| 摘要 |
PURPOSE:To prevent the release of the dust generated from ball bearings and to facilitate and flatten assembly by providing sealing means to provide a labyrinth effect between the annular wall part provided on a rotor and the annular wall part of a motor housing rotated by maintaining the state facing the above- mentioned wall part in proximity thereto. CONSTITUTION:The annular wall parts which face in proximity to each other and extend in the axial direction of the rotor 36 are positioned around the ball bearing 43 and are respectively provided on the rotor 36 and the motor housing 31. The air tending to pass the spacing between the wall parts 34 facing each other and the sealing part 39a of the peripheral wall part 39 is rapidly expanded in a hollow groove 47 and the pressure thereof is dropped, by which the kinetic energy is reduced. The dust released from the ball bearing 43 is prevented from passing the spacing between the wall parts 34 provided around the ball bearing 43 and the sealing part 39a of the peripheral wall part 39 by such labyrinth effect. The motor is flattened in this way and the number of the parts of the motor is reduced, by which the construction is simplified and the assembly is simplified. |
