Kellogg-American Air Compressor

[JD Dave]

I bought a decent used model 331 Kellogg-American pump years ago. Now I'm putting it in service. It runs good, pumps good but the compressor vibrates. The electric motor and assembly seem fine, - just the compressor vibrates. I noticed the pump pulley has about a 1/8 inch runout. It's a heavy, 18 inch cast iron, 3-belt pulley. The pump runs great and the pulley is tight on the compressor shaft. It runs at about 450 RPM. I'm thinking the vibration is caused by the runout and/or the balance of the pulley. Can anyone comment on this condition? Thank you.

 

[Janicholson]

Measure the runout with it shut off so it can be measured accurately. if 1/8 have the pulley bored out and a new bushing with keyway put in. If not out of round, or much less, maybe the mount needs reinforcement to eliminate the flex. Jim

 

[Russ from MN]

Is the pulley mounted on a taper-lock bushing? Maybe if it is it's not indexed correctly that could cause the vibration, the pulley might have counterweights to balance the compressor. Usually they are keyed pulley to bushing, so they only go together one way.

 

[Hdonly]

Make sure the shaft is not bent. Could be the pump has been dropped.

 

[Steve@Advance]

Is there runnout on the actual belt grooves? Or is the runnout on the unmachined casting part of the flywheel?

If the runnout is on the belt grooves, something is wrong, the hub has spun on the shaft, the shaft is bent, or it was machined wrong.

If the belt grooves are running true, it is a balance problem. Some of the old compressors had a centrifugal unloader built into the flywheel. If that has been removed (there will be evidence of it once being there), you may need to bolt something back on where it was to get the balance back.

If it just seems to be a balance problem, find a way to trial and error add a weight to one of the spokes out near the edge (hose clamp and a wheel weight). Number the spokes so you can record what you do, keep moving the weight, adding, subtracting weight, until you get it running smoother. Once you get it right you can replace the temporary weight with a stick on wheel weight or drill a hole and bolt on some washers.

 

[Phill Tibbetts]

If that big pulley gets hit it will bend the shaft. Ive seen it before and have straightened the shaft. It don't take much of a hit sometimes. Maybe that is why the previous owner got rid of it.

 

[JD Dave]

Many good points I'll look into. Thank you.

 

[Keith True]

I think I would try to find another 331 to watch and listen to,or find somebody familiar with those machines to talk to.They ARE shakers.They don't run smooth and quiet like old,slow turning machines..The older 321's were pretty smooth and quiet,they just didn't make much air.I replaced my 321 with a 331,then replaced that with a 335.I was told to NOT bolt the compressor down to the floor by the Kellog American dealer.They shake so much the platform welded to the tank will break right off the tank.The problem is way worse with a vertical tank.They start and stop with a bang too.They are a good machine,there was a factory about 8 miles from me when I bought mine.

 

[JD Dave]

Keith, Good information., Kellogg-Americans shake. Since Steve responded about the runout, I measured the belt-edge runout and it is also about 1/8. So one could conclude that either the pulley bore was machined incorrectly or the compressor crankshaft is bent and not straight & true. Would that seem to be a correct diagnosis? Thank you. Dave

 

[Hobo,NC]

Yes they shake not vibrate/vibration as in a buzz... I have a 335 and 321 the tanks are mounted to 2X6's on concrete. I moved them several times so left the 2X6" (skids) on it. I would guess side to side shake at 1/8". I have had them both over 40 years.

That being said the faster you turn'em the more they shake. I put a 5HP motor on the 335 with a larger motor pulley yes it elevated the shake.

https://forums.yesterdaystractors.com/viewtopic.php?t=704322&highlight=compressor

 

[Keith True]

Actually lots of the newer big compressors shake.I have an old Wayne from a garage that closed in the 50's,that runs smooth and quiet.It just kind of thumps away.It was fine for garage work,air wrench,the lift,etc,but would not have worked for bodywork.Compressors at auctions have been known to be problematic,but not because of somebody trying to pawn them off.It is from people trying to move them om forks.You get under them,pick them up,and say I've got this.Then,being topheavy they spin.It doesn't take much of a tap on the flywheel to bend the crank.When I bought my 335 in 1993 the guy at the dealership worked pretty hard to talk me into a horizontal tank.I wanted the vertical for the small footprint.My friend bought the same machine with the vertical tank,his tank cranked at all four points that the platform was welded to the tank.He also bolted it to the floor,whick the salesman told him NOT to do.There were come crankshaft problems with some of them in the early 90's,interestingly enough it wasn't with the ones made in China,it was the ones made in Independence Virginia.The ones made in Kingston N.H.were fine too.