Patent ID: 8511196

Claim:
A traction drive system for an articulated robotic arm comprising: an input drive disk; a spider disposed coaxially to the input drive disk, the spider having a plurality of spokes; a plurality of traction balls disposed between the spokes of the spider; a traction plate; an output drive shaft fixed to the spider and disposed coaxially to the input drive disk, said output drive shaft including an embedded permanent magnet; an adjustable clamping device disposed coaxially to said output drive shaft, wherein the adjustable clamping device is a nut threadably engaged with said output drive shaft and exerting a force on the input drive disk, the traction balls, and causing the traction balls to exert a force against the traction plate such that adjustment of the torque applied to said nut adjusts the force applied to said input drive disk, the traction balls and the traction plate; and a rotational position sensor system for providing rotational position feedback.