Cam follower bearings are used mainly in three types of applications: following the surface of a cam, supporting linear motion components, or laterally locating components during linear movement.

Of these, cam follower applications range from simple two-dimensional cams to complex three-dimensional indexing cams with multiple followers.

Linear motion support applications include platform support rollers and die transfer rollers. Supporting a linear motion component with cam follower bearings reduces sliding friction and track wear. By reducing wear, it also helps maintain precise machine motion. Plus, cam follower bearings guide linear motion components in lateral as well as vertical directions.

Basic types

Cam follower types include standard stud, heavy stud, and yoke, Figure 1. Both stud types are mounted cantilever-style on a support housing. The heavy stud version is used for heavy loads, shock loading, or applications requiring minimal deflection. Except for the stud diameter and end plate design, standard and heavy stud versions are essentially the same.

The yoke version mounts on a pin with a straddle or yoke support arrangement. Because yoke mounting distributes load more uniformly over the bearing, the limit or working load rating for a yoke type follower is generally equal to that of a heavy stud follower.

Most cam followers contain needle bearings, Figure 1. These bearings generally handle radial loads only, not thrust or axial loads. Other followers use either cylindrical or tapered roller bearings, or ball bearings. The cylindrical types contain double-row cylindrical roller bearings that handle higher loads and speeds plus light thrust loads.

Units with ball bearings or tapered roller bearings handle combined radial and thrust loads. Such units typically use double-row ball bearings for roller ODs less than 3 in., and double-row tapered roller bearings for ODs 3 in. and larger. They generally have seals and large lubricant reservoirs for operation in dirty environments.

These bearing types (mainly ball and tapered roller) come with various roller configurations, Figure 2, so they can ride on different types of tracks or perform different functions. The cylindrical OD type operates on a flat track or cam similar to needle bearing followers. The flanged OD provides axial location. The Vshaped OD operates on special “V” tracks, square or round bar, or even angle-iron tracks. And the Ugrooved OD unit usually operates as a wire straightener bearing.

Optional features

If the standard cam follower bearings don’t meet your needs, several options are available to help you adapt them for special applications.

Seals. The seal improves bearing life by keeping contaminants out and lubricant in. Some types are made of molyfilled nylon to reduce friction between the roller and the end plate or flange. This type of seal, Figure 3, fits on the end plate or flange OD and provides a closerunning labyrinth sealing effect with the roller. By separating the rotating roller counterbore faces from the end plate or flange, the seal eliminates sliding metalto- metal contact. The resulting lower operating temperatures reduce lubrication requirements and permit higher operating speeds. Generally, lubrication frequency can be cut to about one-third that of conventional cam followers.

Crowned OD. An optional crown on the outer roller OD, Figure 4, compensates for small amounts of misalignment between the cam follower and the track or cam. This helps prevent corner loading of the roller and reduces thrust loads on the bearing. The crowned OD also reduces thrust loading in applications involving circular motion, such as a turntable support.

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