Re: Drive Shaft Axial Loading
How are you defining drift? 
Please clarify "set screw ball bearings"??
Pulley shafts are usually carried between one fixed & one floating bearing. It is normal practice to place the fixed bearing at the drive side to accommodate the slight shortening caused by bending deflections, thermal variations & the like; while maintaining the drive component locations.
Have you done that?
Have you checked the axial load capacity of the plummer block? ■
Re: Drive Shaft Axial Loading
The drive shaft bearings are Dodge SCM's 3-7/16". They are both considered fixed, since they each have 2 locking setscrews. They are not offered with the options for expansion.
So yes, the drive location is maintained by the set screws in teh bearing collar against the shaft.
Do you think these set screws will prevent the shaft from sliding axially if the belt tracks off center of the crowned pulley?
Thanks. ■
Re: Drive Shaft Axial Loading
....more info now.
After some thought, I did some calculations to determine the axial load if the belt were to track off center to the edge of the pulley drum. Using the resultant pulley load at startup, the axial load was negligible and way below the thrust capacity of the bearings.
I also found out that a lot of conveyor mfgs drill holes in the shaft for the bearings set screws to lock into. I like this idea!!
That's all for now on this topic.
Cheers all. ■
Re: Drive Shaft Axial Loading
Originally Posted by designer999
I always thought it was standard engineering practice to at least "dimple" the shaft on assembly to give the grub screws something to bite into?? ■
Re: Drive Shaft Axial Loading
Originally Posted by designer999So yes, the drive location is maintained by the set screws in teh bearing collar against the shaft.
Do you think these set screws will prevent the shaft from sliding axially if the belt tracks off center of the crowned pulley?
Thanks.
I hope that torque values are recommended for the set screws.
Please check up with the manufacturer for the value and schedule.
Regards, ■
Drive Shaft Axial Loading
Hello all,
We have a built a feeder to run at 18 fpm, for 25 tph of coal and coke, on a 36” belt with 16” diameter pulleys. The drive pulley is crowned and the torque arm on the shaft mounted gearbox does not include an axial restraint (only a torque restraint).
If the belt runs off center, would anyone think it is possible for the shaft/pulley/gearbox assembly to drift inside the 2 set screw ball bearings?
If so, we’re thinking of tying the gearbox axially to the frame.
Thanks in advance. ■