While in rolling bearing arrangements the bearing elements are separated by rolling parts (the rolling elements), in plain guidance systems the movable component slides on a static guideway or shaft. Depending on the type of guidance system, the sliding layer is applied to the movable or the rigid component. Lubrication is carried out by means of lubricants embedded in the sliding layer.

Linear plain bearings are linear locating bearings for unlimited stroke lengths. These linear guidance systems are available as a miniature plain guidance system, Permaglide® linear plain bearings and Permaglide® linear plain bearing units as well as a flat guidance system. Miniature plain guidance systems comprise a guideway/carriage system with a maintenance-free sliding layer, Permaglide® linear plain bearing units with a low-maintenance Permaglide® bush seated in a light metal ring. Flat guidance systems are guideway systems in which the sliding surface is provided on the guideway by means of a low-maintenance sliding layer.

Plain bearing guidance systems have low wear and high static load capacity, are insensitive to shocks and contamination, make little noise and operate substantially free from stick-slip. Maintenance-free plain guidance systems do not require lubrication, and low-maintenance materials have good emergency running characteristics. Due to their versatile specific characteristics, plain guidance systems are used in many areas, especially where the bearing position must be maintenance-free or low-maintenance, there is a risk of inadequate lubrication or where lubricant is either undesirable or impermissible.

The life of a linear plain guidance system depends essentially on the load, sliding speed, temperature and operating duration. There are additional limiting factors including contamination, corrosion in dry running or possible ageing of lubricant if lubrication is not sufficient. The basic rating life is therefore only ever a guide value.

Many external influences on linear plain bearings cannot be included in calculation. Tests under operating conditions therefore give the most reliable information on the use and life of the guidance system in the specific application.