Kubota e-pto?

[crazyal]

I'm not sure what attachments would benefit from such a feature. I often run my snow blower at lower RPMs. The only side effect is it just doesn't throw the snow as far into the woods. I guess if the attachment you were using was undersized for the tractor, say a 4' brush hog on a 60hp tractor you might want to but can anyone think of any type of attachment that's sized right for the tractor where you need to be at 540 but need very little HP?

 

[dixstir]

lot of the grey market small ones have a 2 speed pto mine did and wish my john deere would have the option (2305)

 

[rbargeron]

The L series in the '80s had two-speed ptos. My L345 has 540-1000. The high speed is good for the sickle bar mower and for snow blowing. In the '80s the L3 tractors had 540 and 750 but stopped including the higher speed on U.S. machines in the '90s. They were still supplied for other countries so I converted my L5450 to 2-speed (540 and 750 rpm) by installing the missing parts. Project thread here. It's a handy feature.

 

[Johndeere3720]

The L series in the '80s had two-speed ptos. My L345 has 540-1000. The high speed is good for the sickle bar mower and for snow blowing. In the '80s the L3 tractors had 540 and 750 but stopped including the higher speed on U.S. machines in the '90s. They were still supplied for other countries so I converted my L5450 to 2-speed (540 and 750 rpm) by installing the missing parts. Project thread here. It's a handy feature.

Very interesting thread. My Yanmar has a two speed PTO, 540 and 770 RPM. Guess i will have to try it out and see how the E-PTO works out. :thumbsup:

 

[kennyd]

The biggest problem with running at low rpm is the governor becomes unresponsive so as loads change your voltage will be all over the map.

Ahhhh, Good thinking......that I wouldn't think of....

Not just the voltage suffers, but frequency as well. Both are very very bad for electronics.

 

[rbargeron]

Yes, maintaining proper speed is important with a pto generator. As pointed out above, the e-pto concept is best when the tractor is capable of a lot more power than the job needs.

If a 30 hp tractor is connected to a 15kw generator, the 540 pto speed (engine at 2400) should be used - so the governor is responsive and rpm is stable with changes in load. But the same generator with a 60 hp tractor and 750 pto, the engine can loaf along at around 1700 and the speed will be stable. (my experience)

Running a generator with the e-pto there isn't much difference in fuel consumption - power delivered is power delivered, independent of rpm. At lower engine speed there is less friction, less wear, and less noise, but the fuel saved running the same load is small if anything. If you look at a curve for the typical diesel engine, there isn't much difference in efficiency between 1700 and 2400 rpm.

 

[RobertN]

Interesting thread. My old ~1985 B8200HSTD had a shifter for two range PTO. It also had an installed mid PTO. I got it with ~425 hours; it did not look like the mid-PTO cover had ever been removed. 540rpm was on range setting; I don't remember exactly, but the other speed was around 800rpm. I don't recall that the manual really said what you would run at the higher RPM.

My current NH TC40D has a single speed independant PTO with the option for a mid-PTO.

 

[MessickFarmEqu]

the poster is probably asking about a farm sized tractor, as this is where Deere offers this feature today. Kubota does not have this on the M-series right now. You will find it on several of the New Holland tractors.

I agree with the sediment that this feature is of limited use.

 

[trook]

I think it would be of great use. For example, when brush cutting with my 40 pto hp JD4320, I will routinely keep my rpm's around 1700-1800 unless I am in tall / thick grass and need the power.

The e-pto will certainly save a large amount of fuel if you use a 60-70hp tractor with a 6ft brush cutter in short or thin grass. There is no need to keep the rpm's at 2300 when you have plenty of engine power at 1700. Not to mention that less engine noise would be nice as well...

 

[rbargeron]

......if you use a 60-70hp tractor with a 6ft brush cutter in short or thin grass....you have plenty of engine power at 1700.

That's true - but cutting the thin grass may only take 20 hp - so it doesn't call for much fuel. Keeping the rpm's up doesn't necessarily use proportionally more fuel.

Compare going up a long hill with your car in 4th gear vs 3rd gear. Either may work ok and fuel use will be close to the same. Need to press the gas pedal a little more in 4th, less in 3rd, even less in 2nd.