Dealing with Oil Leakage at the Shaft Neck of a 400-ton Hydraulic Press
Dealing with Oil Leakage at the Shaft Neck of a 400-ton Hydraulic Press:
1.To prevent oil leakage at the shaft extension, install two self-tightening rotating rubber seals at the shaft neck when designing the gear pump.
2.External leakage in a long-term used gear pump is generally caused by the aging or deterioration of seals in the pipeline connections and factors such as high oil temperature and low oil viscosity.
During the machining process of the control valve, if the coaxiality and chamfering requirements specified in the design drawings are not met, it is a major cause of oil leakage. The chamfer at both ends of the valve spool should not habitually adopt a 45-degree chamfer, as it poses a significant risk. When assembling the valve spool into the valve body, there is a risk of damaging the O-ring. There are three scenarios:
1.When the coaxiality between the valve body hole and the O-ring groove exceeds the specified value, the O-ring is placed in the groove, with one side experiencing significant compression and the other side less compression. In mild cases, oil leakage may occur. In severe cases, when assembling the valve spool into the valve hole, the O-ring may be cut off by half or a full circle. During factory tests on the test bench, oil leakage may not be observed due to the short duration, low oil temperature, and no back pressure. However, oil leakage may occur after using the hydraulic equipment for some time.
2.The coaxiality between the O-ring at both ends of the valve body and the main valve hole is qualified. The chamfer at both ends of the valve spool should be between 15° and 20°. If it exceeds the specified value, it may also cut the O-ring.
3.Lubricating oil was not applied to the valve hole, O-ring, and valve spool during assembly, which may also result in cutting a portion of the O-ring when fitting the valve spool into the valve body.