There are usually three types of hydraulic pump constructions found in mobile hydraulic Hydraulic Pump china applications. These include gear, piston and vane; however, there are also clutch pumps, dump pumps and pumps for refuse vehicles such as dry valve pumps
The hydraulic pump may be the element of the hydraulic system that takes mechanical energy and converts it into fluid energy in the form of oil flow. This mechanical energy is taken from what’s called the prime mover (a turning power) like the power take-off or directly from the vehicle engine.
With each hydraulic pump, the pump will be of either a uni-rotational or bi-rotational design. As its name implies, a uni-rotational pump 
is made to operate in one direction of shaft rotation. However, a bi-rotational pump has the ability to operate in either direction.