Skeleton oil seal is a typical representative of oil seal. Generally speaking, oil seal refers to skeleton oil seal. Generally, the function of oil seal is to isolate the components that need lubrication from the output components, so as not to let the lubricating oil leak. The skeleton, like steel bars in concrete members, plays a role in strengthening and keeps the shape and tension of the oil seal. It can be divided into single lip skeleton oil seal and double lip skeleton oil seal according to the structural form. The secondary lip of the double lip skeleton oil seal plays a dustproof role to prevent the external dust and impurities from entering the machine. According to skeleton type, it can be divided into internal skeleton oil seal, exposed skeleton oil seal and assembled oil seal. According to working conditions, it can be divided into rotary skeleton oil seal and reciprocating skeleton oil seal.
According to different types to distinguish different categories. Today, we will mainly talk about skeleton oil seal. The skeleton oil seal structure consists of three parts: oil seal body, reinforcing skeleton and self-tightening coil spring. Sealing body is divided into bottom, waist, cutting edge and sealing lip according to different parts. Generally, the inner diameter of skeleton oil seal in free state is smaller than the shaft diameter, that is, it has a certain “interference”.
Therefore, after the oil seal is installed on the oil seal seat and shaft, the pressure of the oil seal cutting edge and the contraction force of the self-tightening coil spring produce a certain radial tightening force on the shaft. After a period of operation, the pressure will rapidly decrease or even disappear, so the spring can compensate the oil seal self-tightening force at any time.
Sealing principle: Because there is an oil film controlled by the oil seal cutting edge between the oil seal and the shaft, the oil film has fluid lubrication characteristics. Under the action of liquid surface tension, the stiffness of the oil film just makes the contact end between the oil film and the air form a crescent surface, which prevents the leakage of working medium, thus realizing the sealing of the rotating shaft. The sealing ability of oil seal depends on the thickness of oil film on sealing surface. Excessive thickness and oil seal leakage; If the thickness is too small, dry friction may occur, causing oil seal and shaft wear; If there is no oil film between the sealing lip and the shaft, it will easily cause heat and wear.
Therefore, during installation, some oil must be coated on the sealing ring, and the skeleton oil seal should be perpendicular to the axis. If it is not perpendicular, the sealing lip of the oil seal will drain the lubricating oil from the shaft and cause excessive wear of the sealing lip. During operation, the lubricant in the casing slightly oozes out, so that it is ideal to form an oil film at the sealing surface.
The skeleton oil seal is made of high-quality nitrile rubber and steel plate, with stable quality and long service life.
The use of oil seals should also pay attention to several points: some equipment uses harsh environments, such as extreme cold. At this time, the oil seals selected should be made of relatively cold-resistant materials; Or it is used outdoors, exposed to the sun and rain, and ordinary rubber is easy to age under such circumstances.
Company Name: Yiwu Great Seal Rubber Products Company
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State: Zhejiang, 312300