The role of the skeleton oil seal is generally to isolate the parts of the transmission part that need to be lubricated from the output parts, so as not to let the lubricating oil leak, and is usually used for rotating the shaft, which is a rotating shaft lip seal. The skeleton acts like a reinforcing bar inside the concrete member, which acts to strengthen and maintain the shape and tension of the oil seal. 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.