Efficiency of chain drives,

[David Powell]

I understand that roller chains when properly aligned and tensioned running in enclosed oil bath housings reach efficiencies of about 95 % or more,
I have added a gearbox to our 4 inch scale Clayton steam wagon, that involved adding 2 chains, both #40 chain. These will be running in the open,one having 24 tooth sprockets as driver and driven and one having a 14 tooth sprocket driving a 40 tooth sprocket.
They are in pretty good alignment and will be run with the chains slightly slack.
Have there ever been tests done on chain drives run in these circumstances? Are they going to soak up much of my, none too great, power?
Regards to all David Powell.

[redlee]

https://www.powertransmission.com/bl...ve-technology/

[BCRider]

We cyclists suffer from some of the least energetic "engines" around... And that is certainly true to a fault in my case.... But chain drives on cycles are still known to be one of the most efficient.

It's so noticeable that I can say that I honestly feel the difference when going from my geared bike running the chain through a rear derailleur and with some combos having some cross chaining angle compared to my single speed bike (freewheel, not a fixed gear). The single speed has proven to have a slight advantage for the level ground riding over the geared bike when running the same ratio.

So if you're looking to keep the most power through the transmission line as you can I'd say that chain and sprockets is the way to go. And DO take the time to line up the sprockets via shimming if needed. The wider the chain the more important. On drive chain the sprockets are typically less wide than the distance between the plates. So that's how much leeway you have with aligning the sprockets. It's enough that a straight edge long enough to span the two sprockets can be used to get the placement lined up by eye close enough that it's within the play of the sprockets in the chain.

[wierdscience]

Roller chains are about the same efficiency as V-belts, except they don't slip. A shear pin might be a good idea.

[tom_d]

Chain will probably soak up the least amount of power, but they can take additional effort if they are run too tight. The tighter the chain the more the friction in the pins come into play as the chain rolls over the sprockets.

[David Powell]

The rear wheels sit on 3/4 in diameter axles, drive is by 1/4in bolts in reamed holes, through the axles. With a loaded semi trailer she will snap them if you get heavy handed with reverser and regulator. At least they are easy to get at. Anything further back in the drive train would be harder to reach, and with steam up likely hot to handle or access. But thanks for the thought. Regards David Powell

[David Powell]

Steam wagons usually run with slightly slack chains,the slackness helps absorb the variations in power as the pistons reach and pass dead centres. You can see the waves in the chains if you walk beside a loaded wagon moving slowly. Regards David Powell.

[JRouche]

Steam wagons usually run with slightly slack chains,the slackness helps absorb the variations in power as the pistons reach and pass dead centres. You can see the waves in the chains if you walk beside a loaded wagon moving slowly. Regards David Powell.

Ha! Very nice, I am not the only one that gets mesmerized with the slack chain. Love that system.

To your Q: "Efficiency of chain drives,"

I think the types used today are very good.

IMO just follow the auto manufactures, the main ones, not the esoteric. If they are using chains that would surprise me. I think belts are better all around. My wifes toyota has prolly 50 feet of chain drive for the cams. 5.7L toy engine.

And yes, my favorite engine (diff 355ci) has a chain drive LOL. JR

[Rich Carlstedt]

50 years ago, i worked for a company that had extensive work using chains on their production machines under terrible conditions.
Brand new chains lasted one month before failure. After a 2-3 year test and trial period , They extended it to 3 months by pre-treating chains with Molybdenum Di-sulfide ( Moly lube)
New Chains were washed with solvent ( get rid of factory oils) and then placed in a pan with Moly Lube ( Powder and solvent and soaked overnight with some agitation)
The Moly "plates' the steel microscopically as there is no oil in the way !. The Moly prevents welding/scuffing and lowers friction-- then the chain is used and normal lubes applied.
Putting Moly lube on a prelubricated chain made little difference, it needs to touch bare metal.

My neighbor about 20 years ago was building a junior dragster (s !) for his son. This where they take a 8 HP B&S engine and get 35 HP out of it - His son won the NATS with it.
He was getting 2 runs per chain until Ii told him about the Moly treatment and he tried it and said it more than doubled the life and saved him a few bucks $$$

Rich

[old mart]

Motorcycles today are likely to use roller chains with built in o rings to keep the lubricants in and some of the dirt out.

[strokersix]

What about silent chain versus roller chain? I've wondered. I think the silent chain lacks the chordal action that you see with a roller chain? Could be an advantage for higher speed. But I'm not sure about this.

Like most things, I expect application dependent. Anyone have a reference?

[oxford]

Motorcycles today are likely to use roller chains with built in o rings to keep the lubricants in and some of the dirt out.

They do use them for longevity but the “O” rings do eat some power. Race bikes will use a non o-ring chain.

[jmarkwolf]

A popular experimental 2-seat helicopter originally had a chain drive to turn the main rotor. It ran in a fiberglass oil bath. Mandatory change-out was at 100 hours of run-time. I flew mine for 5 years with that chain They've since changed to a super strong cog belt system. Flew mine for an additional dozen years with that.

[Arcane]

50 years ago, i worked for a company that had extensive work using chains on their production machines under terrible conditions.
Brand new chains lasted one month before failure. After a 2-3 year test and trial period , They extended it to 3 months by pre-treating chains with Molybdenum Di-sulfide ( Moly lube)
New Chains were washed with solvent ( get rid of factory oils) and then placed in a pan with Moly Lube ( Powder and solvent and soaked overnight with some agitation)
The Moly "plates' the steel microscopically as there is no oil in the way !. The Moly prevents welding/scuffing and lowers friction-- then the chain is used and normal lubes applied.
Putting Moly lube on a prelubricated chain made little difference, it needs to touch bare metal.

My neighbor about 20 years ago was building a junior dragster (s !) for his son. This where they take a 8 HP B&S engine and get 35 HP out of it - His son won the NATS with it.
He was getting 2 runs per chain until Ii told him about the Moly treatment and he tried it and said it more than doubled the life and saved him a few bucks $$$

Rich

I read long ago about a mechanic who would wash out the timing chain in a V-8 engine and then immerse it in a very hot half and half mixture of 50 weight engine oil and moly lube and then let it all cool down. He claimed doing that would drive out any air in the chain and when it cooled, it would suck the lube into the chain much better than just immersing it at room temperature. He said it greatly extended the life of the chain, so we know it works.

I betcha doing the same with David Powell's chain but with pure moly lube would work wonders!

[Bented]

What about silent chain versus roller chain? I've wondered. I think the silent chain lacks the chordal action that you see with a roller chain? Could be an advantage for higher speed. But I'm not sure about this.

Like most things, I expect application dependent. Anyone have a reference?

Silent Chain means, less noise.
Auto manufacturers are very concerned with sound which is one reason for polymer belt drives.
Steel chain driving steel sprockets is noisy at best.