Rotary fluid motor with axial thrust balancing means

Claim 1

A FLUID MOTOR COMPRISING: (I) AN INNER, A MEDIAL, AN AN OUTER GENERALLY CYLINDRICAL, HOLLOW RIGID MEMBERS, AXIALLY ALIGNED AND CIRCUMFERENTIALLY SPACED WITH RESPECT TO EACH OTHER; (A) SAID INNER MEMBER EXTENDING SUBSTANTIALLY THE AXIAL LENGTH OF SAID MOTOR AND COMPRISING: (U) A FIRST PORTION HAVING A SMOOTH OUTSIDE DIAMETER; AND (2) A SECOND PORTION CARRYING EXTERNAL HELICAL SPLINES OF A GIVEN HAND; (B) SAID MEDIAL MEMBER COMPRISING AN ANNULARLY SHAPED FLUID-DRIVEN PISTON EXTENDING ONLY A PORTION OF THE AXIAL LENGTH OF SAID MOTOR AND COMPRISING: (1) A PISTON HEAD LOCATED ADJACENT ONE END OF SAID MEDIAL MEMBER; (2) AN INTERIOR SKIRT PORTION LOCATED ADJACENT THE OTHER END OF SAID MEDIAL MEMBER HAVING INTERNAL HELICAL SPLINES THAT ARE ADAPTED TO ENGAGE THE HELICAL SPLINES OF THE SECOND PORTION OF SAID INNER MEMBER IN MECHANICALLY COOPERATIVE RELATIONSHIP; AND (3) AN OUTER PORTION CARRYING EXTERNAL HELICAL SPLINES OF OPPOSITE HAND TO THE GIVEN HAND OF THE HELICAL SPLINES OF SAID INNER MEMBER; AND (C) SAID OUTER MEMBER EXTENDING SUBSTANTIALLY THE AXIAL LENGTH OF SAID MOTOR AND COMPRISING: (1) A FIRST PORTION HAVING A SMOOTH INSIDE DIAMETER CONCENTRICALLY POSITIONED WITH RESPECT TO SAID FIRST PORTION OF SAID INNER MEMBER; (2) A CENTRAL PORTION ADJACENT SAID FIRST PORTION OF COMPARATIVELY SMALL AXIAL EXTENT CARRYING INTERNAL HELICAL SPLINES ADPATED TO ENGAGE THE EXTERNAL HELICAL SPLINES ADAPTED TO MEDIAL MEMBER IN MECHANICALLY COOPERATIVE RELATIONSHIP; AND (3) A THIRD PORTION ADJACENT THE OTHER SIDE OF SAID CENTRAL PORTION CONCENTRICALLY POSITIONED WITH RESPECT TO SAID SECOND PORTION OF SAID INNER MEMBER;