ENGINE SPEED GOVERNORS

[werowance]

the more I look at it the more I realize its almost exactly like the governor on my farmall super A tractor. the throttle has a spring on it so that when I pull the handle say half way the governor can override the half way on the carborator and pull it futher on say 3/4 of the way to compensate for load change. on yours the solid link would not give you that ability but since you don't have a throttle handle anyway on your engine then it wouldn't matter. and on that note of being like my Farmall, its a bugger to adjust correctly after tear down so it doesn't constantly surge under idle...

 

[werowance]

just to share a farmall governor pic for comparison

 

[Brian Rupnow]

At this stage, the governor works. I had it up on the mill chuck, and it does indeed open and close as planned with rpm changes. I was going to make a video, but there isn't anything to really see yet. When I get to the stage of levers moving I will post a video. Something which isn't shown in the 3d model yet is the external counter spring. It has adjustable tension, and is used to fine tune the rpm at which the governor kicks in or kicks out.

 

[Brian Rupnow]

This shows the governor counter-spring which adjusts the governor to engage at different rpm's. The governor is shown as "not engaged" in this model. When the governor begins to spin and "engage" the long blue lever moves to the left at the top end, and a link from it goes to the throttle lever on the carburetor. By turning the knurled adjuster wheel and putting more tension on the red counter-spring, we can control when the governor engages.---I think!!!

 

[stragenmitsuko]

Nice , governors have always been a bit of a "dark area" to me .
They work , or they don't work ,on lawnmowers that is , but that's about all I know about them .
I'll be following along , and beautifull work as usual brian .

 

[canadianhorsepower]

[QUOTE=" it's a bugger to adjust correctly after tear down so it doesn't constantly surge under idle...[/QUOTE]
surging at idle has nothing to do with your governor, it's a carburetor issue. Governor only work at high RPM. matter of fact
your governor is always trying to keep your motor at idle

 

[werowance]

i dont want to take over Brians thread but if you bump the throttle or goose it let it drop back to idle it will keep bouncing until it settles down. the governor keeps goosing it. there is an adjustment on the side of the governor for the farmall - there is a baseline setting for it however you still have to fine tune it and its just a hair of a turn one way or another to get it spot on and then you can goose the throttle or bounce it and it will rev up and drop back down and maybe the governor will only bounce once. but then under load the governor does it thing properly. that fine tune adjustment is what I had a time with when I rebuilt my tractor and put in all new ball bearings and springs and such in the governor. but it works great when adjusted properly. however when its to loose or to tight it will set there and bounce back and fourth rev rev rev rev rev for a long time before it settles down.

 

[Brian Rupnow]

I believe that when a governor does that, it is said to be "Dithering".

 

[canadianhorsepower]

[QUOTE=" "Dithering".[/QUOTE]

Dithering is a term use in hydraulic and pneumatic circuit,
it is cause by al almost equilibrium in pressure

 

[werowance]

Thanks Canadian for the PM that's good info to have. Brian, I really like this build. it could easily be adapted to many different engines. and the adjustment you modeled explains how you will be able to overcome the dithering or surging or what the heck is called I call it a pita lol.

 

[Brian Rupnow]

I didn't do a lot today because I was running all over town with good wife doing things that had nothing to do with machining. But--While we were out running around town, I bought a $20 stick of bronze. Did I ever tell you how much I really HATE machining bronze?-Nasty grabby damned stuff. Made the sliding sleeve and three thrust washers this afternoon.

 

[Brian Rupnow]

No machining today, had too many other things going on. As I sat playing with the governor as built last evening, I came to a sudden realization. When I move the flyweights out away from the center shaft, as they would do from centrifugal force, the fingers contact the end of the sliding spool and make it travel in a linear movement along the center shaft. However, when I move the flyweights back close to the center shaft, there is nothing to make the sliding spool move back to it's original position. Now it is a lot clearer to me about why the counter-spring is attached to a separate lever. The counter-spring pulls the lever back, which causes the shaft to revolve and that movement also moves the two other arms which are connected to the governor thrust collar. The thrust collar which is trapped in one end of the sliding spool forces the sliding spool back until it is once more in contact with the arms on the flyweights. This is going to be very interesting to see in operation.

 

[Brian Rupnow]

 

[Brian Rupnow]

 

[Brian Rupnow]

Bit by bit the plate brackets are coming together.

 

[Brian Rupnow]

 

[werowance]

is that a filing machine in the back ground?

 

[Brian Rupnow]

Werowance--That is an oscillating spindle sanding machine. I just bought it about 4 months ago for smoothing inside corners on things I machine. The spindle comes with five different size drums and rotates and goes up and down while it is rotating.

 

[Brian Rupnow]

Another day--another part. With the help of two young grandsons we finished up the leaves today. Thirty one bags of oak leaves down to the road for the township to pick up. The grandsons age four and seven really thought it was cool riding around in the empty cart behind my lawn tractor. The baseplate which I finished this afternoon looks a bit different than the baseplate in the model. That is because I was trying to make as much as I could from "reclaimed" 3/4" material, and I didn't have a piece big enough to make it the same as the model. That's okay though.--I will make the missing piece of the baseplate a "bolt on" part.

 

[nel2lar]

Brian
That is a thing of beauty. One fine job on design and build.
Nelson