Classification of structural form of outer circle of skeleton oil seal

The outer circle of the skeleton oil seal generally has several structural types, what are the advantages and disadvantages of each?

The outer part of the oil seal is generally divided into three structural forms, namely, the outer full cover, the outer exposed iron and the outer half cover.

As the most commonly used structural type, the outer full-coated product can also be divided into outer corrugated and ordinary outer coated adhesive types. The requirements for the surface finish of the installation seat hole are relatively low (RA1.6-6.3), and it is suitable for the case of large thermal expansion coefficient of the seat hole material, such as copper, aluminum and so on. Because rubber is a poor conductor of heat, this structural form has poor ability in heat conduction and heat dissipation.

Outer round exposed iron products are also a commonly used structural form. The metal outer circle is in direct contact with the seat hole and is sealed by interference fit. Since metal is a good conductor of heat, this type of structure has advantages in heat conduction and heat dissipation.

The same is because the metal outer circle is in direct contact with the seat hole, and the sealing is achieved through interference fit, so the product outer circle surface finish and dimensional tolerance requirements are higher, the surface finish is generally required to be above Ra1.6, and the dimensional tolerance range is generally 0.1mm-0.12mm. Similarly, the requirements for the surface finish of the seat hole are also higher (RA0.8-3.2).

When assembling the outer circle exposed iron products, for the case of relatively poor surface finish of the seat hole, it is recommended to apply the outer circle sealant to enhance the sealing effect and stability, or spray sealing paint on the outer circle of the product.