DSS rail sets are designed to enable quick assembly of the bearing components into your machine. The new compact center rail replaces the inner pair rails which are normally installed in the center against a reference edge. Machining errors of this reference edge and incorrect assembling of the rails against it often result in cage creep and a reduction of bearing life.
DSS rail sets are designed for very smooth and precise operation. The center rail has raceways on both sides. The solid center rail in combination with the crossed rollers offers excellent rigidity in all directions and high running accuracy.
The rail sets are normally sold in sets of two single RSDrails, one center rail DSS, two steel roller cages, and eight end screws.
By assembly of the rail sets special care has to be taken on the supporting structure and fitting edges tolerances. The parallelism of the mounting surface and fitting edges should match the required bearing accuracy. The supporting structure should have increased rigidity and must be ground at 0.2Ra or better.
PM linear bearings are manufactured in 3 superior quality grades. The parallelism of these grades is defined in diagram below.
Q8: standard precision grade
Q4: high precision grade
SF-grade: super finish grade
To reach a high running accuracy PM linear bearings are very close toleranced ( +/- 0.005 mm ). Through this, PM linear bearings can be used indifferently and identification marks are not necesarry.