The friction characteristics of the sliding surface of the oil seal lip are governed by the viscosity of the fluid and the sliding
speed, and there is an oil film on this sliding surface. The mutual sliding surface of the oil seal and the shaft moves in the
lubricated state where the oil film is separated, so the friction force is kept small and the wear is small. The flow of oil on the
sliding contact surface of the oil seal is a cycle from the atmosphere side to the atmosphere side. The sliding surface is well
lubricated to prevent the progress of wear, so there is no leakage. It can be seen that it is very important to subtly control the
two factors of oil seal sealing lip lip material and lip shape to affect the lubrication characteristics and sealing principle of the oil
seal.