Piston pumps

A piston pump is chosen when the hydraulic pressure rises to 350–400 bar or when the flow must adjust to the load. A fixed displacement axial piston pump delivers the same flow on every revolution, while a variable displacement pump delivers only what the system consumes. This category has both for trucks, mobile machinery and industry, including variable displacement pumps with an LS regulator.

A common mounting location is the truck PTO. Truck pumps have a DIN 5462 shaft and can replace equivalent pumps from many other manufacturers. For the tractor PTO there are models with a 1 3/8" shaft, and there are also pumps with SAE and ISO 3019-2 flanges. The direction of rotation is specified when ordering, but on some pumps it can be changed by turning the port end 180°. Dual-circuit pumps and tandem pumps that take a rear pump on a through shaft handle two circuits from one power source, and in a tandem the combined torque must be calculated. Seal kits, LS regulators and bypass valves are in the same group.

If the pressure stays within the gear pump range and the flow does not need to adjust, choose a gear pump.