What does brinnelling refer to in the context of bearings?

Brinnelling specifically refers to the development of indentations on the surface of bearing raceways caused by excessive loads. When bearings are subjected to loads that exceed their designed capacity, the material may deform, leaving permanent indentations. This phenomenon can lead to increased friction, premature wear, and ultimately, failure of the bearing.

Brinnelling often occurs during static conditions, such as when a bearing is under a heavy load without movement for an extended time. The indentations can also lead to a phenomenon called false brinelling, where wear patterns develop due to oscillations rather than constant heavy loads. Understanding and preventing brinnelling is crucial for maintaining the longevity and efficiency of bearing systems.

Other options do not describe brinnelling accurately: corrosion pertains to chemical degradation and is unrelated to mechanical deformation, cracking due to thermal stress involves material failure from thermal cycling, and noise generated by the bearing relates to operational characteristics rather than structural damage.