The pulley is kept from turning on the crankshaft by a key fitting into grooves on the crankshaft and pulley.
Updates in oil seals
Usually, these oil seals are used to seal lubricating oil or grease and contain it within the application, so that moving parts such as bearings are continually supplied with enough lubrication. However, such seals are also used for sealing other liquids, gases, and solids, such as powders or granules.
In addition to their sealing and durability properties, natural rubber gaskets also offer excellent resistance to a wide range of chemicals, including oils, solvents, and acids
. This makes them suitable for use in harsh industrial environments where exposure to corrosive substances is common.natural rubber gasket

EPDM oil seals are less common. They are used in solvent, hot water and steam applications, EPDM resists low temperatures down to -50 °C and UV radiation well. Some types of EPDM are also suitable for higher temperatures up to +150 °C. EPDM oil seals are usually available upon request.