1. Power part-converts the mechanical energy of the prime mover into the pressure energy of the oil (hydraulic energy), for example: hydraulic pump.
2. Execution part-convert the oil pressure energy input by the hydraulic pump into mechanical energy that drives the working mechanism. For example: hydraulic cylinders,
Hydraulic Motor.
3. Control part-used to control and adjust the pressure, flow and flow direction of the oil, such as: pressure control valve, flow control valve and direction control valve.
4. Auxiliary part-connect the first three parts together to form a system, which plays the role of oil storage, filtration, measurement and sealing. For example: pipelines and joints, fuel tanks, filters, accumulators, seals and control instruments, etc.