Operation of Your Proportional Valve

Unique Team Effort Completes Upgrading of Pressure-Relief Valves at Hoover Dam

We think so, because OEMs can reduce the cost of underground construction machines by using Parker's Overcenter Intelligent Flow Control (IFC) architecture.

Closed-loop hydraulic systems are commonly utilized for rotary functions. They provide a simple solution without additional valving but can be very expensive when compared to open-loop hydraulics. In certain applications, closed-loop systems are used, but may be over-specified for the application. In these applications, a partial overcenter solution may be worth considering.

In looking at drills and trencher machines there is an opportunity for OEMs to reduce the costs of small and medium-duty machines using the Parker's Overcenter IFC architecture. The applications where this system could be applied include:

• Trenchers – trencher chain drive
• Directional drill – drill rotate

To see why these machines are an attractive application, think about the typical duty cycles. Reversing applications are rare and typically do not require full flow. The reversals are typically only required when breaking or making pipe, or in the case of trenchers, cleaning out a trench.

During these reversals, other pumps may be available to provide reverse flow such as a mud pump or front implement. This architecture is based on applications where during a reversal, another system on the machine is idle or has capacity to provide flow for reversing the drill rotate or trencher mode. 

Parker's Overcenter IFC architecture uses our uniquely designed overcenter open-loop pump in conjunction with a reversing valve and one additional flow source. This architecture better optimizes the use of pumps on a machine and helps to reduce the need for expensive closed-loop components.  

When applied to a drill, for example, the hydraulic flow from a mud pump function can be diverted to the drill rotate function to provide reversal. During pipe break, the mud function should not be required. This diverter functionality can be added to an existing manifold valve for packaging.

The diagrams below compare a traditional system to Parker's Overcenter IFC system. First, we explore the drilling duty cycle. A traditional system may consist of a closed-loop pump that operates the drill in both directions. When adding a pipe to the drill string, wrenches hold the pipe while the pump reverses direction to unscrew from the pipe allowing a new pipe to be added.

Using the Overcenter IFC system, the duty cycle is the same, however, instead of reversing the drill by changing the direction of a closed-loop pump, flow is diverted from the mud pump function that then reversed the drill motor. The flow then drives the drill pump overcenter returning the flow back to tank.

Traditional System                                                        Overcenter IFC System

Because proportional control is provided by the pump, valves are needed simply to provide direction change, assuming directional control is needed. When designing these systems, pressure drop through a directional valve must be considered. High-pressure drop can lead to excess heat and may reduce system performance. Parker has designed custom low-pressure drop manifolds that can be integrated into existing manifolds or mounted as a standalone component. These directional cartridges and manifolds are designed for high flow while maintaining pressure drop. Our target is to be no more parasitic than a charge system.

The R08E3 cartridge provides simple reliable directional flow control at 300 LPM while maintaining pressure drop at or below 3 bar. The R08E3 is also pressure rated to 420 Bar for high-pressure systems.

There are three main reasons why the Overcenter IFC is superior. The first is cost, the closed-loop systems tend to be more expensive than open-loop systems. The second is that the system reduces complexity. There is no longer a need for a charge filter, and there is no need for a flushing valve in the system. And, finally, the system may provide superior efficiency, it eliminates charge losses, although valve pressure drop should be considered and minimized.

In many applications, we see cost and system simplification advantages to utilizing the Parker Overcenter IFC concept. While not all systems are applicable, it is probably time to consider the Parker Overcenter IFC system during your next machine architecture redesign.  

The Parker Global Mobile Systems engineering team and Hydraulic Pump and Power Systems Division's application engineering experts are available to assist our customers in designing and implementing new systems to meet your application needs.

This article was contributed by David Schulte, P.E., senior systems engineer, Parker Hannifin Corporation.

Related content:

Is It Time to Rethink Open Loop Hydraulics in Agriculture Machines?

Electronic Control Systems for Heavy-Duty Vehicle Implements

Four Check Valves Functions that Keep Mobile Equipment Mobile

Is running at 100% capacity without suffering grain losses and damage even possible with the day-to-day challenges of getting a crop out of the field on time? That’s a balancing act manufacturers are challenged to meet. Today’s combines, however, are so well engineered that they can come close to those targets, provided you are willing to invest in the day-to-day diligence needed to evaluate your harvester’s performance and to fine-tune its operation to support the new generation of advanced technology. 

Machinery breakdowns are costly, and they are especially so during planting and harvesting season, when getting seed in the ground and grain out of the field in a timely fashion are critical to maximizing yield through a reduction of total cost of ownership. Skipping daily maintenance is a common mistake that can cause downtime. For instance, it is important to grease all lube points daily and check engine oil and fluids such as transmission fluid and urea or diesel exhaust fluid. Furthermore, with the new Tier 4 engines, there are issues with people who use a cheaper urea or diesel exhaust fluid and that can cause problems with the exhaust and after-treatment systems. Farmers also should regularly replace fuel filters and check chains, gearboxes and belts for wear and replace when wear is excessive. On gravity wagons, wheels should be checked for tightness and alignment before going to the field.  

During the daily maintenance check it is important not only replace a part that has failed but also check or replace other parts that may have caused the initial failure. Examples include replacing a drive chain when the sprocket was shot or replacing a belt when the pulley was bad. Replacing only the parts that are broken is a temporary fix that can cost money in downtime. When customers don’t replace all the things we recommend need replacing, nine times out of 10 they will come back with bigger problems we’ll end up having to fix.   

Unplanned downtime due to maintenance is one of the culprits to reduced profits, however today, operators have access to a range of technology and enhanced components that are designed to deliver value, improve productivity and simplify the harvesting process that positively impacts profits. The three big categories that continue to capture the most interest within the combine industry are advances in electrification, digitalization and operator comfort.  

Engineers are designing machines that work faster and more efficiently, which also increases the output of the crop, meaning more crops in less time. These enhancements are not only impacting new equipment but within the aftermarket industry as well. For instance, self-propelled combine harvester’s adoption has become a major trend among various agricultural operations. These intelligent combine harvesters are competent in monitoring grain flow rate and yield loss in real-time. As a result, grain growers are making a seismic shift to intelligent combine harvesters over conventional combine harvesters. In addition to monitoring productivity, there are sensors that can be added to enable the operator to recognize problems with the tire pressure equally as quickly as persons in the danger zone of machines and warn of collisions in good time by means of acoustic signals and messages on a master control display.   

These types of IoT enhancement within combines has made the demand for productivity even greater.  Since autonomous machines are still in concept, operators are spending more and more time in the cab.   So, naturally, there is also a focus on all-day comfort for the operator.  A comfortable air-ride seat and the steering column adjust fully needs to be optimized for productivity. Operation of the machines must be fairly straightforward whether the operator uses electronic joysticks, handles with control buttons, switches, or an onboard IQAN system developed by Parker. Operator comfort also includes the climate control system keeps the temperature perfect.  But, issues do arise with air conditioning systems, unfortunately.  Waiting to order the replacement part can cause significant equipment downtime or vehicle operator discomfort. Having the ability to repair the existing assembly with the correct components can be both a time and cost saver. So next time you need to repair an A/C system within a combine, consider Parker’s hose tube assemblies. 

The last item to consider when replacing components should be the implementation of electric components, which can dramatically increase profits. For instance, Parker’s compact EHA  delivers powerful, reliable linear movement. Compact EHA is a fully self-contained electro-hydraulic actuator that combines high power density with lightweight, low sound level and small envelope. Simple “plug 'n play” functionality makes Compact EHA the ideal solution for applications where other conventional linear movement technologies lack the power, speed and durability of compact hydraulics.  Another electrification option could include the addition of an electric linear actuator, which can be used to adjust the position of the cutter bar, the speed of the knives on the bar and/or grain tank covers.  The benefits of electric linear actuators include: 

• Better positioning performance 
• Greater control flexibility 
• Improved energy efficiency 
• Elimination of fluid leaks 
• Maintains the robustness and reliability of existing technology 

Since electrical power is readily available and is in fact needed to create fluid power, it seemed a logical place to start when considering component options for a combine.  

The busiest time of year is harvest. And Parker is here to help.  We understand that there is a lot of preparations that need to be made before combines and tractors hit the fields. And when harvest begins, every hour spent in the field improves yields. Visit our off-road machinery industry page, to identify products and solutions you need to optimize your equipment for harvest.  

How Can Pneumatic Technology Help Farmers Boost Their Crop Yields? Part 1 of 2

How Can Pneumatic Technology Help Farmers Boost Their Crop Yields? Part 2 of 2

Sprayer Steers Clear of the Ordinary

How Will New Trends in Seeding and Cultivation Impact Machine Design?

Sowing the Seeds and Harvesting Innovation in Agriculture

The Move Toward Smart Sprayers

Planting has come a long way from the days of scattering seeds on the ground and hoping for the best. Manufacturers around the globe are introducing several initiatives to improve agricultural practices and productivity. These manufacturers, such as Parker, are promoting the use of advanced technologies and mechanized equipment even in small household farms. 

For instance, in the past few years, drive technology went from sprockets and chains to shafts to hydraulic motors. Now we have electric-drive motors on each row unit. The biggest technologies for planters and other ag equipment now are the electronics and control systems. 

This evolution of planter technology helps farmers automate a large part of their agricultural operations and minimize their input costs.

Speed and the need for more storage is are two of the most important aspects of a planter. One of the elements to make the equipment faster is making components smaller and lighter to increase productivity. On planters there are several different types of hose and tubing that take up a considerable amount of room. To reduce the footprint of hose or tubing, you either need to find a replacement with a reduced outer diameter without sacrificing flow. Furthermore, the replacement hose needs to handle high temperatures and environmental stress to prevent premature hose failure and safety risks. Parker’s push-to-connect thermoplastic hose  offers a wide variety of added value over their rubber counterparts. Thermoplastic hose is built with a high level of contact strength between the layers of core, braid and jacket. The inherent strength of the thermoplastic materials used to make hose allows the use of less material when compared to rubber hose. The outer diameter of thermoplastic hose from Parker can be 20% smaller than outer diameters on comparable rubber hose. This feature is very important on equipment where space is limited and many hoses must fit into a small area, which is common within planters. Furthermore, thermoplastic hoses due to the material and construction, are up to 40% lighter than comparable rubber hoses.  

As the requirements for seeding technology have generally become more demanding, with new features including: changing row widths, grain singling, simultaneous working-in of fertilizer, grain counting sensors, and integration with the tractor and farm information system. Today’s conventional till and no-till planting technology runs the gamut, from large-frame, modular-frame, small-frame and folding planters to air hoe and air disk drills to row-crop planters and seeders.  

Precision control systems take the guesswork out of the planting process and potentially reduces input costs at a time when those costs are continuing to rise. This can greatly increase your efficiency during planting season. 

There are a number of different models of planters that include a variety of options. These include mechanical drives, hydraulic/electric drives, point row clutches, variable rates and more. It’s always a good idea to consider a few different models to determine which one is best for your operation. New advancements in planting technology includes such as down-force management, variable-rate seeding and section control technology allowing users to adjust planting prescriptions on the fly to address changes in field conditions. They also allow the user to automatically turn row units on and off to reduce seed costs and GPS-enabled software ensures that seeds are dropped only where they are needed. This advanced technology is not only for new equipment, you can retrofit your current planting equipment to optimize seed placement. For instance, Parker’s Hydraulic Downforce concept can provide a simple easy to control system to meet the end customer’s needs. Parker’s system approach includes:  

• Single solenoid control for up and downforce  
• Two hose solution for fluid conveyance 
• Low electrical power requirements 
• Fail to downforce in case of power loss 
• Single source global supplier 

Typically a planter downforce system includes an onboard controller which is actively controlling a hydraulic actuator to regulate force based on a force feedback sensor. Parker's wide range of downforce component and system options can provide the best solution for your planter needs while minimizing power requirements with our industry-leading downforce valve. 

Technology has also been enhanced beyond the downforce system.  Variable air pressure systems, or CTIS (central tire inflation systems), has gained popularity within the planter market. The reasons for their increase in popularity and inevitable acceptance span from increased fuel efficiency to reduced soil compaction, but ultimately all the benefits revolve around operating a tire at the exact correct pressure for the load and speed imposed on the tire to increase productivity. 

CTIS systems are already catching on in Europe, where awareness of the cost of soil compaction is high, and so is the percentage of the time tractors spend on the road going from field to field. So far, most American farmers have been reluctant to invest in CTIS. But U.S. and Canadian farmers are starting to realize that in order to get maximum productivity from the horsepower they’re buying -- to make sure all that horsepower is reaching the ground-- they need to manage inflation pressure. And a CTIS package is a small fraction of the cost of a modern tractor and/or planter. 

Technology is and will always be important, but don’t ignore maintenance as one of the main building blocks of productivity and efficiency. Proper adjustment of planting equipment, whether you are a conventional grower or a no-tiller, is very important. That means checking wearable parts, adjusting for and maintaining a level ride for your planter, taking pains to ensure proper planting depth in a variety of conditions and applying adequate downforce for good seed-to-soil contact. 

To enhance the maintenance process, Parker’s innovative component-tagging and asset management solution keeps you more connected and better informed about your asset than ever before. Parker Tracking System can help you identify parts, track maintenance activities, and order replacements quickly and easily. For instance, a customer can scan the barcode on one of Parker’s constant working pressure hydraulic hoses  and immediately find out part number, size, rating, and length of hose; end fitting sizes, and configurations; and where and when the assembly was made. This information can immediately be communicated to the nearest Parker distributor, reducing unplanned downtime to a minimum.   

In planter equipment, it's not just a question of getting bigger and more complex from a technology aspect, but also getting better maintaining and monitoring equipment to reduce unplanned downtime. Parker can help optimize your planter with the right technology that yields the highest profits. Visit our off-road machinery industry page, to identify products and solutions that you need to optimize your equipment.  

The Benefits of Intelligent PCLS and Pressure Compensated System Architecture

Hydraulic Accumulator Services Improve Plant Equipment Efficiency

Sowing the Seeds and Harvesting Innovation in Agriculture

The world is predominantly dependent on food, apart from clean water. Acquiring sufficient food is proving to be a major issue for most people around the world. This grave issue has turned agriculture into one of the most prominent industries in the world. Agricultural productivity defines not only the country's economy but also the health and security status of its population. Therefore, the high importance of agriculture in the economy of a country plays a major role in the growth of the crop sprayer market. 

Population expansion, declined natural sources, increasing incomes and changing climate conditions has led to increased food prices and agricultural productivity has come into question in recent years. As a result, various strategies are being adopted for triggering food productivity. For instance, properly applying chemicals to control weeds, insects, and diseases, provides the best chance for high yields.  

Sensor-controlled precision spray systems are offering attractive opportunities for market growth. When used with foliar application equipment, sensors trigger the opening of valves so that pesticide is sprayed only in the zones where foliage is present. The same sensor systems can be used with herbicide or fertilizer applicators, but for these uses, the application is triggered by the absence of foliage above a specified height, tailoring applications for better reset management.

Precision spray systems can greatly decrease the number of spray materials used without compromising effectiveness and can reduce the potential pollution arising from off-target deposition but must be used properly to achieve these benefits. Each nozzle in a sensor-controlled precision spray system is controlled by its own individual pulsing valve giving you a consistent spray pattern as speed and conditions change.

In the last decade, technical advances have reduced the cost and improved performance and reliability of these systems. These technical advances include:  

• Sensor and control technology - Sensors, monitoring and control technologies are an integral part of sprayer equipment. Parker sensors and controllers provide up to sixteen axes of coordinated motion control for complete digital electromechanical, pneumatic and hydraulic control systems. Sensors are even used to control the pressure of the tires (central tire inflation system) to ensure at the exact correct pressure for the load and speed imposed on the tire to increase productivity.   
• Fitting coating - To extend corrosion protection beyond SAE’s standard 96 hours, Parker developed a proprietary coating, XTR, resists corrosion for more than 720 hours when tested in accordance with ASTM B117. Stainless steel fittings are also an option due to their strength and durability and strong chemical and corrosion resistance that suits hydraulic applications, especially where the fluid or surrounding environment is corrosive. 
• Instant hose connections - Multipurpose push-to-connect hose assemblies, which are durable and color-coded for easy identification, can be made in seconds, saving valuable time and money.  

Additional technologies, such as drones and positioning solutions, are also providing important and attractive opportunities for the growth of the agriculture sprayers market. A drone uses the latest technologies of various tiny sensors, such as accelerometers, GPS modules, powerful processors and digital radios to provide the farmers with information. The use of drones helps farmers in scouting for pests and diseases and in mid-field weed identification. Positioning technologies, such as combining GPS (global positioning system) and GIS (geographic information systems) have made yield mapping very easy and help farmers work in the field even under adverse weather conditions, such as rain, fog, and dust.  

There are companies that have highly indulged in constantly upgrading their technology, in order to meet the growing technology demand. The sprayer industry will continue to build on solutions that create a “smart sprayer.”  Technologies such as telematics, wireless communication, data transfer, and machine information sharing will become much more prevalent. Integrated technologies that allow more acres to be covered in a day will be key. 

As a result, Parker prides itself on our extensive knowledge of the agriculture industry and understanding of the challenges farmers face. For more than 100 years, Parker has helped to shape integrated products and services that simplify installation and equipment service, reduce noise and drive performance for the agriculture industry. Doing so enables farmers to improve efficiency, reduce operating costs and comply with industry regulations, so they can focus on their critical role in our society.

Visit parker.com/offroadmachinery  for additional information on our products and services.  

Related articles:

The Benefits of Intelligent PCLS and Pressure Compensated System Architecture

Central Tire Inflation System for Off-highway Vehicles

Sowing the Seeds and Harvesting Innovation in Agriculture

How Will New Trends in Seeding and Cultivation Impact Machine Design?

Sprayer Steers Clear of the Ordinary

Maintain Your Combine and Enhance the Technology to Optimize Performance

These days, mobile machines used in a broad range of markets such as agriculture, construction, forestry, material handling and transportation are exceptionally sophisticated pieces of equipment. Industry megatrends such as automation, connectivity and electrification have converged to ensure that excavators, loaders and other hydraulic mobile machines have more functional capability than ever before.

In this digitally driven environment, the demand for innovation is relentless. That provides a real challenge for OEMs, who are expected to work faster and smarter to come up with new features that deliver a competitive advantage.  

For engineers, this means developing and prototyping new electrohydraulic systems in the shortest time possible. One means of achieving efficiency in product development is through the use of more high-level graphical design tools to design, simulate and deploy innovations at speed.

That was the inspiration for a collaboration between motion and control technologies specialist Parker Hannifin and computer software giant MathWorks® on IQANdesign 6TM – a new software package with MATLAB® Simulink® integration that has been developed to speed innovation in electronic controls for mobile machines. IQANdesign 6 features an IQAN toolbox for Simulink that can streamline the model-based design, simulation and deployment of electronic controls – a significant development which is expected to transform work that involves the creation or improvement of mobile machine functions. 

Historically, engineers and scientists around the globe have benefitted from the IQAN and Simulink product families, accelerating the pace of discovery, innovation and development in sectors that extend from automotive to electronics. Integrating the two software environments reduces development time with a more efficient and convenient tool chain, offering users an unprecedented way to rapidly deploy code on production-ready hardware in real-time applications. 

But what does that mean in terms of functionality for the design engineer faced with the competitive pressure of bringing new electronic controls for mobile machines to market?  

Firstly, the seamless integration of Simulink models within the IQAN ecosystem enables automatic generation of real-time applications from Simulink models targeting IQAN-MC4x controllers. Concurrent execution of multiple models with individual time bases and priorities are also supported.  

Also, Simulink models are executed in a dedicated real-time kernel, with Inports and Outports available in IQANdesign application logic. Using IQANdesign, users can view and navigate Simulink models, which are also included within system simulations provided by IQANsimulate. In addition, Simulink Testpoints are visible and measurable in IQANdesign/IQANrun. 

In short, the collaboration between Parker and MathWorks is about removing time and resource obstacles for research and development teams. It provides the perfect solution for businesses coming under increasing pressure to innovate at a time when mobile machines will get smarter than ever before.  Learn more about IQAN products, or contact us for more information.  

This article was contributed by Johan Lidén,  product manager IQAN Electronics,  Electronic Controls Business Unit, Parker Hannifin Manufacturing Sweden AB.

Related articles:

What Does State-of-the-art Mean for Functional Safety Control Systems?

Modern Digital Ecosystems Take Mobile Hydraulic Systems to a New Level

Don’t Waste the Opportunity to Take Control with Increased Safety and Improved Efficiency

Glenn O. Hawbaker, Inc. brings over 60 years of experience to the highway, commercial and residential fields throughout central Pennsylvania. They continue to grow their business by expanding their reputation for safety, quality, service and reliability. That's one of the reasons Glenn O. Hawbaker purchased their first PowerTilt Tilting Coupler and continued to purchase several more for their entire backhoe loader fleet. PowerTilt has changed the way they've approached their grading and excavating business while at the same time positively impacting their bottom line and overall customer satisfaction.

Prior to using PowerTilt, Glenn O. Hawbaker faced two challenges on the job site. Genn O. Hawbaker was using large and expensive Gradall specialty machines to grade and slope and spent extra man-hours to swap these machines in and out of job sites.The large rubber tires on the specialty machines often caused the Gradalls to slide or operators to spin around when a rock was hooked, making for an unstable work environment. With PowerTilt, Hawbaker could keep just one machine on the job site without the expense or logistics involved in scheduling the Gradall excavators between the different job sites.

The Hawbaker crew was also having difficulty with the outriggers on their specialty excavator and backhoe fleet - they had to take their hands off of the controls to tilt the outriggers and move the machine at different angles around the job site. When the outriggers were tilted at an awkward angle, the operators felt uncomfortable and unsafe. When they added the PowerTilts to their existing CASE backhoes, they kept just one machine on the job site to tilt their bucket or attachment instead of moving the entire machine to get the right angle.

“Now with PowerTilt, we’re doing everything on the fly - we tilt and grade at the same time."

Paul Peters, backhoe operator for Glenn O. Hawbaker

By switching to PowerTilt, Glenn O. Hawbaker and its customers received a wide range of expected and unexpected benefits.

“We saved on labor, got tasks done faster and safer, and increased the appearance of the end product. What's more, we had the unexpected benefit of people asking us what tool we were using, and how we were getting more work done with less hand work," stated Peters. 

The benefits of switching to PowerTilt were:

Wind turbines are designed to maximize power production based on the predicted wind speeds found at the plant site. However, excessive wind speeds are experienced at times, so it is crucial to limit power generation at those times to avoid spontaneous runaway turbine situations that may cause damage to the turbine rotor or other parts of the driveline or generator. Wind turbine brake systems are a vital safety system. A critical component in the hydraulic braking system is an accumulator, which provides a supplemental flow of hydraulic fluid during emergency braking operations. Diaphragm-style accumulators are standard, although catastrophic failures in the rubber diaphragm are not uncommon. An attractive and more reliable alternative is the piston-style accumulator that is not susceptible to this failure mode. 

Download our white paper Improve Wind Turbine Safety with a Piston Accumulator Retrofit for a closer look into safety systems found in modern wind turbines, failure modes, and the benefits of having your wind turbine retrofitted with a piston accumulator.

Wind turbines are designed to operate reliably over their typically 20-year design life. That means a typical wind turbine may run for more than 130,000 hours over its lifespan. In addition to reliable operation, owners also demand that a wind turbine has robust safety systems that protect their investment and the technicians who perform routine maintenance on the equipment. This point is particularly important as each turbine normally operates without constant human supervision and the period between maintenance visits by technicians often extends to every six months. Safety systems are expected to provide overall protection of the equipment without operator supervision nor frequent maintenance technician visits.

During high wind conditions, a wind turbine may produce higher than rated power generation, so the rotational speed of the blade rotor must be controlled so that the rated power output of the grid-connected generator may be maintained. Should the grid connection be lost for whatever reason, the turbine rotor will immediately begin to overspeed within seconds. Every wind turbine must possess a robust speed control safety system to prevent high rotational speeds during high wind conditions. The turbine braking system is undoubtedly the essential safety system found in a modern wind turbine.

There are many safety systems found in modern wind turbines that provide continuous supervisory oversight without human interaction. For example, vibration sensors placed on the driveline alert operators to its condition and, if vibration reaches critical levels, the supervisory system will automatically shut down the turbine. As in other power generation equipment, sensors measure voltage, current, and frequency of the generator, as well as machinery temperatures. Should an overspeed condition or malfunction occur that allows the freewheeling of the blade rotor, overspeed sensors within the safety system will automatically call for aerodynamic braking to slow the blade rotor. Finally, an anemometer measures the wind speed, another critically important component of the wind turbine’s safety system.

All wind turbines use aerodynamic braking for two principal purposes. The first purpose relates to regular turbine operation. Aerodynamic braking controls the power produced by the generator by properly aligning the nacelle into the wind with yaw control and optimizing the blade longitudinal rotation, typically by full-span blade pitch control. The pitch control system, usually located within the turbine hub, rotates the three variable-pitch turbine blades in unison to precisely control the generator speed based on a feedback signal from the generator.

The second purpose of aerodynamic braking pertains to system safety. Should freewheeling in high winds occur, the aerodynamic braking system will turn each rotor blade 90 degrees on its longitudinal axis to minimize lift and maximize drag, effectively “stalling” the blades. The net result is to stop the rotation of the rotor, often within a few rotations. A mechanical brake is engaged when blade rotation stops to secure the rotor when the wind turbine is out of service, typically for maintenance.

The turbine safety system design is based on the requirement for redundancy. The sensor-based overspeed protection system, for example, is backstopped with a purely mechanical centrifugal brake release system. This concept is not unlike a typical engine generator set where a mechanical centrifugal governor backs up the electronic overspeed controls. On a wind turbine, the safety system backup to aerodynamic braking is a physical disc brake placed on the high-speed gearbox shaft. This approach to stopping the rotor minimizes stress to the blade rotor, tower, or other machinery.

The mechanical turbine brake is placed on the high-speed side of the gearbox before the generator. If the wind turbine rotor turns at 15 rpm, the gearbox will increase the output shaft to 1,500 rpm for the generator. The mechanical brake is actuated by a diaphragm-style accumulator that stores hydraulic fluid under pressure that can actuate a disk brake in the event of an overspeed event during a loss of power (Figure 2).

A diaphragm actuator is shown here of the manual brake actuator handle. The diaphragm accumulator stores a supplemental source of hydraulic fluid under pressure, which is used to actuate the caliper disk brake (shown in red) in the event of an overspeed of the rotor during a power outage. The silver “can” beneath the accumulator is part of the high-speed shaft hydraulic system. The gearbox is in the foreground, and the generator is in the background.

The design of a typical diaphragm accumulator is quite simple. The inlet side of the accumulator is exposed to the pressurized hydraulic oil system. A compressible inert gas, such as nitrogen, fills the top of the accumulator. Separating the two volumes is a flexible rubber diaphragm membrane that compresses the nitrogen to hydraulic system pressure. Should the hydraulic system lose pressure, such as during a power outage or electronics failure, the nitrogen will expand and release the stored hydraulic fluid, which is sufficient to actuate the mechanical brake system and stop the rotating turbine shaft.

Field experience has shown that diaphragm accumulators often catastrophically fail at unpredictable times. The failure mode is illustrated in the above graph. When a rubber diaphragm ruptures, the pressure in the accumulator immediately dissipates, and the wind turbine critical backup braking system is rendered useless. The rubber diaphragm surface area is gas permeable and therefore will require more frequent pre-charge maintenance. The blue region represents the pre-charge gas, typically nitrogen. The bottom of the accumulator is connected to the hydraulic system that will actuate the mechanical brake. 

In a piston accumulator, the sealing surface is minimal compared to the cross-sectional area of a diaphragm. Much like the rings that seal a piston between oil and combustion gases, these seals separate the nitrogen charge from the hydraulic oil. Because the surface area of potential gas leakage is significantly less, the amount of pre-charge maintenance is greatly reduced.

The failure mode with the piston accumulator is also significantly less dramatic. Instead of an instantaneous failure, as in the case of the rubber diaphragm accumulator, the piston accumulator failure mode is very measured. The first scenario in the top right graph occurs when the fluid leaks past an accumulator piston, raising the nitrogen pre-charge pressure. The second scenario in the bottom right graph occurs when the pre-charge gas leaks past the piston, causing the pre-charge pressure to fall. Again, the failure mode is very gradual and never the source of a forced shutdown of the turbine.

The piston accumulator may experience two slowly developing failure modes. The first (top) occurs when the hydraulic fluid seeps through the piston rings and raises the pressure of the pre-charge gas. The second possible failure mode (bottom) occurs when the pre-charge gas seeps past the rings into the hydraulic fluid or otherwise escapes from the accumulator. The blue area represents the pre-charge gas, typically nitrogen. The bottom of the piston-cylinder connects to the hydraulic system of the mechanical brake. 

The failure mode of the piston accumulator seals occurs over a long period, over millions of cycles, allowing for a manual pre-charge adjustment until the equipment’s scheduled maintenance period. The slow leakage allows for increased machine uptime and prevents costly unscheduled maintenance outages. A ruptured rubber diaphragm, on the other hand, creates an instantaneous failure, resulting in a forced outage, unplanned repair costs, and more extended machine downtime. For this reason, diaphragm accumulators are not the best choice for wind turbine safety systems.

The pre-charge gas is separated from the fluid side of the accumulator by the very small cross-sectional area of the piston seal. The piston-accumulator design minimizes the effect of permeation, and thus requires less nitrogen pre-charge maintenance over time. The rubber diaphragm separates the pressurized gas side of the accumulator from the fluid side with a relatively large cross-sectional diaphragm. This design allows the entire diaphragm to be in contact with the pressurized gas, allowing for a larger area for the gas to permeate through. A typical 1-gallon piston accumulator has 97% less exposed seal surface area than an equivalent 1-gallon rubber diaphragm accumulator.

The cause of permeation is directly related to the rubber compound, the type of gas, the temperature of the gas, the pressure differential, its cyclic duty, and the volume of rubber used to form the diaphragm. The rubber diaphragm accumulators are typically limited to two standard diaphragm compounds, nitrile, and hydrin. The piston accumulator has six possible seal compounds with an available seal temperature range for –40F to 325F, so there is a seal for every type of hydraulic fluid and temperature requirement.

There are other application limitations for the rubber diaphragm accumulators. For example, this style of an accumulator is limited to operation in systems with a maximum compression ratio (the ratio of the maximum working pressure to pre-charge pressure) in the range of 4:1 to 8:1. In contrast, the compression ratio of a piston accumulator is unlimited. The technician merely adjusts the pre-charge so that the piston is allowed to ride at mid-stroke, not bottoming out on either end of the accumulator. Other application limitations of the rubber diaphragm accumulators include the limited number of port options and that the orifice limits the design flow rate. The standard piston accumulator allows for multiple sizes and allows for flow rates of eight to 10 times that of diaphragm accumulators. A piston accumulator replaced the failed diaphragm accumulator installed on the disk brake assembly.

The table below illustrates the general characteristics of the piston and rubber diaphragm accumulators.  

Wind turbine maintenance evolutions are scheduled in advance and forced outages will disrupt that schedule. A rupture in a rubber diaphragm accumulator will signal an immediate turbine forced outage, and it will remain idle until a maintenance team is mobilized to replace the failed accumulator. Depending on maintenance team availability, it would not be out of the ordinary for the turbine to be out of service for five or more days before repairs are completed. Assuming this was a 1.5-MW turbine and that it was operating at the 2019 average capacity factor reported by the Energy Information Administration of 34.9%, then the turbine lost approximately 63 MWh of generation.

Depending on the region where the turbine resides, the lost revenue due to a single wind turbine forced outage would be between $1,200 and $2,000. The cost of emergency maintenance and other related expenses could quickly push the total outage expenses up to $5,000. Given that there are almost 13,000 General Electric 1.5-MW wind turbines in North America alone, the potential loss to the wind industry each year is likely in the tens of millions of dollars.

A wind turbine retrofitted with a piston accumulator will experience a completely different, non-emergency response. The piston accumulator is immune from a catastrophic diaphragm failure, but the piston-cylinder seals will slowly wear over time. Only at that time will the pre-charge pressure slowly begin to drop. Instruments will signal and track the pressure decrease so that a work order can be issued for a maintenance technician to merely “top-off” the pre-charge pressure until the piston accumulator can be replaced at the next regularly scheduled maintenance outage. No muss, no fuss.

Download our white paper Improve Wind Turbine Safety with a Piston Accumulator Retrofit for a closer look into safety systems found in modern wind turbines and the benefits of a wind turbine retrofitted with a piston accumulator.

Article contributed by Tom Ulery, business development manager of Renewable Energy

Jeff Sage, product sales manager, Accumulator & Cooler Division

Related, helpful content for you:

How Pitch Control for Wind Turbines Becomes More Accurate and Reliable

Upgrade of Blade Pitch Control Delivers on Wind Turbine Reliability

Theme Park Thrills Owe Much to Hydraulics and Accumulators

Unique Team Effort Completes Upgrading of Pressure-Relief Valves at Hoover Dam

Large Capacity Piston Accumulators Help Subsea Engineers Meet Extreme Demands

In a Concentrating Solar Power (CSP) system, solar radiation is collected and concentrated, multiplying the sun's ambient heat to temperatures in excess of 750°F. In the most common application of CSP today, this is accomplished through parabolic troughs that use reflective mirrors to concentrate the sunlight onto receiver tubes that are connected in a vast plumbing system throughout an array of troughs. The receiver tubes carry a heat transfer fluid, which circulates along the length of each of the troughs and then into a heat exchanger, where the heat is extracted to make steam. The steam is used to create electricity using the same kind of generators that are traditionally driven by steam made from burning of fossil fuels. Currently, there are several parabolic trough concentrated solar power facilities operating in the Southwest region of the U.S.

Crucial to the effective operation of a parabolic trough is the ability to precisely position the concentrator for maximum solar energy capture as the sun moves across the sky. The focal point of the concentrated solar energy must be maintained directly on the receiver tube or the efficiency of the system drops off significantly. In order to maintain optimum efficiency, the trough must track the sun with precise controls and maintain accuracy to within 0.06° (1.0 mrad) with virtually no variation. This challenge becomes more difficult when dealing with the very large collector surfaces required. Each typical parabolic trough collector assembly has a total reflective area of 8,000 sq feet or more and must maintain tracking efficiency with wind gusts of up to 40 mph or sustained winds of up to 25 mph. The collectors also must operate in harsh conditions found in the deserts of the Southwest United States and across the world. Searing heat and dust are their constant companions. Component reliability and low maintenance requirements are a must.

One solution was jointly developed by Parker's location in Enumclaw, Washington, and OnSun in Albuquerque, New Mexico. OnSun is an integrated tracking, control, and drive system for large solar power systems. OnSun is comprised of two major subsystems. First is a helical hydraulic rotary actuator with a sliding spline design. The unique design of its inherent helical gearing allows the rotary actuator to provide increased holding torque of up to 1.8 million inch-pounds, eliminating the requirement for an external holding brake mechanism found on alternative drive systems. The second subsystem is a sun-tracking control system, SkyTrakker, developed by OnSun. Delivered as a compact, pre-fabricated package, the integrated OnSun sun tracking system allows for rapid field installation and system start-up.

Solar energy collection is most efficient at the equator, where gross thermal solar power is approximately 1,000 W/m2 of direct solar radiation. Dependent on geographical location, 6 to 8 solar collector assemblies are required for each MW of electricity to be generated, and each collector assembly requires an individual tracking, control, and drive system. A modest 25 MW solar field will have as many as 200 collector assemblies, each with a drive system that consumes the very same electricity that is being generated. To minimize this energy consumption, the OnSun system uses a variable frequency drive control for the hydraulic pump motor that minimizes startup currents and reduces parasitic power consumption by 50%.

The heat transfer fluid is circulated through a mechanically coupled continuous loop system that traverses through multiple collector assemblies so synchronous coordination of the movement of each collector is vital. With state-of-the-art communications capability, SkyTrakker provides system health monitoring to ensure reliability and system life. High-speed remote monitoring and control are provided using field network communications between SkyTrakker and the control room. Both an RS- 485 optically isolated wired network and 2.4 GHz wireless RF network communications are provided. Heat Transfer Fluid temperature-monitoring capability is provided for high temperature and freeze mode protection. Both remote and local monitoring of the HTF is provided for dual safety operation. In addition, complete monitoring of each SkyTrakker operation is available using a USB connection for field maintenance and debugging operations.

As a better alternative to the complex and inefficient task of actually tracking the sun's position to maintain optimum collector efficiency, SkyTrakker controls the movement of the collector assembly by determining the desired collector position based on the sun's precisely known position in the sky relative to the exact location of the collectors on Earth. This ensures that the collector is always in the best position, even if cloud cover blocks the sun momentarily. As soon as the cloud or other obstruction clears, the collector is in precise alignment to resume maximum thermal efficiency and there is never a ’’hunt' mode due to the collector being off position. A solid-state digital inclinometer is used to ensure the tracking accuracy is maintained to within 0.05°.

The most precise and accurate positioning algorithms and controller would be of little value without a drive system capable of responding with accuracy to the minute positioning commands generated. The sun is in continual motion as it tracks across the sky each day and maximum solar efficiency is only attained when the collector is properly focused. The very large surfaces of the collector assembly require a substantial support structure. Even with state-of-the-art space frame type designs, these structures weigh in at several thousand pounds. Additionally, the large surface area of the collector acts as a sail in even a slight breeze.

Mentioned previously, the OnSun drive system uses a helical sliding spline hydraulic rotary actuator, specifically Parker’s Helac L30 series model 380. The L30 series and its legacy predecessors have been in volume production for 25 years with more than 100,000 units delivered to military, mining and heavy equipment customers for use in extreme operating environments. For this application the actuator design was customized and develops 380,000 inch-pounds of output torque at 3,000 psi and is capable of rotating the collector in precise 0.1° increments through the entire 240° of total rotation.

The L30 series helical rotary actuators use a low hydraulic displacement to drive through their rotation cycle, which facilitates the use of a small pump and motor to supply the high-pressure fluid to the actuator. The self-contained hydraulic fluid system is charged with multi-functional gear oil that ensures long gear life for both the pump and actuator. Strict fluid cleanliness standards are used during the production of the drive unit to ensure that the fluid used is of the highest possible cleanliness standards. As part of this process, each component is thoroughly cleaned prior to assembly and then the completed actuator is subjected to a computer-controlled cycle test where the fluid is analyzed for particulate size and quantity. The actuator is continuously cycled and flushed with fresh ultra-clean fluid until the cleanliness standard is achieved. This eliminates the need for filters, and an associated preventative maintenance headache, thereby contributing to overall reduced cost of operation for the entire solar collector field. Coupled with a small electric motor, with support for 110 Vac and 220 Vac single and three-phase power input, is a single gear pump that provides the hydraulic pressure needed to drive the actuator in both the low-speed tracking as well as high-speed stow modes.

The OnSun system is designed for rapid field installation based on the low number of parts that are involved as well as quick installation and assembly features incorporated into the design. The drive system is delivered as a compact, prefabricated package that allows for rapid field deployment.

This article was contributed by Jessica Howisey, marketing communications manager and Daniel Morgado, applications engineer, Helac Business Unit, Cylinder Division and was originally published by Solar Power World  

Related content:

New Hybrid Actuation System Ideal for Renewable Energy Applications

Hydraulic Power Units Control All Functions of Hydro-electric Turbine

Clean Hydraulic Fluids Are the Key to Top Performance