hydraulic machines is mainly direct drive pump

hydraulic machines is mainly direct drive pump and pump - accumulator drive two types. Such a direct drive pump drive system pumps provide high pressure working fluid to the hydraulic cylinders, with a valve for changing the flow direction for the fluid, a pressure relief valve for regulating the defined system, while the overflow from the security role. This drive system part of a small, simple structure, pressure can automatically increase or decrease in the required work force, reducing power consumption, but the biggest work force and shall be the maximum operating speed of the hydraulic machines to determine the capacity of the pump and its drive motor. This type of drive system used for small and medium sized hydraulic machine, it also directly driven pump large free forging hydraulic press. Pump - storage drive in this drive system has an accumulator or a group. When the high-pressure working fluid pump supplied with margin, store the accumulator; and when insufficient supply amount at the time of need, they supplement supplied by the accumulator. With this system you can choose according to the average amount of the high-pressure working fluid capacity of the pump and motor, but because the working fluid pressure is constant, power consumption is large, and the system of links, more complex structure. This drive system is used for large-scale hydraulic machine, or a drive system with several hydraulic press.