Abstract: A positive gear engagement transmission affords a continuously variable ratio between input and output rotational speeds. A circular rack journalled for rotation about a center axle or hub has inner and outer arrays of teeth. Inner and outer planet gears have arrays of teeth engaged with each other and with the inner and outer rack array of teeth for counter-rotation about their respective axles. The ratio of the rack array radii is equal to the ratio of the velocities of the planet gears along their racks. One or more linking gears can be used in addition to the planet gears to provide any desired axle orientation and force transmitting structure. A control force is applied to the planet gear support structure so as to apply unidirectional or opposing forces upon the axles of the planet gears to accomplish the variation of energy transferred between the rack and the planet gear assembly.

Abstract: This includes a first rotatable gear (such as a sun gear) and a second rotatable gear (such as a ring gear) spaced from the first rotatable gear. A rotatable inner gear is positioned between and meshes with both the first rotatable and the second rotatable gear. A force is selectively applied between the inner gear and the first gear as a second force is applied between the inner gear and the second gear. By properly selecting the magnitude of the first and second forces one can obtain a greater rotational movement of either the first gear or the second gear.