To provide a bearing part having a dynamic pressure groove with excellent concentric accuracy, in particular, in a manufacturing method for a dynamic pressure type bearing part forming each of a dynamic pressure groove for a radial bearing and a dynamic pressure groove for a thrust bearing on each of a first surface and a second surface orthogonally crossed with each other.
This method and device is provided with a process for coaxially forming a cylindrical space 15 and disk-like spaces 13 and 14 continuous to the cylindrical space 15 and having diameters larger than that of the cylindrical space 15 in a state that a worked material 2 is fixed to a rotated and driven chuck, a process for forming the dynamic pressure groove 16 for the radial bearing on a side wall of the cylindrical space 15 by a first cutting tool 4, a process for forming dynamic pressure grooves 17 and 18 for the thrust bearing on bottom surfaces of the disk-like spaces 13 and 14 orthogonally crossed with the side wall of the cylindrical space 15 by a second cutting tool 5 and a third cutting tool 6 and a process for obtaining the dynamic pressure type bearing part by separating a part including the cylindrical space 15 and the disk-like spaces 13 and 14 from the worked material 2.
AKIYAMA YASUO