Patent ID: 9148036
Filing Date: 2015-09-29
Classification: G11B,H02K,Y10T

Abstract:
1. A thin base member for use in a disk drive apparatus in which a bearing mechanism and an actuator are arranged, the base member comprising: a plurality of lower recess portions; a C-shaped smooth surface; and a fan-shaped recess portion; wherein the plurality of lower recess portions are arranged in a region of a lower surface of the base member to at least partially encircle a region where the bearing mechanism is arranged, the plurality of lower recess portions extending in a radial direction and being recessed in an axially upward direction from the lower surface of the base member; the C-shaped smooth surface is arranged in a region of an upper surface of the base member, provided on a side of the base member opposite to the lower surface of the base member, around the region where the bearing mechanism is arranged, the C-shaped smooth surface having a height substantially constant in a circumferential direction, the fan-shaped recess portion is arranged in the region of the upper surface of the base member around the region where the bearing mechanism is arranged, the fan-shaped recess portion being arranged to allow the actuator to come into the fan-shaped recess portion; and at least a portion of each of the plurality of lower recess portions is provided axially below the C-shaped smooth surface, the C-shaped smooth surface having a cross section positioned at the plurality of lower recess portions to protrude in a direction toward which the upper surface of the base member faces or to depress in a direction toward which the lower surface of the base member faces.