Abstract: The present invention relates to a spindle motor mainly used for an apparatus for driving a disc, which can increase the capacity of recorded information and the information transmission speed while reducing the size and thickness of the apparatus. This spindle motor corrects the balance of a structurally unbalanced chucking portion, and reduces the shaft deflection of a motor, non-uniform rotations, the inclination of a disc relative to a head, and the surface deflection of a disc loading portion.

Abstract: A motor bearing device includes a rotary shaft, a bearing housing having a hole, a ball bearing rotatably supporting the shaft and arranged in the hole of the bearing housing and fixed to an outer ring of the ball bearing with adhesive, and an adhesive puddle formed at an inner surface of the hole of the bearing housing on a side of the bearing housing used for inserting the ball bearing into the bearing housing. A part of the adhesive is trapped in the puddle. The puddle can also be formed at an outer surface of the outer ring that corresponds to the inner surface of the hole of the bearing housing on the side thereof used for inserting the ball bearing into the bearing housing.