Thanks for the web sites.

The actual operation of the V-22 CV joint and whether it transmit a true
constant velocity still remains a mystery. Both Bell and Sikorsky have
patents on differing ideas for CV joints but I don't know if they have
implemented them.

The implication of a true CVJ in a rotor-head is interesting, because it
should eliminate the Corollas effect and thereby eliminate a primary source
of lead/lag.

Dave J


"AnyBody43" wrote in message
m...
"Steve R." wrote
Are you folks sure the V22 is using a universal joint like what we find
on
an automotive drive shaft? I would thing that that would be a very
arcaic
way to transfer power. Modern front wheel drive cars us a CV (constant
velocity) joint in place of the old standard universal joint. I'm not
saying that a CV joint fully eliminate the problems you're talking about
with universal joints but they do work significantly smoother at higher
angles.

Some general links with pictures of what I'm talking about a

http://volksweb.relitech.com/tech/cvjoints/cvparts.jpg
http://volksweb.relitech.com/tech/cvjoints/cvfrnt.jpg
"Cam" wrote
It could be two universals close together?
But then it would need a supporting bearing/structure at the rotor end
aswell. ?
Hmmm...
A CV makes more sence.
"Dave Jackson" wrote
Literature mentions that the 3-blade V-22 rotor hub is attached to
the
rotor
shaft by a means of gimbal or universal joint. Gimbal and universal
joints
do not transmit a constant velocity when the hub and shaft axes are
not
aligned.

Does anyone know if the V-22 uses a gimbal joint or if it actually
uses
a
Constant Velocity Joint?

There are all FAR to mathematical for me but there are a few
pictures that I liked too The unicopter link in particular
has a lot of diagrams.

google [v-22 gimbal] returns:

http://rotorcraft.arc.nasa.gov/publi...ree_AHSF02.pdf
Which says:
"The V-22 hub comprises three composite arms, or yokes,
connected to the shaft by a constant-velocity joint."

There is no detail of the CV joint in this document but tehre seem
to be other documents on the same site.
e.g.
rotorcraft.arc.nasa.gov/publications/files/Acree_AHS01.pdf

Note that the google results contain an incorrect space
where in the URL displayed after the summary text.


Google [v-22 "constant velocity joint"]
http://rotorcraft.arc.nasa.gov/resea...amdetails.html
"Gimbaled hub with constant velocity joint (spherical bearing
and elastomeric torque links)"


http://www.unicopter.com/1301.html
Much *detail* and many ##-DIAGRAMS-##
"(Somewhat similar to the V-22 tilt-rotor)"


http://www.aero.polimi.it/~quaranta/...RF-2000-60.pdf
"Significantly,
it considers the gimbal joint, that links the hub to
the mast in order to allow the fapping motion of
the overall hub, and thus implementing a constant
velocity joint, and the swashplate, with all the re-
lated components that are required to transmit the
pitch controls to the rotor blades."


http://pcwww.liv.ac.uk/eweb/fst/publ...SSLA_feb11.pdf
"In contrast, the homo-kinetic, constant velocity joint,
featured on the V-22, requires that the drive
component be connected after the gimbal springs
eliminating cyclic variation of the rotor angular velocity."