The outer case has a gear mount and grooves for the inner tube.

This tube has the front lens integrated and is visible to the outside when the camera is turned on and zooming.

The inner tube moves all 4 lenses.

This groove moves the tube with the front lens.

The three inner grooves moves the image stabilisation, the shutter and an additional lens.

This nip interacts with the grooves in the outer tube.

This is the dust and dirt that was stopping the objective from moving out. It isn't much. So, be careful and keep yours clean. I was not able to completely remove it in my camera, but it is working now with some help.