For bearing arrangements where the load carrying capacity of a single bearing is inadequate, or where the shaft has to be located axially in both directions with a specific axial clearance, SKF can supply matched pairs of single row deep groove ball bearings on request (fig. 1). Depending on the requirements, the matched pairs can be supplied in tandem, back-to-back, or face-to-face arrangements. The bearings are matched in production so that, when mounted immediately adjacent to each other, the load is evenly distributed between the bearings without having to use shims or similar devices.
Depending on the requirements matched pairs can be supplied in three different arrangements:
Tandem arrangement (fig. 2)
A tandem arrangement is used when the load carrying capacity of a single bearing is inadequate. When arranged in tandem, the load lines are parallel and the radial and axial loads are equally shared by the bearings. Axial loads in both directions can be accommodated.
Back-to-back arrangement (fig. 3)
Mounting two bearings back-to-back provides a relatively stiff bearing arrangement, which can also accommodate tilting moments. When arranged back-to-back, the load lines diverge towards the bearing axis. Axial loads in both directions can be accommodated, but only by one bearing in each direction.
Face-to-face arrangement (fig. 4)
Mounting two bearings face-to-face is not as stiff as a back-to-back arrangement, but less sensitive to misalignment. When arranged face-to-face, the load lines converge towards the bearing axis. Axial loads in both directions can be accommodated, but only by one bearing in each direction.
A “V-shaped” marking on the outside surface of the outer rings of matched bearings (fig. 5) indicates how the set should be mounted to obtain it's desired performance . The bearing pairs are supplied as a packaged unit.