DYNAMIC PRESSURE FLUID BEARING SLEEVE MANUFACTURING METHOD AND DYNAMIC PRESSURE FLUID BEARING SLEEVE

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a dynamic pressure fluid bearing sleeve for forming a good dynamic pressure generating groove while reducing manufacturing cost. SOLUTION: The method of manufacturing the dynamic pressure fluid bearing sleeve comprises a primary forming step of filling a metal powder material in a primary forming outer mold 23 into which a primary forming inner mold 21 is inserted and using a primary forming lower mold 22 with its approximately flat thrust face 22a for compressing and forming it in the direction of the axial center with an upper mold 24 and the lower mold 22 to form a primary molding 18 with one approximately flat end face, and a secondary forming step of filling the primary molding 18 in a secondary forming outer mold 33 into which a secondary forming inner mold 31 is inserted and using a secondary forming lower mold 32 with its thrust face corresponding to the flat face of the primary molding 18 and having a protruded portion 32a protruded more near the inner periphery than near the outer periphery in the thrusting direction for compressing and forming it in the direction of the axial center with an upper mold 34 and the lower mold 32 to manufacture a sleeve secondary molding 19 with its inner periphery side portion having a higher compression rate than its outer periphery side portion. COPYRIGHT: (C)2006,JPO&NCIPI