The oil seal is the customary name for a general seal, simply a seal of a lubricant. It is a mechanical component used to seal grease (oil is the most common liquid substance in the transmission system, also refers to the general liquid substance), it isolates the parts of the transmission parts that need to be lubricated from the output parts, so as not to let lubrication Oil leaks. Static seals and dynamic seals (generally reciprocating) are called oil seals with seals.

The representative form of the oil seal is the TC oil seal, which is a double-lip oil seal with a self-tightening spring completely covered by rubber. Generally speaking, the oil seal often refers to this tc skeleton oil seal.

Classification

Oil seals are generally divided into single and assembled types, and assembled types are skeleton and lip materials.

Free combination, generally used for special oil seals.

The seal function, characteristics, structure type, working condition and sealing mechanism of the oil seal can be divided into various forms and different names, but it is customary to call the rotary shaft lip seals as oil seals, static seals and dynamic seals ( Generally reciprocating motion) is called a seal with a seal.

The representative form of the oil seal is the TC oil seal, which is a double-lip oil seal with a self-tightening spring completely covered by rubber. Generally speaking, the oil seal often refers to this tc skeleton oil seal.

Materials

Common materials for oil seals are: nitrile rubber, fluoro rubber, silicone rubber, acrylate rubber, polyurethane, PTFE and so on.

Nitrile rubber (NBR)

It has good heat resistance and wear resistance, and is resistant to various lubricating oils, greases, oil and gas mixtures, etc., suitable for temperatures of -30 to 120 degrees Celsius, but not for phosphate ester hydraulic oils and extreme pressure additives. Used in gear oils, it is stable in gasoline and low aniline point mineral oils.

Polyacrylate rubber (ACM)

Excellent oil and heat resistance, abrasion resistance, ozone resistance, UV radiation resistance, especially lubricating oil, gear oil, motor oil, engine oil, petroleum hydraulic oil, etc. Work in the ~150 degrees Celsius range.

Fluororubber (FPM)

Aging resistance, heat resistance and oil resistance, it is suitable for all lubricating oils, fuel oils and gasoline. It is not easy to harden in oils containing extreme pressure additives, but cold resistance, high temperature wear resistance is poor, permanent compression deformation is better. Large, suitable for temperatures -20 ~ 250 degrees Celsius.

Silicone rubber

With outstanding high and low temperature resistance, it can be used for ultra long-term use at 150 degrees Celsius without performance change; it can be used continuously for 10,000 hours at 200°, and it can maintain its unique elasticity and resistance in the working temperature range of -70~260. Ozone, weather resistance and other advantages.

Teflon

It has outstanding chemical stability, thermal stability, friction reduction and self-lubricity, and its cracking temperature is above 400. Therefore, it can work normally in the temperature range of -200 to 300 degrees Celsius. In addition to free fluorine and alkali metals, it has excellent corrosion resistance to chemicals, solvents, hydroxides and acids.

Nitrile rubber and fluororubber materials are widely used oil seals. The former is cost-effective, but the temperature and sealing properties are significantly improved, but the cost is high, and still have some common commonalities of ordinary rubber materials, such as resistance. Leakage is still common due to poor grinding performance, short service life, and sensitivity to eccentric reactions of the shaft. PTFE oil seal is a product with high technical content and is the direction of oil seal development in the future.

When selecting the material of the oil seal, the compatibility of the material with the working medium, the adaptability to the operating temperature range, and the ability of the lip to follow the high-speed rotation of the rotating shaft must be considered. Generally, the temperature of the lip of the oil seal is higher than the temperature of the working medium by 20~50 °C, and should be paid attention when selecting the oil seal material. The working range of the oil seal is related to the material used in the oil seal: -40 to 120 ° C for nitrile rubber (NBR), 30 to 180 ° C for ACM, and 25 to 300 ° C for fluororubber (FPM).