The skeleton oil seal is a typical representative of the oil seal. Generally speaking, the oil seal refers to the skeleton oil seal. The function of the 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.

Rotary Wheel Of Auto Parts

The skeleton oil seal structure consists of three parts: the oil seal body, the reinforced skeleton and the self-tightening coil spring. The sealing body is divided into bottom, waist frame oil seal structure diagram, cutting edge and sealing lip according to different parts. Generally, the inner diameter of the skeleton oil seal in the 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 the shaft, the pressure of the oil seal edge and the contraction force of the self-tightening coil spring will produce a certain radial tightening force on the shaft. After a period of operation, the pressure will rapidly decrease or even disappear. , Therefore, adding a spring can compensate for the self-tightening force of the oil seal at any time.

Sealing principle: Since there is an oil film controlled by the oil seal edge between the oil seal and the shaft, the oil film has fluid lubrication characteristics.

Under the action of the skeleton oil seal, the rigidity of the oil film just makes the oil film and the air contact end form a crescent surface, which prevents the leakage of the working medium and realizes the sealing of the rotating shaft. The sealing ability of the oil seal depends on the thickness of the oil film on the sealing surface. If the thickness is too large, the oil seal will leak; if the thickness is too small, dry friction may occur, causing the oil seal and shaft to wear; if there is no oil film between the sealing lip and the shaft, it is easy to cause heat and wear. . Therefore, when installing, it is necessary to apply some oil on the sealing ring, and at the same time ensure that the skeleton oil seal is perpendicular to the axis line. If it is not perpendicular, the sealing lip of the oil seal will drain the lubricating oil from the shaft, which will also lead to excessive sealing of the lip. wear. During operation, the lubricant in the casing seeps out a little, so that it is ideal to form an oil film on the sealing surface.

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. It is usually used for rotating shafts and is a kind of rotating shaft lip seal. 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. Internal and external exposed skeleton oil seal. The skeleton oil seal is made of high-quality nitrile rubber and steel plate, with stable quality and long service life.

In order to use the oil seal reasonably, the following points should be paid attention to:

(1) Shaft speed Due to design and structural reasons, high-speed shafts should use high-speed oil seals, low-speed shafts should use low-speed oil seals, and low-speed oil seals cannot be used on high-speed shafts, and vice versa.

(2) When the ambient temperature is high, polyacrylate or silicon, fluorine, and silicon fluorine rubber should be selected. And should try to lower the oil temperature in the tank. When the operating temperature is too low, cold-resistant rubber should be used.

(3) The oil seal with general pressure has poor pressure bearing capacity, and the oil seal will deform when the pressure is too large. In the case of excessive pressure, a pressure-resistant bearing ring or a reinforced pressure-resistant oil seal should be used.

(4) The degree of eccentricity on the installation If the eccentricity of the oil seal and the shaft is too large, the sealing performance will be deteriorated, especially when the shaft speed is high. If the eccentricity is too large, a "W"-shaped oil seal can be used.

(5) The surface finish of the shaft directly affects the service life of the oil seal, that is, the higher the shaft finish, the longer the service life of the oil seal.

(6) Note that there should be a certain amount of lubricating oil on the lip of the oil seal.

(7) Special attention should be paid to prevent dust from immersing in the oil seal.