All compound helicopters, to my knowledge, require a wing. This has meant that the wing is excess baggage in hover and the rotor is excess baggage in fast forward flight. This concept uses the rotor for lift in all modes of flight.
Assume that the helicopter in the sketch is flying at a fast forward speed. It can be seen that the retreating blade has negative pitch at its root. The root of this blade is in reverse airflow, therefor it is contributing to the lift. The root of a convention retreating blade opposes lift.
This is the basic concept. There is much more that can be said, and hopefully Nick will be able to contribute some Sikorsky input.
Shytorque ~ The rotor rpm will be significantly lower than that of conventional helicopters and this will postpone the advancing blade compressibility until a much higher air speed has been reached. I suppose that, theoretically, both the blade and the craft could eventually go supersonic.
Dave J.