Re: What's the big deal about Torsen?

["Graydon D. Stuckey" <graydon@apollo.gmi.edu>]

On Wed, 11 Dec 1996, Jeff W wrote:

> And I think that most people are overblowing the Torsen to be some
> mystical beast that thinks for itself and "kicks in".  It doesn't.  It
> is simply a differential that smoothly applies a ratio of torque bias to
> both outputs.

That's true.

> Which brings us to the Torsen.  BTW, The Gleason Works (AKA DK Gleason)
> sold the business; they are now called Zexel Torsen, Inc. (I think now a
> division of MascoTech?)  The Torsen is unique in that it uses a

Not sure about the Mascotech connection, but the company is Japanese-owned, 
and is called Zexel-Gleason.  "Torsen" is the name of the differential.

> planetary gear arrangement to bias torque to the "low traction" output;
> yet allows differential action.  It performs this action smoothly; not
> like the "kick-in" attributed to electronic traction/locking devices.

There are no planetary gears.  It has a pair of side gears, one each for 
the two output shafts.  The case transfers torque to the side gears 
through 6 worm gears which mesh with the side gears, three on each side 
gear.  The 2 sets of worm gears, left and right, are connected to each 
other through small gears on the ends of each worm gear.  It is the 
friction in all the gears, and the fact that you can not drive a worm 
from the gear that gives the Torsen its tork-sensing attribute.  (in a 
worm gear/spur gear system, you can only transmit torque in one direction 
- torque must be applied to the worm to turn the spur, not the other way 
around.)

	The Quaiffe operates with the use of planetary gears.

> For the racer/wannabee; When you "get on it" with a Torsen, you will
> have the lowest traction axle spinning faster than the other.  (Usually
> the rear)  You won't have this with a locked center.  From this
> perspective the control will not be as defined with a Torsen. (Yet
> control always has its limits)

A Torsen could be biased to transmit more tork to the rear than the 
front.  This is one feature which, if optimized, I think could make the 
Torsen appropriate to a racing car.

Later, ---------------------------------------------------------- 
Graydon D. Stuckey 	'85 Mazda RX7 GS, no toys 
graydon@apollo.gmi.edu 	'86 Audi 5000 CS Turbo Quattro, has toys
Flint, Michigan USA	'89 Thunderbird SC, lotsa toys