Looking at pull type snowblowers

[radios1]

In selecting a blower driven off the rear pto, most buyers overlook the end result of pto joint angles. This is why fan diameter is very important as 1/2 the diameter is what you would like to have match the height of your pto shaft so that joint angles, when working, are as close to zero degrees as possible.

This chart shows how quickly pto joint life can be reduced.

20 hours with 25 degrees and 450 hours with 5 degrees.

Dave M7040

that's for a standard PTO shaft, what about wide angle CV joints?. https://www.tractorbynet.com/forums/build-yourself/61915-source-pto-shafts-wide-angle.html

 

[ruffdog]

In selecting a blower driven off the rear pto, most buyers overlook the end result of pto joint angles. This is why fan diameter is very important as 1/2 the diameter is what you would like to have match the height of your pto shaft so that joint angles, when working, are as close to zero degrees as possible.

This chart shows how quickly pto joint life can be reduced.

20 hours with 25 degrees and 450 hours with 5 degrees.

Dave M7040

My old Lorenz manual said a 5deg (1"/ft) will cut life by 40% and a 10deg (2"/ft) will cut life by 70%. It is sure something to be aware of.

 

[Fallon]

that's for a standard PTO shaft, what about wide angle CV joints?. https://www.tractorbynet.com/forums/build-yourself/61915-source-pto-shafts-wide-angle.html

They dont help a lot I expect. They add a lot of length to a PTO shaft & blowers dont have long shafts to start with.

 

[radios1]

They dont help a lot I expect. They add a lot of length to a PTO shaft & blowers dont have long shafts to start with.

if you completely read the link, they are used on front wheel drive cars, and trucks, and last many thousands of miles, at a much higher HP..

 

[Dave M7040]

that's for a standard PTO shaft, what about wide angle CV joints?. https://www.tractorbynet.com/forums/build-yourself/61915-source-pto-shafts-wide-angle.html

Yes you can buy ag pto shafts with CV joints but at greater expense. They are usually used with 1,000 rpm pto's on large tractors which require a high degree of lateral deflection because they are pulling implements attached to the draw-bar and not to lower arms of the 3 pt.. Not that it makes much difference but with an implement fastened to the 3 pt hitch there is minimal lateral movement and any deflection vertically comes from initial setup and then raising implement. Also the Ag CV pto's are much longer than one needed for a snow blower.

The big factor in any joint, Cardan or CV is the transmission of torque not horse power. What can be deduced from this is that the front axle drives on cars using CV joints are working at much higher speeds than 540 rpm hence their ability to transfer much higher horse power levels across the joint.

My only reason for my initial post was to suggest to buyers of blowers to not be totally focused upon fan diameter.

Dave M7040

 

[leonz]

Rzeppa Univeral joints are very expensive and require a huge amount of greasing at every shift to fill the cage full of grease and they come in five pieces/plates that have a spring cage in them that has to be assembled onlyone way and they would require a carrier bearing to support the short PTO shaft stub with the female end.

 

[Fallon]

if you completely read the link, they are used on front wheel drive cars, and trucks, and last many thousands of miles, at a much higher HP..

I never said they couldn't transmit the power. I said they took up a lot of space. If you have a short shaft at moderate angles then make it even shorter due to longer joints the angles they run at will get a lot sharper. And as others have already pointed out, the sharper the angles you run them at the exponentially shorter their lifespan.

 

[airbiscuit]

Interesting conversation, but has any TBN member wore out a PTO universal joint? They don't cost all that much to replace.

 

[radios1]

Interesting conversation, but has any TBN member wore out a PTO universal joint? They don't cost all that much to replace.

it had to have happened, but, you'd not want to be out in the freezing cold, with a blizzard going on, removing a PTO shaft, and looking for a place that is open at that time, so you can do your snow plowing!..

 

[airbiscuit]

I grew up on a farm, and I only remember changing one on a baler. On sharp turns, you could hear the knuckles knock. Yet, only changed one PTO joint on all our equipment. Not sure this is a very big problem.