| 摘要 |
<p>A hub transmission with a coaster brake unit includes a hub axle (2), a drive member (3) rotatably mounted around the hub axle (2), a hub body (4) rotatably mounted around the hub axle, and a planetary gear mechanism (5) coupled between the drive member (3) and the hub body (4) for communicating rotational force from the drive member (3) to the hub body (4) through multiple rotational force transmission paths. The planetary gear mechanism (5) includes a planet gear (53) supported by a planet gear rack (52) for rotation around the hub axle (2), and a ring gear engaging the planet gear. The gear rack (52) includes a depression (70) formed in a peripheral direction thereof, and the ring gear (54) includes a serration (54a) formed in a peripheral direction thereof. A clutch (6) having an engagement component is movable in a direction of an axis (X) of the axle (2) between a first position (a,b), a standby position (c) and a second position (d). The engagement component (67) engages with the depression in the gear rack for transmitting rotational power to the gear rack when the clutch is located in the first position and the standby position, and the engagement component engages with the serration in the ring gear for transmitting rotational power to the ring gear when the clutch is located in the second position. A biasing means (69) biases the clutch from the second position toward the standby position, and a forcible movement means (71) forcibly moves the clutch from the standby position toward the second position when forward rotational power is applied to the drive member (3).</p> |
