THK BNS-V Series Low-Inertia Precision Ball Screw/Spline

The THK BNS-V Series combines a ball screw nut and a ball spline nut directly on a single shaft, with dedicated support bearings built into the outer periphery of each nut. This lets one shaft perform rotational, linear, and spiral motion just by rotating or stopping each nut, which is especially useful on the Z axis of horizontal articulated (SCARA) robots.

The BNS-V is a downsized version of THK’s well established BNS-A, built specifically to bring inertia down for faster starts and stops. It has a compact 72mm outer diameter, weighs just 1.00kg, and carries a low inertia of 2.00 kg·cm², compared to the BNS-A’s 86mm diameter, 1.67kg weight, and 4.32 kg·cm² inertia. This reduces the load on your motor, cuts heat generation, and helps shorten cycle times.