Linear Stroke Rotary Bushing – SR Type

The NB STROKE BUSH is a linear and rotational motion mechanism utilizing the rotational motion of ball elements between an outer cylinder and a shaft. It is compact and can withstand high loading. The retainer is made of a light metal alloy with high wear resistance. Smooth motion is achieved under high-speed and high-acceleration conditions. Although the linear motion is limited to a specific stroke length, the combined rotation and stroke motion is achieved with very little frictional resistance. The NB STROKE BUSH can be conveniently used in a variety of applications.

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Product Description

NB SR-type linear stroke rotary bushings provide highly accurate linear and rotational motions using a series of precisely machined ball elements located between a shaft and an outer cylinder. Ball elements are retained in a metal alloy retainer to evenly distribute loads while maintaining smooth and precise operation.
With their versatile performance, SR stroke bushings are well-suited to a range of applications, including those requiring high-speed and high-acceleration conditions.

Features and Benefits At-a-Glance

NB linear stroke bushings consist of a high-carbon chromium bearing steel outer cylinder with a precision-ground inner surface, a light metal alloy retainer that keeps ball elements in position, and a stopper ring and inner seal to prevent contamination. While this type of design limits the amount of linear motion stroke, it offers many benefits, such as:

  • High resistance thanks to heat-treated and ground metal and alloy components that are designed for heavy-duty use
  • Smooth performance in both high-speed and high-acceleration conditions, with exceptional rigidity and accuracy
  • Easy installation with uniform dimensions and various mounting options
  • Reduced size and weight for compact equipment
  • Fewer maintenance requirements thanks to an easy-to-lubricate design

Configuration Options

SR linear stroke bushings are available in a range of different sizes and configurations to better suit the diverse needs of today’s equipment and component manufacturers. Specific options within the SR product line include:

  • Standard type SR bushings in a range of sizes from 6-100mm inner contact diameter
  • SR-UU type bushings with dual-sided seals, available in the same sizes as the standard SR-type products
  • SR-B linear bushings, for applications requiring load ratings up to 13,700N (dynamic) and 29,400N (dynamic)
  • SR-BUU type bushings, with double-retainer and double-seal configuration

For a complete list of specifications for each product in the SR family of linear stroke bearings, please download the product catalog.
For additional installation and maintenance requirements, download the product catalog or contact an NB sales representative by phone (800-521-2045)  or email today.

Structure and Advantages

The retainer in the NB STROKE BUSH positions the ball elements in a zigzag arrangement.
The inner surface of the outer cylinder is finished by precision grinding, resulting in smooth motion of the ball elements. Each of the ball elements is held in a separate hole and smooth motion is achieved for both rotational motion and linear motion. The retainer moves half the length of the linear motion, therefore, the stroke length is limited to approximately twice the length the retainer can travel within the outer cylinder. The actual stroke should be limited to 80% of the maximum stroke as listed in the dimension tables.

High Precision

High-carbon chromium bearing steel is used for the outer cylinder. It is heat treated and ground to achieve high rigidity and accuracy.

Light Weight and Space Saving

The use of an aluminum alloy for the retainer and the thin-wall outer cylinder makes the NB STROKE BUSH light weight and compact.

Ease of Mounting and Replacement

The highly accurate fabrication of the NB STROKE BUSH results in uniform dimensions, facilitating parts replacement and housing fabrication.


One lubrication hole is provided on each oil groove of the outer cylinder, making it easy to lubricate the SR STROKE BUSH.

Structure of SR STROKE BUSH

Structure of Linear Stroke Rotary Bushing – SR Type