| 摘要 |
PURPOSE:To prevent scattering of magnetic fluid by providing a stationary member, magnetic fluid sealing means, and a communication hole for communication of an annular space defined by a hub and one side bearing member with the interior of a motor. CONSTITUTION:When a pressure difference is generated in and out of a first annular space 92 due to the difference of atmospheric temperature or pressure, the air flows from the interior of a motor to the space 92 via a through hole 96 or flows out of the space 92 into the motor. When the pressure difference is generated in and out of a second annular space 94, the air from the interior of the motor flows to the space 94 through a communication hole 98 or flows into the motor from the space 94. Thus, the pressure differences between the interior and the exterior of the space 92 and between the interior and the exterior of the space 94 are substantially eliminated. Thus, scattering of the fluid 58 in magnetic fluid sealing means 34, 36 can be prevented. |
