| 摘要 |
<p>A rolling cutter earth boring bit is provided with load bearing surfaces that provide small lubricant reservoirs between the bearing interfaces. At least one of the bearing surfaces between the cutter and bearing pin is first ground, machined, etched or otherwise smoothed to an initial surface roughness of less than 20 Ra. The surface is then roughened by shot peening or other surface roughening techniques, such as electric discharge machining, chemical etching or other standard methods of roughening a surface. The desired roughness should have a value higher than about 20 Ra and less than about 80 Ra. The roughening procedure is limited, generally with less than 50% of the surface area containing indentations. The indentations provide reservoirs for lubricant and a receptacle for debris in the bearing area. The smooth portions of the bearing promote rotation of the cutter on the bearing pin.</p> |
