Stepless speed change traction gear

Claim 1

A stepless speed change traction gear comprising: a housing; an input shaft extending from the housing, having an axis, and operable at a first rotational speed, m N 1 ; an output shaft generally aligned with the input shaft, extending from the housing, and operable at a second rotation speed, N 2 ; a longitudinally slidable speed changing ring, mounted on the output shaft within the housing, and including an internal surface; a shaft holder drivingly connected to the input shaft within the housing; a plurality of generally radially extending support shafts carried by the shaft holder to orbit the input shaft; a plurality of conical rollers, each of which is supported on a corresponding one of the support shafts and each of which is provided with: a conical surface having an axis, at least a portion of the conical surface being parallel to the axis of the input shaft, the conical surface frictionally engaging the internal surface of a speed changing ring, a flat surface generally perpendicular to the axis of the conical surface, and an annular concave surface generally coaxial with the conical surface; a track ring attached to the housing so as to be rotationally fixed, frictionally engaging the flat surface of each conical roller; and a reaction bearing ring which bears against the annular concave surface of the conical rollers and is operable to react a force acting between the track ring and the conical rollers together with a force acting between the speed changing ring and the conical rollers; and the speed change ring being movable along the conical surfaces of the conical rollers to provide a range of speed rations from about zero to nearly 1.0, where the speed ratio is defined as N 2 /N 1 wherein the shaft holder has a plurality of generally radially oriented slots, and wherein a portion of each support shaft is freely slidable in a corresponding one of the radially oriented slots.