There are 
typically three types of hydraulic pump constructions found in mobile hydraulic applications. These include 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 is the element of the hydraulic system that takes Hydraulic Pump china mechanical energy and converts it into fluid energy in the type of oil flow. This mechanical energy is definitely taken from what’s called the prime mover (a turning push) like the power take-off or straight from the pickup truck engine.
With each hydraulic pump, the pump will be of the uni-rotational or bi-rotational design. As its name implies, a uni-rotational pump is designed to operate in one direction of shaft rotation. However, a bi-rotational pump has the ability to operate in either direction.