Generator with Techy engine

[Racinbob 10,322]

I'm not sure what the right category this should go in but I figured this was the closest.

 

I have a 5kw generator with a cranky HM100 Techy engine. I'm going to modify the generator to run off the PTO on my tractor. The problem I'm having is getting the generator removed from the engine. I basically have it down to just the rotor connected to the crankshaft that's still in the engine. It's in place with a tapered crankshaft and a long bolt through the center of the rotor. It's not wanting to come free. All I can think of is to partially thread the long bolt on and rap it with a hammer. There's just no way to get a puller on it. I thought about removing the crankshaft from the engine but that can't be done without getting the rotor off since I can't get to the connecting rod to disconnect it. With the diverse and excellent mechanical skills of the folks here I thought somebody might have an idea that I'm not seeing. Right now I have it sitting with the rotor shaft pointing up and filled with PB Blaster. In a day or two I'll try again and if it still doesn't budge I'll remove the engine side cover bolts so I can suspend the generator end cover and let the engine weight help out. If it pops free then it will be with the engine side cover still attached to the generator end cover.

Edited June 23, 2014 by Racinbob

[oldredrider 2,547]

The crankshaft is tapered and the end bolt holds the generator on much like the flywheel on a Kohler engine.

Although I have never done it, I was told a good rap will set it free (with the end bolt out).

I assume your generator is something like a Coleman Powermate. It won't have bearings to handle a side load drive like a Wheel Horse generator. You may need to incorporate a pillow block bearing in your set up.

[Kai Thomsen 17]

It's probably not the same type of generator..and i'm certainly not the best to explain things in English

But maybe you can do something similiar to what i did when the 10HP Briggs broke a rod on my generator.

Mine also has a tapered crank and a long bolt thru the armature / rotor.  
I found a bolt a little big bigger than the hole in the end of the rotor ( where the long bolt goes )  and cut new threads in the end of the rotor and put a long piece of steel rod thru the rotor. The steel rod will then fit between the end of the crankshaft and the new bigger bolt that i cut the threads for.   Tighten the big bolt and it broke loose.

Sorry for my English spelling..it is the best i can do.

 

[Racinbob 10,322]

The crankshaft is tapered and the end bolt holds the generator on much like the flywheel on a Kohler engine.

Although I have never done it, I was told a good rap will set it free (with the end bolt out).

I assume your generator is something like a Coleman Powermate. It won't have bearings to handle a side load drive like a Wheel Horse generator. You may need to incorporate a pillow block bearing in your set up.

It actually is a Powermate. I figured I'd need a bearing on what's now the engine side. I just need to get it apart to see what I can do. A pillow block bearing likely will be in order. As you said, it is like a flywheel but the only way I can give it a good rap is with the end bolt partially screwed then whack the head of the bolt. Maybe after a night of soaking it will let go. I'll also have to deal with what I can use for a new shaft. I'm think just maybe I can sacrifice the crankshaft by cutting it off and having a keyway milled into it. Don't know yet since I can't see what I'll have to work with

[oldredrider 2,547]

I put an aftermarket carb (about $32) on mine and saved a $1000 worth of headaches.

Just sayin'.....

[Anglo Traction 759]

look's like you'll have much more luck than me with a Genny. I thought I could save and repair one to fit on one of my tractors, but had no through-bolt like you have or Bearing support at the engine end. Also had doubts of a tapered Crank connection, rather a threaded end. had to leave it and put it back as a Genset .... a few pics of it-  

 

 

refurbed Engine-

 

 

Defeated and back as a Genset-

 

 

Hope you have a good outcome.
 

 

 

[Racinbob 10,322]

It's probably not the same type of generator..and i'm certainly not the best to explain things in English

But maybe you can do something similiar to what i did when the 10HP Briggs broke a rod on my generator.

Mine also has a tapered crank and a long bolt thru the armature / rotor.  

I found a bolt a little big bigger than the hole in the end of the rotor ( where the long bolt goes )  and cut new threads in the end of the rotor and put a long piece of steel rod thru the rotor. The steel rod will then fit between the end of the crankshaft and the new bigger bolt that i cut the threads for.   Tighten the big bolt and it broke loose.

Sorry for my English spelling..it is the best i can do.

 

You did just fine Kai. Just don't ask me to try to explain something in your native language   That sounds like a great plan and I'll do it if it doesn't cooperate. I really don't think it's seized up bad because it's not all that old. Thank you.

[Racinbob 10,322]

I put an aftermarket carb (about $32) on mine and saved a $1000 worth of headaches.

Just sayin'.....

Unfortunately, something internal to the engine went bye-bye. I can't even take a look at the internals without getting the rotor off.

[Racinbob 10,322]

Anglo, I don't have a bearing support on the engine side either. I think I can deal with that issue. In reality, I might just totally fail but it's really just something I wanted to mess with. I can't do much painting on my Suburban rebuild due to the heat and humidity right now so I attacked this. If I do fail I'm going to get a PTO belt driven generator and just deal with the mounting bracket.

 

Your genset rebuild looks great! Nice job.

Edited June 23, 2014 by Racinbob

[woodchuckfarmer 333]

Tap the end of the armature for a bolt. Put a long rod into the armature that will bottom out in the crank shaft. Screw the bolt in the armature pushing on the rod. This should separate them. You will have to get a shaft made with the taper of the crank on it, drilled and taped for the draw bolt to hold them together . And a flange bearing the right size will support the armature

[WH nut 553]

I did the same thing. If you have an air chisel, put a Blunt bit in it and rap on the crank end of the gen and it will fall right off. Then remove the crank from the motor and cut the crank as close to the counter weight as you can. I had a machine shop tun the noto end of the crank to accept a 1in pulley and bearing.

[Racinbob 10,322]

So far I'm still trying the PB Blaster and smacking the end of the partially installed bolt. I'm back on the Suburban project so it can just soak for a while. Threading the end will be the next step if continues being stubborn. WH nut, that's what I was thinking too. Until I can actually see it I don't know if the crankshaft will have enough shaft on it before the counter weight but I would think so. Along with dealing with a bearing I'll have to consider what I need to do to hold the rotor in place. Some sort of backer on the shaft on the inside of the new bearing.

[WH nut 553]

Here is what it looks like with just the pulley installed

[shorts 182]

Pretty much all of the small gensets are single bearing units that use the machined pad and bolt pattern on the pto end of the engine to center the field assembly and the tapered crank and main bearing to center and support the stator. you are on the right track by loosening the center bolt on the stator and then hitting it with a hammer, loosen the bolt just enough to be loose, about 1/2 turn clearance and then hit the bolt head with a 2 or 3 pound hammer a good lick while holding the stator, it takes a pretty good hit as you are in effect driving the crank and engine out of the stator and breaking the taper fit at the same time.

 

You may be money ahead to buy a 2 bearing generator head that is already setup with a drive end plate and bearing assembly and stator shaft machined with a keyway for a drive flange or pulley.

[Racinbob 10,322]

You're right shorts. I figured it utilized the engine bearing on that end. I did finally get the rotor to break free (the stator is the stationary windings around the rotor) and there's not much to work with. I was hoping that I would have enough of the crankshaft to allow it to be milled into a shaft for the generator. No such luck but I just had to see. I'm probably going to reassemble the generator head and sell it to someone who has an engine. There's also several excellent parts on the Techy so I'll part it out. I could kick myself. I had a 5kw Wheel Horse branded generator when we lived up north. It went with all the other stuff when we moved here.

Edited June 30, 2014 by Racinbob

[shorts 182]

Bob, the bolt pattern on the block is usually to some standard size and might be a good fit to another engine that you could disassemble and have the end of the crank machined to fit the rotor to get you into a standby power unit, I'm thinking maybe a Honda clone from harbor freight

[WH nut 553]

Another option if your crank is too short to machine, Build a mounting plate for the gen, cut old shaft and mount a love joy coupling to gen Shaft. Have a short shaft made that will take a pulley and the mating love joy coupling. I did this with another old generator but I ran it off an old straight shaft motor.  You are going to mount this to a steel plate anyway, weld an upright to the plate with a hole in it for the shaft and a flange bearing. The drive side shaft use a Pillow block bearing

[Racinbob 10,322]

Some good ideas here. Thanks. I found a 1 3/8" 4 bolt flange bearing that will mount to the current end plate. I'm still not 100% certain if I'll have enough shaft but I don't think so. That bearing is 1.748" high. I could have some milling done to the cut off crankshaft or a new shaft made but I'm thinking the cost would be such that I might as well just buy a pto generator and go from there. That way I can get a 7.5 kw which would actually suit my needs better. The jury is still out.

[WH nut 553]

A 7.5kw gen will take lots of ponys. What are you wanting to run it on

[Racinbob 10,322]

I'll be turning it with a 15hp. I've got the crankshaft removed. The pillow bearing I found is too tall. I'll do a search for a shorter one.

[shorts 182]

The hp to kw conversion is 1.56 hp per kw.  A 15 hp engine will turn a 10 kw generator and give you about 9.5 kw of useable power

[Racinbob 10,322]

That's correct. Actually with everything factored in a 10kw requires a minimum of 13.4hp. I installed a separate panel through a manual transfer switch and picked up the circuits I wanted to 'maintain' the house during an extended power outage. Having sold my Wheel Horse generator when we moved here I didn't have one in 2004 when the hurricanes made a mess of things. I wanted a 7.5 but waited until it was too late and generators couldn't be had. I felt lucky when I just happened to show up at a Walmart when they were unloading these 5kw units so I latched on to one. As I expected, it was a little small for what I intended but it got us through two separate week long outages. If I get this generator set up to operate off the PTO, great. If not, a 7.5 will do a fine job, even in this total electric house by using common sense.

 

Now, back to the project. I know very little about using a mill. If I can get the crankshaft cut tight to the counterweight I may be in business. Can it be cut that tight on a mill?

[WH nut 553]

• "Can it be cut that tight on a mill?"

 

I used a hacksaw

[Racinbob 10,322]

I was wondering about hacksawing it. Before I start cutting up a perfectly good crankshaft I want to find out what some milling would run. I'd like to get it turned down to 3/4". The four hole flange bearing in that size would be a better fit.

[WH nut 553]

I had a buddy turn mine down so it only cost a beer