Need Help with the design of chain drive system
Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 20 of 31
  1. #1
    Join Date
    Mar 2001
    Location
    New Haven, CT
    Posts
    3,499
    Post Thanks / Like
    Likes (Given)
    44
    Likes (Received)
    677

    Default Need Help with the design of chain drive system

    I was wondering if anyone had any ideas. This is the system I have in autodesk inventor;


    I need to drive 3, 3" dia rollers 3.5" on center, with one DC gear motor.
    shot-drive-system1.jpgshot-drive-system2.jpg
    The challenge I am having is the torque/speed torque per roller is about 300in-lbs (each), and the speed is about 20rpm which is killing me on the chain life calculators, and forcing me to go with #50chain. Making matters worse I need to be able to go in both directions, so I don't even think my current tensioning scheme used in the image above will work.

    Anyone have any good ideas here, or should I be looking into other options than using a chain such as either gears, or maybe even going with siderods like on a steam locomotive?

    Has anyone ever used Snapidle tensionersh ttp://www.snapidle.com/products/chain-tensioners.html? I don't know why they are so expensive (I think they run like $60each at McMaster) If I go double chain width over all 3 rollers forming one big loop, and then use something like these;

    I may be able to get away with it, but has anyone ever used Snapidle products? How well do they hold up with time? On the short spans between the 3 rollers do I really need a tensioner or can I get away without one if I break these into 2 separate loops? If anyone has ever used Inventor's design accelerator for chain, any ideas on getting it to recognize this type of tensioner?

    Any other ideas here or am I more or less on the right track?

    Thanks

    Adam

  2. #2
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,450
    Post Thanks / Like
    Likes (Given)
    2176
    Likes (Received)
    3372

    Default

    Can you use cogged belts like HTD or polychain? how dirty is the environment?

  3. #3
    Join Date
    Jan 2010
    Location
    Indianapolis, Indiana, USA
    Posts
    5,473
    Post Thanks / Like
    Likes (Given)
    2426
    Likes (Received)
    930

    Default

    I suggest a motor (with inline reducer) for each roller, direct drive.

    I doubt it will be much more expensive, perhaps cheaper.

    How much HP are you transmitting? If you can't get the HP you need within 3.5 inches diameter, perhaps one on each end.

    No exposed drive, less part numbers to inventory, drive alignments should be easier.

    I wouldn't be surprised if self-contained roller/motors were available, with the motor installed in the roller.

    Integrated Cylinder Roller for Conveyor Tables
    http://www.wittenstein-us.com/Precis...s/LPB070.phtml

  4. #4
    Join Date
    Mar 2001
    Location
    New Haven, CT
    Posts
    3,499
    Post Thanks / Like
    Likes (Given)
    44
    Likes (Received)
    677

    Default

    The horsepower is quite limited, only .2-.3HP it is just the really low speed, (20rpm) that pushes the torque so high. As for individual motors, that just sounds really expensive. I need 18 rollers in the entire assembly! Why the snap idle things are so expensive, I think the one I need for the double #50chain is $100, it just sounds really steep. I suppose when you look at other costs like the 6 gear motors the whole thing isn't going to be cheap overall, but still, it seems like there has to be a better way. I am almost wondering though it will create some higher tolerance demands to get it right if either side rods, or perhaps a gear system could at the end of the day be the way to go. I haven't done any beam calculations as far as what the load that goes through the side rod would be but I do wonder now if it is worth evaluating. I still wonder if there is a better way to do this with chain. Does anyone know of a competing product to the snapidles?

    MUD, I would have to look into polychain, HTD or cogged belts but I would think if I am up against the limits of what chain can do I would have a hard time thinking a belt would work.

  5. #5
    Join Date
    Jan 2010
    Location
    Indianapolis, Indiana, USA
    Posts
    5,473
    Post Thanks / Like
    Likes (Given)
    2426
    Likes (Received)
    930

    Default

    The cogged belt folks have plenty of testimonials where a beefy but troublesome chain drive was replaced with cogged belts, and it results in much much less trouble.

    If you outboarded an additional shaft support, you could have a cogged belt seriously wide.

    Actually, you could have a cogged belt as the conveyor belt, if you desired. Pulleys engaging the interior of the belt, the belt engaging the material.

    Or are you driving directly from rollers to material?

    Gates Corporation

    Gates Mectrol can produce urethane timing belts in widths up to 450 mm. This belt is specifically designed for synchronous conveying applications.
    Wide urethane timing and conveyor belts | Gates Mectrol

    cogged-belts.jpg

  6. #6
    Join Date
    Dec 2009
    Location
    Rhode Island, USA
    Posts
    344
    Post Thanks / Like
    Likes (Given)
    68
    Likes (Received)
    40

    Default

    Well they are flat rollers but must they be timed? Assuming the chain or connecting link proposal and your concern for strength and wear...... the cogged tooth belt might be the easiest, cleanest, neatest way to do this. You have multiple options but say you ran one belt... a single on the drive pulley side and had one idlers between the two end rollers but on opposing sides (like top and bottom viewed from the side) just one idler between each for now and pushing against the back of the belts. This way the middle pulley has sufficient wrap. Now you have one additional idler between the drive and first pulley to get it's proper wrap, so one idler up, one down and one up again. The torque is about 25 ft., lbs and 20 rpm none of which doesn't seem like a lot of force or speed. They have all kinds of idlers, spring loaded, non spring, etc., etc. You may find out you need additional small non adjustable idlers at some point to get the necessary purchase on the pulleys. This looks crazy sometimes but it works and can be done. Look at serpentine belt systems on cars, stock and aftermarket. Look at the belt configuration on commercial mower decks....... that'll give you an education.

  7. #7
    Join Date
    Dec 2009
    Location
    Rhode Island, USA
    Posts
    344
    Post Thanks / Like
    Likes (Given)
    68
    Likes (Received)
    40

    Default

    I don't really know what your making or using it for but yes.... the simple answer is a tiny adjustable sprocket can be used to take up tension, I think also tiny non-tooth idlers are available.

  8. #8
    Join Date
    Mar 2001
    Location
    New Haven, CT
    Posts
    3,499
    Post Thanks / Like
    Likes (Given)
    44
    Likes (Received)
    677

    Default

    Thanks for the replies so far. The rollers are going to be drive wheels running on concrete. One thing I didn't realize is I never thought that belting would be capable of carying more torque than chain/sprocket. But I will have to look into that one further when I get home tonight. One interesting idea I read that I hadn't thought of is can I use a timing belt as almost a tank tread in this application? These will be traveling over concrete, each roller supporting about 5000lbs vertical load on them, and possibly driving over metal chips or whatever else is on the floor. I would think that isn't a friendly environment where a belt would last, but I wonder if they have ones that can do it. If they do that would be almost the ideal situation for me, and then if the center one turns into almost just an idler pully I would think I should be ok. I will have to play with the numbers and see what I can find when I get home later tonight, but has anyone ever seen a belt run directly on the floor as a tank tread?

    At any rate I will have to take another look into belting. It will be interesting to see if I box myself into a similar corner as I did with the close center to center spacing with the chain/sprocket system.

    Thanks,

    Adam

  9. #9
    Join Date
    Dec 2007
    Location
    Southeastern US
    Posts
    6,401
    Post Thanks / Like
    Likes (Given)
    845
    Likes (Received)
    2803

    Default

    Timing belts have come a long way. Gates probably has a 10 mm wide belt that will more than satisfy the requirements for this project. Extrapolating from the fact we have a 30 mm wide timing belt driving a 30 hp spindle on a CNC machine.

  10. #10
    Join Date
    Jan 2010
    Location
    Indianapolis, Indiana, USA
    Posts
    5,473
    Post Thanks / Like
    Likes (Given)
    2426
    Likes (Received)
    930

    Default

    And the belts can have teeth on both sides.

    You might also investigate "table top" conveyor track.

    And what ever those military bomb disposal robots (by roomba) use.

  11. #11
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    26,162
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8249

    Default

    Quote Originally Posted by S_W_Bausch View Post
    And the belts can have teeth on both sides.

    You might also investigate "table top" conveyor track.

    And what ever those military bomb disposal robots (by roomba) use.
    At the loads specified, what may be closer is one of the pendant-controlled units that riggers specializing in office equipment use to move fire-safes up a stairwell when there is no lift in the building.

    Google for 'stair crawler' and look at its tracks and drive system. Not the 'dolly' style, the ones that look like miniature tanks and similar to what BDU guys use, but generally less sophisticated and of heavier load capacity. Also used in 'third world' countries where buildings are more often 'challenged', so cheap ones are made offshore already, and in all sizes and load ranges.

    At the heavier end, look at what rubber-track on a 'Trackhoe' and similar diggers use.

    Rather than reinvent the wheel, I suppose one could reinvent the track...

    ;-)

    Bill

  12. Likes S_W_Bausch liked this post
  13. #12
    Join Date
    Mar 2001
    Location
    New Haven, CT
    Posts
    3,499
    Post Thanks / Like
    Likes (Given)
    44
    Likes (Received)
    677

    Default

    I did a quick search (I am at lunch right now so more time later tonight) none the less most of the tread type designs seem to have splines on the other side. For what I am doing with the heavy vertical load, I think I more would want to run a simple timing flat belt along a smooth floor. Yet the key issue is what happens if it runs over sand, dirt, metal chips etc... will they all the crap lodge in the belt and chew the thing up? Anyone ever seen a timing belt used this way? My testing budget is not huge and it would be real unfortunate if after building the whole thing they just didn't work.

    I was thinking that solid steel rollers with urethane coating would be the way to go like ono rigging skates as at least I know that works. (which this is similar to, but not close enough to use an actual skate). At any rate if anyone has ever seen timing belts used as power treads I would love to know. If there is a good chain type modular tread system I would like to hear of that too. Most systems I saw in my 5mins of search all seemed to be complete treads where if it was the wrong size you were screwed.

    As for the table top conveyr track, I googled that and found some sites. Anyone know of a good supplier for it. I don't have any real time to look into this further till later tonight but if anyone knows of a site with details I would be real interested.

  14. #13
    Join Date
    Sep 2006
    Location
    Lincoln, NE
    Posts
    334
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    5

    Default

    as to timing belts.
    Goodyear Engineered Products has their Eagle line of double-V timing belt. (Not sure if these are available with both sides toothed)
    These belts handle very large loads as compared to the size. An added benifit of the design is that the pulleys don't need flanges as the belts are self-aligning.

    Eagle NRG

  15. #14
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    26,162
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8249

    Default

    Quote Originally Posted by adammil1 View Post
    I did a quick search (I am at lunch right now so more time later tonight) none the less most of the tread type designs seem to have splines on the other side. For what I am doing with the heavy vertical load, I think I more would want to run a simple timing flat belt along a smooth floor. Yet the key issue is what happens if it runs over sand, dirt, metal chips etc... will they all the crap lodge in the belt and chew the thing up? Anyone ever seen a timing belt used this way? My testing budget is not huge and it would be real unfortunate if after building the whole thing they just didn't work.
    ..and no one has ever moved a load before you sat down at a CAD terminal?

    Don't just assume an approach and seek a material.

    Research what has already been done. Search on how the problem has previously been solved. 'Coz it IS solved, every day of the week somewhere ... or many 'somewheres', and was being solved long before the first pyramid was built in Egypt.

    One example among many:

    Hilman Rollers - Leading manufacturer of rollers, load skates, and material handling equipment

    There are others. And they know how to keep their chains and belts from stretching, breaking, or sliding off under turning or lateral thrust, and have experience with uneven floors and debris.

    It's wot they do...

    Bill

  16. #15
    Join Date
    Jan 2011
    Location
    Miami, Fl
    Posts
    239
    Post Thanks / Like
    Likes (Given)
    211
    Likes (Received)
    23

    Default

    I would use two chains. Or, if belts will work , use them to reduce the sprockets needed.

  17. #16
    Join Date
    Dec 2009
    Location
    Rhode Island, USA
    Posts
    344
    Post Thanks / Like
    Likes (Given)
    68
    Likes (Received)
    40

    Default

    You know what makes this difficult to give a sensible answer to...... is that each additional post from the OT provides more information. The rollers are actually running on the ground, over uneven surfaces with metal chips, supporting 5000 lbs vertical load, etc., etc. If this is something you're trying to invent and patent and sell
    it makes sense to play it close to the vest. If it's just for your own personal use...... you should give all available info because then you'll get flooded with different ideas, many might never have occurred to you. You can pick and choose and still build it yourself and it will be your own personal project and success story assuming
    the original premiss makes sense, but even that very well might be answered here. Anyway..... stuff like that is fun to play with and fabricate, good luck with it.

  18. #17
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    26,162
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8249

    Default

    Quote Originally Posted by blue35mm View Post
    I would use two chains. Or, if belts will work , use them to reduce the sprockets needed.
    In diameters that small, be it gears, chain sprockets, or belt sheave ... any of these have to be WIDE to manage the torque because they must use a pitch diameter enough smaller than the 3" rollers to fit.

    Difficult to apply that kind of torque any other way. And there may be no space to go wide, even it it were not subject to damage. Similar limitation on in-hub motors, with or without gears. Small diameter = lower torque.

    So what did Hilman do?

    Hydraulic drive from an external power-cart, IIRC....

    I don't see any braking mechanism in this design, either. Only a 'breaking' mechanism. Of the chain.

    Not all flooring is equally smooth nor equally level. And then there are ramps...

    Bill

  19. #18
    Join Date
    Jan 2010
    Location
    Indianapolis, Indiana, USA
    Posts
    5,473
    Post Thanks / Like
    Likes (Given)
    2426
    Likes (Received)
    930

    Default

    et the key issue is what happens if it runs over sand, dirt, metal chips etc... will they all the crap lodge in the belt and chew the thing up?
    Ask a Harley mechanic....when a pebble gets between the final drive belt (on some Harleys) and the pulley, it seems to fail gracefully, not catastrophically. The pebble may puncture the belt, raise the belt off the pulley etc.

    But Harley hasn't stopped using them.

    http://www.v-twinforum.com/forums/ha...rive-belt.html

  20. #19
    Join Date
    Mar 2012
    Location
    Geilenkirchen, Germany
    Posts
    2,308
    Post Thanks / Like
    Likes (Given)
    1394
    Likes (Received)
    1190

    Default

    The simplest and least expensive way is to use 3 drive gears and 2 idlers. Straight spur gears are available from Boston gear and they are inexpensive. I would use steel drive gears and nylon idler gears. Mounting the idlers with an adjustable flange (slotted holes) would allow fine backlash adjustment. The solution is simple, compact, inexpensive, silent, easy to build and self lubricating. You can order the gears with or without a boss and with or without keyways.

  21. #20
    Join Date
    Mar 2001
    Location
    New Haven, CT
    Posts
    3,499
    Post Thanks / Like
    Likes (Given)
    44
    Likes (Received)
    677

    Default

    Quote Originally Posted by robmc View Post
    You know what makes this difficult to give a sensible answer to...... is that each additional post from the OT provides more information. The rollers are actually running on the ground, over uneven surfaces with metal chips, supporting 5000 lbs vertical load, etc., etc. If this is something you're trying to invent and patent and sell
    it makes sense to play it close to the vest. If it's just for your own personal use...... you should give all available info because then you'll get flooded with different ideas, many might never have occurred to you. You can pick and choose and still build it yourself and it will be your own personal project and success story assuming
    the original premiss makes sense, but even that very well might be answered here. Anyway..... stuff like that is fun to play with and fabricate, good luck with it.
    I am not quite sure what direction to go right now. It sure is fun to play with and an interesting challenge but this may actually be something I want to try to put into production if I can get it to work, and try to sell so I would prefer not to give everything away right now. I think I have mentioned all the major requirements that it has. I expect that this device will perform on level concrete floors similar to what you would place a normal rigger's jack on, there could be crud on the floor just like any other would be. As such original plans were to build this thing very similar to how one would construct a rigger's jack where heavy duty urethane coated wheels support the load, only mine are to be powered.

    ..and no one has ever moved a load before you sat down at a CAD terminal?

    Don't just assume an approach and seek a material.

    Research what has already been done. Search on how the problem has previously been solved. 'Coz it IS solved, every day of the week somewhere ... or many 'somewheres', and was being solved long before the first pyramid was built in Egypt.

    One example among many:

    Hilman Rollers - Leading manufacturer of rollers, load skates, and material handling equipment

    There are others. And they know how to keep their chains and belts from stretching, breaking, or sliding off under turning or lateral thrust, and have experience with uneven floors and debris.

    It's wot they do...
    Which design of Hillman's were you referencing, the only thing that comes close I see is their tracksporter, but other than some exterior photos no clue how how their treads are put together nor do I want to pay $100K to buy one and take it apart either!

    Actually the more I have been thinking of it and looking at the prices of belts, and the likes and realizing I am getting into some real money here, the more and more I can't help but think that this indeed could be the better more time proven system I should be going for;

    In my case since I plan on making the whole thing from a weldament made from flame cut burnouts the holes for the roller bearings to sit in to support the axles will yeild as scrap the perfect pieces to create an eccentric crank with as scrap I am thinking more and more that this may be the way to go? Other than the fact that I will have to keep the tolerances real tight is it possible our forefathers of engineering 100yrs ago had the best solution for very low speed high torque loads or should I still be thinking in terms of belts and or chains here?


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •