PTO shaft adapter

[petegoud]

I'm looking for an adapter to extend a pto drive that is used on a bush hog with a 1 3/8" round shaft. What I'm trying to do is use the same PTO drive for a PTO generator which requires a 1 3/8" six spline hookup. Since the generator may only be used for a few hours each year I thought I could get away with using one PTO shaft instead of buying a drive for each item. Does anyone know if something like this exists? Thanks in advance. Doug

 

[kennyd]

They do exist, but how far do you need to extend it?

HERE is a link to a recent post that covered this topic pretty well.

 

[petegoud]

Thanks for rapid reply Kenny. I just need to extend it far enough to make the transition from 1 3/8" round to 1 3/8" six spline. Doug

 

[kennyd]

Sorry, I mis-read your post...I was thinking an extender-not an adapter

TSC or AgriSupply are both good sources for them...but most new attachments come with a new shaft so you would not need to buy a new shaft anyway.
I guess I am assuming that you already have the rotary cutter and are looking at buying the generator?

 

[Farmerford]

Doug:

If you don't really need any additional length, but only need to attach the 1 3/8 round driven yoke to a 1 3/8 six spline input shaft on the generator, you may not need an adapter.

I have had success (over 200 hours of operation) just slipping the round yoke over the splined shaft and holding them together with a bolt through the shear pin hole in the yoke and the hole in the splined shaft. Something like a generator will have little shock load and the pin is not likely to shear.

The only risk to this approach is that if the pin does shear there is nothing holding the smooth yoke on to the splined shaft. I assume your bush hog prevented this problem with either a clip in a groove on the end of the round shaft or a bolt that screws through the side of the yoke and extends into a groove in the round shaft.

I drilled and tapped the end of the splined shaft for a 1/4" - 20 bolt which, with a 1"OD washer keeps the yoke from slipping off if the pin shears. That seems like a lot of effort to avoid buying a $30 adapter, but in my case there were reasons why an adapter would not work.

 

[Farmerford]

Kennyd:

Some of the places I shop seem to treat the driveshaft like options on cars. If I recall, the 15KW generator cost $1,800 (several years ago) and the barely 30" driveshaft cost $250. I hate to pay $250 for a $75 part as much as the next guy, but more out of spite than cost I decided to deprive all the driveshaft sellers of my coin by making do with a spare driveshaft I already had. I put the generator on a TPH platform with a stick welder, air compressor, etc. and had to install the generator so close to the front that there was not room enough to put an adapter/extender on the generator shaft. Thus all the extra effort to make the round yoke work directly on the splined generator shaft.

 

[petegoud]

Farmerford, thanks for that idea. As soon as the new generator arrives I'll try running it that way. Going through my parts pile I did find another shaft that may work, the only problem is that it's for my tiller and has a slip clutch. I'll have to see if there's a minumin torque that the generator would require so it doesn't start slipping under a load. Doug.