| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an outer-rotor type electric capable of more surely preventing the infiltration of foreign substances into the interior of an electric motor. <P>SOLUTION: In an outer-rotor type motor, a rotor 2 is outer fitted to a stator 1 so as to insert a stator 2 into an opening of a rotor 1, the rotor is rotated by causing an electric current to flow through a coil provided in the stator 1. An axial concave groove 8 is provided circumferentially at the end of the opening side of the rotor 2, while a cylindrical cover member 9 enclosing the surrounding of the stator is provided; and the end of the cylindrical cover member 9 is inserted into the concave groove 8. By means of this groove structure, a substantially U-shaped labyrinth R is formed between inner and outer circumferential surfaces of the concave groove 8 and inner and outer circumferential surfaces of the cylindrical cover member 9, and the inside and the outside of the motor are made to communicate with each other via the labyrinth R. The labyrinth R has a spacing T which is about twice as large as the spacing t, between the stator 1 and the rotor 2. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
