At 09:55 AM 12/8/98 +0100, you wrote:
>
>I know that the "CV" in "CV-Joints" refers  to "constant velocity".  But
>what exactly does this mean?  Under which conditions  and where is there
>a  constant velocity?
> Rainer
>
Think of an input (driving) shaft attached to an output (driven) shaft:  if
the two shafts are directly in line, no matter the connecting mechanism,
the output shaft will turn in exactly the same manner as the input shaft.
If however there is an angle between the two shafts and they are connected
by a 'universal ' joint there is a tiny amount of acceleration/deceleraton
of the driven shaft because of inherent 'sin' (angular) error - this can
really be noticed if the shafts approach 45 degrees included angle.  With a
constant velocity joint there is no locked element between the two shafts
(like the 'spider' or cross piece of a universal joint); instead there are
caged balls that allow a moving contact point between the shafts, which
results (by inherent design) in the two shafts turning with an identicle
angular velocity - within the constraints designed in...i.e., automotive cv
joints won't allow anywhere near 45 degree engagement!

Austin