The hub is the mechanism by which the conveyor pulley is affixed to the shaft. There are many types of hub connections, all of which offer individual advantages and disadvantages.
The following variables should be considered when selecting a hub connection type for a conveyor pulley:
Pulley Position: The location/purpose of the pulley in the conveyor system may impact which hub types will be best suited for the pulley. Some may allow several hub options while others may require a specific hub style.
System Load: Some hub types will be better suited for heavier load environments due to their robust design.
Cost: The type of hub selected may drastically impact the overall cost of the conveyor pulley assembly.
Maintenance: The design of the hub will either allow for replaceable components or require the entire conveyor pulley be replaced after operation in an application. If the intent is to maintain the conveyor pulley by replacing individual components, choose a hub type that offers this feature.
Pre-Stress: The act of installing a compression style hub in a two hub application leads to pre-stressing of end disks. As the bolts are tightened, the bushing is drawn into the hub causing it to compress onto the shaft. At a certain point the shaft will no longer be able to move within the bushing. Further tightening of the bolts will draw the hub outward instead of drawing the bushing inward (assuming the bushing on the opposite side has already been fastened in place). This will cause the end disks to bow outward or pre-stress on the shaft and end disks. The shallower the hub taper, the greater the amount of pre-stressing. Ideally, this pre-stress would be primarily absorbed by the end disks, as depicted in the illustration below. However, if the end disk is built to be more rigid than the shaft, the pre-stressing will not be absorbed by the shaft in place of the end disk, causing the shaft to deflect.
1. Fixed Bore End Plates.
2. Fixed Stub Shafts.
3. Removable Stub Shafts.
4. Keyed Hub with Set Screw.
5. ER Style Internal Bearings.
6. Weld-On Hubs & Compression Bushings.
7. Keyless Locking Devices.
8. Flat End Disk with Integral Hub.
9. Contoured End Disk with Integral Hub.
10. Dead Shaft Assembly.