Hydraulic pump is the power source of the excavator hydraulic system, it is to convert mechanical energy into hydraulic energy conversion device can. In hydraulic excavators hydraulic pump is usually in fault element, and a hydraulic pump faults will immediately affect the normal work of the hydraulic system in excavator, even can't work.

1 common faults, gear pump, mostly by its internal friction and wear caused by. The normal wear of the radial clearance and axial clearance (i.e. section gap) increases, the gear pump in the pump body hole leakage phenomenon aggravating, or both sides of the plate is unable to repair serious. In addition, the shaft seal is often damaged parts.

2, vane pump and gear pump is different, the wear volume is small, the service life of the parts is longer. The main cause of vane pump failure is oil pollution, this is because the kinematic pair with vane pump is precise, when pollutants enter the friction, easy to produce abnormal card lag or wear. In addition, self-priming performance is not as good as the gear pump vane pump vane pump, especially a small displacement is even more so, so the oil is clean and oil is smooth, two questions need to pay special attention to in the operation of vane pump.

The 3 weakness of radial piston pump, plunger pump in the structure and movement performance is larger radial force, self suction capability is poor and with the plunger and the plunger hole precision is high; the machining precision of the parts of the axial piston pump high requirements. So the plunger pump on the oil's cleanliness requirements of high filter precision, i.e. piston pump for oil requirements than the high gear pump.