Any New Thinking on Most Slip-Resistant Drive Belts?

[Jim Mc]

So...

Looks like it's been a few years since I even thought about Listeroid stuff.  I have an 8/1 India clone - now 13  years old, and, HOLY COW, I've still not built a genset out of it...

Back when I started on this, the Poly V drive was all the rage.  As I recall, the main advantage was that it's possible to run the belt over the flywheel, thus saving the cost of a big sheave for the engine side.  But now as I troll around eBay, there's plenty of BIG Browning Sheaves that wouldn't break the bank...

I want what's going to work best, with less regard to the cost, and my main concern is belt slip.

Anybody using a  decent-sized (say 10-15") conventional 'A' or 'B' section belt sheave for the engine side of the drive?  How's it workin'?

(Note that my engine is rated at 850 rpm, so I'm not needing quite the ratio of a 600 rpm engine and I have a 6 pole and 4 pole generator available)

1200/850 = 1.41
1800/850 = 2.11

[mobile_bob]

if you have a 6 pole head, i would probably lean toward a pair of AX belts
the require very little power and will handle all the power you have available without
undue tension or wear problems.

this of course means driving with a dual groove pulley

bob g

[standish]

Hi, I picked up these pulleys and belts at a local bearing supply house in Grants Pass Oregon
I have a 10/1 and found a sweet spot (where the engine ran smoothly) near 700 RPM and figured out the ratio so the output of the gen head will give me 60 hertz.

My head needs to run at 1800 RPM and my pulleys are approximately 10 inch diameter on the engine and 4 inch diameter on the gen head which gives me about 720 RPM on my 10/1. I get very good fuel economy, better than 5 hours per gallon of fuel.

[standish]

I forgot to add in my previous post that I have never had any problems of slipping no matter what load I've placed on the system. I think the highest load I've ever used has been near 4 kw.

[millman56]

Not sure what AX belts are but I have used 2 off  Z section belts (3/8" X  1/4") extensively, driving  2 pole 4 KVA alternators off the rims of CS and CD flywheels, the belts will run upright mostly but it`s no problem if they lay over on their sides around the flywheel.   There is so much contact area that slippage is not a problem.
I have also used 2 sheave Z section driving pulleys on this type application with many hours racked up using 1 belt only.
The latest CS generator set up has a 6  groove 94.5" poly-vee belt around a 25" SOM type flywheel driving a 2 pole 4KVA via a modified 5 1/2"dia  auto crankshaft pulley, this set now has over 350 hours on it and the only wear noticeable, is a slight flattening of the belts vee apex points,   these belts I understand  absorb less power than normal vee belts for any given rating and do look neat.

Vee belt drives operating in ideal conditions using good quality belts with correct tension and alignment are a reliable system, witness a 15 Kw 6 groove  5 :1 increasing "B" section belt drive in a water turbine instalation which  has run 24/7/365  and has had no adjustments since I initially tensioned the drive in Oct 2011, one belt is running a bit slack and has a slight chirp, apart from this no problems.

Mark.

[Tom]

If by Poly V you mean the 6 rib serpentine belts, mine has been working great with no slippage on a 6/1 for 8 years and 1700 hours now. My fuel tank arrangement is not the best, diesel and bioD tend to spill on the flywheel the belt is on if the tank is over filled and despite the contamination the belt is still in great condition.

[millman56]

Yes thats it,  semantics differ, divided by a common language and all that, I always think of serpentine as being the way these belts are routed in an auto situation.
Mine grabbed a short "Z" section belt and whipped it round the driven pulley with no ill effects.

Mark.

[BruceM]

I use a B belt for my 6/1 Listeroid driven air compressor, running on a big cast iron pulley (about 20").  It and the 15'' fan/pulley on the air compressor are dual, but I have no belt slipping even with just one belt, and not too much tension.

I use a serpentine belt for my ST-3 generator head.  It has to be kept quite tight or it slips and chirps starting even a 1/2hp motor. The slippage is not on the flywheel, it's on the generator pulley, which as I recall is about 9-10". With your higher RPM your generator pulley would be larger an that should help reduce the necessary belt tension.  My serp belt setup works fine with sufficient belt tension, but if I was starting over I think I'd do Vee belt(s) for the ST-3, with the belt(s)on the flywheel. (I'd try a single B belt for convenience.)  I think the extra tension required for the serpentine belt  is a bearing eater, and I suspect the belt loses are insignificant. Certainly lots of guys use the serp belt setup, and it does work fine.

[mobile_bob]

my mention of the AX type belt is as follows

an A belt is a common belt with a solid body
and AX belt is the same size (width and length) as an A belt, however
it has its underside notched so that it can wrap over tighter pulley diameters and it also
has the ability to handle about 40% more power than a standard A section belt.

i use dual AA belts on my larger unit, changfa s195 and st7.5
they are basically hexagonal in cross section allowing them to drive from either the top
or the bottom of the section, which is quite useful for serpentine drives.

i chose to go with them based on the design of the unit and my not wanting to have trapped belts
which would necessitate removal of my direct drive coupler system to the st7.5

the AA belts drive dual 110-555jho alternators and a sanden A/C compressor

they do not slip or even run much over about 100 degree's on a 70 degree ambient day, this at full rated load on the engine which equates to about 7.5kwe

i think the lowly V belt has gotten a bad wrap from folks that insist on using stamped steel pulleys, misalignments, or worse cheap belts and pot metal pulleys that are no where near up to the task at hand.... when they don't work well the belt system is always to blame or so it seems.

now having said all this

there is much to be said for the poly groove belt, mainly because they are so much more widely available these days just about anywhere, whereas v belts are not so well represented in the autoparts stores.  then there is something to be said for economies of scale, choosing a very common automotive belt usually means the lowest cost to the end user... something like using a belt made to fit a small block chevy maybe or whatever is the equivalent these days.

don't forget the hd truck dealers either, all of them have monthly sale fliers with loss leaders and often have belts at prices so low it is hard to imagine wanting to design around anything other that what is available.

i think belts bought when prices are low, can be wrapped in paper and kept in a cool dry and dark place and probably last for decades.

bob g

[Jim Mc]

Thanks for the  comments, guys.  Sounds like there's been no bad experience with V belts, so that's probably what I'll do.  I agree the AX or BX belts look like a good choice...

[millman56]

Thanks for the explanation Bob, we call AX belts cog belts over here.

Mark.

[38ac]

The only (slight) knock on V-belts is they use a bit more power than the serp belts.  V-belts can be run over the flywheel rims just like a serp and drive a much easier to source pulley on the head, easier meaning you can vary the diameter to suite and by it in your own town,,, well if more than 5-6 stop lights    Dont get me wrong! The serps are a great drive and as long as there was demand and people willing to make up the parts and ices needed in bulk (and thus reasonably priced)  they were a good route to take. Problem is that is not the case now. I used a serp when I built my 6/1 set but I can make the pulleys in the shop. Sets built since that have used V-belts over the rims.

[cujet]

While many people have good results with poly v belts on top of the flywheel, my 20/2 w/15KW ST head, squeaks on every power stroke. It may take time to wear in, dunno. Bruce runs his setup exactly the same way as mine, and his does not squeak or slip.

Maybe it's the fancy paint I used on the flywheels...

[mike90045]

While many people have good results with poly v belts on top of the flywheel, my 20/2 w/15KW ST head, squeaks on every power stroke. .... 

   Wipe belt surface, and both pulleys with alcohol and then try a bit of rosin (or belt dressing - rosin spray)