economy PTO...what is that?

[slowzuki]

It is basically a mid speed on the pto, like some greys have, between 540 and 1000. Still uses a standard 6 spline 540 pto.

 

[yellowsocks93]

Henro,

You are right when you say there is a limiter on the throttle. We have the 540E on our 5320. When you flip the lever forward for economy mode you can only move the throttle lever so far. There is a stop that prevents over reving the motor. We have used it quite a lot when using the smaller implements we have from when we bought our 1991 or 1992 JD 970. The 5320 has a lot more power so that's why we run in 540E mode.

 

[WVBill]

My 1978 Kubota B6100 has a selectable PTO speed - and there's no need to change the PTO shaft.

I have run my rototiller at the 1000 RPM setting on the final pass to "fluff up" the dirt.

I don't see why I couldn't set the PTO selector at 1000 RPM and run the engine at lower than normal PTO RPMs so that the PTO is actually turning at 540. Thus - an economy PTO (?) /forums/images/graemlins/wink.gif

 

[rambler]

</font><font color="blue" class="small">( I don't see why I couldn't set the PTO selector at 1000 RPM and run the engine at lower than normal PTO RPMs so that the PTO is actually turning at 540. Thus - an economy PTO (?) /forums/images/graemlins/wink.gif )</font>

Yes, that would be the same exact thing - only you do not have an interlock on the throttle to prevent over-reving your implement. It appears the E-pto has such an interlock, and would be about the only difference.

It is not wise to over rev your tiller as you mention doing, you are putting a lot of excess stress on the bearings & gears spinning them faster than designed, and hitting a rock can be a shattering experience.

--->Paul

 

[MicroPilot]

Something I saw while reading an article about PTO generators mentioned that generators that were ran on an economy PTO settings didn't perform well. This article attributed this to the fact that when running at half speed your engine is "ahead" of the torque curve, and when it comes under load there is no reserver torque to fall back on and the engine will bog down. When running the engine at rated RPM you are "behind" the torque curve and have some reserve torque to overcome loads on the engine.

I hope I explained this right, as I'm a diesel newbie and have never really paid a lot of attention to torque, HP, etc. in my vehicles.

 

[ZJ_HR]

<font color="green"> This article attributed this to the fact that when running at half speed your engine is "ahead" of the torque curve, and when it comes under load there is no reserver torque to fall back on and the engine will bog down. When running the engine at rated RPM you are "behind" the torque curve and have some reserve torque to overcome loads on the engine. </font>
This is true if you use 1000rpm step like 540PTO. I'll try to explain it.

PTO speed 540E is allways behind max. torque curve, as engine revs achieve 2/3 of nominal engine speed.
This can be a case only when you want to use 1000rpm PTO as 540E, and run engine about half of nominal speed.

Just for example:
My smaller tractor has 540rpm PTO at 1908rpm engine. At nominal speed (2200rpm) it is 623 rpm at PTO. Max engine torque is at 1400rpm.

Bigger tractor has shiftable PTO, so
540rpm @ 2077rpm engine
540E @ 1656rpm engine
1000 @ 2300rpm engine = 540rpm @ 1269rpm engine

Engine nominal speed is 2350rpm, Max torque is at 1400rpm, so if I'll use 1000rpm as 540, engine will cool bad, and run under max torque, on unstabile curve.

Attached picture shows engine torque curve for bigger tractor.

 

[Kaliburz]

As explained, it's a way to get 540 RPM at the PTO w/out the high engine speed.

I rented a JD 5500N a while back and it had this function. I didn't think about it, but I prefered having the engine at a lower engine RPM personlly.


Granted, on my own tractors, I don't run the engine at the PTO recommened RPM. I think it's just too fast for what I'm doing (mowing). I have enought HP and torque that I run my engine about 1500rmps w/ a 540pto, even though the rated engine RPM is about 2300rpms......