Dry linear bearings run on and on

A new line of dry running antifriction precision linear bearings are guaranteed free of organic lubricants, sulphur-containing solid lubricants and are also free of soft metal coating lubricants.

A new line of dry running antifriction precision linear bearings are guaranteed free of organic lubricants, sulphur-containing solid lubricants and are also free of soft metal coating lubricants.

Although the running surfaces in standard linear bearings without organic lubricants are completely destroyed after only 10,000 rolling element overruns, Schneeberger DryRunner bearings run dry for more than 100 million overruns.

This represents an improvement by four orders of magnitude in dry running lifetime.

Lubricant-free linear bearings are desirable in applications requiring a clean environment or where periodic lubrication is not practical.

At the heart of Schneeberger DryRunner products are rails with running surfaces coated with a very hard and abrasion resistant thin film coating of tungsten carbide.

This coating has an excellent adhesion to the steel surface, a low coefficient of friction against a steel counter body, and a very high resistance to surface fatigue.

The rails are coated in a PVD process (physical vapour deposition) and applied under very clean and well-controlled high-vacuum conditions.

Because cage creep has been identified as a serious issue with dry running linear bearings, the same cage centring technology featured in the Schneeberger Formula S Bearing is also included with DryRunner.

Cage creep occurs in cross roller type bearings that are subject to high accelerations, especially in vertical orientations with oscillatory motion.

Once a cage migrates out of position, the result is reduction of travel and eventual damage as it repeatedly contacts the end piece and skids back.

With the Formula S, cage creep is completely eliminated.

The DryRunner is available in sizes RN3, RN4, RN6, RNG4, and RNG6 (the numbers indicating the diameter of the rolling element, rollers or balls, in millimetres) and maximum lengths are available up to 900mm.

Maximum speeds of 1m/s and maximum accelerations up to 150m/s2 can be reached.

Operating temperatures are from -40 to +80C (120C for short intervals).

Cross roller linear bearings offer extreme smoothness and virtually zero friction in a low-profile package.

Compared to recirculating type linear bearings, cross roller guides have no pulsation effect caused by the rolling elements entering and leaving the bearing load zone.

Schneeberger manufactures six types of linear bearings including the first standardised linear bearing in the world - Type R.

The complete line up which includes cross roller bearings with a zero-cage-creep assist option (Formula S) and needle bearings, consists of Type R, RN, RNG, RD, N/O and M/V.

Back to top