Rotary air motor with curved tangential vanes

In a rotary fluid handling device including a stator having a cylindrical inner surface defining a cylindrical chamber, a cylindrical rotor mounted by hub structure for rotation within the chamber, and end plates respectively disposed for closing the opposite ends of the chamber and respectively spaced by rotor end clearance spaces from the adjacent ends of the rotor, the rotor having a plurality of slots therein extending the length thereof and respectively slidably receiving a plurality of vanes dimensioned so that when the rotor is rotated the outermost edges of the vanes are centrifugally urged into sliding engagement with the inner surface of the stator, the improvement comprising:

• the hub structure including a cylindrical shaft extending coaxially through the rotor and through the end plates and a pair of hub members fixed on said shaft and respectively spanning the end clearance spaces at the opposite ends of the rotor, each of said hub members having a cylindrical outer surface intersecting each of the slots along said end clearance spaces, each of the slots and the vanes being so dimensioned that each vane tangentially engages said cylindrical outer surface of said shaft along substantially the entire axial extent of the end clearance spaces in all positions of the vanes thereby to provide an effective seal between the vanes and said hub structure.