Different PTO types??

[jwk]

Reading through these posts, I can't get a grip on how the different types of PTOs work, ie. live, or 2-stage clutch, or other types. Can someone explain the different types and why one is better than another? /forums/images/graemlins/confused.gif

I've decided on HST for my future tractor--does that make a difference in PTO operation? I've seen threads that seem to say that HST effects how the PTO operates.

 

[johndeere2210]

jwk, I will give this a shot. A two stage clutch is usually associated with a gear drive transmission. When the pto is engaged and the clutch depressed half way, the pto will still operate while you change transmission gears. When the clutch is depressed all the way, the pto and motion of the tractor are both disengaged. With live pto, when the pto is engaged, it turns all the time reguardless of the motion of the tractor. With HST the pto is considered live and is usually engaged electrically. Hope this helps. /forums/images/graemlins/smile.gif Forgot to mention that with HST the pto does not have a direct connection to the movement of the tractor. /forums/images/graemlins/smile.gif

 

[ronjhall]

Here is a link to Tractorsmarts page on educating yourself about different tractor features. It includes information on PTO's.

 

[Soundguy]

</font><font color="blue" class="small">( With live pto, when the pto is engaged, it turns all the time reguardless of the motion of the tractor )</font>

That's better described as independent pto. Since a 2 stage clutch gives you live pto. Independednt pto is also 'live'... ( but live is not necescarilly indepentent... )

Soundguy

 

[Panache]

And some MFs (that is Masey, not the other one) could be engaged to go either live or transmission driven. My mid 70's 230 did.

 

[rambler]

</font><font color="blue" class="small">( And some MFs (that is Masey, not the other one) could be engaged to go either live or transmission driven. My mid 70's 230 did. )</font>

That is known as 'ground speed' tranny.


So, there is the old 'non-live' or standard or transmission pto where, any time you push in the clutch pedal, both the tranny & pto are disengaged from power. This makes baling, snow blowing, and other jobs where you want to stop moving but keep the pto spinning a real pain. Also if you have a big bush hog on it, when you push in the clutch, the implement will continue to rotate the rear wheels like a big flywheel - dangerous. You need a an Over Running Coupler to make this safe - add-on device like a big socket wrench on the tractor pto.

Ground Speed pto is often in addition to one of the other forms of pto - it will match the pto speed to the gear you are in, spin slow in first, fast in high. Only useful for a few pto hay rakes & some powered 2wheel trailers.

Live pto or 2-stage pto lets you shift the tractor in & out of gear or go to nuetral while the pto continues to recieve power. Push the clutch all the way down and then the pto also stops getting power. This is good, most will be fine with this system. The below 2 systems are also considered 'live' tho they do not use the foot clutch at all:

Independent pto uses a totally seperate clutch & lever to engage or disengae the pto at any time - does not matter at all what you are doing with the tranny clutch - in, out, shifting, whatever.

Hydraulicly operated Independent pto uses a lever to change some hyd ports that activate or deactivate the clutch for the pto and have a pto brake to stop it from spinning when not on. This was supposed to be the best, but it is my least favorite type of 'live' pto. Most of them are like a light switch, either full on or full off with no in-between slipping of the clutch. With a heavy load like a big brush hog, that is just too darned hard on the implement, pto shaft, and tractor.

The tranny/ non-live/ standard pto gets it's power from the clutch output shaft, so when pto is on & tranny is in a gear, the rear axle & the pto are locked together. It operates fine in nutral, just that the pto and the tranny share the one clutch. Trying to shift either one affects both.

2-stage or live pto has an inner & outer clutch plate, stepping the pedal down 1/2 releases the tranny clutch but keeps the pto clutch engaged. Stepping the clutch pedal all the way down also releaces the pto clutch. There is one input shaft into the tranny, but 2 output shafts - one for the tranny and one for the pto.

Independent pto totally avoids the foot clutch, and gets it's power from it's own independent clutch setup on a contantly spinning shaft. Totally different & independant of the tranny clutch & shafts.

--->Paul