Technical method to eliminate abnormal noise of main pump of excavator

The abnormal noise of the main pump of the excavator began to be analyzed, and it was believed that it was caused by the pump suction or air mixed in the oil circuit. Therefore, first adjust the operating equipment to the oil level detection position, and check that the oil level of the hydraulic oil tank is below the low level of the oil standard, which is an oil shortage position. After inquiring, the driver learned that the sealing ring of the high-pressure oil pipe leading to the rodless cavity of the stick cylinder was replaced due to oil leakage during operation, but the oil level was not checked in time after the replacement. Therefore, first fill the hydraulic oil tank to the standard oil level, and the test machine indicates that although the abnormal noise has decreased, but still exists; then, the main pump is exhausted through the main pump exhaust valve and the machine is retested, and it is found that the abnormal noise still exists , To clarify that this noise cannot be caused by the pump emptying.

Next, the oil suction filter element and the oil return filter element of the hydraulic oil tank were checked, and it was found that the oil suction filter element became black with sludge, and the oil return filter element was stuck with brown metal particles. Therefore, the above filter element was replaced; considering the oil return filter element There are brown metal particles sticking to it, so the oil of the main pump was discharged and inspected. It was found that there were also brown metal particles. At the same time, when the main pump was collapsed, it was found that the piston, valve plate, swash plate, etc. were not damaged. The shoes are worn out. After replacing it, the assembly was strictly carried out as required, the hydraulic system was cleaned, and the oil was changed. When the test machine was started again, the abnormal noise disappeared and the fault was swept away.

Under normal circumstances, the possible causes of abnormal noise around the main pump of the excavator are as follows:

The hydraulic oil cannot constitute the main pump suction; air is mixed in the suction pipeline; the suction filter element is blocked and the main pump is suctioned; the internal wear of the main pump causes abnormal noise in the operation of the main pump.

The abnormal noise of the main pump of the excavator is caused by two reasons: the failure of hydraulic oil and the wear of the sliding shoes in the main pump. The reason is that the oil level is not checked in time after the seal is replaced, which causes the hydraulic oil to fail, causing the main pump to empty; when the oil mixed with air flows through the main pump, the sliding shoes cannot float or float for some moments Insufficient, resulting in the failure to form an outstanding smooth oil film between the sliding shoes and the swash plate, causing the sliding shoes to wear and eventually cause abnormal noise in the main pump operation.