Timing belt - altered return path

[Tmox-1130]

Good day,

I have an application where a long (400') timing belt rides perpendicular atop a flat belt to form a side with no relative movement.
The current (side)belt drive has a vertical drum about 16" diameter on each side of the flat belt. Currently the belt rolls over onto its back (naturally) and travels the length of the conveyor on this line.

I have been asked to move the return path of the belt to allow operator access, so that they can get closer than the 16 " will currently allow. I have come up with one method to roll the return side of the belt over almost 90 degrees so that it is running "almost" perpendicular to the driven side just a few inches away. At the far end of the conveyor the belt is returned to its normal attitude. However, there still may be mechanical interference along the path and so I am considering other options.

I wonder about using a "capstan" type of device to translate the belt path vertically in a helix. Essentially returning the timing belt below itself in the opposite direction.
I will need to deal with the tension on the belt separately on the drive and return sides keeping tension on in the drive side and looser on the return side of the loop.

Has anyone seen such an item? Can this trick be done? Does anyone have an example?

thanx for your help with this

cheers

t

 

[EngineerTex]

With a capstan, you get a huge amount of shear on the belt and sliding wear on the capstan itself as the belt moves down the capstan in the axial direction.

Can you add a 15" idler that puts the returning side belt an inch away from where it travels when it's with the timing belt?

Do you have a picture or sketch to share?

Engineering is not the science behind building. It is the science behind not building.

 

[racookpe1978]

You will still need a mechanical shield between the operator's hands and the moving belt.

 

[dvd]

Try researching "belt turnover"

Here is data taken from DIN 22101 which discusses turnover length - bottom line is that it takes considerable distance to get the belt on edge.

 

[Tmox-1130]

Hey
thanx for your replies..
@ engineerTex - yes I considered idlers to position the belt close to the same path. in this case there are things in the way and the belt path would need to be altered vertically and then it interferes with the conveyor bed. Hence the initial plan to roll it over on an angle. Still on the same path without interference (sort of ). The structure for the guards and belt support are a problem (challenge)for the return belt. I had planned to guide the belt with a series of rollers similar to @dvd's diagram (thanx).
I was asked to return the belt ( on edge with wide side vertical ) several inches below itself. Can it be done??
Impossible happens every day. Maybe just not right here right now.