摘要 |
FIELD: transport. ^ SUBSTANCE: invention relates to bicycles with pedal drive crank mechanisms that comprises levers of self-adjusting length that run along elliptic trajectory or other noncircular rotational trajectory. Pedal drive with chain or belt transmission comprises pinion frame 1 with its first end coupled with shaft of carriage 2, lever 3 with pedal 4 rigidly fixed with sun gear 5, stationary gear 6 with gear ratio of 2:1 with respect to sun gear 5. Stationary gear 6 is fixed relative to bicycle and coupled with sun gear 5 by chain or belt transmission. Second end of pinion frame 2 is articulated with sun gear 5 at the point shifted from its center while stationary wheel 6 features shape other than circle. ^ EFFECT: reduced drive forces due to mismatch between passing top dead center and bottom dead center of pedals. ^ 4 cl, 4 dwg |