A CV (constant-velocity) joint allows a drive shaft to
transmit
power through a variable angle, at constant rotational
speed.
I have come up with a new CV joint that is probably worse
than other CV joints (especially the Rzeppa) in every way,
except that it is flatter which may be useful
in some
applications.
In the illustration the inner ring is attached to the outer
ring with four rods. Each rod (orange) is connected to the
outer ring with a ball and socket. Each rod is connected to
the inner ring via a follower (white) running on a curved
cam track (blue). Each rod can slide within a pivot (purple).
In the illustrations, the first image is with the rings aligned
while the second image shows the outer ring at an angle
compared to the inner ring.
When the outer ring turns, the rods slide thus varying the
effective length of the rod between the pivot and the outer
ring.
The main application I had in mind for this was a gimbal for
a
ring flywheel.