NSK Matched Angular Contact Ball Bearings

Matched angular contact ball bearings come in a variety of arrangement types to suit loads for a partciular application.

Types and Features of Matched Angular Ball Bearings

Arrangement

Back-to-back (DB)
Example: 7208 A DB

Features

Radial loads and axial loads in both directions can be sustained.

Since the distance between the effective load centers a0 is large, this type is suitable if moments are applied.

Arrangement

Face-to-face (DF)
Example: 7208 B DF

Features

Radial loads and axial loads in both directions can be sustained.

Compared with the DB Type, the distance between the effective load centers is small, so the capacity to sustain moments is inferior to the DB Type.

Arrangement

Tandem (DT)
Example: 7208 A DT

Features

Radial loads and axial loads in one direction can be sustained. Since two bearings share the axial load, this arrangement is used when the load in one direction is heavy.

Features

• Flexible arrangements
  Angular ball bearing sets are defined by how the bearings are oriented when combined. Bearings can be arranged with their outer ring front faces together (face-to-face/DF), with their back faces together (back-to-back/DB), or with faces aligned in the same direction (tandem/DT).
• Support axial and radial loads
  DF and DB arrangements can sustain radial loads and axial loads in both directions. DT arrangements are used for large axial loads in a single direction.
• High precision
  Precision class (P5 or above) arrangements are often used in the main spindles of machine tools. In these cases, a preload is applied based on operating conditions to adjust internal clearance. They also use a special fit.

Applications

• Pumps, compressors, screw chillers, elevator hoists