tractor pto torque

[pairofhounds]

Working on a brush cutter project and need to decide on a hydraulic motor. I need a motor that will provide comparable torque to the pto of a 80-150 hp tractor at 540 rpm. Can anyone come up with a torque range in inch lbs or ft lbs?

 

[ishiboo]

Working on a brush cutter project and need to decide on a hydraulic motor. I need a motor that will provide comparable torque to the pto of a 80-150 hp tractor at 540 rpm. Can anyone come up with a torque range in inch lbs or ft lbs?

That is QUITE the hydraulic motor. Your scale is also pretty insane, you are only sure within 70hp?

80hp @ 540rpm = 778 ft-lb.

150hp @ 540rpm = 1458 ft-lb

 

[candoarms]

pairofhounds,

Any hydraulic motor requiring that much torque output is going to require one **** of a lot of fluid passing through it. You're looking at a motor that will require somewhere in the neighborhood of 70 gallons per minute.

Here's one that just might suit your needs.

29.3 cu in CHARLYNN 10000 SERIES MOTOR 119-1033

Surplus Center Part Number 9-7075-1033

Hope this helps.

Joel

 

[candoarms]

To convert inch pounds of torque to foot pounds, multiply your inch pounds by .0833. In this case, the motor above puts out 13,000 inch pounds of torque, continuously. That equates to about 1087 lb. ft. of torque. Please note that you'll get 540 rpm out of this motor with about 65 gallons per minute from your pump.

Joel

 

[pairofhounds]

Thanks for responding. Still a bit confused. .what makes the following motors "pto/ag" if they are not comparable to the torque an average pto provides?

 

[candoarms]

pairofhounds,

In many cases you'll find that the tractor is simply way bigger and more powerful than the implement in question needs for power. A good example of this would be a PTO operated grain auger. It's possible to power a grain auger using a 230 horsepower tractor, but 40 horses will do the trick.

Here we have hydraulic motors that can be powered by much smaller engines yet produce about the same RPM as as a tractor's PTO output shaft. Now you can power that piece of agriculture equipment with something more reasonable, and far more fuel efficient.

Hope that helps.

Joel

 

[pairofhounds]

Surplus Center

Forgot to copy link

 

[SPYDERLK]

Thanks for responding. Still a bit confused. .what makes the following motors "pto/ag" if they are not comparable to the torque an average pto provides?

... As candoarms said. -- Also, think where you would get the ~100 hyd HP you would need to run the motor. Hydraulics are much less efficient than a geared PTO; 80% vs above 90. The flow you need will be very high. Way above normal tractor hyd output so youll probably have to drive an auxiliary pump from your pto. Now youre at ~ 0.8 X 0.9 = 72% efficiency. You can incorporate lots of neat stuf into hydraulics, but you have to live with the losses. Lots of heat.

Chances are you will have many applications that are fine with 40HP or less. MUCH more manageable.
larry

 

[90cummins]

To convert inch pounds of torque to foot pounds, multiply your inch pounds by .0833. In this case, the motor above puts out 13,000 inch pounds of torque, continuously. That equates to about 1087 lb. ft. of torque. Please note that you'll get 540 rpm out of this motor with about 65 gallons per minute from your pump.

Joel

To convert inch pounds (in/lbs) to foot pounds (ft/lbs) you divide by 12.
150hp @ 540 rpm = 1458.8 ft/lbs or 17,506 in/lbs.
As mentioned above that is a huge hydraulic pump, motor and hydraulic reservoir and you need a means to cool it.
90cummins

 

[pairofhounds]

I may be getting close figuring it out. How about this gearbox with this motor? My excavator has around 20 gpm and 3300 psi. Need speed for grasses and torque for brush. have 4' deck. I can also get a heavier stump jumper and blades to give some inertia and weight for heavy brush. Here is what I'm after but want to use a deck mounted gearbox coupled to a hydraulic motor.

Mini X Bushmaster - MX401-48SL

What are your thoughts?

6.20 cu in CHAR-LYNN 106-1009 HYDRAULIC MOTOR

1:1.93 80 HP ROTARY CUTTER GEARBOX

 

[pairofhounds]

Just want it as heavy duty as possible. .thanks all!

 

[SPYDERLK]

I may be getting close figuring it out. How about this gearbox with this motor? My excavator has around 20 gpm and 3300 psi. Need speed for grasses and torque for brush. have 4' deck. I can also get a heavier stump jumper and blades to give some inertia and weight for heavy brush. Here is what I'm after but want to use a deck mounted gearbox coupled to a hydraulic motor.

Mini X Bushmaster - MX401-48SL

What are your thoughts?

6.20 cu in CHAR-LYNN 106-1009 HYDRAULIC MOTOR

1:1.93 80 HP ROTARY CUTTER GEARBOX

What rpm is the MiniX supposed to run. Is yours complete with direct hyd drive or just the deck? The gearbox will cause power loss over direct hydraulic drive.

 

[pairofhounds]

Not sure excavator rpm. starting from scratch with deck only. At 20 gpm and 3000 psi and around 700 rpm it seems the motor should handle torque and speed necessary to handle thick brush. Coupled with a 1:1.93 gearbox the blade fps should be good too. I know the torque will be reduced by using a gearbox.am I thinking correctly?

 

[pairofhounds]

Sorry I wasn't thinking correctly. I know torque will be reduced but will it be enough not to bog?

 

[SPYDERLK]

Not sure excavator rpm. starting from scratch with deck only. At 20 gpm and 3000 psi and around 700 rpm it seems the motor should handle torque and speed necessary to handle thick brush. Coupled with a 1:1.93 gearbox the blade fps should be good too. I know the torque will be reduced by using a gearbox.am I thinking correctly?

The question first would be What speed is the rotor designed to operate at. Then run it at that speed range with the biggest motor you can drive with 20GPM. 20 GPM @ 3000psi should give you about 30HP. Yes it will bog if you crowd it too much, but it will certainly perform respectably.
larry

 

[pairofhounds]

Some of the Bush hog brand mowers that claim to handle 4" material with 5' diameter bla design are in the 14000 to 16000 fps range. That's kinda what I'm after as long as I can produce comparable torque. At high speed I would think torque becomes less important but still necessary. .

 

[SPYDERLK]

If you are basing this cutter on a MiniX 48" chassis and parts you need to know what blade speed those specific components were made to support. Going much above that design value is a big risk. I dont think you will find many 48" cutters running at 15000 feet per minute. Maybe 12 or 13000.