Patent ID: 8152688

Claim:
A continuously variable transmission for producing a variable drive ratio between an input and an output, the transmission comprising: a shaft rotating about a rotating axis, the shaft defining an axial spring rate; an input disc fixed to the shaft having a skewed driving surface with respect to a plane orthogonal to the rotating axis of the shaft; an output disc fixed to the shaft having a skewed driven surface with respect to the plane orthogonal to the rotating axis of the shaft, the skewed driving surface of the input disc and the skewed driven surface of the output disc generally facing each other, the input and output discs are deflected as the drive ratio is varied; a split idler disc assembly for compensating deflection of the input and output discs as the drive ratio is varied, the split idler disc being slideable along the rotating axis and rotateable on the shaft about the rotating axis, the split idler disc assembly comprising: a first disc having a skewed driving surface with respect to the plane orthogonal to the rotating axis of the shaft, the skewed driving surface of the first disc generally facing the skewed driving surface of the input disc; a second disc having a skewed driven surface with respect to the plane orthogonal to the rotating axis of the shaft, the skewed driven surface of the second disc generally facing the skewed driven surface of the output disc, the first disc gapped away from the second disc to allow the first and second discs to be deflected as the drive ratio is varied; and a strain compensator being a tube and defining first and second opposed ends which abut medial sides of the first and second discs, the strain compensator defining an axial spring rate matched to the axial spring rate of the shaft so that the first and second discs are deflected an appropriate amount to compensate for the deflection of the input disc and output disc as the drive ratio is varied: an input roller connected to the input, the input roller having a conical driving surface drivingly engaged to the skewed driving surfaces of the input disc and the first disc; an output roller connected to the output, the output roller having a conical driving surface drivenly engaged to the skewed driven surfaces of the output disc and the second disc.