20090080821 | PLAIN BEARING - A plain bearing capable of suppressing occurrence of bearing damage in a primary load portion is provided. The primary load portion in the center of at least one of the plain bearings that mainly receives load during rotation of a shaft is subjected to inner surface working by broaching so that roughness is 1 μm Rz or less, while a light load portion at 10° to 60° from a bearing mating surface of the plain bearing that receives load smaller than that received by the primary load portion is subjected to inner surface working of a circumferential fine groove by boring so that the depth is 1 μm to 15 μm. | 03-26-2009 |