Patent ID: 8403801
Filing Date: 2013-03-26
Classification: B62M

Abstract:
1. A bicycle hub transmission comprising: a hub axle; a driver rotatably supported by the hub axle; a hub shell rotatably supported by the hub axle; a power transmission mechanism operatively disposed between the driver and the hub shell to transmit rotational power from the driver to the hub shell through a plurality of power transmission paths; a shift mechanism operatively coupled to the power transmission mechanism to select one of the power transmission paths; and an auxiliary power transmission mechanism disposed between the driver and the hub shell to transmit rotational power from the driver to the hub shell through an auxiliary power transmission path during shifting such that load paths of the power transmission mechanism for the plurality of power transmission paths are in a substantially unloaded state with no rotational power being transmitted therethrough with the auxiliary power transmission path carrying the load transmitting the rotational power between the driver and the hub shell wherein the auxiliary power transmission mechanism includes a power transmission unit coupling the driver to the hub shell and a clutch unit selectively actuating the power transmission unit, the clutch unit includes a control ring which is coupled to the shift mechanism and movably disposed to selectively couple and uncouple the auxiliary power transmission mechanism, the control ring being rotatably and axially movably disposed relative to the hub axle, the control ring also being supported by a differential rotation body and rotatably movable relative to the differential rotation body, and the differential rotation body is axially movable relative to the hub axle.