Picked up half a megawatt worth of Caterpillar power, think I'll make a PTO generator

[strantor]

IMO, you don't have near enough hp to gear it any other way than to run your tractor at pto speed.

As for your gear box question, yes most do, BUT bigger boxes have more rolling resistance too, they should be sized properly, not waay over sized like a truck rear end.

SR

The hypoid gearing in a typical automotive differential is very efficient (94% - 97% typ.) and sourcing an industrial/farm duty gearbox which could compete with it would be difficult & expensive. Also, 540 axle RPM is relatively low speed (about 49mph for a truck with 31" tires) so fluid churning losses should be minimal. I suppose it doesn't have to be a huge truck diff; I could find a diff from a smaller RWD car. I'm inclined toward the differential instead of a traditional gearbox in the interest of efficiency, cost savings, robust construction, and availability of parts. What I don't like about the diff approach, is the 90 degree turn. I would much rather have a straight drivetrain. If I happen to find a regular in-line gearbox which competes with a diff in all those areas, then I will abandon the diff idea.

 

[fried1765]

Here's one off of a 747. It's only 2500HP. :laughing:

eBay

Better have a GREAT set of ear plugs, for either the 737 or the 747 version.

 

[radios1]

Better have a GREAT set of ear plugs, for either the 737 or the 747 version.

you would have to make a muffler for it..

 

[radios1]

The hypoid gearing in a typical automotive differential is very efficient (94% - 97% typ.) and sourcing an industrial/farm duty gearbox which could compete with it would be difficult & expensive. Also, 540 axle RPM is relatively low speed (about 49mph for a truck with 31" tires) so fluid churning losses should be minimal. I suppose it doesn't have to be a huge truck diff; I could find a diff from a smaller RWD car. I'm inclined toward the differential instead of a traditional gearbox in the interest of efficiency, cost savings, robust construction, and availability of parts. What I don't like about the diff approach, is the 90 degree turn. I would much rather have a straight drivetrain. If I happen to find a regular in-line gearbox which competes with a diff in all those areas, then I will abandon the diff idea.

there are places that will shorten the tubes and axle right down to the case. what you could try is a manual transmission run backwards. drive it from the driveshaft end..

 

[MossRoad]

you would have to make a muffler for it..

Why? :laughing:

 

[Industrial Toys]

That is just too cool! I hope they are wearing ear plugs.

And I thought there was nothing louder than a 3600 RPM Generac Screamer!

 

[strantor]

If power is that critical, why not just go on E-Bay and buy some nice appropriately sized, quality, used, low running Diesel, Generator. End of project and story.

I have a 1000# cutting flywheel in my 15" PTO chipper meant for a larger HP tractor than the 70 something JD I have. Our tractor has a tough time getting that flywheel moving and I'm sure the PTO clutch doesn't like it. That large genend rotor could be similar.

If power were that critical, I would. But it isn't, really. We're about done with hurricane season for this year and I hope to have it ready by next year. I don't expect I'll need it this year, so I have spare time to play with this. Plus a diesel generator wouldn't work well as a PTO dynomometer, which is the secondary purpose of this project.

 

[aczlan]

How about making a chain "step up box"?
45T #60 sprocket on the input shaft (ie: X1-1/2B 1-1/2" Bore Hub | Weld-On Sprocket Hubs | Sprockets | Power Transmission | www.surpluscenter.com and X1-1/2B 1-1/2" Bore Hub | Weld-On Sprocket Hubs | Sprockets | Power Transmission | www.surpluscenter.com )
15T #60 sprocket on the output shaft (ie: 15T 1-1/2 Bore 6P Sprocket | Finished Bore Sprockets | Sprockets | Power Transmission | www.surpluscenter.com )
A box of 60H chain (ie: #6-1 H 1' Box Of #6 Heavy Duty Roller Chain | Roller Chain | Roller Chain & Links | Power Transmission | www.surpluscenter.com )
Mount them in a box that you size so that one side matches the SAE #2 bell on the generator head and fill with enough oil that the chain runs through it and slings it around and off you go.

Aaron Z

 

[Industrial Toys]

I thought I scored earlier this year. A friend gave me a (maybe 20KW) Stamford brushless head, 110/220V. It had a minor issue with the exciter board, but the customer had money and just insisted, change the whole thing. I thought it would make a great genend if I ever got a Listeroid. Trouble is, it only had one bearing, and when I checked with Stamford as to what it would cost to convert it to a two bearing unit, well, forgetaboutit! Now it's just scrap! Crying Shame!

It just goes to show. More and more, you can even get such stuff for free (except for the farting around) and it still isn't worth anything.

 

[strantor]

I thought I scored earlier this year. A friend gave me a (maybe 20KW) Stamford brushless head, 110/220V. It had a minor issue with the exciter board, but the customer had money and just insisted, change the whole thing. I thought it would make a great genend if I ever got a Listeroid. Trouble is, it only had one bearing, and when I checked with Stamford as to what it would cost to convert it to a two bearing unit, well, forgetaboutit! Now it's just scrap! Crying Shame!

It just goes to show. More and more, you can even get such stuff for free (except for the farting around) and it still isn't worth anything.

These are single bearing units as well. I'll have to come up with my own solution for the 2nd bearing. Caterpillar doesn't make any two-bearing solution for it, not even an expensive one. The clutch bellhousings recommended earlier seem like they could help, but the flanges are inverted as they're meant to bolt to an engine, not a generator. And they're prohibitively expensive. I think I might repurpose the bolt-on section of housing which covers the fan, from the 2nd head, bolt it to first head, which will leave the shaft end recessed inside. From there I can fabricate a piece of plate with a hole and the center and bearing bolted in the center, and machine a stub shaft adapter which bolts where the existing flex plate is, and extends through the plate & bearing.