15 Feb 2003, 08:11, JEAN PARROT (1:123/140), wrote to ROY J. TELLASON:

Hi JEAN.

 JP>>  Yes. And the French Citro‰n was the first one to use it.

 RJT>> No,  really?  When was that?

 JP>  I do not have the date in mind but it was after 1920  
 JP> when hey introduced their first front drive.

 JP>> Remember the symbol on the front grill ? 

 JP> It was 3 pointed down chevrons, like a sargent's.advertising the
 JP> gear as an peculiarity of the car.

But they were not the first to use that gear, perhaps the first in an auto though.

They have been used on ships for at least a century.  

Why you might ask?  

There were no thrust bearings that could withstand the end thrust of
single-angled gears for the duration of a trans-oceanic crossing.

Since they are still used in large ships, I would guess that there may not
yet be bearings and gear cases that can 'routinely' withstand 10K to 50K
horsepower for extended duration trips.

Someone mentioned the 'notch' at the "V".  Herringbone gears have
a tendency to create extreme oil pressures at the point of the
"V" as the gears rotate and this leads to erosion and self
destruction.  

The 'incomplete "V" ' also allows dirt to be flushed out, which
would otherwise become trapped inside the apex of the "V".


     Good luck...  M.

--- Msged/386 TE 06 (pre)