The function of a bearing cage (also known as a separator or a retainer) is to hold rolling elements in proper orientation so they don’t group together.
Cages/separators are produced in a wide variety of materials and for a wide variety of manufacturing processes.
Materials for Bearing Cages:
- Molded plastic – polyamide (nylon), acetal (delrin), polyetheretherketone (PEEK), phenolic resin
- Stamped metal – steel, brass
- Machined metal – steel, brass
Additionally, some metal cages are assemblies (e.g. two halves riveted together.) Furthermore, some ball or roller bearing assemblies do not use a cage / separator. They use the maximum number of rolling elements than can fit in the allotted space. These bearings are called full complement bearings.
Bearing Cage/Separator Applications:
- Rotative bearings
- Linear bearings
- Slide bearings