Ball Screw Support Bearings

Part Numbers & Interchanges

Configurations

To assist with orientation during installation, JTEKT has added a “V” mark on the outside surfaces of single row “G Type” Singular Angle Contact Bearings (SAC Series). It is very common for these type of bearings to be used in matched pairs or stacks – to ensure proper installation please use the chart below as reference:

Features & Benefits

Introduction

Ball screw drive systems are used in machine tools (CNC machines) where rotational motion needs to be translated into linear motion, with low friction (high mechanical efficiency) and a high degree of preciseness. For high precision (micrometer level) applications where, besides radial loads, also axial forces come into play, special attention to the design of the ball screw drive as well as the ball screw shaft and its bearing support are essential.

The critical role for ball screw shaft support bearings

During the development of a new ball screw system typically a lot of attention is paid to the proper design of the ball screw drive (with internal ball recirculating system) and the spindle/ball screw shaft (precision ground or rolled/cold formed), however the importance of the shaft supporting bearings is often underestimated. For applications where ball screw positional accuracy and repeatability is essential (like in machine tools), the shaft bearings must absolutely immobilize the shaft axially when subjected to varying degrees of axial loads from motor power and inertia forces, to avoid backlash.

Single Angular Contact bearings for spindle shaft support

JTEKT has developed a dedicated type of SAC bearing with special internal geometry (including a 60° contact angle) that provides maximum running accuracy and the radial/axial load support that is typically required for modern (high speed) machine tool applications. The SACs can be configured to accommodate specific application conditions, including two, three or four-row matching types and optionally facing in opposite directions to support bi-directional axial loads.

To maintain their inherent accuracy and ensure long life, great care is needed to avoid contamination with dirt and abrasive particles. Precise pre-load setting is imperative to reduce slack (screw shaft axial free play), while optimizing bearing life (cost economy) and minimal internal friction (rotation efficiency – energy consumption). JTEKT engineers can advise on the proper configuration, sealing solution and pre-load setting depending on the specific application.

Our Expertise

Support is everything.

It's something we've learned through a legacy supporting the world's premiere machine tool manufacturers and by having two experts—Toyoda and Koyo—in our DNA.

Toyoda Machine Works, LTD. (machine tool manufacturing) and Koyo Seiko Co., LTD (manufacturing of roller bearings) merged to create JTEKT Corporation, in 2006.

Why that matters has to do with what has happened since, something unparelled in either industry. Engineers from both divisions have worked closely, sharing their expertise to develop bearings optimized for state-of-the-art machine tools.

Now available to the Repair & Rebuild aftermarket, JTEKT Single-Row Angular Contact Bearings deliver P4 grade precision to keep tools dialed and in stock availability to keep you running. Available through authorized distributors at competitive pricing only possible from an OE supplier.