Patent ID: 8403084

Claim:
A friction drive device, comprising a main wheel including an annular member and a plurality of driven rollers arranged along a circumference thereof so as to be each rotatable around a tangential direction of the annular member at a part thereof where the driven roller is located, a pair of drive disks located on either side of the main wheel so as to be rotatable around a central axial line thereof and a plurality of drive rollers mounted on each drive disk so as to be rotatable around an axial line in a skewed relationship to the central axial line of the of the drive disk and engage an outer circumferential surface of the corresponding driven roller at an outer circumferential surface thereof: wherein the friction drive device further comprises a connecting mechanism that connects the two drive disks to each other so as to be rotatable to each other while restricting at least one of a radial displacement and an axial displacement between the two drive disks.