| 摘要 |
PROBLEM TO BE SOLVED: To reduce a deflective rotation due to a half whirl at the time of a high speed rotation. SOLUTION: This bearing structure is provided with a sliding bearing 9 axially supporting in a radial direction, a fixed shaft 1 supported freely rotatably to the sliding bearing 9, a mean relatively rotating the sliding bearing 9 and the fixed shaft 1 and a polygon mirror 13 fixed to one side among the fixed shaft 1 and the sliding bearing 9, In this case, the thrust direction of the fixed shaft 1 is supported by arranging the ring-shaped magnet M enclosing the fixed shaft 1 in the axial direction of the sliding bearing 9 side by side, by constituting the fixed shaft 1 with magnetic material and also by forming magnetized parts MM in the whole parts of the radial direction of the ring- shaped magnet M, by making the magnetic parts MM and the magnetic material attract each other while constituting magnetic circuits Z in-between and moreover by making attracting forces asymmetric in surroundings of the shaft while forming the notched part 1c of the axial direction in the fixed shaft 1. |
