Skeleton oil seal structure and sealing principle of knowledge - bearing

Skeleton oil seal is simpler, generally speaking, there are three parts: the oil seal body, strengthen the skeleton and the spiral spring. Seal according to the different parts of the body is divided into the bottom, waist, blade and sealing lip, etc. Usually, in the free state of skeleton oil seal, the inner diameter smaller than the diameter of axle, which has a certain 'interference'. Therefore, after the oil seal in oil seal and shaft, oil seal edge pressure and self-tightening helical spring contraction force on the shaft of the radial force, after a period of time after the operation, the pressure will be reduced and even disappear quickly, thus, combined with spring can compensates for oil seal force at any time. Sealing principle: due to the exist between oil seal and the shaft seal edge control of oil film, the film with fluid lubrication properties. Under the effect of the surface tension of liquid, oil film stiffness just makes the oil film is exposed to air end to form a new moon face, prevent the leakage of working medium, so as to realize the sealing of the axis of rotation. Oil seal sealing ability, depend on the sealing surface of the oil film thickness, the thickness is too big, oil seal leakage; Thickness is too small, dry friction may occur and cause oil seal and shaft wear; No oil film between the sealing lip on the shaft, easy cause fever, wear and tear. At installation time, therefore, must put some oil on sealing ring, at the same time guarantee the skeleton oil seal and the vertical axis, if not vertical, oil seal sealing lip lubricating oil from the axis line to do, can also lead to excessive wear of the sealing lip. In operation, the casing of the lubricant leakage point, slightly on the sealing surface in order to achieve the most ideal forming oil film.