SPINDLE MOTOR AND RECORDING DISC DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a spindle motor which can avoid the eccentricity or backlash of the hub body caused by temperature change. SOLUTION: A spindle motor is equipped with a fixed shaft 21 fixed to the housing 12 of a recording disc device, and a hub body 24 supported by the fixed shaft 21 rotatably around the immobile shaft 21 through paired upper and lower rolling bearings. A part of the hub body 24 is surrounded by a member 23, around the rolling bearing 23. The thermal expansion of the hub body 24 is suppressed by a member 321 smaller in thermal expansion coefficient than the hub body 24.