Conveyor System

It is also possible to cut the supply for the not working motor. Electromagnetic clutches work at any speed even at zero as brakes.

Yes this is true, but I have a reductor between the motor and the shaft. Ok, I have draw a bad picture, because you can not see the reductor from it. Sorry :).

In my case the problem with electromagnetic clutches is that I have rotation of 29rpm. You can not engage a electromagnetic clutch at low speed and have a momentum like 100Nm. It wont work. It is possible if you "run-in" the clutch. If you engage clutch at 1000rpm and then you drop the rotation to 30rpm. In this case it is possible, but I don`t have the possibility to do that.

If it is a friction coupling you can engage it at any speed! In your situation I would NOT use any other kind of coupling

You have available of the shelf multidisk couplings with nominal torques up to 2000 Nm.

The 100 Nm you mention are not a problem at all. From wear point of view it would be better to use a 200 Nm and make a soft start via a current ramp in the coupling.

I will check it out to see if it will help me

I believe Garthh has your best solution bar none. At first I was going to suggest an overrunning clutch, but that is exactly what the "one way bearing is".

Check the catalog to find that the company builds the one way bearings specifically designed for your conveyor application problem.

Thanks for the download Garthh!

I very much doubt that your solution will work but of course I may be wrong here are the reasons for my doubt:

Those are the schematics of the overrunning clutches you suggested.

They will work as follows:

input is the shaft i.e. the inner ring in above sketches. When it turns right (for the bottom sketch and left for the upper) the elements between the 2 rings will block and drive the outer ring in same direction as the shaft against the resistance of the load. If the shaft+inner ring turns in opposite direction then either the ball or the intermediate piece will become free and the outer ring will not change its rotation. If the outer ring turns more rapidly than the inner ring in same direction as the shaft the elements between the 2 rings will become free and will not oppose a resistance to the "over drive" or if you prefer the overrun. This is the reason for the name of this type of clutch.

In fact the system blocks when the outer ring has a rotation speed smaller than the inner ring in same direction or the trend (given by a load) to turn in opposite direction.

In present case the function is as follows:

-the motor is active the overrunning clutch becomes active and pulls the conveyor with outer ring turning in same direction as inner ring.

-the above mentioned motor is not active, the other motor becomes active and pulls the conveyor in the opposite direction with respect to the first, which means that the outer ring of the inactive overrun clutch turns in the opposite direction with respect to the direction it had to turn when active. The shaft is connected to the drive and presents a resistance due to frictions and inertia to the inner ring so that the last will show the trend to turn as the outer ring but at a lower speed and this will block the clutch so that the active motor will drive in opposite direction via the drive the inactive motor. If the drive is not reversible (for instance a worm drive) the whole system will be blocked independently of how many will be the persons to give a a GA to the suggested solution.

An overrunning clutch is sensitive to the RELATIVE rotation of the 2 rings and can work transmit power) only in one direction with respect to it.

I brought this explanation since I once more notice that suggestions are made and solutions are proposed in an superficial way which is not a good point for the CR4.

If you do not believe above explanations contact a overrunning clutch supplier who will tell exactly the same, if of course he knows how the product he sells works (what I hope for him).

If more explanations would be required I am willing to give them for the quality of CR4.

You must be misunderstanding. The one way clutch mounts on the shaft driving the belt, not the output of the gearbox.

The one's I used had the figure 8 shaped "rollers" & the chamber was filled with #10 oil. We also used them on a flying press that ran 40 strokes per minute, I only saw 2 failures in 15 years, both were from the clean up crews & their pressure washers [rust].

We also had electric & pneumatic clutches of various brands, all of which include control devices, which add complication & expense.

The Original Posters stated what he wanted to do. Without having much more information, I gave a solution I have used with success for a similar problem.

I would try to use the center drive solution if it were at all possible.

He can use the reversing wiring setup suggested by several others for the motor(s).

I would certainly be concerned about driving a slated belt backwards...

If I am wrong I will always accept it since nobody detains the "truth" ! But to accept it please make a sketch how you used it and where you suggest to put it in the power path from motor to belt. It will help me to see where I am misunderstanding.

A description is not as well understandable as a drawing.

I think that nick name has the right answer to my question. Today I do more research about this one way bearing (freewheel clutch) and figure it out that it is not possible.

The inner race is fixed with flat key to the shaft and the shaft is connected to the reductor(motor). The outer race is in fix contact with the cylinder which drives the belt(or chain, what ever you like). When you switch the motor on then the shaft rotate let say clockwise. If the motor rotate clockwise then it also rotate the inner race of the clutch and if you rotate the inner race of the clutch then you also rotate the outer race of the clutch and the cylinder is rotating clockwise (also torque and power are transmited from the engine to the cylinder).

Then you switch off the motor and I want that the belt(or chain) rotate the cylinder anti-clockwise and don`t want to transmit power(or rotation) to the motor(to the inner race of the clutch). With this type of clutch that nick name has attached in this forum is not possible. Because if you rotate the shaft in clockwise(you have a ACTION) and to transmite the rotation or torque to the cylinder you MUST have a REACTON (this reaction is from the belt which rotate the cylinder to the opposite way). I have drawn an example how I understand this

sorry for any misspell or any vocabulary mistakes.

what about a one way bearing?

u kno, treat it like a bicycle sprocket. free motion one way and mechanical work the other way. if they conveyor is moving right the motor at the right of the conveyor will be doing all the work because the sprocket transmits torque from the motor to the teeth. however if the conveyor is moving left the sprocket on the right motor is free spinning because it is turning the other way in relation to the shaft rotation of the right motor.

this way there is no need for electromagnetic clutches, and the technology is reliable and cheap.

Interesting point of view, but the III. Newtons law says that in every action there is a reaction. Sou if the right sprocket transmit torque to the conveyor (action from motor), then the reaction is in the opposite way, which is coming from conveyor. When the left motor is spinning in the opposite way, then this is like the reaction from conveyor and it will turn the right motor also in the opposite way, because it engage the one way bearings. Because of that I`m not 100% shore if it will work. I need some proof if is this possible.

throwing this out there...would you consider a center drive conveyor.....see below.

You would eliminate one drive motor and only have to control one motor.

p911

Just curious.

Can't you use just 1 motor & reducer and run the motor in reverse?

Depends on the belt type.

modular or endless. You would like to pull an endless belt because pushing a endless belt is like pushing a rope. Not impossible, but difficult.

p911

Good point.

I was thinking of a chain or slat conveyor style.

mr.simke

What style of conveyor is this?

Endless belt, chain, screw, slat, overhead? or ?

It`s a slat conveyor. If choose to use one drive for both direction, then we must have much more force for pulling a slat chain (this means more power for the drive) and also a long slat chain elongate more, because of the force, materials of chains, linkage of chains...

What happens if you put one drive motor on the opposite side of the conveyor at the other end? Both motors are on the same side, but opposite ends, of the conveyor, as drawn.

Does that make the anti-rotation problem go away? (I don't fully understand the problem here, anyway)

Just for clarity, you say, "One motor will rotate the shaft in one direction and on the opposite side there will be another motor to rotate the opposite shaft in the opposite direction."

Don't you mean, "One motor will rotate the shaft in one direction and on the opposite END _{(of the conveyor)} there will be another motor to rotate the opposite shaft in the opposite direction."?

If you put one drive motor on the opposite side, doesn`t make any changes, because we need that one motor rotate in one direction and other motor rotate in the opposite direction.

For the last question I mean it like you say it.

I also think that the only way to solve the problem is to use the electromagnetic teeth clutch.

Torque converter or fluid coupling. With out the motor running it should turn free.

A plus will be if by chance both motors ran at same time. Neither motor would lock up causing them damage.

It`s like that, we will use multi-flexing chain and we need to move the material from one point to another and vice-versa. Sou we need the upper branch to be always in tension. Because of that we need one drive for one direction and another drive for the other direction. The first picture that I attached was just a simple case, just to understand what I want it to do. Here I draw a schematic of how it will be.

I want to know how to do this in the simple possible way. When the motor 1 is engage, then the motor 2 must not rotate or get any torque from the conveyor. And also for vice versa. I try something like the sistem for fishing "fishing reel" but I`m not sure if it is good or if exist for a conveyor sistem.

Modular?

Heres a start.

With a center drive conveyor you can mount it on the long leg. And use the natural catenary sag for belt tensioning.

There are requirements as to the width of the belt as to radius (usually ID R = 1.8 - 2.1 x the width of the belt)

And enough straight length before entering the drive or end of the belt to get the belt a chance to expand.

Are you using existing motors or do you have to spec them yet?

Or are you set on having (2) drive motors?

p911

Why not use reversing starter change rotation of the motor?

I understand that when a motor drives the other drive has to stay.

If you use the Ring-span systems then you have a problem since even if the motor is not powered the one which drives will also turn the whole drive of the other side!

Look at the principle of those directional free running couplings and you will see why only a friction coupling can be the solution since it makes all mechanical connection free.

How it works: it blocks if the outer ring meets a resistance that means it has the tendency to move in the contrary direction of the active drive.

Now when the motor is not powered the belt moves in the contrary direction of previous movement so that the drive will be for the coupling a resistance and will turn.

If you use worm gears then it will totally block! If you use spur gears the e box will be turning in the direction contrary to the one it turns when active.

Sorry to say but above solution will not be THE solution if the intention is to have the not powered drive not moving and not at all a solution if the drive is a worm type one.

Actually the directional free running couplings I suggested, should be paired with a chain or belt final drive, only the chain & 1 sprocket would turn backwards. The coupling would be mounted on the shaft that actually drives the belting.

The mechanism is some rollers from roller bearings on ramps, the whole thing is sealed & suspended between 2 ball bearings

I used to use them on a U shaped conveyor with interlox belting, which originally came with the center drive Phoenix911 suggested, the radius on the conveyor was a little too tight, it had a nasty habit of popping out of the guides & ripping all the ears off one edge of the belting in one direction. We left the Tensioner assembly in place & removed most of the guides underneath.

I've worked on plenty of reversible L shaped conveyors with one motor & centerdrive, that have been trouble free...

The style of belting is important, some belting even though it's supposed to be unidirectional doesn't like to be run backwards.

Why 2 motors? All you need is one.

Use two motor starters with a couple of relays to reverse the phases of the motor. The torque will be fine. We have several motors set up in this manner in our facility and they work great.

Also you should use a chain and sprockets rather than a direct connection from motor to shaft.

All you need is one.

and

We have several motors set up in this manner in our facility and they work great.

Ask maintenance at your plant about that conmveyor, how it works.

If you look at the sketch provided, it has a 90 degree curve to it. Try pushing a slat belt through there.

With the lack of design info, such as belt width, straight lengths and radius. Its risky.

I am maintenance at my facility.

I unfortunately went by his original "sketch" of the belt. With a 90 degree turn to the belt neither idea will work, his or mine. it will not be possible to have a belt run straight, turn 90 degrees then run straight again unless he goes to a plated system like a baggage carousel at the airport or uses 3 seperate sections of belt.

Look at the products of STROMAG and you will find what you need.