Xu Xinhua rubber seals Seal

 

Seal rubber seals commonly used materials include: nitrile rubber, fluoro rubber, silicone rubber, acrylic rubber, polyurethane, polytetrafluoroethylene and the like. In choosing the material seal rubber seals must be considered material to the work of media compatibility, the ability to follow the operating temperature range of adaptability and high-speed rotation of the lip of the rotary axis. When the general work of its seal lip higher than the operating temperature of the medium temperature 20 ~ 50 ?, should pay attention to when selecting seal material. For more details, please refer to: rubber types and characteristics. Material scope seal and seal rubber seals used about: material nitrile rubber (NBR) when -40 ~ 120 ?, Aggreko rubber (ACM) -30 ~ 180 ?, Viton (FPM) -25 ~ 300 ?.

Seal oil seal rubber seal, characteristics, structure type, job status and the like from the sealing mechanism can be divided into many forms and different names, but the habit is generally called the rotary shaft lip seals seals rubber seals, static seals and dynamic seal (general reciprocation) seals called rubber seals. Representative form seal rubber seal is TC oil seal, which is a rubber seal lips completely covered with a self-tightening spring, the general said oil seal often refers to this tc seal, who operate inside the body with a liquid lubricant but connected with the external parts are required seal. Some are rubber, some are metal, mostly steel reinforced rubber, such as the crankshaft rear oil seal, front and rear gearbox oil seal around axle seal, before the final drive oil seals, air compressor crankshaft oil seals and other rubber seals seal seal sealing principle o-ring rubber seal principle and reciprocating motion, it is due to the oil seal between the rubber seal and the shaft there is a seal lip controlled hydrodynamic oil film. Rigidity just make the film in contact with air to form a meniscus at the end under the action of surface tension of the liquid to prevent leakage of the working medium, a seal axis of rotation.

 

Seal rubber seal sealing capacity depends on the thickness of the hydrodynamic oil film. Film thickness is too large, the oil seal leakage; film thickness is too small, dry friction may occur, causing seal wear. The most ideal film thickness is "critical film." Direct factors affecting the film thickness is oil seal lip contact pressure on the shaft seal, only the highest pressure point in order to form the critical film, then sealed the best results. In order to maintain a stable fluid film to be properly selected lubricating fluid to seal parameters with suitable characteristics, so as to achieve the sealing effect.