Hydraulic Pump If the hydraulic system is compared to the human body, the pump is the heart of the hydraulic system, as it converts mechanical energy into an increase in the hydraulic energy of the fluid. The pump is operated by a shaft that takes its movement from a source of mechanical energy, whether it is an internal combustion engine, an electric motor, or even a hydraulic pump turbine. It is considered one of the important parts in the process of managing a hydraulic circuit that pumps oil to other parts. The types of hydraulic pumps differ according to the areas of application used. There are two types of pumps: fixed displacement and variable displacement, according to the needs of the work. The types of gear, piston, and vane pumps, each according to the needs of the work in terms of pressure and capacity.