Open Differential theory of operation???
 

Anyone have any links (Bill?) that describe exactly
how the power is applied to the rear wheels on
a open differential?
I'm having a disagreement with one of our
software engineers. I say the power is applied
to one wheel only. He says otherwise.
Maybe we're both wrong.
Thanks in advance
Cheers
Frank

Re: Open Differential theory of operation???
 

Boy it's confusing :-)

http://auto.howstuffworks.com/differential6.htm

I guess to sum it up, Is that when going straight
both wheels get power/torque until there more power than traction,
then only one wheel gets it.

FrankW wrote:
> Anyone have any links (Bill?) that describe exactly
> how the power is applied to the rear wheels on
> a open differential?
> I'm having a disagreement with one of our
> software engineers. I say the power is applied
> to one wheel only. He says otherwise.
> Maybe we're both wrong.
> Thanks in advance
> Cheers
> Frank
>

Re: Open Differential theory of operation???
 

Boy it's confusing :-)

http://auto.howstuffworks.com/differential6.htm

I guess to sum it up, Is that when going straight
both wheels get power/torque until there more power than traction,
then only one wheel gets it.

FrankW wrote:
> Anyone have any links (Bill?) that describe exactly
> how the power is applied to the rear wheels on
> a open differential?
> I'm having a disagreement with one of our
> software engineers. I say the power is applied
> to one wheel only. He says otherwise.
> Maybe we're both wrong.
> Thanks in advance
> Cheers
> Frank
>

Re: Open Differential theory of operation???
 

Boy it's confusing :-)

http://auto.howstuffworks.com/differential6.htm

I guess to sum it up, Is that when going straight
both wheels get power/torque until there more power than traction,
then only one wheel gets it.

FrankW wrote:
> Anyone have any links (Bill?) that describe exactly
> how the power is applied to the rear wheels on
> a open differential?
> I'm having a disagreement with one of our
> software engineers. I say the power is applied
> to one wheel only. He says otherwise.
> Maybe we're both wrong.
> Thanks in advance
> Cheers
> Frank
>

Re: Open Differential theory of operation???
 

This describes the "ideal" open differential, which doesn't exist. All
differentials have a certain amount of internal friction, which makes the
behavior less ideal. Because of this, you can get off of ice with a thin
film of water on top of it, which is the slipperiest road surface that I
have encountered. Other things to keep in mind, are the effect of
"stiction", which is a physical concept, that says that you have more
traction, if you are not spinning your wheels, and the ability of a quick
tap on the brakes, to restore the state, where there is more traction than
power.

Earle

"FrankW" <fworm@mxznorpak.ca> wrote in message
news:5LSdnTsSCNwHl9neRVn-pg@magma.ca...
> Boy it's confusing :-)
>
> http://auto.howstuffworks.com/differential6.htm
>
> I guess to sum it up, Is that when going straight
> both wheels get power/torque until there more power than traction,
> then only one wheel gets it.
>
> FrankW wrote:
> > Anyone have any links (Bill?) that describe exactly
> > how the power is applied to the rear wheels on
> > a open differential?
> > I'm having a disagreement with one of our
> > software engineers. I say the power is applied
> > to one wheel only. He says otherwise.
> > Maybe we're both wrong.
> > Thanks in advance
> > Cheers
> > Frank
> >
>
>

Re: Open Differential theory of operation???
 

This describes the "ideal" open differential, which doesn't exist. All
differentials have a certain amount of internal friction, which makes the
behavior less ideal. Because of this, you can get off of ice with a thin
film of water on top of it, which is the slipperiest road surface that I
have encountered. Other things to keep in mind, are the effect of
"stiction", which is a physical concept, that says that you have more
traction, if you are not spinning your wheels, and the ability of a quick
tap on the brakes, to restore the state, where there is more traction than
power.

Earle

"FrankW" <fworm@mxznorpak.ca> wrote in message
news:5LSdnTsSCNwHl9neRVn-pg@magma.ca...
> Boy it's confusing :-)
>
> http://auto.howstuffworks.com/differential6.htm
>
> I guess to sum it up, Is that when going straight
> both wheels get power/torque until there more power than traction,
> then only one wheel gets it.
>
> FrankW wrote:
> > Anyone have any links (Bill?) that describe exactly
> > how the power is applied to the rear wheels on
> > a open differential?
> > I'm having a disagreement with one of our
> > software engineers. I say the power is applied
> > to one wheel only. He says otherwise.
> > Maybe we're both wrong.
> > Thanks in advance
> > Cheers
> > Frank
> >
>
>

Re: Open Differential theory of operation???
 

This describes the "ideal" open differential, which doesn't exist. All
differentials have a certain amount of internal friction, which makes the
behavior less ideal. Because of this, you can get off of ice with a thin
film of water on top of it, which is the slipperiest road surface that I
have encountered. Other things to keep in mind, are the effect of
"stiction", which is a physical concept, that says that you have more
traction, if you are not spinning your wheels, and the ability of a quick
tap on the brakes, to restore the state, where there is more traction than
power.

Earle

"FrankW" <fworm@mxznorpak.ca> wrote in message
news:5LSdnTsSCNwHl9neRVn-pg@magma.ca...
> Boy it's confusing :-)
>
> http://auto.howstuffworks.com/differential6.htm
>
> I guess to sum it up, Is that when going straight
> both wheels get power/torque until there more power than traction,
> then only one wheel gets it.
>
> FrankW wrote:
> > Anyone have any links (Bill?) that describe exactly
> > how the power is applied to the rear wheels on
> > a open differential?
> > I'm having a disagreement with one of our
> > software engineers. I say the power is applied
> > to one wheel only. He says otherwise.
> > Maybe we're both wrong.
> > Thanks in advance
> > Cheers
> > Frank
> >
>
>

Re: Open Differential theory of operation???
 

Basically 100% of the torque goes to 'both' rear wheels in an open diff
'all' the time.

Where you get into trouble is when one wheel is say on ice and the other
is on dirt. Then 100% of the torque still goes to both wheels but the
torque needed to make the ice wheel spin is really low, say only 1 or 2
foot lb. so the same really low 1 or 2 foot lb. goes to the dirt wheel
and you go nowhere.

To overcome this you can apply the emergency brake (according to the
Jeep owners manual) or as I do and hit the brake pedal so you add a pile
of resistance to the ice wheel. This raises the torque needed to turn
the ice wheel and it can/will get high enough to break the dirt wheel
free so you drive off shooting two rooster tails.

With practice this works really well. I have managed to go from one
front and one rear wheel spinning on ice with me stopped and the boys
laughing and going for straps, to me pulling away with all 4 tires
shooting rooster tails.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

FrankW wrote:
>
> Anyone have any links (Bill?) that describe exactly
> how the power is applied to the rear wheels on
> a open differential?
> I'm having a disagreement with one of our
> software engineers. I say the power is applied
> to one wheel only. He says otherwise.
> Maybe we're both wrong.
> Thanks in advance
> Cheers
> Frank

Re: Open Differential theory of operation???
 

Basically 100% of the torque goes to 'both' rear wheels in an open diff
'all' the time.

Where you get into trouble is when one wheel is say on ice and the other
is on dirt. Then 100% of the torque still goes to both wheels but the
torque needed to make the ice wheel spin is really low, say only 1 or 2
foot lb. so the same really low 1 or 2 foot lb. goes to the dirt wheel
and you go nowhere.

To overcome this you can apply the emergency brake (according to the
Jeep owners manual) or as I do and hit the brake pedal so you add a pile
of resistance to the ice wheel. This raises the torque needed to turn
the ice wheel and it can/will get high enough to break the dirt wheel
free so you drive off shooting two rooster tails.

With practice this works really well. I have managed to go from one
front and one rear wheel spinning on ice with me stopped and the boys
laughing and going for straps, to me pulling away with all 4 tires
shooting rooster tails.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

FrankW wrote:
>
> Anyone have any links (Bill?) that describe exactly
> how the power is applied to the rear wheels on
> a open differential?
> I'm having a disagreement with one of our
> software engineers. I say the power is applied
> to one wheel only. He says otherwise.
> Maybe we're both wrong.
> Thanks in advance
> Cheers
> Frank

Re: Open Differential theory of operation???
 

Basically 100% of the torque goes to 'both' rear wheels in an open diff
'all' the time.

Where you get into trouble is when one wheel is say on ice and the other
is on dirt. Then 100% of the torque still goes to both wheels but the
torque needed to make the ice wheel spin is really low, say only 1 or 2
foot lb. so the same really low 1 or 2 foot lb. goes to the dirt wheel
and you go nowhere.

To overcome this you can apply the emergency brake (according to the
Jeep owners manual) or as I do and hit the brake pedal so you add a pile
of resistance to the ice wheel. This raises the torque needed to turn
the ice wheel and it can/will get high enough to break the dirt wheel
free so you drive off shooting two rooster tails.

With practice this works really well. I have managed to go from one
front and one rear wheel spinning on ice with me stopped and the boys
laughing and going for straps, to me pulling away with all 4 tires
shooting rooster tails.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

FrankW wrote:
>
> Anyone have any links (Bill?) that describe exactly
> how the power is applied to the rear wheels on
> a open differential?
> I'm having a disagreement with one of our
> software engineers. I say the power is applied
> to one wheel only. He says otherwise.
> Maybe we're both wrong.
> Thanks in advance
> Cheers
> Frank