What causes brinelling of a bearing race?

Brinelling of a bearing race is primarily caused by excessive shock loading. This condition occurs when a sudden impact or force is applied to the bearing, creating indentations or permanent deformation in the raceway of the bearing. When shock loads exceed the bearing's design limits, they can result in significant stress on the material, leading to microscopic fractures and burring on the surfaces where the rolling elements make contact.

This impact loading can be a result of conditions such as misalignment, bearing installation issues, or equipment malfunctions that lead to sudden spikes in load. The result is a compromised bearing surface, which can increase friction, lead to heat generation, and ultimately reduce the lifespan and efficiency of the bearing.

Understanding this phenomenon is crucial for millwrights as it emphasizes the importance of correctly loading equipment and monitoring operational conditions to prevent excessive forces that could lead to premature failure.