Spindle motor, disk drive apparatus, and method of manufacturing base unit of spindle motor

摘要

A method of manufacturing a base unit of a spindle motor includes the steps of: defining a base plate including a support fitting portion; fitting a support to a hole portion passing through the support fitting portion; measuring an inclination of the support fitting portion; calculating a laser irradiation area and a laser irradiation output based on the inclination; irradiating the support fitting portion with a laser beam; and measuring the inclination of the support fitting portion again. The base plate is made of a metal, and is defined by press working, casting, or forging. The support is fitted to the hole portion by crimping, press fitting, or welding. This method reduces the inclination of the support fitting portion, thereby reducing a distortion of the support, which serves as a rotation center of an access portion.

主权项

1. A disk drive with a spindle motor, comprising:
a stationary portion including an armature and a base plate to which the armature is fixed; a rotating portion including a magnet, and arranged to rotate about a rotation axis with respect to the stationary portion; and a head portion that performs at least one of reading and writing of information from or to a disk supported by the rotating portion of the spindle motor; wherein the base plate is defined by press working, casting, or forging; the base plate includes:
a flat reference surface;a plate-shaped support fitting portion that extends parallel or substantially parallel to the reference surface, the support fitting portion including a recessed lower surface which is recessed axially higher than a lower surface of the base plate which completely circumferentially surrounds the recessed lower surface; anda hole portion that passes through the support fitting portion; the head portion is positioned to rotate about an axis defined by a substantially columnar support, the substantially columnar support extending along a central axis and fitted to the hole portion by crimping, press fitting, or welding; the support fitting portion includes a melting mark defined at at least a portion of the recessed lower surface surrounding the support, the melting mark being depressed axially upward; and a central angle of the melting mark is in the range of 60° to 120°, both inclusive.