This animation is similar to the others, except the rotor orientation is fixed, while the housing moves around.
Welcome to Adobe GoLive 6
Rotor-Centric - 2.4mb QuickTime
This animation takes you out of the position of stationary observer by null'ing out the rotation of the rotor, so you can see one of the chambers more clearly through its full cycle. Watch as the intake port "rises" and "sets" on different side of the rotor face, and see how the chamber expands and contracts with each stroke.