Installation and Maintenance Manual: RLVAC
Published February 2022
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9. If the back side of the sprocket teeth are unworn, the sprockets may be rotated (swapped left-for-
right so the chain engages with the unworn “back” side of each tooth). If both sides of the teeth
are worn, the sprockets should be replaced.
10. When rotating or replacing sprockets, ensure that the distance of 8 1/2” between the inner faces
of each sprocket is maintained, and that the sprockets are centered with respect to the two drive
frames. It is not necessary to remove the sprocket shaft or bearings.
11. Compare the new chain with the removed chain to make sure the new chains have the same
number of links.
12. Install the new chains. Make sure that the number of links between the sprocket engagement and
the takeup carriage is the same on both sides.
13. Manually retract the tensioning cylinder until there is no slack left in the chain (52), to avoid shock
loading the takeup mechanism on first startup. Verify that both sides are taking tension evenly.
14. Replace any guards that were removed.
15. See section 5.12.2 for belt tensioning and tracking instructions.
6.6.5 Idler Roller Replacement
1. Ensure air pressure is removed from the tensioning cylinder (55) and the belt is slack. It may be
necessary to remove one of the takeup guards and manually extend the tensioning cylinder to
provide extra belt slack. See Figure 30: General Arrangement, Belt Under Roller AC, Pneumatic
Takeup Drive, Sheet 1 of 1 for details.
2. Remove conveying rollers and one pressure module to access the idler roller from above. See
section 6.8 for details.
3. Unbolt the affected roller (46) or (47) from both sides of the drive, and raise it until it can be slid
out from the belt.
4. Insert the replacement roller (46) or (47). Note that the roller (46) is a crowned roller, which can
be identified by the shiny machined surface. The crown is very slight and will generally not be
visible without a straightedge to compare against. Item (47) is a non-crowned roller with a mill
finish tube.
5. Verify correct belt routing using the arrows on the side of the drive section. See Figure 15:
Pneumatic Takeup Drive Belt Routing in section 5.5.2 for confirmation.
6. Replace the bolt and lock washer on both sides of the roller. If the adjustment brackets were not
moved during the procedure, the previous tracking setting may be maintained; otherwise, set the
roller square to the conveyor frame.
7. Replace any guards or conveying rollers that were removed.
8. See section 5.12.2 for belt tensioning and tracking instructions.
6.6.6 Bearing Replacement and Maintenance
1. Periodically grease each bearing following the instructions in the ABB Motors MN3016 bearing
manual. Do not over-lubricate. Too much grease can damage bearing seals or cause excessive
heating.
2. If bearing replacement is necessary, follow the instructions in section 6.6.2 for the drive pulley
bearings (49), or in section 6.6.3 for the takeup pulley bearings (48).
3. If the takeup sprocket bearings (49) need to be replaced, follow the instructions for replacing
sprockets in section 6.6.4 until both sprockets are removed, then continue by removing the shaft
and bearings.
4. Ensure the shaft is centered when replacement bearings are installed.
5. Slide the shaft through both bearings before tightening down the bearing fasteners, to ensure
alignment. Torque the set screws per ABB Motors MN3016 only after both bearings are fully
installed and their mounting bolts are torqued.
