need to determine torque required

[emzee6]

Hey all. You helped me alot on a thermo problem and never formally thanked you, so please consider this it. In the meantime, I need to figure out how to determine the torque required to move a load horizontally with either a hydraulic motor/gearbox or an electric motor/gearbox. I would prefer hydraulics because I have speed control at my fingertips with a needle valve.

I plan on using 1 drive source turning a shaft at 20 rpm. this shaft will have 3 driven 12" spockets - 1 at about 6" from the gearbox, and the next 2 at 4 feet and 8 ft. These are the drive sprockets. Each drive sprocket will have a driven sprocket approximately 10 feet away. The top portions (from the top of each sprocket) of each chain will be taut, and there will be a spring loaded ider sprocket holding the chain down taut on the bottom (or return) portion of the chain. The idea is to actuate the chains in motion and drop a pallet weighing up to 7,000 pounds over an edge into a scrap bucket.

The 12" sprocket and speed was determined by a very basic need of moving the load at approximately 1 foot per second. The chain is specially designed and used in another area of our facility to move much larger loads around (up to 50,000 pounds). They system works pretty well and I am trying to adapt it on a much smaller scale for a different application. Only problem is that each link of the existing chain is about 10 inches long - way way more than we need.

 

[chicopee]

About showing a schematic particularly showing where the load is attached to the system since I got most of the description until you mentioned the load; also what is the reason for an idler sprocket to keep the bottom of the chain taut when you could device a tightening system on the driving or driven sprockets?

 

[rb1957]

so are you ...
1) dragging a pallet untill it falls into the scrap bucket ... "drop a pallet weighing up to 7,000 pounds over an edge into a scrap bucket."
or 2) pivoting the scrap bucket untill the 7000 lbs of scrap falls out.

i'm having a little trouble seeing how three chain drives will drag a load; and push it back again ??

Quando Omni Flunkus Moritati

 

[emzee6]

I didn't word that very well. The pallet I am describing is actually the heads and tails of steel coils we unwind and cut to length. There are inherent problems with the first and last 10 feet of the coils that we automatically scrap. The idea is to pull them off the line during processing rather than run them out all the way down to the end of the line where we have to remove them piece by piece with a forklift. The dimensions of these pieces are 8 feet wide x 10-15 feet long x up to 1" thick. They are flat plate by this time. Sorry for the confusion.

 

[chicopee]

So are the pallets (head and tail of steel coils) sliding on rollers when they are dragged by the chains before the pallets are dropped into scrap buckets?

 

[emzee6]

Not rollers, but some micarta like material that will be a consumable. Hopefully mu is available for micarta.

 

[emzee6]

Also, i am heading out on business till next Thursday. I will do my best to check in if at all possible.

 

[Ron]

How far do you have to move this "pallet"? Have you considered a magnet on a trolley (get it off the line quickly, then dispose at slower rate)?

 

[dvd]

Twenty questions is an okay game, but a sketch of what the system is/does would probably generate quicker results.

 

[chicopee]

I agree with DVD about an elevation sketch or profile, particularly of the head and tail of steel coils pulled by the chain and dropping into the scrap buckets before we can commit ourselves to help you. Positions of the sprockets and idler should also be included in the sketch.

 

[emzee6]

Back in town. Heres a couple pics. the first is of the tables where we want to convey the scrap off. The conveyor chains would go between the table rolls. We would elevate the chains to higher than the rolls and move perpendicularly off the line till the scrap dropped off. The second pic is of an existing set up we have with massive chains that move huge tons. To the poster that mentioned cranes and magnets, we are considering it, but the $$$s are substantial. If the pics dont come through, if someone can send me an address I can forward them to I will be happy to forward them. thanks, Mark

 

[emzee6]

Looks like only one pic went through. Here is the first.