Robotics rotary ball spline
Nippon Bearing's rotary ball spline has a nut that rolls on the ball spline shaft making it capable of linear and rotary motion, and consistently provides sub-millimeter accuracy.
There is a lot of torque acting on a robotic arm, which is transferred by a ball spline. In addition, it can be customized to allow cabling to run the length of the robotic arm by using a hollow shaft ball spline.
For greater load rating without increasing the size of the machine, users can specify a ball spline with cross rollers as opposed to balls in the rotary motion.