China
Africa
Explore chapters and articles related to this topic
Design Perspective of Wear Behavior
Published in Raymond G. Bayer, Engineering Design for Wear, 2019
Brinelling: Indentation of the surface of a solid body by repeated local impact or impacts, or static overload or damage to a solid bearing surface characterized by one or more plastically formed indentations brought about by overload.
Types of Surface Damage and Wear
Published in J. Blau Peter, Tribosystem Analysis: A Practical Approach to the Diagnosis of Wear Problems, 2017
There is a related damage phenomenon called false brinelling that is sometimes confused with fretting. There are some differences [37]. False brinelling results from the minute rocking of a concentrated contact that produces a feature that can look like a hardness impression. There are no sliding or abrasion-like striae as might be observed in the case of fretting contact. True brinelling, by contrast, is the action of a high-load indentation or impact to produce a depression like a hardness indentation. Such phenomena as false and true brinelling are commonly associated with damage to the races in rolling element bearings.
Effect of Lubricant Properties and Contact Conditions on False Brinelling Damage
Published in Tribology Transactions, 2023
Rachel Januszewski, Victor Brizmer, Amir Kadiric
False brinelling was reported in the literature as early as 1937. Almen (3) first investigated surface marks found on bearings in cars during transport by train. He recognized that these were similar in appearance to the craters found in true brinelling in the Brinell hardness test but that they were caused by different mechanisms, hence the term false brinelling. False brinelling is a tribological wear process, whereas true brinelling is caused by plastic deformation of a surface during an indentation process. It is this wear process that results in one clear distinction between false and true brinelling: the indentations caused by true brinelling show the original surface machining marks despite the macro plastic deformation of the surface (4), whereas these have been rubbed off in the case of false brinelling resulting in a relatively polished, shiny surface. False brinelling continues to be an issue during transport of machinery as globalization sees equipment transported around the world, with risk of damage increasing with transport distances (3). It is a recognized issue in standby machine units that are stored close to running equipment and hence subjected to vibration for prolonged periods of time. The damage is often discovered only when the standby equipment is put to use and the bearings are found to be noisy. More recently, false brinelling has been recognized as a major failure mode in two modern engineering applications, namely, wind turbine pitch bearings (5), particularly in the designs where individual pitch control for each blade is employed (6), and in hybrid vehicle bearings (7, 8). Wind turbine pitch bearings can spend long periods of time under a nominally stationary condition while subjected to vibrations from the operating turbine, and when in actual operation, they oscillate through small angles, in the range of 5°, both of which increase the risk of false brinelling. In hybrid vehicles, one of the two power sources, either the internal combustion engine or the electric motor, is often stationary while being subjected to vibrations caused by the operating power train and/or from the moving vehicle.