Abstract: A stepless speed change traction gear includes a plurality of conical rollers, each having a conical surface frictionally engaging with an internal surface of a speed changing ring, a flat surface perpendicular to the axis of the conical surface frictionally engaging a non-rotating track ring, and an annular concave surface coaxial with the conical surface and frictionally engaging a bearing ring. The speed changing ring is longitudinally adjustable between limits so that a speed ratio range from 0 to nearly 1.0 is developed. This traction gear is not provided any additional gearing or speed increasing device to widen the speed range. A clutch, brake, and operator can permit a direct drive condition between the input and output shafts.

Abstract: Disclosed is a stepless speed change gear including a plurality of conical rollers each of which is provided with a conical surface frictionally engaging with a ring-member moved by a speed changing assembly. A surface of concave cross-section frictionally engages with a sun-member on an input shaft, and a flat surface frictionally engages with a non-rotatable disc member. A gear train is provided to extend the speed range to include a speed ratio of 1:1. A release mechanism is provided for the non-rotatable disc member, and a clutch mechanism is provided for direct coupling of the input and the output shaft. Power is transmitted by direct coupling of the input and the output shaft.