| 摘要 |
PURPOSE:To prevent an end plate from causing its stress to be locally concentrated, by fixing an auxiliary plate in small diameter connecting its rotary center part to the end plate of a rotary unit and mounting a rotary part annular magnet to this auxiliary plate. CONSTITUTION:An end plate 2 of a rotary unit fixes an auxiliary plate 11, having a diameter smaller than the diameter of this end plate 2, connecting the rotary central part of said plate 11, and this auxiliary plate 11 fixes a rotary part annular magnet 3. The auxiliary plate 11 press fits its central opening part 11a to be fixed to an annular part 2a protrusively provided in a central opening edge part of the end plate 2. While a rise-up edge 11b, being formed in a peripheral edge part of the auxiliary plate 11, fits a non-magnetic cover 6 so as to perform positioning of the annular magnet 3. The non-magnetic cover 6, supporting the annular magnet 3, is fixed to the auxiliary plate 11 by bolts 7. Then the auxiliary plate 11 is press fitted to be fixed in its central part to the end plate 2. In this way, the end plate 2 never causes its stress to be locally concentrated even when the rotary unit is rotated. |
