PTO HP

[tonystep]

Please forgive a newbie tractor owner from asking what you may find to be a stupid question but...I have a TYM T554 hydro-static drive tractor with rated 42hp pto. I plan on purchasing an erskine 73" hydraulic front attach snowblower and associated hydraulic pump/power pack. One dealer I spoke with who has sold and installed several of these said I should get the 20GPM flow power pack even though it is rated for 44 - 53 pto hp. He said unless I was into 6 foot drifts in canada or something it would provide better performance on the 73" blower than the 15GPM power pack which is rated for 30 - 43 pto hp.

I've tried doing some research and believe rated pto hp is at 540 rpm but maximum pto hp is slightly higher by changing engine rpm. This part gets confusing to me because i've read reducing rpm increases hp and i've seen various torque/power curves and am unsure what to think

1) Is it a bad idea to go with the 20GPM power pack whichj is rated at 2 hp more than my pto
2) can someone advise as to rated versus maximum pto hp
3) what happens if you have an implement that is rated at much less hp than the pto? seems like that would not be problem if shear pins work properly

Thanks for all you help

 

[Peter 315]

That's a close match on both I would go with the 20gpm one...

 

[K5lwq]

Tony welcome to TBN! I hope you will stick around as you will find lots of great advice on this forum.

You should be fine with the 20GPM pump depending on the operating pressure of the blower. You can always take smaller bites and slow down some if it becomes too much for your tractor.

 

[oosik]

Welcome to TBN and the forum Tony. Engine hp & pto hp can be misleading. This is because many manufacturers do their own testing. Some will submit their tractor to the "Nebraska tractor testing lab" for analysis.

Under the best of conditions - max pto hp and max torque would be at the same rpm. And this engine rpm would be what it takes to turn the pto at 540 rpm.

I recommend that you go with the 20 gpm power pack. Like K5LWQ says - if it gets tough - take smaller bites and slow down.

 

[Kingston61]

Hey folks - I am going to use this thread because it seems as relevant to my questions as any I have seen (recent posts anyway). I have been using a tractor on a regular basis for about three years now and have a few questions beyond the basics and I am hoping you can offer wisdom. Here goes:
1) 540 RPMs seems to be the standard for majority of PTO driven implements -
a) why is 540 the number?
b) although it is obvious the results if operate below 540 (or other rated RPM) BUT - are there risks/benefits for operating above 540/rated RPM? Example - I have a PTO chipper rated for 540RPM. If I run the tach up above the 540 rate mark am I generating
more RPM at the PTO and am I getting more "power" for the chipper to work harder and do more (quicker) or am I just wasting fuel and possibly putting the implement at risk to damage for exceeding recommended PTO RPM?
2) If I have an implement that is optimum at a higher than 540RPM (don't think I do but I assume there), how do I know what engine RPM to run to achieve the recommended PTO RPM? The tach has a mark for the 540 (on mine it is an arrow head on the tach) but
that is the only one.
a) or is 540 the only PTO speed or at least the standard for all/most implements?
b) if 540 is the industry standard then see #3 below related to 1000RPM PTO
3) In my homework on this I found some converters to make a PTO a 1000RPM PTO (converted from 540) -
a) relevant to question 2 above and for general knowledge - why is there a need for 1000RPM?
b) for curiosity sake - if I hade a 1000RPM PTO adapter, could I run the engine slower so the 1000RPM PTO turned slower to run at 540 (realize not good for hydraulic flow/pressure and cooling but trying to understand the dynamics)
4) any other general device/insight on the topic would be greatly appreciated as I am really collecting the inventory of implements with the most recent being a front attach rotary cutter with its own hydraulic power pack driven by the PTO. BTW, it says DO NOT OPERATE ABOVE 540RPM, which ties into 1), b) above.

Thanks guys - not trying to become a tractor geek but I retired recently so getting 15-20 hours a week in the tractor seat (and loving every minute) and starting to be more curious about these work horses.

 

[ericm979]

Power is torque*rpm. Getting X amount of power at 540 rpm means nearly twice the torque than at 1000 rpm. More torque means a a heavier duty driveline is required. 1000 rpm implements tend to be the higher power ones on large farm tractors.

Some tractors have a two speed PTO. Some CUT markets have or had different speed standards. My Branson has 540 and 750 rpm. In the US where 750 impements are rare it's marketed as an economy pto. Instead of running the engine at 2500 rpm to get 540 you can put it in the 750 gear and run the engine at 1800 rpm to get 540 at the pto.

Implements made to run at 540 generally work best at 540. The engineers designed the gearing of the implement to make the working parts run at optimum rpm when the pto is 540 rpm. They may not be safe at a higher rpm. That said I have run a chipper at higher rpms and it worked better and did not explode. Your results may not be good or may be catastrophic.

 

[TerryR]

1. Why 540? It's buried in early tractor history. There are several articles around on that, which I'm not sure actually agree. Mostly it seemed a good speed for early implements.

2. 1000 rpm is also a standard, used mainly for higher horsepower tractors and implements. As Eric says, it takes less stout hardware to convey the same power at the higher speed. It's not intended for use with implements designed for 540, but some advocate using it but lowering the engine speed proportionately, if you tractor delivers enough power for the implement at lower engine speed, supposedly as an economy move.

 

[K5lwq]

I have run many PTO implements above the 540 mark on the tach. Sometimes tractor at the highest rpm setting. Never had a problem but can not recommend it because as soon as I do, your stuff will come all apart. But I will say sometimes people forget this is equipment and does not have to be babied all the time. Just need to be well maintained.

 

[ptsg]

I have run many PTO implements above the 540 mark on the tach. Sometimes tractor at the highest rpm setting. Never had a problem but can not recommend it because as soon as I do, your stuff will come all apart. But I will say sometimes people forget this is equipment and does not have to be babied all the time. Just need to be well maintained.

Exactly. Implements don't need to run dead on 540. Some are sensitive to that, like a PTO generator, but most not so much.

Most times I run my tiller and mower at 540E. But every once in a while I use the other PTO gear and run those implements at around 470 ish rpms, which puts the engine at around 2100 rpm. I get less noise, less drive-line vibrations in the back and still does the same work as running at 540.

Some implements work better at lower or higher RPM, it's just a matter of trying it out and see what works better. If ran at higher RPMs, just keep an eye on temperature of the implement gearbox.

I ran my tiller at 750 rpm once, just to try it out. Got a bit too hot for my liking and vibrated a bit too much so I just went back to normal. My tiller does have a slight bent on the rotor and couple bent tines.

 

[cruz54982]

for winter use the cooling fan is not needed I purchased my blower from the company that made it and that is what they advised me . on another thought that may be helpfull when parking with the blower attached always leave it tilted slightly forward as the warm unit will melt snow in the blower bottom and freeze so the next time you go out it will not spin.