Abstract: An epicyclic speed reducing mechanism employs, as torque transmitting elements, a series of rolling elements which are constrained to travel along a substantially trochoidal path defined by means of complementary or conjugate surface regions formed on the driving and driven members. The invention is applicable to single or multiple stage speed reducers, and may be of the counterweighted or counterbalanced variety, the latter including a constant velocity coupling operating between an orbiting and rotating element and a further element. In the disclosed embodiments, the rolling elements may be either balls or rollers, and the surface regions may be conjugate epitrochoidal and hypotrochoidal grooves.

Abstract: A nutating gear reduction mechanism employs two series of rolling elements in the form of balls as the means of torque transmission. In this manner, gear teeth are eliminated and replaced with conjugate pairs of trochoidally cut grooves, with the rolling elements operating between the grooves formed in a wobble member, on the one hand, and a stator and an output member, on the other hand. Either single or multiple stage speed reduction may be achieved, the single stage version being obtained by replacing one set of conjugate trochoidal races with oval races coupling the wobble member and either the stator or the output member in a constant velocity fashion.

Abstract: A torque transmitting gearing system of the nutating type is equipped with a nutating idler member which is in torque transmiting engagement with both a stator and an output gear. Torque transmission between the respective elements is achieved via respective series of rolling, torque transmitting elements in the form of tapered rollers. The rollers are maintained in substantially continuous contact with both their respective driving and driven raceway surfaces, which are formed with trochoidal curvature. Within a given pair of coacting gear surfaces, one surface will be formed with epitrochoidal curvature, and the other with hypotrochoidal curvature.