MANUFACTURING METHOD FOR RADIAL BEARING PARTS

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method for a cylindrical radial bearing parts of a fluid bearing device in which a small diameter part which supports a shaft in the radial direction and a large diameter part on which a thrust bearing is mounted are formed, in which dynamic-pressure generating groove is formed on an inner peripheral face of the small diameter part, and in which a steel ball which removes burrs and raised parts to even an inner diameter is inserted through the large diameter part into the small diameter part, thereby eliminating damage to thrust bearing parts resulting from raised parts generated by a steel ball and enahcing dynamic pressure. SOLUTION: At cutting work for forming a small diameter part 4 and a big diameter part 3, an inner peripheral edge 7a surrounding a communicating opening 7 is chamfered. The step part 11 following the chamfered part 10 is formed on the inner face opposed to the thrust bearing parts. The inner face is evened by a plastically deformed part 12 generated by a steel ball.