A. Introduction

These thin cross section bearings consist of a family of seven series of open bearings and five series of sealed (standard sealing is Buna-N, low drag or non-contact. Other types are available as well) bearings. Bore sizes range from 1.000” to 20.000” and are available in three confiturations; radial contact, angular contact and 4- point contact.  In applications where contamination is present the use of sealed bearings can be provided, and in fact, recommended. A modified bearing (angular contact) is also available for DB, DF, DT matchings.

Thin cross section bearings, due to their very specific design (ball and raceway cross sections are constant, regardless of bore diameter) have a much less inertial mass then conventional bearings of equal bores. Further, they require a much smaller envelope that in turn results in a greatly reduced, overall drive weight. So where a standard ball bearing has a bore diameter that increases with outside diameter, hence increasing bearing weight, the thin section bore diameter remains the same regardless if outside diameter is 4.00” or 20.00”.

The thin cross section bearing is available with ball rolling elements and cylindrical (cross roller) roller elements. Choosing one vs. the other is based upon the same criteria as it is for standard bearings. Radial contact bearings primarily support radial loads. Angular contact bearings support radial as well as unidirectional thrust loads. Four point contact bearings support radial loads and bi-directional thrust loads. Cross roller bearings support bi-directional axial loads as well as radial loads and strong moment loads. When preloaded, rigidity is increased and positioning accuracy is improved. In some cases, these bearings may be furnished with seals.

Conversely, thin cross section bearings cannot match nor support the load capacities of conventional bearings of equal bores. Further, they are not well suited for continuous operations at high speeds. When load, space, weight and speed permit their use, thin cross section bearings allow lighter, more compact designs thus resulting in space, weight, reduced friction and resulting in energy efficient drive systems. Though standard bearing installation practices can be carried out, particular care, especially w/non-sealed bearings needs to be observed. Clean, virtually contamination-free locations should be used in order to avoid any contamination, even grit sized. There is however, some attention required when measuring (for fits) bore and outside diameters. The average after gauging the bearing circumferences of three to five point measurements should be used in determining the true measurement of the bearing (in the unmounted state). This procedure will take into consideration the natural, out-of-roundness condition of thin cross section bearings.