Gentlemen, what is this device? What is the working principle?

Question

Electronics

Answer 1

We reason logically. The windings are arranged so that their axes are parallel to the shaft axis of the structure, and not perpendicular to it. Because it cannot be the engine. There are few windings for the engine in any case. The presence of screws indicates that these parts do not rotate relative to each other. But the presence of a spring on the shaft hints at the fact that there is some other part that is missing in the photo, and which is attracted by electromagnets in these covers. So the design is more like a magnetic clutch or a magnetic disc brake. But without additional data, you can only guess or find out by sight if you have seen this before.
For example, here is an image of several electromagnetic brake assemblies for forklifts. The general principle is the same. But much can be built on this principle.

Answer 2

what kind of analog sensor for rotation, movement, or something else
like a selsyn

Answer 3

The spring and transverse lamellas hint that this is some kind of electromagnetic clutch
. It seems like there is still not enough thin intermediate disk