Sprocket and Chain -or- Pulley and Belt?

[srjones]

Hi all,

I'm working through a design question and I'm looking for advice and input.
I've got a slow speed (1800rpm) import ST Gen (12Kw) that I want to run from a 540 PTO. I've looked at both sheaves and belts as well as sprocket and chain. For sprocket/chain I'm looking at ANSI 50 sprockets but using 530 motorcycle chain. For pulley (sheaves) I'm thinking a triple sheave.

I've made a list of the pros and cons of each, but I'd really appreciate additional thoughts and/or considerations.


"Chains"
Pro:

• The cost of a chain solution is around a third to half of that of a belt solution.
• Chains don't slip.

Con

• they can break
• need some degree of lubrication (depending on the chain)
• they are noisier than belts
• less rotational mass
• I might need an idler sprocket?

"Belts"
Pro:

• The belts themselves are available at any auto parts store.
• They're quieter
• More rotation mass, (ie. more of a flywheel to help smooth startup load surges)
• dry and clean (no lube needed)

Con

• More expensive initial setup.
• Belts themselves may be more expensive than a single chain.
• can slip if they're loose

Anything else I should consider?

Thanks,

-Steve

 

[Egon]

From my limited observations of industrial drive situations that were run continuously I'd prefer the belt drive system.

 

[RonMar]

Have you looked at serpentine belts? That is what I am running on my slow speed generator(6/1 listeroid and ST-5 generator) and it works great. There are people running them on 10-12KW gensets with no issues. They are smooth and quiet and you don't have any belt balance issues like with setups using multiple "V" belts. Another pro to add to your list with a micro-v serpentine is efficiency. The micro-v serpentne belts are capable of a high ammount of friction/torque transmission, but not a lot of actual drag associated with the larger groove "v" belts. That is why just about every auto on the road today uses them... Turning diesel fuel into electricity is expensive enough without additional drive losses.

 

[srjones]

Have you looked at serpentine belts? That is what I am running on my slow speed generator(6/1 listeroid and ST-5 generator) and it works great. There are people running them on 10-12KW gensets with no issues. They are smooth and quiet and you don't have any belt balance issues like with setups using multiple "V" belts. Another pro to add to your list with a micro-v serpentine is efficiency. The micro-v serpentne belts are capable of a high ammount of friction/torque transmission, but not a lot of actual drag associated with the larger groove "v" belts. That is why just about every auto on the road today uses them... Turning diesel fuel into electricity is expensive enough without additional drive losses.

Actually, I started out with the idea of a serpentine belt as I saw on sites like utterpower. The challenge was to find a flywheel like those on listeroids that was large enough to support the sheaves commonly available. But if I did find a flywheel like that, it sure would have a lot of rotational energy Thanks for the idea.

 

[srjones]

From my limited observations of industrial drive situations that were run continuously I'd prefer the belt drive system.

Any reason in particular? Even though I can't put my finger on why, I'd tend to agree.

 

[Skyco]

IIRC the taper (V section) of industrial belts and automotive V-belts is different. IOW you can't pick up the pulleys (sheaves) at an industrial house then necessarily find belts at an auto parts store to use on them.
Just something to consider.

 

[blacksmith]

Here is the set up that MTD used on their larger GT's. I hope this will help. 540 in to 16 sprocket -chain to 8 sprocket same shaft 15 sprocket chain to 8 sprocket out(2025 RPM)

 

[Egon]

[QUOTEAny reason in particular?][/QUOTE]

Just the ease of operation over a system that will require lubrication.

 

[SPYDERLK]

use a toothed HTD belt. No maintenance, no slip, efficiency as good as a well maintained chain.
larry

 

[alchemysa]

I've never built anything with a sprocket and chain, but I have built a saw bench with a belt and pulley. I was pleased with the result. A belt is very 'forgiving'. The most expensive part is the belt (or belts). I picked up new belts at 10 for $1 (10c each!) from a discount machinery and scrap dealer, and then I built the saw bench to fit those cheap belts.