大型三相异步电动机轴端密封的改进设计

Transformation Design on the Shaft End Seal of Large Three-phase Asynchronous Motor

分析某石化公司大型三相异步电动机漏油的原因,指出电动机外漏的原因为油封内的压力高于外界压力,内漏的原因为内风扇转动时在轴承处产生局部负压,使油封内的压力大于机腔内的压力。针对电动机存在的密封环磨损问题,设计可调式自动跟踪密封环,并根据密封试验中出现的密封环断裂问题,提出用石墨填充聚四氟乙烯密封环代替石墨密封环。实际工程应用结果表明,可调式自动跟踪密封环很好地解决了电动机轴承油封漏油问题。

The oil-leaking＇s reasons of a large three-phase asynchronous motor in a petrochemical were analyzed, lhe reason oi exter- nal leakage is that the pressure in the seal is higher than that of the outside pressure. There is a negative pressure exists near the bearing, which results in that the pressure in the seal is higher than that in the cavity. According to the seal ring wear of motor, an automatic adjust- able seal ring was designed. The graphite sealing ring is replaced by the sealing ring made of graphite filled PTEE for the graphite sealing ring is easy to be broken in the seal test. The actual application result shows that the oil spill .of the motor＇s bearing seal is resolved by using the automatic adjustable seal ring.