I was using a newer version of ANSYS than you so it may have worked better for me, you might have to do some more work.

I recommend you take a circle that generates the cylindrical surface adjacent to the orange face I showed above.  Use a cylindrical surface with a length longer than the thickness of the ring so it sticks out both ends. Then use that cylindrical surface to slice all the bodies.  That will make a large number of six-sided bodies that will mesh with Hex elements.

After that, we can address the special circumstances around the blind hole.