universal joint question

[Cord]

I'm working on a drive line to power a snowblower. I just realized that I'm facing some severe drive shaft angles. The angles are definetly beyond the capacity of a single U joint. I've seen some double U joints used but have little experience with them. Can I have a double U joint at BOTH ends of a driveshaft? All the applications that I can think of only have the double U joint at one end and then a single cross at the other.

 

[Egon]

If you are building it yourself can you use the CV joint from a vehicle.

Egon /forums/images/graemlins/grin.gif

 

[beenthere]

Maybe some belt or chain transfer to get the offset you need.

What angle are you trying to get to transfer the drive power?

 

[slowrev]

You might need a carrier bearing in the middle with a double joint on both ends. Not sure, I have never done that though. But it seems that the middle might have too much wobble.

Ben

 

[Cord]

Yes, I'm toying with the idea of using a automotive CV joint. The problem is trying to adapt one to a ag drive line. Most of these CV joints have funky ends specific to the vehicle.

The chain would be the perfect solution, but the attachment swings in an arc so the pulleys would never be aligned. Otherwise it would be the perfect solution. I'm going to ballpark some angles tonight.

My research shows that you would need a center bearing if you used a double universal joint. There is a "Carden" constant velocity joint that is capable of locating the knuckle so the shaft doesn't need to be supported. I'm still trying to get some pricing on the unit, but they sound pretty expensive. Several hundred for each assembly and I need two of them.

Somehow I may need to adapt those auto CV joints...

 

[Taylortractornut]

Cord Ive adapted a few cv joints to pto shfting before its not too hard, theres several ways most of the time adpters can be found at ag shops. If you want a heavyduty one get one off an old Eldorado Ive got a few on hay bailers and pull type combines Ive fixed for neighbors.

 

[Egon]

</font><font color="blue" class="small">( funky ends specific to the vehicle )</font>

Might have to do some welding to the proper ends.

Egon /forums/images/graemlins/grin.gif

 

[beenthere]

</font><font color="blue" class="small">( The chain would be the perfect solution, but the attachment swings in an arc so the pulleys would never be aligned. )</font>

The 'arc' you speak of is the raising and lowering of the snowblower? There isn't a need to also angle the blower is there?
Seems a telescoping drive shaft is what is needed with simple u-joints on each end. But I don't know exactly what limitations you are faced with, I admit. /forums/images/graemlins/tongue.gif

 

[BGL990]

Here's an idea, just for the sake of brainstorming.

How about a hydraulic drive system. A pump on the PTO and motor on the snowblower. The hoses in between are about the most flexible driveline you are likely to ever get. /forums/images/graemlins/tongue.gif

I don't know what the availability of surplus hydraulics is like in your area, but if you can find a source, you might be able to find a suitable pump and motor as cheap or cheaper than those fancy driveshafts you mentioned. You'd need to choose pump and motor displacements appropriately to get the blower going the right speed, and of course choose parts rated for the power you'll be transferring through them.

Good luck whatever method you use ...
/forums/images/graemlins/cool.gif

 

[Cord]

Well, I measured the angles tonight. 20 degrees on both ends. That's well beyond the capability of a regular U-joint.

Hydraulics would be the perfect solution. Unfortinatly they are horribly inefficent. The best pumps are 80% efficent. The best motors are 80% efficent. That's a bunch of hp lost and I don't have any to spare. Great suggestion though!