During the installation of SKF Bearing, engineers are concerned about how to operate correctly. If it is not operated properly, it is likely to cause damage to SKF Bearing. If it operates at high speed and the working temperature is high, special attention shall be paid to that the fitting of rotating ferrule shall not be too loose to prevent eccentric vibration, and the fitting of fixed ferrule shall not have clearance to prevent deformation and vibration of ferrule under load.
The burning interference of rotating ferrule should also be small within the possible range. As long as the effect of thermal expansion at working temperature and centrifugal force at high speed are ensured, the creep or sliding of tight fitting surface will not be caused. According to the working load and SKF Bearing size, the fixed ring selects a very small clearance fit or interference fit. Too loose or too tight is not conducive to maintaining the original accurate shape.
The roundness of shaft and seat hole and the perpendicularity of retaining shoulder shall be required according to the corresponding accuracy of SKF Bearing.
The assembly accuracy of cage is guaranteed by special assembly mould, which can fully meet the assembly accuracy requirements of SKF Bearing.
The condition of small interference fit for the fixed ring is that both sides of the matching surface have high shape accuracy and small roughness, otherwise it will be difficult to install and more difficult to disassemble. In addition, the influence of thermal elongation of the main shaft needs to be considered.
Swing load and indefinite load shall be treated as rotating load in terms of fit. Too loose fit will cause damage to the mating surface.
Transition fit or interference fit shall be selected for the ferrule rotating relative to the load direction and the shaft or seat hole. The interference size is based on the principle that when SKF Bearing works under load, its ferrule does not produce “creep” on the shaft or on the mating surface in the seat hole. When the load is very light or the ferrule rotates occasionally at low speed under heavy load, the transition fit can be selected. At this time, the shaft surface should have high hardness and small surface roughness.
The heavier the load, the greater the fit interference. The main shaft with paired double angular contact ball bearings has light half load. If the fit interference is too large, the internal axial preload will be significantly too large, resulting in adverse effects. The load of the spindle with double row short cylindrical roller bearing and the spindle with tapered roller bearing is relatively large, so the fit interference is also relatively large.
Sometimes the direction and size of the load cannot be determined accurately. For example, in high-speed rotating machinery, in addition to the load bearing the rotor weight is fixed in the direction, there is also the rotating load caused by unbalanced mass. If this rotating load is much larger than the fixed load, the combined load is still rotating load;
If the rotating load is much smaller than the fixed load, the composite load is the swing load. The size and direction of SKF Bearing are constantly changing regardless of rotating load or swing load. In the variable working state, the load on some ferrules may be rotating load, fixed load or swinging load. This load is called indeterminate load.