What factors will cause the oil seal not to seal

With the widespread use of oil seals, we must have some understanding of oil seals. The oil seal seals its lubricating oil so that it does not leak, is the customary name of the seal. It is a mechanical part that can seal grease, and it will isolate the transmission parts that need lubrication from the output parts, so that the lubricating oil does not leak as much as possible. The reason why the oil seal is loved by people is its sealing effect. So do you know what factors will affect the sealing performance of the oil seal?

The end face of the oil seal seat should be matched with the oil seal. A chamfer should be set for 15 to 30°, and the bottom rounded Angle R≤0.5mm. The seat hole should not be damaged.

Due to the gap during the movement, the high-speed rotation axis has a large number of axial runouts. For example, if the shaft of the reducer is not properly adjusted, a large amount of shaft cross-over, and the high-speed movement of the shaft will aggravate the wear of the lip.

Different temperature differences will lead to the expansion or contraction of the oil seal and skeleton. Since the expansion coefficient of metal and rubber is different, the expansion amount will change at a certain temperature. Most oil seals have spring rings. Since it is made of fine metal, the expansion caused by temperature is very obvious, and the tension of the spring ring after elongation is reduced, which may lead to insufficient lip pressure and leakage.

The difference between the lip diameter and the axle diameter in the free state is called interference. The interference can generate part of the radial force and compensate for the eccentricity caused by the shaft. However, it should also be within certain limits. If the interference is too small, the sealing performance will be reduced; If the interference is too large, the lip edge will be close to the axis. If the collar is tightened too tightly, the oil film on the friction surface will be damaged. Under the high-speed rotation of the shaft, the temperature between the lip and the shaft surface will rise rapidly, accelerate the cracking of the lip, and even burn the seal lip, which will cause the seal to fail.

There are many sealing materials commonly used, and the role of these sealing materials is also very different. When we choose to use, please consider from various different aspects, such as ambient temperature, whether the material is resistant to media, the hardness of the material, compression deformation and wear resistance and so on