Reasons for the explosion of large gear pumps and their repair methods

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Many customers have reported that gear pumps often experience explosions of the large pumps. What is going on? Based on over a decade of experience in repairing hydraulic pumps, Autos has summarized the reasons for the failure of gear pumps and the methods for repairing them. These can be categorized as follows: According to the working principle of gear pumps, it is possible to determine the causes of their failure. Specifically, there are two main reasons: First, the pilot pressure regulating valve or relief valve in the control valve becomes stuck, resulting in a blocked oil circuit; this leads to an extremely high system pressure, which ultimately causes the gear pump to fail ； Second: The operators adjusted the pressure without following the instructions in the copy order, causing the system pressure to exceed the specified value, which can easily lead to the explosion of the gear pump. When a large gear pump bursts, the operation of the hydraulic system should be stopped immediately, and efforts should be made to replace it in order to prevent further damage. Based on Autos’ over a decade of work experience, the following three methods have been identified to reduce the risk of gear pump failure: First, adjust the pressure by turning the pilot pressure adjusting bolt clockwise by one full turn; this will increase the system pressure by approximately 3.0–4.0 MPa ； Conversely, the system pressure can be reduced by approximately 3.0–4.0 MPa. Second: The pressure relief grooves on the side plates should be installed in the high-pressure chamber of the gear oil pump, to prevent the oil pump from experiencing \"oil trapping\", which could lead to its explosion. Third: Sometimes, the bolts cannot be tightened due to the shallow depth of the bolt holes; in such cases, the bolts should be shortened accordingly. The pressure resistance of gear pumps made of aluminum alloy materials is 38–45 Mpa; under conditions free from manufacturing defects, the explosion of such gear pumps is definitely caused by sudden high pressure. Gear pumps come in left-rotating and right-rotating versions; if the direction of rotation is incorrect, the pressure oil generated by the volume difference resulting from the meshing of the internal gears will cause the oil seal to be damaged and lead to oil leakage. This is also the reason why large gear pumps explode and the methods for repairing them; it is hoped that people will use them properly in the future to reduce the likelihood of failures.