How to repair rolling bearings
Maintenance of rolling bearings
If the bearing does not heat up during operation, then its inspection and grease change are carried out during subsequent repairs. Before changing the grease, the bearing with the caps removed is washed with gasoline with the addition of 6 - 8% of the spindle volume or transformer oil. Flushing is done by slightly turning the rotor until clean gasoline starts to flow from the bearing. The bearing is then dried with compressed air. their parts. The space between the balls with the balls is filled with grease all around.
After assembling the bearing assemblies, manually check the ease of rotation of the rotor, and then turn on the electric motor for 15 minutes. If the bearings are in good condition, a steady hum will be heard without knocking or knocking.
Installation and repair of rolling bearings
Before installation, the new bearings are thoroughly washed for 10 — 20 minutes in a bath of transformer oil heated to a temperature of 90 — 95 ° C. Then they are washed in gasoline.The use of kerosene to flush rolling bearings is not recommended as it cannot be completely removed from the bearing and will cause bearing corrosion over time.
At the end of the flushing, the ease and smoothness of the bearing rotation is checked. At the same time, attention is paid to the absence of congestion, stoppage and abnormal noise.
If the new bearing does not match the inner or outer diameter, as well as the width of the old bearing, it is allowed to install repair bushings or thrust rings.
To reduce the diameter of the shaft or increase the diameter of the hole in the cover in the range of 0.02 — 0.03 mm, use sandpaper. In case of large deviations, an intermediate sleeve is installed on the shaft or in the hole.
Before installing the bushing, turning work is required to rotate the shaft.
The outer diameter of the sleeve should be 3-5 mm larger than the inner diameter of the bearing, and the inner diameter 0.3-0.4% smaller than the diameter of the shaft machined under the sleeve.
Before installing the sleeve on the shaft, it must be heated to 400 — 500 ° C. After cooling, the sleeve installed on the shaft is machined to the final size according to the inner diameter of the bearing.
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