The hydraulic pump is the power source of the hydraulic system. We should choose a pump that can adapt to the pressure generation circuit required by the actuator, while fully considering other factors to ensure that the selected pump can operate stably for a long time.
1. Is a variable required
According to different structures, hydraulic pumps can be classified into vane pumps, gear pumps, plunger pumps, and screw pumps (not commonly used). According to whether the flow rate changes, it can be divided into quantitative pumps and variable pumps.
Constant speed, choose quantitative pumps, including gear pumps and double acting vane pumps; If the flow rate of the pump is required to be variable, single acting vane pumps and plunger pumps can be selected.
2. System pressure
When choosing a hydraulic pump, consideration should be given to providing the pump with a certain pressure reserve, and the rated working pressure of the hydraulic pump should be 10% -20% higher than the system working pressure.
Generally speaking, any type of pump can be used under low pressure (high pressure less than 7Mpa) conditions. When working under high pressure (less than 60Mpa), a plunger pump should be selected, while a gear pump is more commonly used in medium pressure (less than 32Mpa) conditions. Vane pumps and screw pumps are more economical to use under low pressure.
3. Working environment
The resistance to pollution sources, among which gear pumps have the best resistance to pollution, followed by blade pumps. The plunger pump has the highest requirement for oil cleanliness.
4. Noise index
Under the same operating conditions, the noise generated by hydraulic pumps varies depending on the type of pump. The noise of external gear pumps and plunger pumps is the highest, while that of screw pumps is the lowest. The noise of blade pumps and internal gear pumps is between the two.
The noise generated by hydraulic pumps increases with the increase of pressure and displacement, and also increases with the increase of speed.
