ROTARY DRIVE DEVICE AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To prevent lubricating oil from leaking out of a sleeve in a rotationally stopped state, and prevent a rotary shaft rotated from coming into contact with the sleeve.SOLUTION: A rotary drive device having a fluid bearing part includes: the rotary shaft having a radially expanded portion for preventing an oil leakage from one end of the sleeve; a permanent magnet fixed on a rotor including the rotary shaft; an electromagnet for moving the rotary shaft axially by a magnetic action with the permanent magnet; and a control circuit for causing the electromagnet to move the rotary shaft axially in a first direction such that a distance between the radially expanded portion and the sleeve increases at a rotational start of the rotor, and causing the electromagnet to move the rotary shaft in a second direction opposite to the first direction such that the distance decreases at a rotational stop of the rotary shaft.