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Can Three/Four sprockets in a horizontal line can be run by a chain?

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Shanky.j

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Three/Four sprockets in horizontal line can be run by chain ?

3 sprockets.png 1904972_orig.jpg

Hello people, I have a serious design problem for designing a sprocket-chain system. I want to know that can three sprockets as in picture (in attachment) can be rolled by a chain? The main concern is for middle sprocket it have few teeth above and few teeth in bottom connected to chain. The other two sprockets (left one and right one) have maximum teeth connected with chain (In "C" and "Ɔ" shape as you can see in picture). The right sprocket will be connected to motor shaft (Motor have 16kg torque (Rotational force)). The middle and right sprocket will be connected to load shafts, both will need 8-8kg torque to be rolled. So if there is only two sprocket and chain (which is common in most applications) then there will be no problem to roll two sprocket. But the problem here is that THE MIDDLE SPROCKET. Can this middle sprocket be run well in this three sprocket-chain system as in first pic. The sprocket will need 8kg torque to roll. So can anyone help me out to tell that can this MIDDLE sprocket be run well in this three sprocket-chain system ?? I will be very sad if it wont run. If it wont run can you give any open mind idea to run this kind of system. An added option to answer is that if there are four sprocket in the chain in place of three as in first pic can this four sprocket-chain system will be able to run well ?? Your any opinion and solution will be a lot welcomed. Thanks in advance. :smile:
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

I'm not a mechanical engineer, but I did take some rudimentary classes in statics an dynamics in college and did a lot of cycling in the past. The teeth of the center sprocket will experience a much higher likely hood of slippage as there is more force driving the chain away from the teeth than there is force holding the chain to the teeth when the chain is under tension (any stretch in the chain will make this worse). If you want to drive two sprockets from a single drive sprocket you should place them in a equilateral triangle or add rollers above and below the middle sprocket to keep the chain in contact with the teeth so the chain won't ride up the teeth. Another option is to do what is done on tandem bicycles, make the center sprocket a two sprocket design so that the center sprocket "drives" the last sprocket.

Oh, yeah there is no pushing of the chain so only the pulling of the middle sprocket can occur, therefore only one side that is in contact with the chain is really applying torque to the shaft of the middle sprocket. Not a good design.

To reiterate
1. sprockets in a triangle
2. tandem bike dual middle sprocket
3. rollers on the middle sprocket to keep the chain in contact. (worst solution IMO)
 
Re: Three/Four sprockets in horizontal line can be run by chain ?

Thank you ads-ee.

And any other person reading this please give your knowledge or ideas if you have. Thanks in advance.

1. Ads-ee your first option of putting the sprockets in triangle is not permissible, only the sprockets can be put in horizontal line as I told in name of thread.

2. But your second option of tandem cycle seems little helpful, that will make it. i will choose it if I wont find any other better idea, because it will occupy more space (atleast 1.5cm) on the side of middle sprocket and an extra sprocket will be needed to make it happen, space on side of sprocket is an important parameter to consider, should not use extra space.

3. Your third option of putting rollers is also used in some applications in industry but I don't want to use it because it will make the design bulky and expensive. I cant opt for make it expensive. Second option was better then this option.

You told the chain will put only pulling force on upper teeth of middle sprocket. Can chain be not kept tight so that it also touches bottom teeth of middle sprocket and helps the sprocket more to roll. If the chain can help the middle sprocket from bottom side too it will help the sprocket to roll more. Then may be it might be able to bear 8kg load on its shaft. what do you think ? This option can only be considered if the chain can be kept tight in the whole system. I don't know if the chain can be kept tight or it needs to be some loose to work.
 
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Re: Three/Four sprockets in horizontal line can be run by chain ?

You told the chain will put only pulling force on upper teeth of middle sprocket. Can chain be not kept tight so that it also touches bottom teeth of middle sprocket and helps the sprocket more to roll. If the chain can help the middle sprocket from bottom side too it will help the sprocket to roll more. Then may be it might be able to bear 8kg load on its shaft. what do you think ? This option can only be considered if the chain can be kept tight in the whole system. I don't know if the chain can be kept tight or it needs to be some loose to work.

Well you can get some pull from the trailing side but that is only if the chain has absolutely no stretch or you add some tensioner rollers on that side, of course you will only get as much pulling tension as you have in the tensioner. The chain stretching is the main problem with this, once that chain stretches you won't get any appreciable pull going on from the last sprocket back to the middle one.

FYI all chains stretch, it's one of the reasons they have tensioners in the derailleurs of a bycycle.

Besides any chain sprocket arrangement if you analyze it has all the forces applied on the first few sprocket teeth that are on the leading edge (pulling side). I remember seeing a picture of the forces involved in this arrangement, after the first 1-2 (possibly 3) teeth all the forces taper off and the other teeth are just there to guide the chain around the sprocket.

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Take a look at figure 9 of this. As you can see the forces drop of dramatically after the first 2 teeth.

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You should only need one roller to keep the tension at an angle that keeps the chain snug against the middle roller.
Capture.JPG

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The forces on that roller though are going to be pretty high so it better have a strong shaft.
 
Re: Three/Four sprockets in horizontal line can be run by chain ?

3. Your third option of putting rollers is also used in some applications in industry but I don't want to use it because it will make the design bulky and expensive.

It's wise to install something to lift up the chain's bottom span, so it maintains contact with the middle sprocket(s).

If you don't do this then it's best to have short spans of chain. A long chain tends to sag. Expect it to lose contact with the bottom of the middle sprocket(s). This makes it easy for the chain to jiggle side to side. The chain might slip off an end sprocket.

A long chain also becomes loose more quickly, due to numerous links, compared to a short chain.

You need to make the chain very easy to tighten, or people will delay doing the job of tightening it.
 
Re: Three/Four sprockets in horizontal line can be run by chain ?

Just put two sprockets on the centre shaft and run two chains.

It will save you from a lot of trouble, and be far more reliable, especially after the chain wears and stretches over time.
 
Re: Three/Four sprockets in horizontal line can be run by chain ?

It is correct that the most force will be on first 1-2 teeth and they must engage securely. I think the suggestion in #6 is the most suitable for power transmission.
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

Thank you ads-ee, BradtheRed, Warpspeed, and c_mitra. Your all gave me some good information and by all of your's information I came to know what needs to be done for running this horizontal sprocket-chain system as per my requirements. I found out this low cost, less space consuming tensioner for my requirement.

40ec27714a8f98f3c4fbd58bc57a200e.jpg

It can be used as :

criteria-2.png

I hope it will work well and bear the load it will get during operation. Any feedback or important things which needs to be considered for using it will be a lot appreciated if you can give. Thank you veryyy much everybody for helping me. :-D:-D:-D
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

Hey friends I posted the same question in another forum but there I got replies that this system will not work fine with these tensioners. So I suggested rollers in place of these tensioners. The discussion is still going on for this design. I request if anybody can give any good information or suggestions on this design.

You can read the replies on that forum it might help people more reading this thread. And can reply here on this thread to take this thread to conclusion.

https://www.physicsforums.com/threa...line-can-be-run-by-chain.872565/#post-5480875

Thank you everybody.
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

It depends how much power you plan to transmit.
Any serious torque, and the centre sprocket is just going to jump teeth.

If its just driving a pointer, or something with virtually zero load, then fine.

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The only way I can see a single chain transmitting decent power would be like this:

Sprockets.jpg

Of course the sprockets need to be different sizes, and fairly large to get enough wrap, and the direction reverses, but at least it should be reasonably reliable.
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

As I stated in one of my earlier posts a tandem arrangement with a dual center sprocket would likely be the best solution.
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

@Warpspeed and @ads-ee i have made new drawing for this sprocket-chain system check it :

Sprocket Chain Design.jpg

in this way i think chain will not slip on teeth of middle sprocket because the chain will be tight due to rollers and rollers will make the chain to cover teeth from upper and bottom sides.
The middle sprocket will have 7kg of load on its shaft and the system will roll at 80 RPM.
The distance from centre of one sprocket to centre of other sprocket i might take any from 11cm-20cm. But i still need to decide whats MINIMUM distance from centre of one sprocket to centre of other sprocket i can take for this system. Please anybody tell me the MINIMUM distance i can take if anybody can tell ???

The size of sprocket is as Z(No. of teeth) = 38 as in this table :
03B-1.png

so by the sprocket size from table you can get an idea of how many teeth of middle sprocket will touch the chain as you can see pitch of sprocket is 5mm. So people please tell what do you say will this system work fine ??
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

Hi,

If you want minimum distance, then why do you use a chain?

Maybe three cogwheels do the job.
If you need all three wheel rotate in the same direction, then you need two extra cogwheels.
Use all three (five) cogwheels the same size.

Klaus
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

A chain drive must have some lag on the other side. If the chain fits tight, it will wear off fast.
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

I'm thinking a simpler solution with less wear issues and probably way more reliable is to use gears (teeth not to scale ;-))

Capture.JPG

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edit:

Besides gears are much better at power transfer than using a chain. When was the last time you saw a chain driven high performance motorcycle or a car transmission that works like a bicycle chain?

Sure a chain system is somewhat lighter (hence why they're aren't shaft drive bicycles with transmissions), even then a single ratio system would probably be better on a bicycle than a chain.

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take a look at this chain drive motorcycle drag race video I found: https://www.youtube.com/watch?v=u6ZsWwQ072E, talk about chain stretch under load. 8-O
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

and probably way more reliable is to use gears

But in long distances it has the disvantage to be more expensive in terms of both material cost and maintenance if compared to a chain :bang:...
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

One thing that isn't addressed in this thread is how the 16 Kg force motor is going to turn two 8 Kg loads as there isn't going to be 100% power transfer.

I can envision the motor failing before either a chain or a gear arrangement failing first.
 

Re: Three/Four sprockets in horizontal line can be run by chain ?

Besides gears are much better at power transfer than using a chain.

The gears always take the full load on one tooth (unless it is somewhat like herringbone type). Because there is some inherent elasticity in the chains, the force is distributed over 2-3 teeth in a chain drive.

Chain drives are similar to ropes and pulleys.

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One thing that isn't addressed in this thread is how the 16 Kg force motor is going to turn two 8 Kg loads as there isn't going to be 100% power transfer..

In the steady state, the full power must be delivered to the load; there is no other place the energy can be dissipated.
 
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