An oil seal is a device used to prevent dirt, dust, water, or any other foreign matter from contaminating shafts and bearings in the rotary shaft equipment. Also known as a shaft seal or dirt seal, it also blocks the leakage of lubricants such as grease and oil along a rotating shaft.
Obtaining adequate adhesion of fluoroelastomer compounds to metal inserts is a major consideration in fabrication of shaft seals. Adhesive systems worked out for bisphenol-cured VDF/HFP/TFE elastomers often do not perform adequately for peroxide-curable fluoroelastomers and more base-resistant polymers that contain little or no VDF. The trend toward use of more resistant fluoroelastomers in shaft seals has necessitated considerable effort on compounding and adhesive system development to get adequate bonding of the new materials. Silane-type primers are often used to coat metal inserts; these contain residual active groups such as amine functions that interact with the fluoroelastomer compound to attain good adhesion, especially for VDF/HFP/TFE elastomers. Other adhesive systems, using epoxy compounds or tie-coats, may be necessary for difficult bonding situations.3

car engine oil seal. Additionally, oil leaks can also damage other engine components, such as the timing belt or spark plugs, leading to further costly repairs.
Metal O.D. wall type (with a reinforcing inner metal case) Protects the main lip.
When they are subjected to hot & pressured oil, or hot & pressured gas, they will compress. These seals reduce in size and become more compact. Afterward, they store the mechanical energy generated by the heat and pressure, which is why they can maintain a leak-proof mating surface.

Figure 5: JTEKT seal numbering system
Table 6: Codes and numbers used in seal numbers
Oil seals are available in an immense range of sizes, for shafts from a few millimetres to several metres. Once the shaft diameter, groove diameter (housing diameter) and groove width are known, selecting an appropriate oil seal is a simple task. An oil seal or its product description is usually associated with three dimensions, for example 6x15x4. These refer to the sizes of the hardware for which the oil seal is designed. In this example, this oil seal is suitable for: 6-mm shaft diameter x 15-mm groove diameter x 4-mm minimum groove width.
Choosing high-quality oil seals for your roller bearings, precision bearings, and more is an important decision, so at Emerson Bearing Company, we do more than manufacture oil seals. We draw from over 50 years of expertise in the area of bearings and bearing-related components so that our team can help you choose the right oil seals for your exact needs, regardless of the nature and complexity of your application. Should we not have a particular part in stock in our vast inventory, we also utilize a worldwide sourcing network to deliver on premium products. The Emerson team strives to provide a one-stop experience for our customers, from sourcing and budgeting to assistance in oil seal selection and timely delivery with same-day shipping options.