I've attached a picture:
(consider opening on another tab to make it easier to see - middle button on many browsers)
1 - An axle/arbor (Pinned coincident to a datum axis - free on other directions)
2 - A gear (Well attached to the Axle, where it IS to be)
3 - Washer/Separator (attached to the gear and the arbor) [there's another one behind the gear]
4 - Inner runner of a ball bearing (Attached to the Washer/Separators (3))
5 - Outer runner of a ball bearing (pinned and aligned with the inner runner) - This part is important, because when I attach these parts to another assembly, the outer runner is the interface
More clarifications:
If I restrain the movement of the outer runners, I can still move (spin) the gear (which also moves the axle and the inner runners)
Which is the behavior I want
Why Creo disallows converting the gear onto a gear (when I attach these parts to another assembly containing another gear) ?
(Unfortunately, the orange circled arrow belongs to the bearing, not the gear)