1. AN AIR COMPRESSOR HAVING AN INTEGRAL VACUUM DRIVEN PRIME MOVER COMPRISING A PAIR OF AXIALLY ALIGNED CYLINDRICAL HOUSINGS, A PAIR OF END CAPS AT OPPOSITE ENDS OF SAID HOUSINGS, RESPECTIVELY, A BEARING RETAINER BETWEEN SAID HOUSINGS, A BEARING IN SAID BEARING RETAINER HAVING A CENTRAL AXIS RADIALLY SPACED FROM THE CENTRAL AXIS OF SAID HOUSINGS, A DRIVE SHAFT JOURNALED IN SAID BEARING AND EXTENDING INTO SAID HOUSINGS, AN INLET DISC IN ONE OF SAID HOUSINGS ADJACENT SAID BEARING RETAINER HAVING AN INLET APERTURE THEREIN, AN OUTLET DISC ADJACENT THE END CAP AT THE END OF SAID ONE HOUSING HAVING AN OUTLET APERTURE THEREIN, A GENERALLY CYLINDRICAL COMPRESSOR ROTOR BETWEEN SAID INLET AND OUTLET DISCS DRIVABLY KEYED TO SAID DRIVE SHAFT SO AS TO BE ROTATABLE ABOUT AN AXIS EXTENDING GENERALLY PARALLEL TO THE CENTRAL AXIS OF SAID HOUSINGS IN RADIALLY SPACED RELATION THERETO, SAID COMPRESSOR ROTOR HAVING A PLURALITY OF GENERALLY AXIALLY EXTENDING RADIALLY DIRECTED SLOTS, A PLURALITY OF GENERALLY RADIALLY SLIDABLE VANES IN THE SLOTS IN SAID COMPRESSOR ROTOR, SAID VANES SLIDABLY ENGAGING THE INNER PERIPHERAL SURFACE OF SAID ONE HOUSING AND SAID INLET AND OUTLET DISCS TO DEFINE A VARIABLE VOLUME CHAMBER FOR THE COMPRESSION OF AIR THEREIN UPON ROTATION OF SAID COMPRESSOR ROTOR RELATIVE TO SAID ONE HOUSING, AN INNER DISC IN THE OTHER OF SAID HOUSINGS ADJACENT SAID BEARING RETAINER HAVING AN INLET APERTURE THEREIN, AN OUTER DISC ADJACENT THE END CAP OF SAID OTHER HOUSING HAVING AN OUTLET APERTURE THEREIN, A GENERALLY CYLINDRICAL VACUUM MOTOR ROTOR BETWEEN SAID INNER AND OUTER DISCS HAVING A CENTRAL BORE THEREIN FOR THE ACCEPTANCE OF SAID DRIVE SHAFT SO AS TO BE ROTATABLE COAXIALLY WITH SAID COMPRESSOR ROTOR, SAID MOTOR ROTOR HAVING A PLURALITY OF GENERALLY AXIALLY EXTENDING RADIALLY DIRECTED SLOTS, AND A PLURALITY OF GENERALLY RADIALLY SLIDABLE VANES IN THE SLOTS IN SAID MOTOR ROTOR, SAID VANES SLIDABLY ENGAGING THE INNER PERIPHERAL SURFACE OF SAID OTHER HOUSING AND SAID INNER AND OUTER DISCS TO DEFINE A VARIABLE VOLUME VACUUM CHAMBER WHEREBY ROTATION OF SAID MOTOR ROTOR RELATIVE TO SAID OTHER HOUSING EFFECTS CONCOMITANT ROTATION OF SAID COMPRESSOR ROTOR.