SKF launches new modular high load, high speed linear profile rail guides

The modular design concept of the new range of LLT profile rail guides give design and production engineers a wide range of system build options, in terms of rail length, carriage size and profile, and for factors such as levels of accuracy, stiffness and preloading. For example, systems can be supplied for loads between 8,400N and 128,500N, operating at speeds of up to 3.0m/sec, with a choice of six types of carriage and unlimited stroke length.

In addition, the LLT system is unique in enabling the four ball bearing raceways that sit between each rail and carriage to be configured either in a conventional O-shaped or X-shaped arrangement, based on the contact angle of the rolling elements. Both systems provide excellent load bearing, acceleration, deceleration and side load characteristics, with the special X-shaped raceway configuration also offering superior self-aligning properties, combined with the ability to virtually eliminate variations between the rail and carriage, even under preload conditions; for example, lateral deviation between carriage and rail is within plus or minus 10 microns. This makes the new guides ideal for use in high performance single and multi-axis applications.

Perhaps as importantly, the arrangement of four raceways, each set with a 45° contact angle, ensures equal load capacity while reducing frictional losses to a minimum, with low break-away forces. This helps to produce smooth, easily controlled operation, even at extremely slow speeds, and plays a crucial role in providing extended operating life with minimal maintenance.

Each of the new LLT profile rail guides has a robust construction, from inductive and case hardened steel, and is supplied pre-lubricated, with specially developed double-lip seals at either end of each carriage, plus side and inner seals to ensure that lubricants are retained and to prevent in the ingress of contaminants. Operating temperatures range from -20°C to +80°C, although each unit can withstand temperatures of up to 100°C for short periods.