旋转轴唇形密封圈的结构及优点（Structure and advantages of rotary shaft lip seal）.doc

旋转轴唇形密封圈的结构及优点（Structure and advantages of rotary shaft lip seal） Rotary shaft lip seal is usually called seal, gearbox, widely used in construction machinery drive axle components, such as before and after the output shaft of the gear box, the main reducer of the drive axle wheel, etc., its function is to put the oil cavity and the isolation of sealed oil, external dust. At present, a large number of oil seal structures are adopted in China, including the rubber seal, metal frame or metal shell and metal spring. I. the sealing mechanism of the oil seal The sealing of the oil seal is formed by the interference fit between a flexible sealing element (leather, rubber, Teflon, poly three fluorine chloride or polyimide, etc.) and a rotating shaft. Its sealing mechanism is: the oil seal, the lip and the axis of the contact surface simultaneously exist dry friction, boundary lubrication and fluid lubrication three cases, and constantly alternate generation. Dry friction and wear, resulting in leakage of fluid lubrication, boundary lubrication, a stable layer of fluid dynamic pressure oil film is formed between the seal lip and the axis of the interface, the oil film thickness is about 00025mm; this layer in addition to used lubricating oil film, but also has the function of sealing. If the oil film is too thick, the fluid will leak; the oil film is too thin to form a fluid lubricating film, and the lips will wear out. Therefore, in order to obtain good sealing performance and long service life, provide the conditions of boundary lubrication oil film requires people in the structural design, design and installation of rubber should be used for the formation of thin and stable. In terms of structural design, installation and use, the conditions commonly used in domestic oil seals are very demanding, which has also laid a hidden danger for the frequent occurrence of leakage faults. Two, the existing oil seal deficiencies 1. in the structural design, because the seal is the a