| 摘要 |
PURPOSE: To reduce a noise and to prolong the life in a bearing even in high speed rotation by non-contact supporting a rotary body in the axial direction and the radial direction also. CONSTITUTION: A rotary shaft 40 is hydraulically born with a radial bearing member 16 through lubricant, and a rotor 60 is magnetically born with a housing 10 by combinations of a core 17 and a driving magnet 63, and a U-shaped ring 65 and a magnetic bearing magnet 11. Usually, pressure inside the bearing becomes low by centrifugal force due to the high speed rotation, and the lubricant is scattered to an outer peripheral side, and the noise and vibration occur due to the reduction of the lubricant. However, outdoor air flows in through at least one opening part 100 penetrated through the rotor 60 and arranged on a position close to the rotary shaft 40 of the rotor 60, and the pressure inside the bearing becomes near to outside pressure, and a difference of pressure between an outer peripheral part and an inner peripheral part is eliminated, and the scattering of the lubricant is reduced, and the noise is reduced and the life is prolonged in the bearing. |
