Epicyclic transmission having free rolling roller driving elements

A speed reducing transmission, comprising;

• input means, gear means orbited by said input means, and a stator, said stator and said gear means each including a substantially trochoidal surface, said trochoidal surfaces comprising radially confronting conjugate trochoidal surfaces, a set of rollers radially entrained between and contacting both said trochoidal surfaces and freely rollingly transmitting torque therebetween, said rollers travelling in a substantially trochoidal path as they roll, and an output member driven by said gear means.

A speed reducer, comprising;

• a first orbiting gear,
• a second orbiting gear, stator means engaging said first orbiting gear via a first set of rollers, and output means engaging said second orbiting gear via a second set of rollers in a number different from that of said first set of rollers, said first orbiting gear and said stator each having a substantially trochoidal gear surface in substantially constant freely rolling contact with each one of said first set of rollers, and said second orbiting gear and said output means each having a substantially trochoidal gear surface in substantially constant freely rolling contact with each one of said second set of rollers.

A speed reducer, comprising;

• first and second orbitally driven gears, each of said gears including a substantially trochoidally shaped gear surface;
• an output gear, and a stator, said output gear and said stator respectively including gear surfaces of conjugate trochoidal curvature with respect to said trochoidally shaped gear surfaces of said second and first orbitally driven gears;
• and first and second sets of rollers respectively radially entrained between said trochoidal surfaces of said first orbitally driven gear and said stator and between said second orbitally driven gear and said output gear, said first and second sets of rollers being in substantially constant freely rolling torque transmitting contact with both trochoidal surfaces respectively entraining the same.

In a speed reducing transmission of the epicyclic type and including an input means, idler means, a stator and an output member, and means for converting a rotary input to said input means into an orbital movement of said idler means;

• the improvement comprising a plurality of rollers disposed at least between said stator and said idler means, said idler means and said stator being formed with conjugate substantially trochoidal surfaces for engaging said rollers, said rollers transmitting torque between said stator and idler means, said conjugate trochoidal surfaces comprising one substantially epitrochoidal and one substantially hypotrochoidal surface, said epitrochoidal and hypotrochoidal surfaces being formed such that said rollers are maintained in substantially continuous rolling contact with both said epitrochoidal and hypotrochoidal surfaces.

In a speed reducing transmission of the type including an input means, idler means, a stator, an output member and means for converting a rotary input to said input means into an orbital motion of said idler means;

• the improvement comprising a plurality of rollers disposed at least between said stator and said idler means, said idler means being provided with at least one gear surface of substantially trochoidal curvature, said stator being provided with a gear surface of substantially trochoidal curvature, each of said rollers rollingly contacting both said idler gear surface and said stator gear surface substantially constantly, said rollers being substantially the sole means transmitting torque between said idler means and said stator.

A transmission, comprising;

• a first gear member for receiving an orbital input, and including a first gear surface of generally epitrochoidal curvature;
• a stator member including a second gear surface of generally hypotrochoidal curvature and arranged to coact with said first gear surface;
• a set of rollers arranged between said first and second gear surfaces, and arranged to transmit torque between said stator and said first gear member by rollingly engaging both said first and second gear surfaces simultaneously, said rollers rolling over the entire periphery of said stator and said first gear member as said first gear member is orbited.