Patent ID: 8654478

Claim:
A rotating member assembly comprising: a rotating member including a shaft and a hub fixed to an upper portion of the shaft, wherein perpendicularity of the hub with regard to the shaft satisfies the following Conditional Equation a and Conditional Equation b: 2* B≧SL Conditional Equation a TP≦ 2* RG, Conditional Equation b TP being provided at a position spaced apart from a center of rotation of the shaft in an outer diameter direction by 2*B or more, where B indicates a position at which the perpendicularity of the hub with regard to the shaft is measured, SL indicates an axial length for which the shaft is fitted into the sleeve when a motor is at rest, and TP indicates the perpendicularity of the hub with regard to the shaft when the motor is at rest, an axially spaced distance from a virtual line perpendicular to the center of rotation of the shaft to a center line of the hub coupled to the shaft, the virtual line perpendicular to the center of rotation of the shaft and the center line of the hub meeting the center of rotation of the shaft.