Patent ID: 8225767

Claim:
An apparatus comprising: a first rotor having a first rotor cavity therein defined by first and second inner side walls and by a first rotor inner perimeter wall, the first rotor mounted so as to rotate about a first axis; a second rotor having a second rotor outer face, first and second sides, a second rotor slot formed in a region of the outer face, and a seal contained within the slot, the second rotor mounted so as to rotate about a second axis parallel to and offset from the first axis; and a blade fixed to the first rotor inner perimeter wall and to the first and second inner side walls, a portion of the blade extending into the second rotor slot and the seal, and wherein a portion of the second rotor rests within the first rotor cavity, the second rotor outer face is configured for rolling contact with the first rotor inner perimeter wall, the first and second rotors are configured so as to alternately expand and contract a first inter-rotor chamber during the course of two full revolutions of the first and second rotors, the first inter-rotor chamber having a first end defined by the blade and a second end resulting from the rolling contact between the first and second rotors, the first and second rotors are configured so as to simultaneously expand a second inter-rotor chamber while contracting the first inter-rotor chamber, the second inter-rotor chamber also includes a third end defined by the blade and a fourth end resulting from the rolling contact between the first and second rotors, the first side of the second rotor has a first opening formed therein, the second side of the second rotor has a second opening formed therein, during at least a portion of a complete revolution, the first opening is in fluid communication with the first inter-rotor chamber and not the second inter-rotor chamber, during at least a portion of a complete revolution, the second opening is in fluid communication with the second inter-rotor chamber and not the first inter-rotor chamber.