The structural parameters of the oil seal are the root factors that affect the sealing performance of the oil seal. The rationality of the structural parameters will enhance the leak-proof ability of the oil seal. A simple classification description of the structural parameters of the oil seal and its influence on the oil seal seal is made:

1. Interference:

• The oil seal interference refers to the difference between the inner diameter of the lip and the outer diameter of the shaft in the free state. It can provide a pre-tightening force between the oil seal and the shaft. The parameters of oil seal sealing performance such as contact pressure, equivalent stress and temperature have an impact. If the amount of interference is too small, it will not be able to closely fit the shaft surface, which will naturally cause leakage; while the amount of interference is too large, it will make the lip fit too tightly on the shaft surface. When the shaft is running at high speed, the lip and The shaft surface will quickly generate high temperature, accelerate the aging and cracking of the lip, and even burn the sealing lip, which will cause the seal to fail.

2. R value:

• The R value refers to the axial distance between the cutting edge of the oil seal lip and the center of the spring ring, and represents the theoretical value of the contact width between the oil seal and the shaft. A smaller R value is conducive to the main lip cutting edge to produce a concentrated radial distribution on the shaft. Contact stress helps to control the oil film, but too small R value will make the oil film unable to be stable continuously, and too large R value will cause the contact surface to be too large, which will cause high temperature when there is relative movement between the shaft and the oil seal. Wear the lip, causing the seal to fail;

• The above is a connection between the parameters of the oil seal and the sealing performance.