Diesel Power Generator Question

[Kubotafan]

I have a 3 cylinder 16 hp Kubota diesel engine that I could use to power a generator. What else would I need, and where would I go looking for what I need? Looking for help and ideas for this possible project.

 

[Kyle_in_Tex]

find a burned out Kubota GL 11000 generator and put your engine in it.

 

[KubotainNH]

Maybe find a used unit with a bad motor and attach it somehow? Or a PTO unit. You would have to match the speed properly so you get 60 Hz out of the unit. Gas units run quite a bit higher in RPM's but I think the diesel could run half the speed (1800 rpm?) and get the same frequency. What would be cool is attaching it to an inverter style unit with throttle control, I think those run DC into the inverter.

 

[Groo]

they sell generator powerheads. if you want to directly couple it, make sure it is rated for the same speed as you will want to run the engine.

 

[buickanddeere]

eBay has all kinds of ST type alternator heads.

 

[FredH]

First find a generator , be it a power head or a PTO . From there you decide if direct couple via shaft or possibly belt drive .

Belt drive requires specific sizes in pulleys and belts to get proper speed . Two links along that route include these :

Pulley Calculator. RPM, Belt Length, Speed, Animated Diagrams

Single Groove Pulley & Sheaves for Electric Motors

Looking at power heads and PTO types , with that size engine , some were between 7500 and 9000 watts ???

Fred H.

 

[Dave M7040]

Purpose built generators support one end of the generator rotor on the end of the engine crankshaft which is tapered on a generator engine. An engine for other uses except water pumps do not use a tapered shaft. The governors on generator engines are designed for fixed speed operation to achieve the proper 60 cycle ac power. An engine which was used on something where the speed could be varied will have a different governor. I am presently turning a Honda generator engine into a pressure washer after the rotor failed and I am finding I could buy a factory designed pressure washer for less than the conversion will cost me. I had to deal with the fact that the engine housing was different for a generator engine but managed to find one from a Honda utility engine which fit. Unless funds are no object and you have a love of technical challenges I would find another use for the engine.
Dave M7040

 

[Kubotafan]

Purpose built generators support one end of the generator rotor on the end of the engine crankshaft which is tapered on a generator engine. An engine for other uses except water pumps do not use a tapered shaft. The governors on generator engines are designed for fixed speed operation to achieve the proper 60 cycle ac power. An engine which was used on something where the speed could be varied will have a different governor. I am presently turning a Honda generator engine into a pressure washer after the rotor failed and I am finding I could buy a factory designed pressure washer for less than the conversion will cost me. I had to deal with the fact that the engine housing was different for a generator engine but managed to find one from a Honda utility engine which fit. Unless funds are no object and you have a love of technical challenges I would find another use for the engine.
Dave M7040

This is the kind of information I need. Thanks to all who have replied.

 

[BHD]

small generators some times used what is called the generator taper, under 20 HP usually.
(the shaft of the generator is hollow, and a bolt or draw bar, is used to tighten the alternator to the engine via the taper).


many larger units use a flex plate attached to the flywheel of the engine, if the engine has a SAE bell housing most likely one can get a one bearing generator to bolt directly to it, some what like a automatic transmission hooks up to a engine,

but if one wants to use a flex coupling one could use a two bearing generator.

not really sure how the pictures will line up but the taper, the flex plate, the flex drive, and the belt drive, these would be your basic choice types, the flex coupling could be a few different types,

 

[franklin2]

I bought a old Honda 4.5kw generator that had a blown engine. It was one of those really old units that used a belt between the engine and the generator.

I have a f2000 kubota mower with a 72" deck. I wanted to use that to power the generator. A long time ago the Surplus Center had mower deck driveshafts and one of them plugged right into my pto. I took the blown engine off, used two pillow block bearings and a shaft with brackets and mounted all that in place of the blown engine with a new belt.

Then came the calculations for rpm. First off, my engine is 20hp. This generator would not need all that horsepower, and I didn't want it screaming at high rpms constantly wasting fuel while running the generator. With the 72" deck still on it, I played with the rpms to see where the best spot was were the engine seemed to have power and the governor could kick in when it needed. I found I could run the engine at about 1600rpm, and it still seemed to react ok to a load.

I then measured the pto speed, and in high, the pto speed was exactly the same as the engine speed. The specs on the honda generator called for 3200 rpm for 60hz full output operation. So I knew I needed to double the speed of the shaft I installed.

I measured the pulley diameter at the generator, and it was 5 inches, so I knew I needed a 10 inch pulley for the drive. I called some local places and they wanted right much money for the proper pulley, and by the time I paid shipping from the Surplus Center, it would have been close to the same price. So I went to tractor supply, they have those universal pulleys where you weld in the hub. All they had was a 12 inch, so being cheap I bought it.

Theoretically the 12 inch is too big,, but in reality it works ok. I still run it at around 1600 rpm, and when a load is put on it, the tractor slows to about 1450-1500rpm. It seems to work fine, I have used it already during one power outage. And with the 5+ gallon tank, it should run a long time like this without needing re-fueling.

 

[BHD]

the Rpm of a generator head is

3600 RPM @ 60 cycle for a two pole,
1800 RPM @ 60 cycle for a 4 pole,
1200 RPM @ 60 cycles for a 6 pole generator

 

[franklin2]

the Rpm of a generator head is

3600 RPM @ 60 cycle for a two pole,
1800 RPM @ 60 cycle for a 4 pole,
1200 RPM @ 60 cycles for a 6 pole generator

3200rpm is what came out of the owners manual. That must have been the engine rpm, and they had a certain size pulley on the engine to make it work out, since what you are saying makes sense. I don't have the original pulley that came with the Honda engine. Somehow it all worked out with what I have.

 

[buickanddeere]

The generator's head rpm has to stay at 3600, 1800, 1200 or what ever is required to make 60HZ.
The engine and generator slowing down is not acceptable.
There is not enough savings in fuel or wear to make it worth belting rpms to operate the engine at half rpms.
1800rpm is minimum rpm to operate that engine . Lower rpms and making the engine work will over heat an air cooled engine. It was engineered to operate with that cooling fan up to rates rpm.

 

[buickanddeere]

10KW or 12.5KW would be a good match with 16HP. I don't like operating small generators at or near max nameplate capacity. Manufactures are often optimistic on their equipments capacity. Or the capacity is a peak or intermittent rating.

 

[Kubotafan]

I have herd that a regular generator makes "dirty power" with more variance in power and an inverter generator "clean power" with less variance. If a regular generator is used and only operating at 2/3 or 3/4 of its capacity does this make less variance in the power generated?

 

[franklin2]

The generator's head rpm has to stay at 3600, 1800, 1200 or what ever is required to make 60HZ.
The engine and generator slowing down is not acceptable.
There is not enough savings in fuel or wear to make it worth belting rpms to operate the engine at half rpms.
1800rpm is minimum rpm to operate that engine . Lower rpms and making the engine work will over heat an air cooled engine. It was engineered to operate with that cooling fan up to rates rpm.

In my case, I am using a 20hp diesel engine to run a generator that used to have a gas engine rated around 10hp. It seems very happy to run at 1500rpm running that little 4.5kw generator. It has a hz meter on it but it's broken. It would be nice if I could fab up a control panel that had a nice voltmeter and some other type of setup to measure the frequency. I already have plans to give the generator a permanent home beside my garage with a little roof over it to keep the weather out. When the power goes out, I can take the mower off the tractor and drive up to the side of the garage and hook up the pto and let it run.

 

[bigdeano]

Harbor freight has a 7200 watt 3600 rpm generator head on sale for $300. Get some cast iron pulleys from surplus center, build a frame and you're almost done.

I built a generator with an Isuzu diesel car engine and a 10kw gen head. It's worked very well. I had to machine a shaft to mount a pulley to the flywheel. It's some work to make, but it was worth it.

 

[Groo]

I bought a old Honda 4.5kw generator that had a blown engine. It was one of those really old units that used a belt between the engine and the generator.

I have a f2000 kubota mower with a 72" deck. I wanted to use that to power the generator. A long time ago the Surplus Center had mower deck driveshafts and one of them plugged right into my pto. I took the blown engine off, used two pillow block bearings and a shaft with brackets and mounted all that in place of the blown engine with a new belt.

Then came the calculations for rpm. First off, my engine is 20hp. This generator would not need all that horsepower, and I didn't want it screaming at high rpms constantly wasting fuel while running the generator. With the 72" deck still on it, I played with the rpms to see where the best spot was were the engine seemed to have power and the governor could kick in when it needed. I found I could run the engine at about 1600rpm, and it still seemed to react ok to a load.

I then measured the pto speed, and in high, the pto speed was exactly the same as the engine speed. The specs on the honda generator called for 3200 rpm for 60hz full output operation. So I knew I needed to double the speed of the shaft I installed.

I measured the pulley diameter at the generator, and it was 5 inches, so I knew I needed a 10 inch pulley for the drive. I called some local places and they wanted right much money for the proper pulley, and by the time I paid shipping from the Surplus Center, it would have been close to the same price. So I went to tractor supply, they have those universal pulleys where you weld in the hub. All they had was a 12 inch, so being cheap I bought it.

Theoretically the 12 inch is too big,, but in reality it works ok. I still run it at around 1600 rpm, and when a load is put on it, the tractor slows to about 1450-1500rpm. It seems to work fine, I have used it already during one power outage. And with the 5+ gallon tank, it should run a long time like this without needing re-fueling.

some electronics are real sensitive to "bad" power. Dad's cordless tool charger wont run on his generator, but motors are fine.