To select a manual hydraulic pump, many factors should be considered, such as material, driving mode, purpose, pump shaft position, flow, principle, number of impellers, performance, lift, etc., such as cast iron, cast steel, glass, aluminum alloy, titanium alloy, etc.; chemical pump, pipeline pump, metering pump, fountain pump, booster pump, etc.; axial flow pump, diaphragm pump, roller pump, gear pump, etc, Slide pump, etc.
Generally, it is determined by the pressure, displacement and driving power of the hydraulic pump. (1) The pressure of the selected hydraulic pump should be slightly higher than the required pressure of the actuator. At present, the standard pressure of the hydraulic pump used in China's machine tool industry is generally below 6.3MPa. According to different working conditions, the following conditions should be paid attention to when selecting the pressure: 1) according to a certain output power, the volume of pump or motor should be as small as possible under the same pressure and flow. 2) With the increase of pressure, the oil will be heated, the oil temperature will rise, and the leakage of valve and seal will increase. 3) Too high pressure will increase the structure of the valve and transmission system, and it is difficult to realize the lightweight and miniaturization of the pump. (2) The selection method of the displacement of the hydraulic pump depends on the size of the actuator (hydraulic cylinder, motor) and the load requirements. (3) The driving power of the hydraulic pump is determined according to the working pressure and effective oil discharge of the pump.