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Matching of precision bearings

1. The roundness of the shaft and the seat hole and the verticality of the shoulder shall be required according to the corresponding accuracy of the bearing.
2. It is necessary to accurately calculate both the interference of the rotating ferrule and the appropriate fit of the fixed ferrule.
3. The interference of rotating ferrule should also be small within the possible range. As long as the influence of thermal expansion at the working temperature and the influence of centrifugal force at the highest speed are ensured, the creep or sliding of the tight fitting surface will not be caused. According to the working load and bearing size, the fixed ferrule selects a very small clearance fit or interference fit. Neither too loose nor too tight is conducive to maintaining the original accurate shape.
4. If the bearing runs at high speed and the working temperature is high, special attention should be paid to the matching of the rotating ring not to be too loose to prevent eccentric vibration, and the matching of the fixed ring should not have clearance to prevent the ring from deforming and exciting vibration under load.
5. The condition for adopting small interference fit for the fixing ring is that both matching surfaces have high shape accuracy and small roughness, otherwise it will be difficult to install and disassemble. In addition, the influence of thermal elongation of the main shaft needs to be considered.
6. For the main shaft using paired double angular contact ball bearings, most of the half loads are light. If the fitting interference is too large, the axial preload inside will be significantly too large, causing adverse effects. The load of the spindle using double row short cylindrical roller bearings and the spindle using tapered roller bearings is relatively large, so the fitting interference is also relatively large

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