Input: yellow shaft.
Blue pin is fixed to red bush to create helical joint with blue shaft. Helix angle of the screw is 45 deg. to ease the motion. This joint can be of regular nut-screw type (multi-start thread).
The red bush has prismatic joint (sliding key) with green gear.
Turn violet screw for moving cyan slider to adjust relative positioning angle between yellow and blue rollers. In this animation the yellow shaft is supposedly kept immobile.
The adjustment can be performed even during transmission.
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