does anyone make a gearbox to increase pto speed for generator?

[top gnome]

The guy I buy my beef from has a pto generator and mentioned to me that he needs to find a way to increase the pto speed as he has to run close to wot on his 45 hp tractor to get the correct frequency. I thought I would ask on this knowledgeable site to see if any one knows of a gearbox to increase the pto speed

thank you

 

[tinkerwitheverything]

Just did a search on google and there is many different companies on the net . You have a wide variety to choose from.

 

[GreensvilleJay]

hmm 'pto generator'..... how many KW is it ? Make/model ? Most tractors can run '540 ' and 70-80% WOT

 

[top gnome]

hmm 'pto generator'..... how many KW is it ? Make/model ? Most tractors can run '540 ' and 70-80% WOT

I think it was 12kw I am having trouble finding a speed increaser in canada. I don't know much about it but he said he has to run to a point where he gets the correct frequency which I assume means 540 rpm. I think because his tractor is oversized 45hp. If he could find a speed increaser he could run at a lower engine rpm and stlll get the needed 540 rpm at the generator. He mentioned The unit would work on a 20hp tractor. I think the fuel cost is pretty high for the amount of power he is getting.

 

[William1]

Many speed reducers can be installed 'backwards' to function as speed increasers.

Gensets frequency is a function of genset rotor rpm, typically either 1800 or 3600 rpm.

Rough example/mindset: If you use a RPM speed increaser, say 2X, you will more or less have to have 2X the HP available at the desired input RPM. So if your genset needs 12 HP for full output, you have a 30 PTO Hp tractor and at the PTO desired RPM on the dyno chart, it makes 20 HP, it will not work as your require 24 HP at the PTO. You need to do some math first.

 

[mendonsy]

I did a quick search for "PTO speed increaser" and found about a dozen companies that list them.

 

[top gnome]

I did a quick search for "PTO speed increaser" and found about a dozen companies that list them.

thank you any in Canada?

 

[top gnome]

Many speed reducers can be installed 'backwards' to function as speed increasers.

Gensets frequency is a function of genset rotor rpm, typically either 1800 or 3600 rpm.

Rough example/mindset: If you use a RPM speed increaser, say 2X, you will more or less have to have 2X the HP available at the desired input RPM. So if your genset needs 12 HP for full output, you have a 30 PTO Hp tractor and at the PTO desired RPM on the dyno chart, it makes 20 HP, it will not work as your require 24 HP at the PTO. You need to do some math first.

thank you I will pass that on to the owner I think he has a 45 hp tractor so now he is wasting fuel as he has too much power and has to run at a higher rpm to get the correct speed for the pto but I think what he is thinking is he can run at a lower rpm and get a speed increaser to save fuel. I should probably just let it go, It is well beyond my skill set. but he treats his animals well and has a young family and he has been fair in his dealing with me when we buy our side of beef from him so I would like to help him if I can.

 

[PoTreeBoy]

thank you I will pass that on to the owner I think he has a 45 hp tractor so now he is wasting fuel as he has too much power and has to run at a higher rpm to get the correct speed for the pto but I think what he is thinking is he can run at a lower rpm and get a speed increaser to save fuel. I should probably just let it go, It is well beyond my skill set. but he treats his animals well and has a young family and he has been fair in his dealing with me when we buy our side of beef from him so I would like to help him if I can.

Gear boxes tend to be pretty expensive. Some rotary cutter gear boxes have 30% or so increase, so possibly one could be mounted on its side and the fill/vent relocated. Mounting arrangements would have to be changed, obviously.

 

[William1]

thank you I will pass that on to the owner I think he has a 45 hp tractor so now he is wasting fuel as he has too much power and has to run at a higher rpm to get the correct speed for the pto but I think what he is thinking is he can run at a lower rpm and get a speed increaser to save fuel. I should probably just let it go, It is well beyond my skill set. but he treats his animals well and has a young family and he has been fair in his dealing with me when we buy our side of beef from him so I would like to help him if I can.

Wastefull, sort of but not entirely.
There is a difference between no load rpm and load rpm and the amount of throttle needed to maintain it. A laymans example is driving a car on a flat road. Loafing along at 2,200 rpm, foot barely on the pedal. Apply a load (go up a hill) and while the rpm will not change, you will be pressing the pedal further down. Using more fuel because you need more power to deal with the load.
With a genset, the same thing happens. No load fuel draw is very different from 1/2 load Vs full. A perfect system, you have just enough HP to power what you are running and you run at full load. You'll never run a genset at full load, usually 80% or less. You also have to vary the throttle as the load increases or decreases to maintain rpm.

 

[top gnome]

Wastefull, sort of but not entirely.
There is a difference between no load rpm and load rpm and the amount of throttle needed to maintain it. A laymans example is driving a car on a flat road. Loafing along at 2,200 rpm, foot barely on the pedal. Apply a load (go up a hill) and while the rpm will not change, you will be pressing the pedal further down. Using more fuel because you need more power to deal with the load.
With a genset, the same thing happens. No load fuel draw is very different from 1/2 load Vs full. A perfect system, you have just enough HP to power what you are running and you run at full load. You'll never run a genset at full load, usually 80% or less. You also have to vary the throttle as the load increases or decreases to maintain rpm.

Thank you at least I know now that it is not a simple answer or a simple solution. It would not be a choice I would have made as after a hurricane is a busy time for both generator and tractor. thank you all again for the help I am going to let this one go.

 

[GreensvilleJay]

re: after a hurricane is a busy time for both generator and tractor.

I'm thinking unless you have a 2nd tractor, the genny should have it's own, dedicated engine ? That way tractor can be used for cleanup detail and not supplying power ? I know $$$ is an issue, if genny's only needed 2-3 times a year......

 

[Magicman]

The genny is designed to run at 540 so the only logical solution is a lower HP tractor. Logical?? Sure because everyone needs another tractor.

 

[Henro]

Many speed reducers can be installed 'backwards' to function as speed increasers.

Gensets frequency is a function of genset rotor rpm, typically either 1800 or 3600 rpm.

Rough example/mindset: If you use a RPM speed increaser, say 2X, you will more or less have to have 2X the HP available at the desired input RPM. So if your genset needs 12 HP for full output, you have a 30 PTO Hp tractor and at the PTO desired RPM on the dyno chart, it makes 20 HP, it will not work as your require 24 HP at the PTO. You need to do some math first.

Are you sure about this? That would have to be a terribly inefficient speed increaser.

Generally power into a system minus losses equals power out. Your example would indicate a 2X speed increaser would be 50% efficient. I find this doubtful, but you did say “rough example”.

 

[BruceP]

Perhaps your belief that spinning the engine slower would be more efficient is flawed. It is not always true that lower engine RPM is more efficient. The enigne would likely be running below its peak efficiency.

If the genset is DESIGNED for 540RPM and the tractor is DESIGNED to spin the PTO at 540.... I am not sure what the problem is.

Many tractors are engineered to be most efficient at the rated PTO RPM. (engine torque-peak)

 

[GreensvilleJay]

What we don't know is make/model/condition of the '45 HP' tractor. It could be a new tractor with a problem or an old gal on her last legs. Agree with BP that tractors generally are designed to USE the PTO, so 'something' is wrong. I KNOW my tired forklift 4BD153 engine does NOT have the 35HP is had when new.

 

[William1]

Are you sure about this? That would have to be a terribly inefficient speed increaser.

Generally power into a system minus losses equals power out. Your example would indicate a 2X speed increaser would be 50% efficient. I find this doubtful, but you did say “rough example”.

'Rough' was an understatement, my 'push' was to think beyond basics. Like a 40 HP engine making 40 hp no matter the gearing rpm or design parameters. A genset load varying but the engine rpm being able to hold steady irrespective of load (without adjustment).
To see how gearing affects output, you'd have to have a dyno run done at the output intended RPM and see how may HP are available. You'd also have to see relative throttle position at that rpm over the range from no load to max load.
A shame it is never simple. But if it were, a tiny DC motor running on a single D cell would power a ocean liner.....