Abstract: A rolling friction transmission apparatus of a wedge roller type is provided with: a rolling-surface-shaft; a ring; and three transmission rollers in an unequally-spaced space generated between the rolling-surface-shaft and the ring. The two of the three transmission rollers are fixed, and the rest is used as a wedge roller supported with its axis rotatable. The wedge roller is placed at a spatial position where the unequally-spaced space is wider than in the middle of the spatial position where the unequally-spaced space is at the widest and the spatial position where the unequally-spaced space is the narrowest. Friction forces generated by torque on the contact surfaces among the rolling-surface-shaft, the ring, and the transmission rollers cause large normal forces on the contact surfaces.

Abstract: A drive arrangement clamps an output disc such as a tire with two driving rollers so as to drive the output disc. The drive arrangement is compact, light-weight, low-noise and inexpensive, and can be used for a bicycle equipped with an electrical assist drive or various kinds of welfare-specific vehicles. The drive apparatus includes an input shaft and two output shafts extending in a single plane in parallel to each other. The input shaft has an input roller, and each of the output shafts has an output roller. A loading roller is located between the input roller and one of the output rollers, and an axis of the loading roller is slightly spaced from the plane of the two output shafts. An outer peripheral surface of each roller is a substantially cylindrical rolling surface. The loading roller is preloaded by a preload spring such that it squeezes between the input roller and one of the output rollers.