Bicycle hub planetary geardrive with automatically variable gear ratio

摘要

The planetary geardrive has a variable angle gear (10) and a fixed right-angle gear connected to the driveshaft (2) and central shaft (4) respectively. These engage a pair of fixed right-angle gears (z3) and a pair of variable-angle gears (z3') fixed for rotation on two planet gear shafts (3). The shaft spacing and thus gear ratio varies according to the deflection of the variable-angle gears. The planet gear carrier (5) is keyed to the wheel hub (1) via a spring (14), a follower (13) and an adjustor wedge (13'). The gears all have external ball gear surfaces.