An oil seal normally consists of three basic components: the sealing element, the metal housing and the spring. The purpose of the sealing element is to prevent fluid from leaking between the shaft and the housing. The metal housing will give rigidity and strength to the retainer while remaining in the bore or recessed groove. The spring ensures constant pressure and maintains radial force to the shaft, flattening the sealing edge to a defined width. The spring maintains the radial force exerted by the sealing lip around the shaft surface. All materials should be selected based on the environment in which the seal will operate.
The purpose of the checkpoints is:
- Prevent lubricating oil from leaking to the outside even under high oil pressure.
- Act as a physical barrier that retains the lubricating oil where it belongs.
- Act as a barrier and prevent dirt, contamination and other external entities from entering the system containing the lubricating oil.