METHOD AND APPARATUS FOR MOLDING DYNAMIC PRESSURE PRODUCING GROOVE OF HYDRODYNAMIC BEARING

摘要

PURPOSE: A method and an apparatus for molding dynamic pressure producing groove of hydrodynamic bearing are provided to mold the dynamic pressure producing groove within a short period of time at a low price. CONSTITUTION: The apparatus includes a cylindrical core rod(50) having outer diameter smaller than the inner circumference(41) of the metal blank so that the core rod is inserted into inner circumference of bearing body forming metal blank(40); a molding pattern tool(60) projectingly installed on the outer circumference of the core rod in a certain pattern corresponding to a dynamic pressure producing groove molded on the inner circumference(41) of the metal blank; and a pressing means which is installed between the molding pattern tool and core rod and molds the dynamic pressure producing groove by forcibly moving the molding pattern tool to the inner circumferential side of the metal blank when the core rod is inserted into the inner circumference of the metal blank, wherein the pressing means comprises a piezoelectric element(70) expanded by impressed power supply so that the piezoelectric element presses the pattern tool to the inner circumferential side of the metal blank.