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Fan Clutch Idea [message #175015] Fri, 29 June 2012 11:08 Go to next message
A Hamilto is currently offline  A Hamilto   United States
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I started thinking about electric fans and how to get around some of the disadvantages, when it struck me that one of my ideas didn't require an electric motor. All you need is a clutch like the one on the AC compressor to engage the fan. It would be controlled by a theremal switch just like the electric fans on newer cars. It would then be free-wheeling when not engaged (like the current clutch) and would engage when the ENGINE TEMPERATURE demanded it, NOT when the thermal goo in the existing one sensed the temperature from the radiator, or blowback from the exhaust manifold makes it think it is time to engage. Seems like an improvement over the OEM method.
I imagined a hollowed out AC compressor with the shaft being driven off the WP and the fan being a replacement of the pulley. When the clutch engages, the shaft turns what would have been the pulley on an AC compressor, but in this implementation, it is a fan. Instead of the pulley turning the shaft when engaged, the shaft turns the fan when engaged.
Maybe someone out there smarter than me can come up with a simpler way to install an AC compressor clutch on the radiator fan than that.

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Re: [GMCnet] Fan Clutch Idea [message #175018 is a reply to message #175015] Fri, 29 June 2012 11:22 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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Many small agricultural tractors use an electromagnetic clutch to engage
power take off accessories like mowers, tillers etc. They handle 20
horspower or so for years with no protest. They are 12 volt as well. They
bolt onto a flat surface with four cap screws, are grounded through one of
the screws, and have one wire to a 12 volt source. The more sturdy ones
draw 4 or 5 amps or so. If you think on this one a little, it shouldn't be
too much of a stretch to come up with brackets, fan etc.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Fri, Jun 29, 2012 at 9:08 AM, A. <markbb1@netzero.com> wrote:

>
>
> I started thinking about electric fans and how to get around some of the
> disadvantages, when it struck me that one of my ideas didn't require an
> electric motor. All you need is a clutch like the one on the AC compressor
> to engage the fan. It would be controlled by a theremal switch just like
> the electric fans on newer cars. It would then be free-wheeling when not
> engaged (like the current clutch) and would engage when the ENGINE
> TEMPERATURE demanded it, NOT when the thermal goo in the existing one
> sensed the temperature from the radiator, or blowback from the exhaust
> manifold makes it think it is time to engage. Seems like an improvement
> over the OEM method.
> I imagined a hollowed out AC compressor with the shaft being driven off
> the WP and the fan being a replacement of the pulley. When the clutch
> engages, the shaft turns what would have been the pulley on an AC
> compressor, but in this implementation, it is a fan. Instead of the pulley
> turning the shaft when engaged, the shaft turns the fan when engaged.
> Maybe someone out there smarter than me can come up with a simpler way to
> install an AC compressor clutch on the radiator fan than that.
> --
> '73 23' CanyonLands
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
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Re: Fan Clutch Idea [message #175021 is a reply to message #175015] Fri, 29 June 2012 11:37 Go to previous messageGo to next message
Michael Leipold is currently offline  Michael Leipold   United States
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Location: Greensboro NC
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Senior Member
We offer an a cooling fan on our trucks that are driven electronically by the engine. Still has fluid in it, but the engine controls whether or not the clutch is engaged.

So, there may already be one available, and just need mounting modifications.

Edit: yes they exist, just did a google search

1973 GMC 26' Glacier - Unknown Mileage - Has a new switch pitch transmission with Powerdrive Smile

[Updated on: Fri, 29 June 2012 11:39]

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Re: [GMCnet] Fan Clutch Idea [message #175022 is a reply to message #175018] Fri, 29 June 2012 11:39 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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James Hupy wrote on Fri, 29 June 2012 11:22

Many small agricultural tractors use an electromagnetic clutch to engage power take off accessories like mowers, tillers etc. They handle 20 horspower or so for years with no protest. They are 12 volt as well. They bolt onto a flat surface with four cap screws, are grounded through one of the screws, and have one wire to a 12 volt source. The more sturdy ones draw 4 or 5 amps or so. If you think on this one a little, it shouldn't be too much of a stretch to come up with brackets, fan etc.
Jim Hupy
Salem, OR
78 GMC Royale 403
What's the HP draw on an A6 compressor? How does the current draw on the tractor EM clutch compare with an AC compressor clutch? If this mod requires upgrading the 80A alternator to 100A and adding the 2-belt pulley to it, then it is growing out of bounds.

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Re: Fan Clutch Idea [message #175029 is a reply to message #175015] Fri, 29 June 2012 11:51 Go to previous messageGo to next message
John Heslinga   Canada
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Registered: February 2011
Location: Edmonton, Alberta, Canada
Karma: 4
Senior Member


Cool Project Idea:

Manufacturers have put in Electro viscus and electromagnetic fan clutches in for years on heavy trucks and diesel engines. some of them were even geared for two or three speeds. Some new vehicles and some high end imports use them as well. The Control Computers will turn them on and off

There are many kinds of models available ( However they are very expensive) You would be looking for one that would be an easy modification to fit

some 2002 to 2006 V8 GM trucks had them as one example.

Here are a couple of pictures.

http://www.gmcmhphotos.com/photos/discussion-photos/p44588-electric-fan-clutch.html

John and Cathie Heslinga 1974 Canyonlands 260 455, Manny tranny and 1 ton, 3:70 LS, Red Seal Journeyman, DTE, BEd. MEd. Edmonton, Alberta

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Re: [GMCnet] Fan Clutch Idea [message #175032 is a reply to message #175029] Fri, 29 June 2012 12:01 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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Mark, I think the A6 compressor in full tilt boogie mode uses about 12-15
horsepower. Much less than the fan would. The agricultural EM clutches use
less amp draw than the A6, but total load on the GMC alternator is not
limited to just fan and AC loads, and each GMC probably has a different
total load depending upon onboard equipment. Add up the loads, stay under
70% of the Alternator's rated output, and it should work.
Jim Hupy
Salem, OR
78 GMC Royale 403

On Fri, Jun 29, 2012 at 9:51 AM, John Heslinga <rbeeper@hotmail.com> wrote:

>
>
>
>
> Cool Project Idea:
>
> Manufacturers have put in Electro viscus and electromagnetic fan clutches
> in for years on heavy trucks and diesel engines. some of them were even
> geared for two or three speeds. Some new vehicles and some high end imports
> use them as well. The Control Computers will turn them on and off
>
> There are many kinds of models available ( However they are very
> expensive) You would be looking for one that would be an easy modification
> to fit
>
> some 2002 to 2006 V8 GM trucks had them as one example.
>
> Here are a couple of pictures.
>
>
> http://www.gmcmhphotos.com/photos/discussion-photos/p44588-electric-fan-clutch.html
>
>
> --
> John and Cathie Heslinga
> 1974 Canyonlands 260
> TC4W "Too Cool For Words"
> Retirement Projects Galore
> Edmonton, Alberta
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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Re: Fan Clutch Idea [message #175035 is a reply to message #175029] Fri, 29 June 2012 12:11 Go to previous messageGo to next message
C Boyd is currently offline  C Boyd   United States
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Rob is probably already thinking of adapting a changeable pitch fan like they had on them aeroplanes. Actually it would not have to be electric. It could be air off the coach or hydrolic off the ps pump. The different control valves are still 12v and could be triggered off anything from engine temp to head pressure. The advantage to having a manually controlled fan is that it can be triggered from different sources and does not depend on temp of the engine compartment to control.






John Heslinga wrote on Fri, 29 June 2012 12:51



Cool Project Idea:

Manufacturers have put in Electro viscus and electromagnetic fan clutches in for years on heavy trucks and diesel engines. some of them were even geared for two or three speeds. Some new vehicles and some high end imports use them as well. The Control Computers will turn them on and off

There are many kinds of models available ( However they are very expensive) You would be looking for one that would be an easy modification to fit

some 2002 to 2006 V8 GM trucks had them as one example.

Here are a couple of pictures.

http://www.gmcmhphotos.com/photos/discussion-photos/p44588-electric-fan-clutch.html

C. Boyd
76 Crestmont
East Tennessee

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Re: [GMCnet] Fan Clutch Idea [message #175037 is a reply to message #175029] Fri, 29 June 2012 12:37 Go to previous messageGo to next message
Ray Erspamer is currently offline  Ray Erspamer   United States
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Registered: May 2007
Location: Milwaukee Wisconsin
Karma: -3
Senior Member
I think this is a great idea, is there one on the market designed close enough
to work on our coaches ???

Ray


Ray & Lisa
78 Royale "Great Lakes Eagle"
Center Kitchen TZE368V101144
Wauwatosa, Wisconsin 53226
Email: 78GMC-Royale@att.net
414-745-3188
Web Site: http://ray-lisa.page.tl/




________________________________
From: John Heslinga <rbeeper@hotmail.com>
To: gmclist@temp.gmcnet.org
Sent: Fri, June 29, 2012 11:51:22 AM
Subject: Re: [GMCnet] Fan Clutch Idea





Cool Project Idea:

Manufacturers have put in Electro viscus and electromagnetic fan clutches in for
years on heavy trucks and diesel engines. some of them were even geared for two
or three speeds. Some new vehicles and some high end imports use them as well.
The Control Computers will turn them on and off

There are many kinds of models available ( However they are very expensive) You
would be looking for one that would be an easy modification to fit

some 2002 to 2006 V8 GM trucks had them as one example.

Here are a couple of pictures.

http://www.gmcmhphotos.com/photos/discussion-photos/p44588-electric-fan-clutch.html



--
John and Cathie Heslinga
1974 Canyonlands 260
TC4W "Too Cool For Words"
Retirement Projects Galore
Edmonton, Alberta
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Ray Erspamer 78 GMC Royale Center Kitchen 403, 3.70 Final Drive Holley Sniper Quadrajet EFI System, Holley Hyperspark Ignition System 414-484-9431

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Re: [GMCnet] Fan Clutch Idea [message #175045 is a reply to message #175032] Fri, 29 June 2012 14:14 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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James Hupy wrote on Fri, 29 June 2012 12:01

Mark, I think the A6 compressor in full tilt boogie mode uses about 12-15 horsepower. Much less than the fan would. The agricultural EM clutches use less amp draw than the A6, but total load on the GMC alternator is not limited to just fan and AC loads, and each GMC probably has a different total load depending upon onboard equipment. Add up the loads, stay under 70% of the Alternator's rated output, and it should work.
Jim Hupy
Salem, OR
78 GMC Royale 403
Seems like it might be worth pursuing in one's "spare time". What I would like to see is the current draw on only the clutch on the AC compressor when it engages. And if the HP "draw" of the fan would make the clutch slip when engaged. I am leaning towards somehow rigging an AC compressor clutch to a fan and running the power wire for the clutch through a water temperature switch installed in the top radiator hose somewhere around the thermostat to switch the clutch on and off. Just as a proof-of-concept.

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Re: [GMCnet] Fan Clutch Idea [message #175079 is a reply to message #175035] Fri, 29 June 2012 18:15 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Location: Sydney, Australia
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Senior Member
Chuck,

Actually I hadn’t.

The idea is novel; however, the hydraulics / electrics required to control the angle of prop blades would be pretty complicated.

In the simplest system blade angles are changed by a piston which moves offset pins in the butt of the blades. Hydraulic pressure to
the piston is regulated by a prop controller the heart of which is a flyweight governor which senses the speed of the engine. The
pressure sent to the prop is regulated to keep the engine speed constant.

The blades would have to be configured so that in feather (zero thrust / airflow) they wouldn't consume much power. As the
temperature rose the blade angle would increase and move more air through the radiator.

This could be accomplished by a mechanism with a temperature sensor in the water jacket that raised the pressure to the fan as the
temperature increased.

After putting all the above I stumbled on to this on YouTube!

http://www.youtube.com/watch?v=PoNgThzzERI

Regards,
Rob M.
 
-----Original Message-----
From: Charles Boyd

Rob is probably already thinking of adapting a changeable pitch fan like they had on them aeroplanes. Actually it would not have to
be electric. It could be air off the coach or hydrolic off the ps pump. The different control valves are still 12v and could be
triggered off anything from engine temp to head pressure. The advantage to having a manually controlled fan is that it can be
triggered from different sources and does not depend on temp of the engine compartment to control.

C. Boyd

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426

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Re: [GMCnet] Fan Clutch Idea [message #175086 is a reply to message #175079] Fri, 29 June 2012 20:09 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
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That is a very cool RC prop controller! This discussion is interesting, though academic - to my way of thinking. It's just too complex for a critical system.

If bone stock doesn't work for you, then I feel the next best alternative is 2 electric fans. Frankly they have some advantages over stock. The variable speed Thunderbird turbo coupe fans sound like a great choice.

Larry Davick
A Mystery Machine
Sent from my iPad

On Jun 29, 2012, at 4:15 PM, "Robert Mueller" <robmueller@iinet.net.au> wrote:

> http://www.youtube.com/watch?v=PoNgThzzERI
>
> Regards,
> Rob M.
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Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy

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Re: [GMCnet] Fan Clutch Idea [message #175087 is a reply to message #175086] Fri, 29 June 2012 20:23 Go to previous message
Dennis S is currently offline  Dennis S   United States
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ljdavick wrote on Fri, 29 June 2012 20:09

That is a very cool RC prop controller! This discussion is interesting, though academic - to my way of thinking. It's just too complex for a critical system.

If bone stock doesn't work for you, then I feel the next best alternative is 2 electric fans. Frankly they have some advantages over stock. The variable speed Thunderbird turbo coupe fans sound like a great choice.

Larry Davick
A Mystery Machine





You may recall that Shane, aka Duce, installed twin fans and reported successfully operating.

http://www.gmcmhphotos.com/photos/member-galleries/p39774-old-radiator-and-elect.html

Dennis

Dennis S
73 Painted Desert 230
Memphis TN Metro

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