Have You Encountered Such Early Damage to Tapered Roller Bearings? What's The Reason?

Time：2020.04.15  Source：Roller Bearings Suppliers

A netizen asked this question online: "The tapered roller bearing I just bought a few days ago found that the bearing was damaged today, but when I removed the sleeve and found the outer ring, the cage was intact and not damaged. What happened? "I also saw a similar case before. It was a problem that a company discovered after experiments after producing tapered roller bearings.

At that time, the bearing was damaged after less than 200 hours of operation. At the time, the bearing outer ring and cage were found to be intact and undamaged after the sleeve was disassembled, but the working surface of the roller near the small head has varying degrees in the direction around the ring At the same time, there is also a grinding mark in the circumferential direction of the inner ring raceway near the oil groove at the small end surface.

What caused the early damage of tapered roller bearings? It mainly comes down to the following points:

(1)The hardness of the bearing ring does not match the hardness of the roller. The hardness of the inner ring is slightly higher than the hardness of the roller, which enhances the ability of the inner ring raceway to press into the roller.

(2)The contact between the roller and the raceway is a linear contact under the condition of zero load of the tapered roller bearing. Due to the grinding of the inner ring raceway, the contact between the roller and the roller changes from a linear contact to an approximate point contact.Therefore, when the bearing is working, its rollers are subjected to large shear stresses, resulting in stress concentration. When the shear stress exceeds the fatigue limit of its material, fatigue cracks occur. With the effect of cyclic load, fatigue cracks propagate along the grain boundaries and eventually form flaking, which leads to early fatigue failure of the bearing.

(3)Grinding of the inner ring raceway of the tapered roller bearing is due to the improper adjustment of the clamping position of the raceway and the grinding wheel during the final grinding process of the inner ring raceway, or the narrow selection of the width of the final grinding wheel.

From the above analysis, it can be seen that the tapered roller bearing failure here is due to the remaining edge of the bearing inner ring during the grinding process of the inner ring raceway. Therefore, during the grinding process of the inner ring raceway, it is necessary to ensure that the width of the grinding wheel is properly selected and the clamping position of the inner ring raceway and the grinding wheel is accurate, to avoid the occurrence of margins on the inner ring raceway, and thus to avoid early failure of the bearing.

Wuxi Spark Bearing Co.,Ltd provides High Quality Bearings,such as Single Row Metric Size Tapered Roller Bearings and so on.For more details,contact us by e-mail:sales@spark-bearing.com.