Abstract
The fretting wear is caused by the very slight relative slip between the contacting surfaces of the inner ring side face and the backing ring of an axle journal bearing in railway applications, but its mechanism is not clear. In this work, first we have conducted a reproduction test using a full-scale railway axle journal bearing in order to understand the fretting wear behavior of the axle journal bearings. Secondly, laboratory tests using a full-scale railway axle journal bearing were conducted to investigate the contact pressure distributions by inserting a film pressure sensor between the inner ring side face and the backing ring of the axle journal bearing under the conditions of radial loads. It has been found that the fretting wear of the backing ring becomes larger in the proximity to its outside diameter, the contact pressure of the opposite of the load side is larger than that of the load side and the contact pressure becomes larger in the proximity to its outside diameter. Accordingly, the fretting wear area of the backing ring is approximately coincident with the area where the amplitude of the contact pressure is large.
