Input: the green disk.
Output: the blue disk.
The yellow bearing house of the orange roller can rotate around a fixed bearing.
The inside surface ot the disks is created by a round profile, center of which is on the axis of the yellow bearing house. This axis does not intersect the disk axes. There is a offset.
The roller contacts with the disks at its outside edges.
Contact pressure is created by two brown springs.
Turn the yellow shaft to change contact position for various output velocities.