| 摘要 |
An electrical permanent magnet motor has a permanent magnet four-pole rotor 110 surrounded by a generally circular stator 122. Air gaps 130, 132 of length Lg are arranged to be substantially longer than in comparable prior art. The flux path through one of four basic radially magnetic circuits of the motor is shown at line 28, and this circuit includes the total magnet length 2Lm as well as the total gap length 2Lg. An enlarged winding 124 substantially fills the gap Lg. The ratio of the total gap length 2Lg to the total magnet length 2Lm is specially selected to strike an optimum balance between the energy density of the rotor 110 and the energy density within the gap Lg without causing irreversible de-magnetization of the rotor 110 and yet yielding a high energy product. <IMAGE> |
