Author Topic: ENGINE SPEED GOVERNORS  (Read 3660 times)

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #30 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.

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #31 on: May 06, 2019, 03:31:14 PM »

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #32 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.

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #33 on: May 07, 2019, 01:54:27 AM »



Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #34 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.

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #35 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.

Offline crueby

  • Full Member
  • *****
  • Posts: 8788
  • Rochester NY
Re: ENGINE SPEED GOVERNORS
« Reply #36 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?

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #37 on: May 07, 2019, 07:33:11 PM »
Crueby--I've never had  a problem with aluminum for welding fixtures---never.

Offline crueby

  • Full Member
  • *****
  • Posts: 8788
  • Rochester NY
Re: ENGINE SPEED GOVERNORS
« Reply #38 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!

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #39 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

Offline crueby

  • Full Member
  • *****
  • Posts: 8788
  • Rochester NY
Re: ENGINE SPEED GOVERNORS
« Reply #40 on: May 09, 2019, 12:18:54 AM »
Very good! Yes, enjoyed it!

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #41 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.

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #42 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---


Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 5082
  • Barrie, Ontario Canada
Re: ENGINE SPEED GOVERNORS
« Reply #43 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.).

Offline gbritnell

  • Full Member
  • ****
  • Posts: 1946
Re: ENGINE SPEED GOVERNORS
« Reply #44 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
« Last Edit: May 09, 2019, 09:25:26 PM by gbritnell »
Talent unshared is talent wasted.