A patent for an oil seal was filed by Nelson Thomas Edward on August 12, 1937, and published a year later. There were two purposes described. The device was to provide an oil seal between a fixed housing and a rotating part. The seal is described as



The square shape of the gasket allows for a more precise fit in square or rectangular openings, ensuring a tight seal to prevent fluids or gases from escaping. Made from high-quality rubber materials such as neoprene, silicone, or EPDM, these gaskets offer excellent resistance to temperature, pressure, and chemical exposure.
This technique is used when the seal depth must match the housing surface precisely. It involves stopping the installation tool at the machined housing face. Ensure the tool is perfectly perpendicular to the shaft for best results. This technique is ideal for applications requiring exact seal positioning relative to the housing face.
Oil lip seals play a significant role in several industrial applications to avoid intermixing fluids and prevent contaminants and moisture from affecting the bearings. With such a vital role to play, it is essential to choose the right material for these seals. The choice of the material will depend on factors like the type of fluid being sealed, operating temperature, pressure, and compatibility with the operating environment. The following list of materials is typical for making oil lip seals:
MVQ
Like any element of the engine, oil seals are subject to wear. Over time they can lead to possible leaks of lubricating liquid.
Type (type code)
Many seals come with a garter spring, found within the backside of the seal. It provides contracting pressure against the sealing surface. Making sure the spring seats correctly within the seal is an excellent first step.