The function of the skeleton oil seal is generally to isolate the parts that need to be lubricated in the transmission parts from the output parts, so as not to allow the leakage of lubricating oil. The skeleton is like the steel bars in the concrete member, which acts as a reinforcement and enables the oil seal to maintain its shape and tension. According to the skeleton type, it can be divided into inner skeleton oil seal, outer skeleton oil seal, and inner and outer skeleton oil seal. The skeleton oil seal is made of high-quality nitrile rubber and steel plate, with stable quality and long service life. Widely used in automobiles, motorcycle crankshafts, camshafts, differentials, shock absorbers, engines, axles, front and rear wheels and other parts.