Fit of bearing
Rolling bearings must be positioned and fixed with different requirements in the radial/axial direction and axial (tangential) direction when cooperating with the shaft and bearing seat. The axial positioning of bearings is usually realized by nuts, shaft shoulders, end covers, spacers, elastic retaining rings and adjacent parts end faces. The radial and axial positioning of bearings is generally completed by the inner diameter and shaft of bearings, and the outer diameter and the inner hole of bearings.
For high speed precision spindle bearings, in order to ensure good dimensional accuracy and rotational accuracy, excessive interference fit should be avoided to prevent ring deformation due to large interference amount, resulting in loss of bearing accuracy. On the other hand, for high-speed bearings with dmn value greater than 1.0X10 6mm.r/min, if the match between the inner ring and the shaft is not suitable, when the bearing rotates at high speed, the inner ring expands outward due to the action of centrifugal force, resulting in the increase of the clearance between the inner ring and the shaft, which may lead to the occurrence of peristalsis, friction, wear and other phenomena between the inner ring and the mating shaft. Therefore, special attention must be paid to the matching condition of high-speed precision spindle bearings