NBR material TC oil seal Common materials for oil seals are: nitrile rubber, fluoro rubber, silicone rubber, acrylate rubber, polyurethane, PTFE and so on.
NBR material TC oil seal
The outer circle of the skeleton oil seal generally has several structural types. What are the advantages and disadvantages of each?
Zhonggao seal: The outer part of the oil seal is generally divided into three structural forms, namely, the outer round all-inclusive rubber, the outer round exposed iron and the outer round semi-encapsulated rubber.
The outer-circle all-inclusive rubber product is the most commonly used structural type, and can also be divided into outer corrugated and ordinary outer-coated rubber type. The outer-circle all-inclusive rubber product requires relatively low surface finish for the mounting hole (Ra1.6-6.3), and is suitable for the case where the thermal expansion coefficient of the seat hole material is large, such as copper, aluminum and the like. Since rubber is a poor conductor of heat, this type of structure is inferior in heat conduction and heat dissipation.
The outer round iron product is also a common structural form. The outer circumference of the metal is in direct contact with the seat hole and is sealed by an interference fit. Since metal is a good conductor of heat, this type of structure has advantages in heat conduction and heat dissipation.
The same reason is because the outer circle of the metal is in direct contact with the seat hole, and the sealing is achieved by the interference fit. Therefore, the outer surface smoothness and dimensional tolerance of the product are required to be high, and the surface finish generally requires Ra1.6 or more, and the dimensional tolerance range is generally 0.1 mm- 0.12mm. Similarly, the surface finish of the seat hole is also required to be higher (Ra 0.8-3.2).
When assembling the outer round iron product, for the case where the surface finish of the seat hole is relatively poor, it is recommended to apply the sealant to the outer circle to enhance the sealing effect and stability, or to spray the seal on the outer circumference of the product.