There are usually three types of hydraulic pump constructions within mobile hydraulic applications. Included in these are equipment, piston and vane; nevertheless, there are also clutch pumps, dump pumps and pumps for refuse automobiles such as dry valve pumps
The hydraulic pump may be the component of the hydraulic system that takes mechanical energy and converts it into fluid energy in the type of oil flow. This mechanical energy can be taken from what’s called the primary mover (a turning force) like the power take-off or directly from the vehicle engine.
With each hydraulic pump, the pump will be of the uni-rotational or bi-rotational design. As its name Hydraulic Pump china implies, a uni-rotational pump is made to operate in one direction of shaft rotation. However, a bi-rotational pump 
has the capacity to operate in either path.