METHOD OF ELECTRO-CHEMICAL MACHINING, AND METHOD FOR MANUFACTURING HYDRODYNAMIC BEARING APPARATUS, AND HYDRODYNAMIC BEARING APPARATUS MANUFACTURED BY THE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To make it possible to machine a precise recess by electro-chemical machining with a simple structure at a low cost. SOLUTION: A shape of a pattern provided on an electrode tool 35 can be accurately formed on a workpiece 23' by carrying out electro-chemical machining by transmitting ultrasonic oscillation generated by means of an ultrasonic generator to electrolytic solution maintaining good electro-chemical machining conditions caused by the ultrasonic oscillation transmitted to the electrolytic solution, even in the case where a gap forming a passage of the electrolytic solution is narrowed by making an electro-chemical machining tool 35 approach to the workpiece 23'.