Installation and disassembly skills of rolling bearings

  The clearance of a rolling bearing refers to the maximum activity of the other ring along the radial or axial direction when a ring is fixed, which is divided into two types: radial clearance and axial clearance. When assembling rolling bearings, the clearance should not be too large or too small. Excessive clearance reduces the number of rolling elements that bear the load at the same time, increases the load of a single rolling element, thereby reducing the rotation accuracy of the bearing and shortening the service life.
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Too little clearance will increase friction, lead to increased heat, increase wear, and also reduce the service life of the bearing. Therefore, the bearing assembly needs to strictly control and adjust the clearance. Pretightening means that an axial force is given to the inner or outer ring of the bearing during assembly to eliminate the backlash and produce initial deformation at the contact point between the rolling body and the inner and outer ring. Preloading can improve the stiffness and rotation accuracy of the bearing in the working state. For bearings that bear large loads and require high rotation accuracy, they usually work in a state with no clearance or a small amount of interference, which requires pre-tightening adjustment during assembly. The adjustment and pretightening of the clearance is usually achieved by making the bearing inner ring and the outer ring make appropriate axial relative displacement.
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Before bearing installation, the bearing, journal and bearing seat holes should be cleaned. When installing, use special tools to press the bearing into the flat and even, avoid using hard objects such as a hammer to hit the bearing directly. If there is no special tool, it should be padded with a copper or wooden rod, and then hammered to ensure that the pressure is evenly distributed on the inner and outer rings of the bearing, avoid applying pressure in a single direction, and prevent the bearing tilt from damaging the mating surface or installing eccentricity.
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In the process of bearing installation, if it is found that the bearing is too tight or too loose in the journal and the bearing seat hole, the installation should be stopped and the suitable bearing should be re-installed. If the journal or bearing seat hole is deviated, it should be installed after repair.
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After installation, the machine should be started to run, measure the temperature of the bearing part housing and listen to its sound. If the temperature is too high, the clearance is too small; If the sound is abnormal, there may be too much clearance. According to the inspection results, the clearance is adjusted after shutdown.