China gear pump clarifies: gear pump oil, that is, hydraulic oil will break through the skeleton oil seal. This phenomenon is widespread, the host factory reflects strong, gear pump oil seriously affects the normal operation of the loader and the reliability of the gear pump and environmental pollution.

If the geometry of the oil seal lip is unqualified, the tightening spring is too loose, etc., causing air tightness test leaking, and the gear pump is loaded into the main machine and then smashed. At this time, the oil seal should be replaced and the material and geometry should be inspected (the domestic oil seal has a larger quality difference than the foreign advanced oil seal).

If there is a problem in the processing and assembly of the gear pump, the center of rotation of the gear shaft is not concentric with the front cover stop, which will cause the oil seal to be eccentric. At this time, the symmetry and displacement of the front cover bearing hole to the pin hole and the coaxiality of the skeleton oil seal to the bearing hole should be checked.

The front cover oil return passage between the CBG gear pump skeleton oil seal and the seal ring is not smooth, causing the pressure here to rise, thereby breaking through the skeleton oil seal. By improving this, the oil slick phenomenon of the pump has been significantly improved.

Usually the working pump is mounted on a variable speed pump, which in turn is mounted on the gearbox. If the end face of the gearbox or variable speed pump is out of tolerance to the center of rotation of the spline shaft, a cumulative error is formed, causing the gear pump to withstand radial forces at high speeds, causing the oil seal to simmer.

Because the gear pump shaft extension spline and the gearbox output shaft have a short effective contact length, while the gear pump works with a large torque, the spline is subjected to large torque and crush wear and even rolling, generating a huge heat. As a result, the rubber seal of the skeleton oil seal is burned and aged, and oyster oil appears. It is recommended that the main engine factory select the gear pump to check the strength of the external spline of the gear pump shaft to ensure sufficient effective contact length.

The outer stop of the gear pump and the inner stop of the variable speed pump and the external spline of the gear pump and the spline in the spline shaft of the gearbox, whether the clearance fit is reasonable, both have an influence on the oil of the gear pump. Because the inner and outer stops belong to the positioning part, the matching clearance should not be too large; the inner and outer splines belong to the transmission part, and the matching clearance should not be too small to eliminate interference.