Precision bearing manufacturer Schaeffler (UK) Ltd, Sutton Coldfield (www.schaeffler.co.uk), has developed an angular measuring system suitable for direct-drive highly dynamic high-precision rotary axes in machine tools. This incorporates an inductive (absolute) angular measuring system integrated in a rotary table bearing.

Moreover, the system combines high measuring speed and measurement accuracy within a robust yet compact envelope — and it is resistant to lubricants and coolants.

The new YRTSMA bearings are available with bore diameters from 150 to 1,030mm and can be fitted to the rotary axes as an alternative to optical angular measuring
systems; and by fitting the YRTSMA bearing to the rotary axis, information about the absolute angle is available immediately after switching on the machine.

The measuring scale of the YRTSMA units is positioned directly on the inner ring; and because inductive measuring is used, YRTSMA bearings are even less sensitive to rolling-bearing grease and contaminants that are normally present in the harsh environment presented by machine tool rotary-table applications.