What is the rolling NSK bearing selection

2011-10-24 10:22    Author:admin   Click:

Select basis

According to the effect on the bearing load relative to the rotating ferrule, bearing the loads is of three kinds: local load, cyclic loading, oscillating load. NSK bearing Usually cyclic loading ( rotation load ), oscillating load the tight fit; local load except with special requirements, should not be commonly use tight fit. When the bearing ring bearing with dynamic load and heavy load, inner, outer ring shall be used for interference fit, but sometimes the outer ring can be slightly a little loose, should be able to bearing shell hole axially moving; when the bearing ring subjected to oscillating load and the load is relatively light, can be used than the tight fit slightly loose the match.

NSK bearing ring and the shaft or housing holes between the magnitude of interference depends on the size of the load, load is heavy, the larger magnitude of interference fit; load is relatively light, with a smaller magnitude of interference fit. General radial load P is less than 0. 07C for light load, P greater than 0. 07C is equal to or less than 0. 15C as normal load, P greater than 0. 15C for heavy load ( C bearing dynamic load rating ).

" Working temperature

When the bearing is running, the ferrule temperature is often higher than the adjacent parts of the temperature, therefore, the inner ring of the bearing may be due to thermal expansion and the shaft loosening, outer ring may be due to thermal expansion effect of bearing in the housing bore axially moving. Help select, the bearing device part temperature difference, expansion and shrinkage quantity should be taken into consideration, large temperature difference, selection of shaft and the inner ring of the interference fit should be greater.

De rotation accuracy

The bearing has high rotation accuracy requirements, in order to eliminate the influence of elastic deformation and vibration, should avoid the use of clearance fit.

The bearing housing, pore structure and materials

On the form of shell holes, and the outer ring of the bearing is matched with an interference fit, should not make the outer ring in a shell hole rotation. For installation in thin-walled shell hole, light metal shell hole or hollow shaft bearings, should use ratio thick wall casing cast iron shell holes, holes or solid shaft closer cooperation.

NSK bearing , convenient mounting and dismounting

For heavy machinery, bearing should adopt the loose fit. The tight fit, can choose the separation bearing inner ring with a taper hole, and the tight sets or unloading sleeve bearing.

The axial displacement of the bearing

Fit, when asked to bearing a ring in operation can move in the axial direction, the outer ring of the bearing and the bearing seat shell holes shall be with the use of loose.

Fit selection

NSK bearing  and shaft with hole base, and the casing are matched with the shaft basis system. Bearing and shaft with the machine manufacturing industry in the tolerance and fit system is different, the bearing inner diameter tolerance zone in the change, therefore, in the same match conditions, inner diameter of bearing and the shaft with the match more closely than usual. Bearing outside diameter tolerance zone and on the basis of shaft axis tolerance zone while in zero line, but its value is not the same as with the general tolerance system.