1. Single lip rubber oil seal: This is the most common type of oil seal. It consists of a flexible lip made of rubber or elastomeric material. It is used in various low-speed, low-pressure applications to prevent lubricant or fluid leakage.

2. Double lip rubber oil seal: Similar to the single lip oil seal, the double lip oil seal has an extra lip, which has a better sealing effect and is suitable for applications that require better sealing performance.

3. Spring-loaded oil seal: Spring-loaded oil seals contain a spring that keeps the lip in constant contact with the shaft, thereby maintaining a tighter seal. These seals are used in applications where shaft motion varies or consistent sealing force is required.

4. PTFE lip oil seals: These seals use polytetrafluoroethylene (PTFE) lips, which have low friction properties and can resist a variety of chemicals and high temperatures. They are used in applications that need to resist corrosive fluids.

5. Cassette seal: Cassette seals are oil seals with an integrated housing or cassette box. They are easier to install and provide additional protection against contamination, suitable for applications where cleanliness is critical.
6. Rubber-Coated Metal OD Oil Seals: These seals have a metal housing with the sealing lip side coated with rubber or elastomeric material. They have enhanced durability and wear resistance for demanding applications.

7. V-Ring Seals: V-Ring seals are commonly used as shaft seals, but are also classified as oil seals. V-Ring seals have a V-shaped cross-section and are primarily used to prevent contaminants and debris from entering the sealing area.
8. Rotary Shaft Lip Seals: This seal features a lip that is elastic and rotates with the shaft. It is used in applications where the shaft rotates relative to the housing.

9. Wear Sleeves: Wear sleeves are not traditional oil seals, but are used to repair or enhance worn shaft surfaces. They can be used with oil seals to improve the sealing performance of damaged shafts.