| 摘要 |
PROBLEM TO BE SOLVED: To uniformize dynamic pressure generating force and to improve shaft support performance by aligning concentricity of protrusions and grooves of the sintered oil impregnated bearing. SOLUTION: A protrusion straightening part 11, which has an outer diameter equal to an inner diameter of many protrusions formed on an inner peripheral face of the sintered oil impregnated bearing 14, is arranged to a straightening bar 10. A groove forming part 12, which has an outer diameter equal to an inner diameter of many grooves forming an inner peripheral face of the sintered oil impregnated bearing 14, is arranged at a lower side of the protrusion straightening part 11. A protrusion forming part 13 arranged to the straightening bar 10 is formed to a recessed shaped groove extending in the axial direction so as to be pushed into the inside of the straightening bar and to be protruded in the process the sintered oil impregnated bearing 14. Further, the the straightening bar 10 is enclosed with a hollow frame, a upper part punch and a lower part punch elevating up/down are arranged between the frame and the straightening bar 10. |
