Rotary Ball Spline SPR

The NB ROTARY BALL SPLINE can be used for both rotational motion and linear motion. The applications include SCARA robots, the vertical shaft of assembly equipment, tool changers, and loaders, etc.

Download Catalog
Download CAD

Product Description

You can use NB rotary ball splines in many applications requiring linear and/or rotational motion, such as automatic tool changers, SCARA robots and pick-and-place assembly equipment. Their unique design features a spline nut with a rotating portion that moves via cross rollers. This configuration offers many advantages, including high accuracy and a substantial reduction in installation costs.

Ball Splines Presentation Video

Please play the video to watch NB’s Ball Spline and Rotary Ball Spline Series.

Key Features At-a-Glance

NB ball splines provide linear and rotational motions using a combination of spline nut and rotary cross roller bearing design. Splines feature arch-shaped grooves on both the shaft and inner portion of the cylinder. These grooves approximate the diameter of the ball bearings, allowing them to carry a high load in a linear motion. Notable features of this type of design include:

Increased load capacity

The rotary to linear mechanism of NB ball splines can typically handle 10 times the load of conventional ball bushings, which only maintain a single point of contact at any given time.

Greater travel life

By utilizing the large ball contact surface of arch-shaped grooves, travel life is extended by up to 700 times (compared to conventional ball bushings).

Fewer number of parts

Similarly, by providing both linear and rotational motions, NB ball splines effectively perform the work of two components. In addition to allowing for smaller devices, this also minimizes the number of parts required, which saves you money and reduces maintenance requirements.

Increased opportunities for miniaturization

NB ball splines feature a single-axis configuration that, when compared to the dual-axes system of most ball bushings, allows for smaller and lighter systems overall.

High Accuracy

NB ball splines’ cross rollers provide exceptional accuracy in any application in which precision is a necessity.

Higher rigidity

The compact design of NB ball splines doesn’t come at the expense of rigidity, thanks to their four-row ball circuit structure.

For a complete list of operating instructions and technical specifications, please download the product catalog or consult with an NB representative today.

The NB ROTARY BALL SPLINE nut consists of a spline nut and a rotating portion using cross rollers.

Reduced Number of Parts
Because of the single-body construction consisting of the rotating element and the spline element, the number of parts is reduced so that the accumulated errors are also reduced.

High Rigidity
The use of cross rollers and 4-row ball circuits structure provide high rigidity in spite of the compact design.

Compact and Light
The cross rollers are directly attached to the ball spline’s outer cylinder, resulting in a compact and light design.

Substantial Reduction in Installation Cost
The use of cross rollers keeps the housing thickness to a minimum, making the ball spline light and easy to install.

High Accuracy
The cross rollers ensure accurate positioning in the rotational direction.


Structure of NB rotary ball spline SPR type