Abstract: A vacuum motor comprising a housing with a eccentrically mounted rotor composed of a rotor-body having a plurality of radially extending equi-spaced slits extending axially and a plurality of slidable vane members, one of which is in each of said rotor slits; there are a plurality of passageways in a sleeve coaxially lining the stator and a pair of spaced holes are provided in a control member slidable captivated on the stator to selectively control suction forces applied to the vanes from a source so as to provide a differential pressure on one of the vanes on one face while the other face of the vane is exposed to atmospheric pressure, whereby, upon selective operation of a trigger mechanism to control suction application, the rotor will turn to deliver power to drive a gear train or other suitable mechanical mechanism for producing useful work, as is set forth more fully hereinafter.