I am doing a project where there is a plate with a hole on it where one ring will be mounted. The ring and plate need to be attached somehow. However, the ring must be able to rotate around the roll axis. I already have some ideas, but there are too complicated. (with bearing, etc) My questions is: what are some similar mechanisms that I can inspire? (The picture shown below is the basic demonstration of the project. The ring which is needed to be able to rotate is shown with the red color)
Commercial display stands may give you an inspiration. You can simplify the idea for your project.
For example: https://tr.aliexpress.com/item/32915896443.html
Make the external surface of the red ring have a bearing track and the matching track on the interior of the black plate so you have a roller bearing created by the two items.
Or have the track on the red ring with 4 or even 8 holes drilled into the plate which have screws with a roller at the tip.