| 摘要 |
<p>The present invention relates to a power transmission device combining electric power and non-electric power, and more specifically relates to a power transmission device which, for example, gives practical form to an electric bicycle when used as an intermediate member disposed between the cranks and the rear wheel in a chainless bicycle, and which can be used notably in electrically powered bicycles but also in other such fields as it allows manual movement under a pedalling force or automatic movement under a motor rotational force in accordance with the action of a clutch. The power transmission device according to the present invention comprises: an outer covering; a rotary shaft which is provided inside the outer covering and is supported by means of a bearing; an electric power unit which comprises a rotor that surrounds the rotary shaft with a bearing in between, and a stator that surrounds the rotor; and a first clutch whereby the power of the electric-power-unit rotor is either transmitted to or isolated from an output gear of the rotary shaft.</p> |
