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

The THK BNS-V Series is a ball screw and spline in one, with a ball screw groove and ball spline groove sharing a single shaft. A dedicated support bearing is built directly into the outer periphery of both the spline nut and ball screw nut.

By rotating or stopping each nut, the BNS-V can perform three types of motion on a single shaft: linear (moving up and down), rotary (rotating in place), and spiral (moving up and down while rotating). This makes it especially useful for the Z axis of horizontal articulated robots, where a more compact, lightweight design helps achieve low inertia. That lower inertia supports faster motion, quicker starts and stops, and shorter cycle times overall.

This series features a large lead and doesn’t require preload, simplifying installation while still delivering precision positioning.

The BNS-V Series has a DN value of 100,000 and is available in screw shaft diameters of 16mm, 20mm, and 25mm.