Pump oil leakage causes a large amount of hydraulic energy to be converted into thermal energy, leading to an increase in oil temperature and deterioration of working conditions. The oil leakage of gear pumps can be divided into two types: internal leakage and external leakage. Internal leakage reduces the output flow rate of the pump and does not increase the pressure, while external leakage also pollutes the environment. Therefore, it is necessary to reduce internal leakage and avoid external leakage. The method to reduce internal leakage is to adjust the movement clearance of the pump appropriately. If the clearance is too large, internal leakage will increase; If the gap is too small, the friction increases. Reasons for external leakage:
1) The oil return holes on the front and rear pump covers are blocked, or this hole was not drilled through during processing. This requires cleaning or drilling through.
2) The pump cover and sealing ring are too loose to fit and form oil leakage, which can be solved by adjusting the clearance.
3) The lip of the shaft seal is scratched by the spindle keyway or the framework spring falls off. This can be done by replacing the oil seal or reinstalling it.
4) The sealing surface of the parts is severely scratched. Re grind the sealing surface to eliminate scratches.
5) The inner diameter of the oil seal groove is too small or the chamfer of the groove is too small, which causes the oil seal to tilt and cause oil leakage. The size of the groove should be checked and the groove or chamfer should be processed according to regulations.
6) If the chamfer of the shaft is too rough or too small, causing the sealing lip to roll over, the roughness or chamfer should be checked. During assembly, grease should be applied to the chamfers.
7) Seals that have been used for too long at high temperatures, have poor adhesive properties, or have lost elasticity due to improper assembly, all require replacement.
During installation, the pump body is installed in the opposite direction, connecting the oil outlet to the unloading groove. Or during the trial run, if the steering is incorrect, the oil seal on the shaft may be broken and cause external leakage. This is because the oil inlet of the pump is connected to the oil seal through a return channel. When the pump reverses, the oil inlet becomes the oil outlet, and the pressure oil penetrates the oil seal through the return channel, or pushes the oil seal out of the pump body to form an external leak. This should correct the steering of the pump and replace it with a new oil seal.