The NB rotary ball spline has a cylindrical nut that rolls on the ball spline shaft. Rotary ball splines can be used for both rotational motion and linear motion, providing sub-millimeter accuracy every time. Popular applications include SCARA robots, the vertical shaft of assembly equipment, automatic tool changers, and loaders.
A ball spline’s forte is the transfer of torque. Splines feature arch-shaped grooves on both the shaft and the inner portion of the cylindrical nut. These grooves approximate the diameter of the ball bearings, allowing them to carry a high load in a linear motion. Rotary ball splines with cross rollers — as opposed to balls — provide higher load ratings without increasing size. In addition, ball splines can be customized so cabling can run the length of the robotic arm by using a hollow shaft ball spline.