Think of a typical manufacturing or warehouse that benefits from the speed and efficiency that a forklift brings to the production. The forklift makes work easier, whether it be in terms of better efficiency or lowering production costs and is a needed piece of equipment. But, what if the forklift noise were reduced and helped to make the working environment quieter and less difficult and distracting to work in? Reducing noise has a noticeable effect on operations that are typically quite loud. It is amazing how the work environment can be improved and can become more productive when quieter.
Acoustic emissions in hydraulic systems is generated primarily by the mechanical works of the pump and fluid pulsations exiting the pump as it supplies the flow for the system. Hydraulic pumps generate noise and/or vibration levels that can be unacceptable for many applications especially if operating indoor.

This is the main reason why Parker has introduced a new gear pump generation, the 500H Series Pump, capable of minimizing acoustic emissions. The engineering phenomenon that influences the emission of hydraulic noise include:
• Cavitation
• Pressure peaks arising from fluid trapped between gear teeth
• Ripple or flow pulsation
Helicoidal rotor profileParker 500H Series Pump is capable of minimizing those parameters causing noise. The especially studied helicoidal rotor profile has a single point of contact between the two gears, eliminating any trapped volume of fluid during rotation. The result is a silent, continuous transmission of fluid. Extremely low pulsation (“ripple”) levels are delivered into the hydraulic system. Internal hydrostatic mechanisms are in place to avoid trade-off with efficiency.
As the market shifts toward electric solutions, the need for noise reduction becomes a requirement which the 500H Series Pump matches perfectly.
The 500H Series Pump is two-quadrant technology, enabling it to operate as a pump and a motor too, in the energy recovery phase typical of new generation forklifts. This technology offers many benefits;
• Reduced energy requirement
• Lower noise levels
• High speed of operations: possible up to 4000rpm
• Continuously variable flow rate: 0% to 100%
• Pressure up to 250 bar
• Response time < 100ms due to very small internal mechanical inertia
Thanks to the revolutionary helicoidal rotor profile design concept, screw step and inner force balancing, Parker 500H Series Pumps have several advantages over standard competitor's pumps, including:
• A huge noise emissions reduction, on the average of 15 db(A) less.
• Reduced noise levels for the machine operators and their surroundings.
• Cancel the need of sound barriers, saving on costs.
• Helps meet noise limits required by laws and regulations.
Here's a look at a pulsation-rate comparison between Parker 500H Series and competing technologies.

Now, listen to the silent operation of the 500H Series pump.
By using variable speed motor systems, it is possible to create energy-efficient hydraulic drives where depending on the machine cycle, the energy saving can be as much as 30% when compared to a metering-controlled drive. Losses are largely eliminated when the supply flow is matched to demand. An optimum solution is provided by Parker 500H Series Pump driven by servo-motor where shaft speed is controlled by a frequency inverter. Since the supply flow is proportional to pump speed, the result is a variable flow from a fixed displacement pump.
It is easy to see and hear why Parker’s 500H Series Pump is ideal for forklift applications.
