Hydrodynamic bearing, method of manufacturing the same, method of manufacturing shaft member for hydrodynamic bearing, spindle motor, and recording disk driving apparatus,申请号US20040829332-传众专利搜索

Hydrodynamic bearing, method of manufacturing the same, method of manufacturing shaft member for hydrodynamic bearing, spindle motor, and recording disk driving apparatus

申请公布号：US2004213489(A1)

申请号：US20040829332

申请日期：2004.04.22

申请公布日期：2004.10.28

申请人：

NIDEC CORPORATION

发明人：SUMI SHIGEHARU;OHIRO TAKESHI;YOSHIDA TATSUYA

分类号：F16C33/14;F16C17/04;F16C17/10;F16C33/10;G11B19/20;(IPC1-7):F16C32/06

主分类号：F16C33/14

摘要：According to the invention, a shaft as a component of a shaft member of a hydrodynamic bearing and a disc member such as a thrust plate are joined to each other by welding by a simple method with high precision. A shaft having a cylindrical outer circumferential surface, in joint surfaces which are joined to each other of the shaft and a disc member having a flat surface facing an end surface of the shaft, a circumferential projection having a diameter smaller than the outside diameter of the shaft and projected in the axial direction and a recess at least of which outer periphery has a diameter smaller than the outside diameter of the shaft and larger than the diameter of the projection and has a circular shape are provided. By applying a predetermined voltage across the shaft and the disc member in a state where the joint surface of the shaft and the joint surface of the disc member are in contact with each other, the projection is melted. The melted matter is housed in the recess. At the time of the welding, the end surface of the shaft and the flat surface of the disc member are in contact with each other in a portion outside of the recess, and perpendicularity of the disc member to the shaft is set with high precision. At the time of joining the shaft and the disc member, the thrust plate is held by an axis adjusting jig made of a resin to position the center position of the thrust plate, thereby eliminating an influence of a process tolerance or the like and obtaining excellent coaxiality with the shaft.