| 摘要 |
PURPOSE:To fit a polygonal mirror to a revolving shaft with a high precision by providing the motor revolving shaft and the hole part of the polygonal mirror with taper parts to arrange an aligning ring and pressurizing the polygonal mirror toward the revolving shaft through the aligning ring by a pressure ring. CONSTITUTION:Concentric taper parts 1d and 2d are formed on a columnar projecting part 1c of a hub 1 of the revolving shaft and a hole part 2c of a rotary polygonal mirror 2. A doughnut aligning ring 3 is arranged on these taper parts 1d and 2d and is pressurized by a pressure ring 4 and a snap ring 5. As the result, a component FR of force in the peripheral direction and a component FA of force in the axial direction are generated in the taper part 1d by a pressure FO of the pressure ring 4. Since this component FR of force has an action to be uniform in the peripheral direction, a gap G is made uniform. Thus, the concentricity of fitting between the polygonal mirror 2 and the hub 1 is improved and the polygonal mirror 2 is fitted to the revolving shaft with a high precision. |
