The oil leakage of the pump turns a large amount of hydraulic energy into heat energy, which increases the oil temperature and worsens the working conditions. The oil leakage of gear pump can be divided into internal leakage and external leakage. Internal leakage reduces the output flow of the pump and the pressure rise is not high. In addition to the above disadvantages, external leakage also pollutes the environment, so it is necessary to reduce internal leakage and avoid external leakage. The method to reduce internal leakage is to properly adjust the movement clearance of the pump. If the clearance is too large, the internal leakage will increase; If the clearance is too small, the friction increases. Causes of leakage:
1) The oil return hole on the front and rear pump covers is blocked, or the hole is not drilled during processing. This requires cleaning or drilling.
2) The pump cover and sealing ring are too loose to form oil leakage, which can be solved by adjusting the clearance.
3) The lip of the shaft seal is scratched by the keyway of the main shaft or the skeleton spring falls off. This can be replaced or reinstalled.
4) The sealing surface of parts is severely scratched. The sealing surface shall be grinded again to eliminate scratches.
5) The inner diameter of the oil seal groove is too small or the groove chamfer is too small, which makes the oil seal inclined, resulting in oil leakage. Check the size of the groove and process the groove or chamfer according to the regulations.
6) If the shaft chamfer is too rough or too small, so that the lip of the seal is turned over, the roughness or chamfer shall be checked. During assembly, grease shall be applied to the chamfer.
7) If the seal has been used for too long at high temperature, or the rubber of the seal is not good, or the seal loses elasticity due to improper assembly, resulting in external leakage, the seal shall be replaced.
During installation, the pump body is installed reversely, so that the oil outlet is connected to the unloading tank. Or when the test run is correct, the steering is wrong, and the oil seal on the shaft is broken down, resulting in external leakage. This is because the oil inlet of the pump is connected with the oil seal through the oil return channel. When the pump reverses, the oil inlet becomes the oil outlet, and the pressure oil breaks through the oil seal through the oil return channel, or the oil seal is washed out of the pump body to form external leakage. This should correct the steering of the piano and replace the oil seal with a new one.
