This is a magnetic u-joint.It is made of two magnets, instead of normal u-joint structure.The magnets must be powerful.This u-joint
can't carry too much force.The amount of force it can carry depends on the power of the magnets.But it has some other advantages.
1.Electro magnets can be used, thus it can be smaller and its shape can be changed.
2.There can be a small air gap between the magnets if the magnets are powerful enough.
I made a real model of the mechanism and it worked.
If you want to see the animation from other points of view, please send me an e-mail.