Mounting

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5.1 Cam Followers

For greatest rigidity and strength, the end plate should be drawn up snugly against a boss or other flat surface of the housing. The tables on pages 5 throughout 27 list maximum recommended clamping torque for lubricated threads, which is the normal condition. Use up to twice the listed torque for completely dry threads.

The housing bore should be drilled and reamed to the recommended tolerance. If a greater tolerance is needed, it should be added to the plus side to prevent cam follower damage during assembly. If the cam follower stud fits tightly into the housing bore, use an arbor press and apply pressure against the central portion of the flange. Never press against the rim of the flange or the outer ring.

Although wide blade screwdrivers may be used to hold cam followers during assembly, rounded tools conforming to the slot are preferable to avoid plastic deformation in the slot area.

RBC offers a convenient socket (W suffix) for hex wrenches to provide a more substantial grip, especially for 'blind hole' applications. (Note this series can only be relubricated from the thread end or through the housing).

5.2 Eccentric Cam Followers

Eccentric cam followers are used when there is a need to make height adjustments between the cam follower and the track. By simply turning the entire cam follower inside the housing it is possible to adjust the distance between the cam follower and the track by twice the eccentricity. However, due to the mechanical advantage that the eccentricity provides, it is inadvisable that the cam follower be adjusted over this entire range.

A very large force can be exerted on the track for a small applied adjusting torque as the eccentricity of the cam follower approaches ±90 degrees from a starting position parallel to the track, in the housing. Adjustments should be limited to ±45 degrees and the resulting preload should not exceed 10% of the cam followers capacity.

The following equation can be used to find an appropriate adjusting torque.

(13)
where   

T = appropriate adjusting torque [lbf]
C = cam followers dynamic capacity [lbf]
e = eccentricity of cam follower [in]

 

Example 5 Cam-centric cam follower S48LWX has a dynamic capacity of 4,600 lb, and an eccentricity of 0.03 in. Determine the appropriate adjusting torque.

Solution:

5.3 Yoke Rollers

RBC yoke rollers correspond in many respects to the same size cam follower, except they are mounted on a pin for use in yoke type applications for greater shock resistance.

Yoke rollers should be clamped axially or mounted within closely fitting side rails to prevent displacement of the end plates. For applications with heavy loads, it is recommended to heat treat the pin and use a press fit for the inner ring. A soft pin and light press or push fit are sufficient for lightly loaded applications. When press fitting a yoke roller, pressure should be applied centrally and uniformly against the end plate, never against the outer ring.

The pin should have a suitable lead-in chamfer or radius to prevent scoring and to hold the mounting force to a minimum.

5.4 Caged Roller Followers

Caged roller followers can operate directly on a hardened and ground shaft (HRc 58 min, 16 rms min surface finish) or can be used with matching inner rings. Operating without an inner ring yields the largest possible shaft diameter with greatest strength and rigidity. Axial guidance must be provided by the application. It is recommended to use hardened steel or bronze thrust washers with radial lubricating grooves as needed.