Abstract:

The wear mechanism of rock bit bearings is discussed on the basis of the results from a variety of experiments. Because of heavy load and low peed of rotation, it is difficult for rock bit bearings to form a fluid film between the sliding surfaces, and, therefore, they may be in boundary lubrication. The failure of rock bit bearings is mainly caused by adhesive wear, and abrasive wear. The working capacity of rock bit bearings depends on their materials, hardness, microstructure and their structure. The problem of lengthening the rock bit service life and increasing the rotation speed is also mentioned in this article.