How do ball screws work?

Ball screws utilise ball bearings recirculating within a nut, which transmit the load to the shaft. They are a very efficient method of converting rotary motion to translational movement.

There are two main types of ball screw ~ rolled and ground. With the advent of precision rolling technology most ball screws are now of the rolled type, as these can offer up to G5 lead precision and excellent running characteristics. For applications with higher accuracy requirements, or specific preloads/axial clearances then ground ball screws are used.

SKF has an extensive range of precision rolled ball screws, including miniature ball screws (available in stainless steel). SKF SD, BD, SH, SX, BX, SND, BND, PND, SN, BN, PN, SL, TL, SLT and TLT are all available from Acorn.

THK offers a vast range of both rolled and ground products, with rolled products being manufactured in Europe. DIN standard EBA, EBB, EBC, EPB, EPC and EPA ball screws are available.

Both THK and SKF offers a range that includes long lead ball screws and rotating nut ball screws.

As all ball screws can only ‘see’ axial forces then some form of linear guidance is usually required; shafts, linear profile rail guides and roller guides are all available from Acorn ~ please see the relevant product pages for details.

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