Model Engine Maker

Engines => Your Own Design => Topic started by: Brian Rupnow on April 27, 2019, 09:04:07 PM

Title: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 27, 2019, 09:04:07 PM
Lets talk about engine speed governors. I am well acquainted with flyball governors and flywheel mounted governors to control the lockout rod on hit and miss engines. I have built many of them with varying degrees of success. Having just completed my sideshaft horizontal engine, I am interested in putting a governor on it, similar to the governor envisioned by Edgar Westbury who originally designed a governor as an "add on" to the Centaur engine. This governor fits onto an extension of the sideshaft and movement of the governor weights control how much the carburetor throttle-plate is opened or closed, by a linkage between the governor and the throttle on the carburetor. It is a centrifugal governor, controlled by the speed of the engine. Let us assume that I want the engine to run at an idle speed when under no load, but as the load increases, the engine will open it's throttle proportionally to compensate for any load which makes the engine want to stall. In order to do this, the governor weights would have to be at the full extent of their travel, outwards away from the center shaft when the engine is running at idle speed. As load from a driven device caused the engine to slow down, the weights would begin to move closer to the shaft because of spring tension and a lessening of centrifugal force. This in turn would move the lever, causing the throttle to open more and increase the engine speed to offset the slowing caused by the load.----SO--My question is, where would those governor weights lie in relation to the central shaft when the engine was shut off. Would they lie close to the central shaft causing the carburetor throttle to be "wide open", but with very weak springs so that they fly out quickly to their full extent and close the throttle plate to "idle" condition as soon as the engine goes from zero rpm to idling speed? I can't really see it working any other way. Does this mean that when I start the engine I am always going to be starting it with the throttle plate in the "wide open" position, and as soon as it starts the governor closes the throttle to "idle" speed?
(https://imagizer.imageshack.com/img923/9627/oFwSxr.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Rustkolector on April 28, 2019, 04:20:41 AM
Brian,
With a constant speed mechanical governor the governor spring tension is fixed. When the engine is shut off the governor spring wins the tub of war and the throttle gets pulled to wide open. This is the way most all mechanical governors work on generator sets or other constant speed engine applications. The stiff springs are quick acting so overspeed is not a problem. With a variable speed governor you can vary the tension on the governor spring thereby allowing the engine to start and stop at, or near idle speed. The trade off between fixed and variable speed mechanical governors is in speed regulation. Fixed speed mechanical governors will give 3-5% spreed regulation no load to full load. Variable speed mechanical governors will normally do about 10% speed regulation at best, which is generally fine for most variable speed engine applications. With their softer springs using levers for mechanical advantage against the fly weights they are more complicated when reasonably good regulation is needed . With a slow speed model engine such as your side shaft a simple fixed speed governor is preferred, however a wide open throttle will definitely aggravate starting without a physical override at starting to close the throttle a bit. 
Jeff
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 28, 2019, 06:18:16 PM
I modelled the governor based on Edgar Westbury's drawing, and it doesn't look that bad.
(https://imagizer.imageshack.com/img921/4761/UitjpD.jpg)
(https://imagizer.imageshack.com/img923/4219/r8Dkhk.jpg)
(https://imagizer.imageshack.com/img924/7941/ve2o1N.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 28, 2019, 09:14:43 PM
(https://imagizer.imageshack.com/img923/7914/8mFw2z.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 29, 2019, 01:23:46 PM
My original idea was to build this governor and add it to the sideshaft horizontal engine. The sideshaft engine runs so well as it currently sets that I have decide not to change anything on it. I may however build the governor as a "stand alone" unit and drive it with a coupling on the end of the horizontal sideshaft camshaft.
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 29, 2019, 03:15:22 PM
Just as I thought, this governor lends itself very well to being a stand alone unit. This is something that could be attached to the end of my engine baseplate and coupled to the end of my camshaft. Having it's own ball bearing in the support brackets would take all the loading away from my engine cam bushings.
(https://imagizer.imageshack.com/img923/7827/xVcb1n.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 29, 2019, 03:30:34 PM
(https://imagizer.imageshack.com/img921/606/XlLPH3.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 29, 2019, 08:51:57 PM
Knowing my limitations as a machinist, I decided to make the flyweights from two pieces.
(https://imagizer.imageshack.com/img923/274/8xIo5s.jpg)
(https://imagizer.imageshack.com/img921/9802/baHLX2.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 29, 2019, 09:48:41 PM
(https://imagizer.imageshack.com/img923/3324/ZHhSyO.jpg)
(https://imagizer.imageshack.com/img924/5056/FywWzR.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 30, 2019, 12:24:33 AM
A very pucker-worthy job so far. I started out earlier today with a crusty old chunk of 3" diameter shaft. So far--So good.
(https://imagizer.imageshack.com/img924/4721/YRcGFz.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 30, 2019, 03:28:06 PM
Somebody said they were confused because they didn't see any springs on the flyweights. Here they are. I just want you to know that springs are one of those things that I find absolute S.O.B. to model. I can do it, but it takes me a long time, and since I only do it about every three years, I never remember quite how to do it.
(https://imagizer.imageshack.com/img924/4211/GvmHEE.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 30, 2019, 05:39:05 PM
We got PARTS!!! These two flyweights came out very nice. Not really the weight of a fly though. More like maybe a full size rat. I have to go rake leaves for a while now before wife shoots me. Might get a start on the parts which bolt to these later today. There is a heavy rain warning for Barrie and surrounding area for tomorrow, so tomorrow will definitely be a work in the shop day.
(https://imagizer.imageshack.com/img923/1466/DK0Xoj.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 30, 2019, 06:13:27 PM
Jeez, what an old pussy I am!!! Raked leaves for half an hour and I have a blister the size of a dime at the base of my thumb. Rake handle wound. First layer of skin is gone. Second layer is red as  an apple. Work related injury. Guess what my son. I have your weekend all planed out for you!!!
Title: Re: ENGINE SPEED GOVERNORS
Post by: crueby on April 30, 2019, 06:20:33 PM
Jeez, what an old pussy I am!!! Raked leaves for half an hour and I have a blister the size of a dime at the base of my thumb. Rake handle wound. First layer of skin is gone. Second layer is red as  an apple. Work related injury. Guess what my son. I have your weekend all planed out for you!!!
Rake? Rake? Considering how many IC engines you have made, I am surprised you have not made a leaf blower!   :stickpoke:
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on April 30, 2019, 11:49:04 PM
Today I made the second part of the flyweights. They don't look like a lot, but it's taken a good share of my day.
(https://imagizer.imageshack.com/img921/6746/acIgvq.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 01, 2019, 06:33:25 PM
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.
(https://imagizer.imageshack.com/img921/8054/b7WKgs.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: crueby on May 01, 2019, 06:59:46 PM
Very interesting mechanism, following along closely...   :popcorn:
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 01, 2019, 10:53:22 PM
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!!!
(https://imagizer.imageshack.com/img921/6869/Mu3HnL.jpg)
(https://imagizer.imageshack.com/img923/1631/rfOJ5G.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 02, 2019, 11:46:51 PM
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.
(https://imagizer.imageshack.com/img924/3268/kLvNx4.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: crueby on May 03, 2019, 12:58:01 AM
Is that bearing bronze? I find it machines very easily. Phospher bronze is nasty.
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 03, 2019, 01:09:49 AM
Chris--I don't know what kind of bronze it is. Nasty stuff to machine though.
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 03, 2019, 11:18:32 PM
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.
Title: Re: ENGINE SPEED GOVERNORS
Post by: crueby on May 03, 2019, 11:26:51 PM
Hmmmm... I had assumed (with no knowledge of governors or how they work) that the weights would push the spool in both directions - is the reason that it has the seperate spring and lever to return them that it allows you to over-ride the weights when desired?
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 03, 2019, 11:42:40 PM
(https://imagizer.imageshack.com/img923/770/CqoU5u.jpg)
(https://imagizer.imageshack.com/img921/1014/vvVzMV.jpg)
(https://imagizer.imageshack.com/img924/3125/zkieQt.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 03, 2019, 11:46:18 PM
Crueby--Yes, if the flyweights were tied to the spool so that they drove it in both directions, then the only way you would have of changing the "default settings" is to keep trying different spring strengths until you got it right. Being able to change the setting of the counter-spring tension accomplishes the same end result without changing springs.
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 03, 2019, 11:49:16 PM
(https://imagizer.imageshack.com/img923/1491/i8YSp8.jpg)
(https://imagizer.imageshack.com/img924/3046/uIdULv.jpg)
(https://imagizer.imageshack.com/img924/2032/4pHZ4u.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 04, 2019, 06:54:19 PM
Bit by bit the plate brackets are coming together.
(https://imagizer.imageshack.com/img921/2417/CkwGwY.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 05, 2019, 12:29:11 AM
(https://imagizer.imageshack.com/img921/6669/1npuxC.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 05, 2019, 10:35:07 PM
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.
(https://imagizer.imageshack.com/img921/8773/Rdrp9A.jpg)
(https://imagizer.imageshack.com/img924/3043/Grdho5.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Ian S C on May 06, 2019, 02:12:29 PM
The governor is coming along nicely. I sympathize with you and the oak leaves, my street is lined with oak trees, all different varieties that drop their leaves all through the winter, the one at my gate looses most of it's leaves as the new ones come in the spring.
Ian S C
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 06, 2019, 03:09:19 PM
Here's a little tip on threaded spring tensioners like the one in my model. If you make them as a single threaded shank with an eye at one end, they will rotate when you tighten or loosen the adjustment finger wheel. If however, you make them as seen in this model with a double shank and slot the piece they pass thru, then they won't rotate when you are trying to adjust spring tension.
(https://imagizer.imageshack.com/img923/1156/OspUbf.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 06, 2019, 03:31:14 PM
(https://imagizer.imageshack.com/img924/8839/QgJ87n.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 06, 2019, 09:29:25 PM
Edgar Westbury called up #20 swg. for the springs which keep the flyweights together. 20 swg (which I assume to be "standard wire gauge") is listed as being 0.036" wire diameter. The closest I could buy to that is actually 0.038" diameter wire. It feels like it would take seven men and a bulldog to pull the flyweights apart with these springs in place, but we're in "Try it and see" mode here. I'll let you know how that works out. The rather puny looking tension spring on the left is one I had selected out of a 200 piece spring kit that I had, but it looks pretty wimpy beside the .038" springs.
(https://imagizer.imageshack.com/img923/8513/SfSZ26.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 07, 2019, 01:54:27 AM
(https://imagizer.imageshack.com/img923/2218/jrQiCV.jpg)
(https://imagizer.imageshack.com/img923/2262/jFgvlW.jpg)
(https://imagizer.imageshack.com/img921/631/tPohEp.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 07, 2019, 06:55:11 PM
This governor has four arms with hubs on them. I decided that the easiest and most accurate way to make them was to make the arms and hubs as separate pieces and then silver solder them together. These pieces are way too small to hold in the correct relationship for soldering, so I made up a couple of jigs from short pieces of .093 " round-bar, some round 3/16" stock, and  scrap aluminum. The aluminum is counterbored by the amount which the hub runs past the arm it is mated with, and the 3/16" round rod keeps things from tipping and getting crooked while being soldered.
(https://imagizer.imageshack.com/img921/7500/CxjHs7.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 07, 2019, 07:23:46 PM
Well, that didn't turn out too shabby at all!! Everything fits where it's supposed to. I'm coming right down to the short strokes on this governor. I only have a couple of pieces left to machine.
(https://imagizer.imageshack.com/img921/5802/sPOvLA.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: crueby on May 07, 2019, 07:25:08 PM
I've never used aluminum for soldering jigs, figuring the melting point was too low and it would soften up - any problem with that?
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 07, 2019, 07:33:11 PM
Crueby--I've never had  a problem with aluminum for welding fixtures---never.
Title: Re: ENGINE SPEED GOVERNORS
Post by: crueby on May 07, 2019, 09:17:46 PM
Crueby--I've never had  a problem with aluminum for welding fixtures---never.
Excellent - I had never tried since the solder flow temp is so close to ali melting point, but it probably wicks away the heat from the hottest spot quick enough. Ali would be a lot cheaper material for those one-off fixtures - thanks!
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 08, 2019, 08:00:57 PM
And here we have a video of the first dynamic test of the governor mechanism. I am pleased with the results. I still have to make an adjusting screw and knob for the counter-spring, but it seems to work exactly as I hoped it would.---Brian
tsYjVU5YVpw
Title: Re: ENGINE SPEED GOVERNORS
Post by: crueby on May 09, 2019, 12:18:54 AM
Very good! Yes, enjoyed it!
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 09, 2019, 12:20:36 AM
An observation---The governor seems to want to start moving the arm at about 650 rpm. This initial test was made with the counter-spring at it's maximum setting. I am assuming that if the counter-spring was adjusted to not have so much tension on it, the arm would start to move at a lesser rpm. (Hopefully I will find that out tomorrow.) This governor was designed to run off the cam shaft of an engine. The part that I find interesting is that my engines generally idle at about 1000 rpm, and there power band is around 1400 to 1500 rpm. The cam shaft rotates at 1/2 of the crankshaft rpm. --So, it seems that the governor engaging at 650 rpm fits right in with a 1300 rpm crankshaft speed. This could be purely coincidental, or it may be that Westbury actually made this governor, and the spring size he specified for the flyweights is based on actual testing at the time it was designed.
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 09, 2019, 03:32:15 PM
I lay in bed last night thinking of just how this throttle was going to work. If there is anything a bit fishy about this throttle governor, it is the fact that when the engine is shut off, the governor parks itself with the throttle held wide open. I don't like the idea of having to start the engine with the throttle wide open and waiting for the governor to spin up to speed to close the throttle. The answer would be to find a way to disengage the governor when the engine was at rest. Without going thru a complex bunch of maneuvering to install a clutch between the governor and the engine camshaft, I have an idea. If the link between the governor and the throttle arm were made as shown here, I could use a mechanical means to lock the carburetor throttle in the closed (idle) position. The governor would still work as expected, but instead of moving the throttle arm, the spring in the linkage would simply compress and not move the throttle arm. As soon as I unlocked the mechanical throttle over-ride, the governor would once again turn to it's normal function. thinking--thinking---
(https://imagizer.imageshack.com/img924/9757/6lcwDm.jpg)
(https://imagizer.imageshack.com/img923/7436/MU2Mz4.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 09, 2019, 04:51:19 PM
More dynamic testing this morning showed that what I thought is true. The less tension there is on the counter spring, the sooner the lever moves (at less rpm of the spindle.).
Title: Re: ENGINE SPEED GOVERNORS
Post by: gbritnell on May 09, 2019, 04:57:02 PM
Hi Brian,
Actually you are thinking about how the governor works all wrong. You stated you can't wait for the governor to spool up to shut the throttle when in fact the governor should be doing just the opposite.
The throttle control is set for a desired RPM, one the engine is put under load and slows down the governor opens the throttle to maintain the preset RPM.
On an implement with a throttle controlled governor there are 2 controls both connected with springs. The engine starts with the throttle at the idle position. When the speed control lever is moved for a higher RPM it doesn't pull directly on the throttle plate lever but on a spring connected to it. The lever moved by the governor also has a spring which connects back to the throttle lever. It is the interaction between these 2 springs that controls the throttle under load.
Here's a simple explanation. You take your lawnmower out and start it. Your grass isn't too high and you start cutting. The engine is doing a good job at the speed you set but now in one corner of your yard you have a wet spot where the grass is a little higher. The engine starts to bog down so the governor opens the throttle more to provide more power without having to constantly move the handlebar lever for varying conditions.

gbritnell
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 09, 2019, 06:12:14 PM
George--we may be on the same page. The way I see this is that when the flyweights are close to the center spindle, in a static no load position, the throttle is held wide open. As soon as the engine starts, the open throttle spins the engine and governor up to a speed where the flyweights come out under centrifugal force, and force the lever back to whatever rpm you have the governor set for. The engine is driving something that imposes a varying load on the engine. As the load increases and makes the engine slow down, the governor senses this loss of speed and consequently moves the arm to open the throttle a bit more to increase the engine speed back to whatever speed its was at before the load was imposed. So--The natural movement of the governor is to increase the throttle opening as it senses less speed at the engine. When it senses zero movement of the engine, the governor reverts to it's "at rest" position with the throttle held wide open. We have a finger adjusted "knob" which tightens or loosens the counter spring, which works against the flyweight springs on the governor. By increasing or decreasing the tension in the counter spring, we are able to adjust the rpm at which the governor responds.  If we want to start the engine with the throttle in the closed or "idle" position, we have to find a way of removing any effect the governor is exerting on the throttle. My idea is to install a positive "stop" at the throttle so that it can not advance to a higher rpm. The governor now still works the same as ever and tries to initially move the throttle to a wide open position, but it can't, because of the positive stop I have on the throttle plate. So---All that happens is that the spring in the linkage between the governor and the throttle is compressed but there is no resultant movement at the throttle end of the linkage. When I want the governor to work, I remove the positive stop and everything reverts to "governed rpm".
Title: Re: ENGINE SPEED GOVERNORS
Post by: gbritnell on May 09, 2019, 09:01:01 PM
Hi Brian,
On a governor for a small engine the engine starts with a closed throttle. Otherwise it won't start. The throttle lever on the handlebar is in the idle position and the throttle plate is closed, or almost closed. Idle setting) The engine is started and the throttle lever is moved to the operating speed. The cable doesn't open the throttle but pulls on a spring hooked to the governor lever. The governor lever has a rod that goes to the throttle plate. There can't be any solid mechanical connection between the throttle lever and the throttle plate otherwise the governor couldn't control it.
So when the engine starts and is throttled up it pulls on the spring hooked to the governor lever. The governor lever also has a load or return spring, whatever you choose to call it. This spring controls the rate of movement of the governor weights and therefore the governor shaft. Once the engine is started the handlebar lever is moved to increase the engine speed. This movement pulls on a cable which pulls on a spring which pulls on the governor lever thus overriding the control of the governor and speeding the engine up. At this point the linkage spring and the governor spring are basically in balance for the desired engine speed. As the engine is put under load and slows down. the governor starts to close down because of the reduced speed allowing the tension of the cable spring to override the governor and speed the engine up.
You can start a lawnmower engine and set the throttle. Now you can reach down to the lever hooked to the governor shaft and pull on it which will increase the engine speed but you will feel the resistance increase from the governor trying to control the engine.
gbritnell

Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 09, 2019, 09:53:32 PM
Okay George--I will have to think on this. Thank you for your help and guidance.---Brian
Title: Re: ENGINE SPEED GOVERNORS
Post by: gbritnell on May 09, 2019, 11:08:30 PM
Hi Brian,
Here's quick sketch of the typical governor linkage.
When the engine is at idle the cable link hasn't loaded the spring between it and the governor link. The throttle plate is closed. Engine can be started.
When the engine starts at slow speed the governor is keeping the throttle closed.
When the throttle lever is opened it moves the cable link and therefore pulls on the spring hooked to the governor link. This opens the throttle plate, increasing the engine speed.
If the engine were to go too fast the governor would override the spring and close down the throttle to a speed controlled by the tension of the spring and the centrifugal force of the governor weights.
As the engine slows down the governor link moves to the right being pulled by the spring and increases the engine speed.
You can't just have the throttle plate hooked to the governor, well you can but you have no way of increasing the speed because as the governor spins it wants to keep the throttle closed. You need another adjustment (spring) to load the governor arm.
Most newer mowers have no manual throttle control. You start them and they run to a preset speed. When the engine needs more power (slows down) the govenor opens the throttle more to maintain a set RPM. The governor never slows them down past the pre adjusted running speed.
gbritnell
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 09, 2019, 11:15:21 PM
This is going to get very interesting. I ordered a 3/8" Lovejoy coupling today, and I will use it to connect the camshaft of the horizontal sideshaft engine I just finished to the governor, all on a common base. The engine will eventually drive something with a varying load to see how the governor responds.
(https://imagizer.imageshack.com/img921/8972/mui5oZ.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 09, 2019, 11:26:45 PM
This is the sketch George Britnell sent me re. governors. Thank you George.
(https://imagizer.imageshack.com/img923/6093/RQuNkU.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Ian S C on May 10, 2019, 03:22:21 AM
A problem was found with early mill engines that if the drive belt to the governor broke the engine went to full throttle, sometimes with devistating effect, burst flywheel that sort of thing, so a mod was made , a jocky wheel ran on the belt, and when the belt broke the jocky wheel closed the throttle. This was steam, but the same with IC engines.
Ian S C
Title: Re: ENGINE SPEED GOVERNORS
Post by: gbritnell on May 10, 2019, 11:58:33 AM
Actually the jockey wheel was part of the steam governor. The governor valve was loaded with a coil spring and ratchet mechanism. When the belt broke the arm that the jockey wheel rode on would fall with gravity and trip the ratchet mechanism causing the governor valve to close. The governors on gas engines are mechanically driven so they don't have the weak link (the belt) like steam engines.
gbritnell
Title: Re: ENGINE SPEED GOVERNORS
Post by: Ian S C on May 10, 2019, 01:43:35 PM
The governors on 'most' gas engines are mechanically coupled, some such as the NZ built Anderson stationary engine, an enclosed vertical either single or twin cylinder motor has the governor driven from a pulley on the crankshaft, originally by a round leather belt similar to the old treadle sewing machine, although our motor has a bit of rope at the moment. For about 60 years the motor was used by the local council driving a concrete mixer until about 20 years ago when we obtained it in rough but going condition.
Ian S C
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 10, 2019, 05:13:05 PM
(https://imagizer.imageshack.com/img923/1614/fKVoMS.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: gbritnell on May 10, 2019, 05:58:26 PM
This was a model of a Pickering steam engine governor in 2 inch scale that I made. It shows the latch and release mechanism to shut the valve off should the belt break.
gbritnell
Title: Re: ENGINE SPEED GOVERNORS
Post by: john mills on May 11, 2019, 02:07:16 AM
the petrol engines I have ronaldson tippett   and villiers engines all the governors hold the throttle fully open
when the engine is stopped on starting the throttle closes to the set speed if it has unadjustable speed then
it controls the speed to what ever the adjustment is set and can be altered as required.
Title: Re: ENGINE SPEED GOVERNORS
Post by: gbritnell on May 11, 2019, 10:15:04 AM
My mower is also like that but it has a primer bulb to basically flood the carb for starting. I have never been able to start my model engines with the carb wide open. Maybe a finger over the carb while cranking to choke it might help.
gbritnell
Title: Re: ENGINE SPEED GOVERNORS
Post by: Captain Jerry on May 11, 2019, 05:37:03 PM
Governor accidents were occurring well into the 1970's.  Foundries commonly used an air powered grinder to clean up cast iron municipal  castings, manhole covers, etc.  The tool was a 4-6 horsepower air motor directly driving a a 6" abrasive cup wheel.  They were supplied with guards but the guards were seldom used.  The shaft speed was controlled by a governor and the operator usually held the throttle wide open, letting the governor provide full power when he hogged down on a rough casting.  Ingersol-Rand an Chicago Pnuematic were major suppliers.  Under such heavy use, the governor springs were known to fail, with catastrophic results.  The shaft speed could accelerate from 3000RPM to well over the max safe speed of the abrasive wheel before the operator could release the throttle lever and the wheel would explode. A smaller company, Master Air Tools introduced a grinder with a fail safe governor and made a great impact on the industry.  I don't have any details of the  governor design but it saved a lot of legs.


Jerry
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 11, 2019, 10:13:13 PM
Hi Captain Jerry--Glad to see you are back in the saddle again. Haven't heard much from you in quite a few years.---Brian
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 11, 2019, 11:12:33 PM
Just for the heck of it, at the end of my very long install a dishwasher at my oldest son's house day, I thought I would try this set-up. Driving the governor at 1:1 ratio off the crankshaft to see what would happen. What happened was that even at idle speed the governors swung out to their largest travel and no amount of tightening or loosening the counter spring would make them return to the "parked" position in close to the center spindle. Okay--driven at 1:1 off the camshaft they will be turning at half this speed. I'll let you know what happens when driven from the camshaft.
(https://imagizer.imageshack.com/img923/3751/DeeKqp.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Captain Jerry on May 12, 2019, 05:50:04 PM
Hi Brian. I do try to keep up with whats going on and occasionally feel moved to make a comment.  If I understand your current setup, you are trying to adjust the governor response to the speed range of your engine.  If you cannot get the weights to move back in at normal operating speed by adjusting the knob, then you either need to increase the strength of the spring or increase the length of it's lever arm.  Once you have the weights running at about the middle of their range, you can connect the lever to the throttle plate.


For the weights to fly out, they must overcome all spring tension holding them in.  That includes the springs on the weights themselves as well as the spring tension in the control linkage. Slowing the governor shaft speed will help but the governor will be less sensitive to speed changes. 


I have always thought of governors as a means to control power rather than speed.  When the engine slows down as a result of increased load, it needs more power so the governor does its job and provides it. Maybe backwards thinking but it works for me.


Jerry
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 12, 2019, 06:43:26 PM
Today I rearranged things a bit and drove the governor with a 1:1 ratio from the camshaft. Very pleased to report that when driven off the camshaft, the governor will both engage and disengage by changes in the engine speed resulting from changes in the throttle setting. Yesterday I tried this same trial by running the governor off the crankshaft, but  the governor was driven so fast that it would not disengage regardless of what engine speed I was able to achieve.
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Title: Re: ENGINE SPEED GOVERNORS
Post by: Ye-Ole Steam Dude on May 12, 2019, 08:33:48 PM
Hello Brian,

Congratulations, looks good in action :cheers:. That little engine sure does sound good besides looking good.

Have a great day,
Thomas
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 13, 2019, 07:54:04 PM
So there we have it, and its a beautiful thing. The engine is bolted to the sub base. The governor is just setting in the correct position, but not bolted down yet. I will wait until I have the Lovejoy coupling in place between the engine and governor before I drill and tap the holes which mount the governor. I did some more testing of the governor attached to the camshaft via pulleys and belt like shows in my last video, and I'm quite comfortable now that the cam shaft turns at the right speed for engagement and disengagement of the governor with slight variations in engine rpm.
(https://imagizer.imageshack.com/img923/517/Dy1dx6.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 13, 2019, 08:00:23 PM
(https://imagizer.imageshack.com/img921/3119/YUjbJf.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Johnmcc69 on May 13, 2019, 10:55:51 PM
 :ThumbsUp:
 Nice work as usual brian!
Will you be attaching the governor lever to the engine throttle after you get the coupling in to verify the governor works with some sort of load on the engine?

 I imagine you using some sort of engine braking & maybe a hand held tach?

 John
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 13, 2019, 11:13:38 PM
Yes John--There will be  link from the end of that long arm to the carburetor throttle lever. Concept is to set the governor so that with no load on the engine  the engine coasts at a fast idle. When load is imposed on the engine, engine and governor will slow down, to which the governor responds by opening the throttle to give the engine more speed to offset the amount of rpm drop that the load has caused. When rpm is back to desired speed, governor holds it there. When load is removed, governor responds by closing the throttle and returning engine to desired rpm. For now my "imposed load" will probably be my thumb against the flywheel. That may change, depending on results.---Brian
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 15, 2019, 12:15:32 AM
The link that ties the governor arm to the carburetor throttle arm isn't going to be rocket science. Just a turned brass end and a piece of 1/16" diameter bent wire. My Lovejoy coupling won't be here until Thursday, so maybe tomorrow I will make the machined brass part of the link. I won't bend the wire until the governor is bolted down in it's final position, as dictated by the coupling.
(https://imagizer.imageshack.com/img921/741/oWsaU1.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 17, 2019, 06:51:52 PM
We are ready to Rock and Roll!!! My Lovejoy coupling came in this morning and I immediately went down to Canadian Bearings and picked it up. Some of you may wonder why I waited until I had the coupling before I drilled the holes in the sub base to mount the governor to it.--Well, it's a matter of trust. I simply don't trust the solid models that are available from suppliers websites.---and in this case, my distrust was quite justified. The solid model I downloaded from Lovejoy had the center spider at 0.280" thick. In reality, it measures at about 0.400" thick. If I had positioned the governor based on their 3D cad model, all of my drilled and tapped holes would have been out by half a hole. Two years ago, a company I was doing some work for had me design about 15 dies based on the customer supplied 3D cad models. The dies were designed, machined, and sent to the customer. The parts they made from the dies were all way out of spec. What the Hell??? Turns out the customer parts had went thru 3 or 4 revisions and nobody updated the solid models. They fired the guy responsible at their end and the guy I was doing the work for had to eat about $30,000 in rework of all the dies. I have finished the link between the governor and the carburetor to what I hope is the correct length and soldered the ends on. I'm going to go eat a bowl of soup  and give the Loctite holding the pivot pins for the linkage time to set up a bit, and then start things up and see what happens.
(https://imagizer.imageshack.com/img924/7348/qt01m3.jpg)
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 17, 2019, 07:52:37 PM
It works!! I had to take one of the springs off the governor body, because it just wasn't sensitive enough with two springs on. Now I can start the engine and let the governor adjust the rpm the engine runs at in a no load situation. When I push hard on one flywheel with my thumb to load up the engine, you can see and feel the governor reacting to the load by opening the throttle to give the engine more gas to keep the rpm that the governor wants.  I will now try and make a video of this so you can see the action happening.
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 17, 2019, 08:22:53 PM
This is the video which shows the governor working to maintain a constant rpm at the engine, whether it is in a "no load" situation or a "loaded" situation. I am pleased, it does work quite well. I may, in future, hook the engine up to some machine I build, but for now my thumb works pretty good as a "loading device".---Brian
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Title: Re: ENGINE SPEED GOVERNORS
Post by: crueby on May 17, 2019, 08:30:51 PM
Excellent!!
Title: Re: ENGINE SPEED GOVERNORS
Post by: Admiral_dk on May 17, 2019, 09:15:31 PM
You must be happy with that result Brian  :ThumbsUp:
Title: Re: ENGINE SPEED GOVERNORS
Post by: gbritnell on May 17, 2019, 09:16:23 PM
Nice job Brian.
gbritnell
Title: Re: ENGINE SPEED GOVERNORS
Post by: Art K on May 18, 2019, 12:39:14 AM
Brian,
It definitely works, great job.
Art
Title: Re: ENGINE SPEED GOVERNORS
Post by: Brian Rupnow on May 18, 2019, 03:17:00 PM
Thank you gentlemen, for your kind comments. I am very pleased with the outcome of this project.---Brian