How does a governor/unloader work?

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  #1  
Old 03-17-12, 02:10 AM
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Talking How does a governor/unloader work?

My electric Air Compressor Motor died.

I'm thinking of using a small B&S to run the compressor.
I'm told this "governor/unloader" vave is the thing that senses the Tank is full, and backs off the B&S throttle to Idle till we use up the air in the tank.

I wonder how that thing works.
 
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Old 03-17-12, 04:38 AM
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You need two pieces for a gas engine governor to work.
The unloader is an air operated pilot valve that connects to an air receiver tank in place of an electric pressure switch.
When the air pressure on the valve reaches the cut-out point it opens the air flow to a fitting on the valve.
You then connect this fitting to a small throttle control which is a small air driven piston.
This piston connects to the gas engine's throttle to increase the engine speed when air is needed and slow it to idle when the air tank is full.
The pilot valve also has a bleed line to discharge the small amount of air the compressor delivers when at idle.

Like this:

Click image:


Image courtesy of amazon.com

It is certainly doable but it is a lot of work.
I put together a two cylinder air compressor using a 5 hp B&S engine and it took quite a bit of time to mount the throttle control and make it work.
You have to disable the governor on the engine but leaving the mechanism that moves the throttle intact.
You then need to mount the piston in the correct spot so that it pulls on the throttle in the right direction.

Good project if done right but would be much simpler to replace the motor.
 
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Old 03-17-12, 07:19 AM
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Talking

Thanks for the EX. It does seem like a lot of tedium.
I guess I'm back to locating the company in China that can help me wire the original Electric motor up.

http://i55.photobucket.com/albums/g1...ngOHMsjpeg.png

Maybe sombody can tell me from my "Ohm" readings?
 
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Old 03-17-12, 03:43 PM
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The image that your link points to is just a small thumbnail and is too small to read.
The image you upload to photo bucket needs to be a readable size.
There is a button above the reply box where you can paste your link and have it appear in your post.

Also, you have asked a question in the electrical forum but the links you provided there didn't work.
I deleted that thread and we can try to answer your questions here.
 
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Old 03-17-12, 04:15 PM
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Greg your a good guy, no matter what all those Girls say about you!

I'll see if I can make that photo better. When I created that Drawing I'm sure it was a 640/480 for std Internet moving. I'll squirm harder....
I'm having a real bad day with stuff that should fix easy, but without an Air Compressor a lot of chores become labor intensive struggles.



Here's what I think. I'm kinda skeert of trying it though.

I think the black is the Switched/fused Hot.
I think the White and Green 1 get tied as the Neutral.

That should get the Start windings going though the Cap. Then when the Cap is charged, the Nuetral is the return from the Run windings.
This thing has no brushes. I dont really know how it works.
 

Last edited by hoary; 03-17-12 at 06:14 PM.
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