The skeleton oil seal is the typical representative of the oil seal. The role of the oil seal is generally the transmission parts need to be lubricated parts and output components isolated, not to let the oil leakage. The skeleton is like the steel bar in the concrete component, which plays an important role in strengthening, and keeps the shape and tension of the oil seal. According to the structural form can be divided into single lip framework oil seal and lip frame seal. The lips of the lip oil seal to prevent dust, impurities, etc.. According to the skeleton type can be divided into the inner package skeleton oil seal, exposed skeleton oil seal and assembly seal. According to the working conditions can be divided into rotary skeleton oil seal and reciprocating skeleton oil seal. For gasoline engine crankshaft, diesel engine crankshaft, gearbox, differential, shock absorber, engine, axle and other parts.

The framework oil seal structure is composed of three parts: an oil seal body, a reinforcing frame and a self tightening spiral spring. According to the different parts of the seal body is divided into the bottom, waist framework oil seal structure

Skeleton oil seal structure

Part, blade and sealing lip. Usually, in the free state of the skeleton oil seal, the inner diameter is smaller than the shaft diameter, that is, a certain amount of interference".

Therefore, when the oil encapsulated into the oil seal seat and shaft, seal edge pressure and self tightening spiral spring contraction force radial tightening force on the shaft, after a period of time after the operation, the pressure decreases rapidly and disappears, therefore, plus spring can seal the self tightening force compensation.

Sealing principle: due to the oil seal between the oil seal and the edge of the oil film, the film has the characteristics of fluid lubrication. Liquid surface tension skeleton oil seal skeleton oil seal

Under the action of the oil film, the rigidity of the oil film forms a crescent surface on the contact end of the oil film and the air, thereby preventing the leakage of the working medium, thereby realizing the sealing of the rotary shaft. The sealing ability of the oil seal, the sealing surface depends on the thickness of oil film thickness, the thickness of oil seal leakage; too big, too small, may be caused by dry friction, oil seal and shaft wear; no oil film between the seal lip and shaft, it is easy to cause fever, wear.

Therefore, at the time of installation, must be in the sealing ring with some oil, while ensuring seal and the axis perpendicular to the line, if not vertical, lip oil seal will put the lubricating oil from the shaft on the stem, can also cause excessive wear of the seal lip. In operation, the lubricant in the shell is slightly leaking, so as to achieve the best condition of forming oil film at the sealing surface.