You probably mean something more complicated than you have described, but assuming you want the two blades to rotate around a central point:
Put them into a new group. Line them up so they are in the right position in relation to each other. Set the anchor point of the group to the position around which you want the rotation to take place.
Finally apply a Spin Behavior to the group – you’ll probably want to pretty high number, e.g. 5000.
I’m guessing that the oval-ish section of the graphic is not meant to be rotating so make sure it’s not in the rotating group.
Hope that’s what you mean.
Simon Ubsdell
http://www.tokyo-uk.com