The choice of oil seal factors - bearing knowledge

In order to give full play to the function of the oil seal, must according to the conditions of use selected the most suitable type and material. Here is the main influence factors for a brief. 1, the surface of the shaft linear velocity: under the condition of the same diameter, different materials of oil seal, the ability to adapt to the axial plane rotation speed is different, their relationship as shown in the figure below. Oil seal use linear velocity range is generally less than 15 m/s, and below the surface of the shaft linear velocity of the given tolerance is a reference, satisfaction of lubrication and good heat dissipation condition is the decisive factor. Corresponding lower data for more stringent conditions. 2, temperature: as the axis of rotation surface and oil seal sealing lips friction, so the sealing lip mouth temperature higher than the temperature of the oil, general oil seal work its lip margin of 20 ~ 50 ℃ temperature is higher than the working medium temperature. With higher speed, the pressure increase the temperature of the sealing lip also will rise. In addition, with dustproof lip seal, than without dustproof lip seal will appear above 20 ℃ high temperature. When more than allowable temperature will shorten the working life of the oil seal, cause the sealing lip premature permanent hardening, as well as wear and tear. Oil seal work temperature range related to oil seal materials used: material is nitrile butadiene rubber ( NBR） For - Rubber (40 ~ 120 ℃, Alec ACM) - - - - - - 30 ~ 180 ℃, fluorine rubber ( FPM) - - - - - - 25~300℃。 3, pressure, oil seal is mainly used for non pressure or under the condition of micro pressure is used, the maximum working pressure of 0. 02 ~ 0. 05Mpa。 When the pressure of work more than this value should be chosen when the compression type oil seal. 4, dustproof: in order to prevent contamination, dust, and moisture from the air side into the sealed cavity in the body, such as it is recommended to use a dustproof lip seal. The two oil seal, if pollutants into serious recommended tandem installed in tandem manner.