| 摘要 |
PURPOSE:To reduce the size and weight of a motor portion and an electromagnetic switch by providing a pinion overhung on a front housing and setting the number of teeth of the pinion to seven. CONSTITUTION:All load applied to a pinion 22a is not born by an output rotary shaft 8, but works on a ball bearing 25 mainly as resistance, so that the output rotary shaft 8 has an outside diameter smaller than that of the prior art device. A clearance provided between the pinion 22a and the output rotating shaft 8, in which there is no bearing unlike the prior art device, so that while the thickness of the root of the pinion 22a is ensured, a tooth of the same module as that of the conventional tooth, that is, M=2.75 or less and particularly M=2.54, is adopted and the number of teeth is set to seven. Thus the pinion 22a with seven teeth is adopted so as to reduce the size and weight of a motor portion, and besides, the pinion 22a is moved forward, so that an electromagnetic switch device 23 holding the pinion can be reduced in size and weight. |
