A stepless speed change gear comprising:
- an input shaft;
- an input shaft crank fitted to said input shaft at a right angle and provided with a connecting part;
- an input connecting rod connected to said connecting part at one end side and being provided with another end side connecting part;
- an output connecting rod connected to said other end side connecting part at one end side and provided with another end side connecting part;
- a one-way clutch to transmit torque in one direction only and being provided with an output shaft disposed in the same direction to said input shaft and an input side member being connected to said other end side connecting part of said output connecting rod at one end side swingably about a center of said output shaft;
- a speed change link connected to said other end side connecting part of said input connecting rod at one end side and positioned at an optional position in a given moving range at the other end side;
- fixing means to fix said other end side of said speed change link;
- said input connecting rod, said output connecting rod, said input side member and said speed change link being swingable in each plane a direction of which is the same as the direction of rotation of said input shaft crank;
- said other end side of said speed change link moving a given locus range from a position where said output connecting rod becomes substantially orthogonal to both said speed change link and said input side member to a position where said output connecting rod and said speed change link substantially line up in a straight line;
- said one-way clutch being a rolling bearing clutch comprising an inner rotation body, an outer rotation body, a plurality of intermediate rotation bodies and energizing means;
- said inner rotation body being provided with an inner raceway surface of a mono-hyperboloid of revolution about an axis of said output shaft;
- said outer rotation body being provided with an outer raceway surface of a mono-hyperboloid of revolution about said axis;
- said inner rotation body and said outer rotation body facing each other to form a raceway;
- said intermediate rotation bodies having cylindrical rolling surfaces and being disposed in the circumferential direction of said raceway with their center lines slanting at a predetermined angle to a section including said axis;
- the surface of each intermediate rotation body contacting in line with said inner and outer raceway surfaces;
- said energizing means energizing either said inner rotation body or said outer rotation body in the direction of said axis to narrow the spacing of said raceway;
- said inner and outer rotation bodies being provided with an annular member at an opposite side of said axis which brings the movement of said intermediate rotation bodies in said axial direction to a stop;
- said outer rotation body being connected to said input side member so that both rotate in one body;
- said inner rotation body being connected to said output shaft so that both rotate as one body.