The basic principle of an oil seal is fairly straightforward. It is installed adjacent to the bearing, with the flexible lip against the rotating shaft and the casing pressed into the housing to hold the seal in place. It’s important that the sealing lip is lubricated to prevent it from overheating as a result of any generated friction. It’s also crucial to understand which type of seal is appropriate for your particular machinery. Before selecting your seal, consider the environment, temperature, pressure and shaft speed of your machine, as well as the type of medium the seal will come into contact with during operation. These considerations will all determine the size, colour, and type of lip material or sealing element to choose, and whether it can be sealed in or sealed out.

Metal inserts must be carefully prepared in operations involving cleaning and roughening surfaces (grit-blasting or phosphatizing), stamping out parts, application of primer (usually by dipping), and curing of the primer (often by baking for a short time at moderate temperature).³ Primer curing minimizes the possibility of wiping primer off portions of the insert by stock flow during molding. The treated metal inserts must be used within a relatively short time (usually a day or less), so that functionality necessary for bonding is not lost by reaction with moisture in the air. Freshness of the primer surface is particularly important for peroxide-cured and base-resistant fluoroelastomer compounds. Compound formulation should be adjusted to attain good adhesion.