| 摘要 |
<p>Disclosed is a power transmission apparatus. The power transmission apparatus includes a ring gear; first and second gears engaged with one side of the ring gear; a clutch interposed between the first and second gears and moved toward one of the first and second gears according to a rotational direction thereof so as to be coupled with one of the first and second gears; and a driving shaft providing power to the clutch.</p> |
