Ball Screw Assemblies

Why Choose Ball Screw Assemblies?

Ball screw assemblies provide an excellent method for translating rotational motion to linear motion for many applications, including those where high loads and close tolerances are required. To apply the correct type of ball screw and nut assembly in a particular application, the design engineer must consider the advantages and capabilities of each. Selecting the right technology can reduce design complexity, improve performance and reduce the overall cost of the assembly.

This image compares the three types of ball return systems (from left to right): internal, button and external.

Mounting Options

Ball screws are mounted in either supported or fixed configurations. A supported end holds the ball screw at one focal point and does not resist bending moments. A supported end is generally easier to align and install than a fixed one, so installation costs are typically lower. A fixed end resists bending moment loads because it is typically based on two bearings spaced sufficiently so the ball screw remains perpendicular to the planes of the rotary bearings. The fixed offers greater column strength and higher critical speed. The image below illustrates four fixity options.

The assembly can be fixed at both ends, fixed at only one end and supported on the other, supported at both ends, or fixed at one end and free at the other.

The Thomson Advantage

Ball screw assemblies are not all alike. Whether it be metric ball screws, inch ball screws or miniature ball screws, key differences affect their performance and extend their lives. These include:

• Design. Through extensive research and evaluations, Thomson engineers have been able to develop a comprehensive ball screw offering that delivers optimal solutions for countless applications. Available in a full range of diameters, leads and ball nut configurations, in either pre-loaded or non-pre-loaded types, and all in industry standard envelopes, our ball screws provide dependable accuracy and repeatability at an economical price.
• Quality. With a vast background in countless applications, Thomson is uniquely positioned to provide the highest levels of quality across our full line of ball screw assemblies. Our fully equipped engineering laboratory performs qualification testing for mechanical performance, environmental effects and structural integrity. Your rotating ball screw nut assembly is inspected every step of the way to ensure top quality and performance.
• Materials. The materials used to manufacture ball screw assemblies are critical to their performance. Our in-house metallurgists control and verify that the materials used are of the highest quality. They can also select and recommend materials best suited to your particular application.
• Manufacturing. Thomson maintains the most modern and complete ball screw manufacturing facilities in the industry. In-house manufacturing capabilities include our proprietary heat treating and plating processes. Expert manufacturing using the most modern equipment available provides ball screw assemblies that set the standards for performance, precision and travel life.
• Application Support. Working with Thomson is like having your own staff of ball screw design engineers able to address application concerns and recommend solutions. Thomson field sales and applications engineering personnel have more ball screw expertise than any other group in the industry. They are skilled at evaluating your requirements and designing assemblies that fit your needs.

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