Acting hydraulic machine used in the working medium pressure not only passed, but also to ensure the machine working parts work is sensitive, reliable, long life and low leakage. Hydraulic basic requirements for working medium are: ① have appropriate liquidity and low compressibility, in order to improve the efficiency of the transmission; ② can prevent rust; ③ good lubricating properties; ④ easy to seal; ⑤ stable performance, long-term work without deterioration. Water as the metric adapters  working medium initially, after the switch in water emulsion was added a small amount of emulsified oil is made to increase lubricity and to reduce corrosion. Oil has good lubricity, corrosion resistance and moderate viscosity, will help to improve the performance of hydraulic machines.  hydraulic adapter fittings drive systems are mainly direct drive pumps and pump - accumulator drive two types. This drive system provides a pump high-pressure working fluid to the hydraulic cylinders, with a fluid supply valve for changing the direction of the pressure relief valve is used to adjust the system defined, and play the role of the safety overflow. This drive system is part of a small, simple structure, pressure can automatically increase or decrease in the required work force, reducing power consumption, but the work force and the maximum shall be the maximum operating speed hydraulic machine to determine the capacity of the pump and its drive motor.