CONVEYOR MAINTENANCE: HOW TO REPLACE THE HEAD (OR "DRIVE") DRUM BEARINGS ON AN INVADER 45

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If you have a problem with your tail drum bearings, you will need to remove and replace the whole tail drum.
Watch our video “How to remove the tail drum assembly of your Invader conveyor” ( • CONVEYOR MAINTENANCE :... ) to see how to do this.
If the head (or "drive") drum bearings become worn or damaged, you’ll need to replace them.
You’ll need two people to do this job.
First remove the external scrapers and belt and remove the head drum assembly from the conveyor. Remove the chain, sprockets and bushes from the head drum assembly.
Watch our videos “How to change the belt on your Invader conveyor” ( • CONVEYOR MAINTENANCE :... ), “How to remove the head unit assembly of your Invader conveyor” ( • CONVEYOR MAINTENANCE :... ) and “How to replace the chain, sprockets and bushes of your Invader conveyor” ( • CONVEYOR MAINTENANCE :... ) to see how to do this.
Remove the four gearbox bolts using a ratchet with a 13mm socket and extension. You can use an air ratchet for this if you have one available.
Lift off the gearbox.
Undo the four cap head bolts holding the middle cross-member in place. There are two on each side. Slide out the cross-member.
On the right-hand side of the drum shaft, loosen the two grub screws halfway, using an allen key. There's no need to remove them completely. Remove the right-hand side plate.
Then repeat the process to remove the left-hand side plate from the drum.
To replace the right-hand side bearing, unscrew the three bolts on the inside surface of the side plate. Lift out the bearing assembly. Insert the new bearing from the inside of the plate, making sure the grub screw holes are towards the outside surface of the plate.
Replace the three bolts.
To replace the left-hand side bearing, remove the tracking plate bolt using a 19mm ratchet. Unscrew the three bearing bolts on the inside surface of the side plate. Lift out the bearing assembly.
Insert the new bearing from the outside of the plate, making sure the grub screw holes are towards the outside surface of the plate.
Replace the three bolts. Replace the tracking plate bolt.
To reassemble the head drum, first lay the left-hand side plate on its side.
The drum is not symmetrical. The longer shaft with the key steel hole belongs on the right-hand side and the shorter shaft belongs on the left-hand side.
Lift the drum onto the left-hand side plate making sure you are inserting the shorter shaft into the plate.
Place the middle cross-member as shown. The side with five holes in must be next to the drum. Make sure the top surface is aligned towards the top of the plate. Secure the cross-member to the plate using two M8 by 20 cap-head bolts.
Lift the right-hand side plate onto the drum, making sure the holes are aligned. Secure the cross-member to the plate using two M8 by 20 cap-head bolts.
To align the drum correctly, insert the head drum assembly halfway into end of the conveyor. You will need to be able to access the grub screws on the bearings.
The drum needs to be centered between the side plates with equal space on either side. Adjust the position of the drum by gently tapping the head drum shaft with a wooden or rubber hammer.
Check the drum can turn freely.
When the drum is aligned correctly, tighten the four grub screws on the bearings.
Remove the assembly from the conveyor.
Lift the gearbox back into place making sure the four holes are aligned. Carefully replace the four M8 by 25 gearbox bolts. Then tighten all the bolts.
Lastly, replace the chain, sprockets and bushes, and put the head unit assembly back into the conveyor.
Watch our videos “How to replace the chain, sprockets and bushes of your Invader conveyor” ( • CONVEYOR MAINTENANCE :... ) and “How to remove the head unit assembly of your Invader conveyor” ( • CONVEYOR MAINTENANCE :... ) to see how to do this.
Then replace the belt and external scrapers, and return the conveyor to it's upright position. Watch our video “How to change the belt on your Invader conveyor” ( • CONVEYOR MAINTENANCE :... ) to see how to do this.
Track and tension the belt. Watch our video "How to track and tension the belt on your Invader conveyor" to see how to do this: • CONVEYOR MAINTENANCE :...
It is now ready to use.