| 摘要 |
PURPOSE:To obtain sufficiently large reluctance, to make it possible to perform self-starting and continue rotation, and to obtain a motor with less noises by providing notch sections at appropriate positions of a stator yoke. CONSTITUTION:A shape of a stator yoke 44 is made up as follows. A virtual X axis line and Y axis line 50 & 49 are set at right angle to each other, and where one field width of a magnet rotor is theta, the first notch ends 51 & 52 extending in the radial direction are formed at positions advanced ahead of about theta/2 widths in the reverse direction of rotation of the magnet rotor by using the central point of the stator yoke 44 as a reference point, the second notch ends 53 & 54 extending to positions of the outer diameter of the stator yoke 44 in parallel with the virtual X axis line from positions of the internal perimeter ends are formed, and the notch ends 55 & 56 having theta+alpha(alpha<=theta/2) degrees of open angle width of a notch periphery section of the periphery section of the first notch ends and the periphery section of the second notch ends are formed. The stator yoke 44 is so placed that its position is a position advanced ahead of theta/6-theta/3 only in the reverse direction of rotation from a position where the first notch ends obtain the maximum starting torque. |
