Rolling bearing fatigue caused by incorrect installation

The fatigue pits of a rolling bearing caused by excessive static load are similar to those caused by foreign particles, and the flipped edges can cause failure. Phenomenon: In the initial stage, the pits distributed with the pitch of the rolling elements are often only distributed on part of the circumference, which eventually leads to cracks. This situation sometimes only occurs on one ferrule. Often asymmetrical with the center of the raceway. Reason: The static load is too large, and the impact load transmits the installation force through the rolling elements. Remedial measures: Operate according to the installation guide to avoid fatigue caused by overload and excessive impact load due to incorrect installation: For angular contact ball bearings, close to There is fatigue in the non-contact area at the small rib, see Figure 46. Reasons: Improper adjustment, insufficient axial contact or insufficient locking of the locking bolts, too large radial interference Remedy: Ensure the rigidity of the surrounding parts and correct installation Fatigue caused by misalignment: The track deviates from the center of the bearing, see Figure 40. There is fatigue on the edge of the track/rolling element, see Fig. 47. The circumferential groove caused by plastic deformation on the whole or part of the surface, so the edge is smooth. In extreme cases, there will be cracks at the bottom of the groove, see Figure 48. Reason: Due to the misalignment of the bearing seat or the deflection of the shaft, the inner ring is inclined relative to the outer ring and causes a large moment load. For ball bearings, this results in forces in the cage pockets (section 3.5.4), more slippage on the raceway and the ball running on the edge of the raceway. For roller bearings, the raceway is asymmetrically loaded. When the ferrule tilts very seriously, the edges of the raceway and rolling elements will bear the load, and stress concentration will occur. Please refer to the misalignment trajectory in chapter 3.3.1.2. Remedial measures: Use self-aligning bearings to reduce misalignment and increase shaft strength. 31 Evaluate the running characteristics and damage of the removed bearing. Rolling contact mode 47: Fatigue occurs on the edge of the tapered roller bearing raceway that causes partial overload due to misalignment. 48: Fatigue occurs on the edge of the ball bearing raceway, such as high moment load (edge u200bu200brunning); the left picture is the raceway edge, and the right picture is the ball.