Gear-Config Icon Challenge

[Egg Bramhill]

Select the next outer circle (NOT the centring circle) Bring to front (Ctrl+F) then shift select the newly created shape. Ctrl+1 (Add Shapes):

[Egg Bramhill]

Finally select the next inner circle. Bring to front (Ctrl+F) then shift select the newly created shape. Ctrl+2 (Subtract Shapes):

[Egg Bramhill]

However as I said earlier all these Combine / Arrange shapes can lead to unwanted nodes, one above another, so it's a matter of selecting the Shape Tool and Tab or Shift Tab deleting nodes (just the straight line ones, not any curved ones). Unfortunately even the Smoothing tool doesn't remove these duplicated nodes: