Rotary radial piston machines with tangential balancing recesses for the pressure balance of the pistons

Claim 1

A ROTARY FLUID MACHINE COMPRISING, IN COMBINATION, A CASING; A BODY FORMED WITH ANGULARLY SPACED RADIAL BORES CONSTITUTING CYLINDERS; MEANS THERETO; PISTONS RECIPROCABLE IN SAID CYLINDERS TO VARY THE EFFECTIVE VOLUMES OF SAID CYLINDERS TO DISPLACE FLUID RELATIVE TO SAID CYLINDERS; PISTON GUIDE SHOES PIVOTALLY CONNECTED TO THE ENDS OF SAID PISTONS FOR PIVOTING ABOUT AXIS SUBSTANTIALLY PARALLEL TO EACH OTHER AND PERPENDICULAR TO THE AXIS OF THE RESPECTIVE CYLINDER, SAID GUIDE SHOES HAVING ARCUATE GUIDE SURFACE MEANS; MEANS RESTRAINING ROTATION OF SAID PISTONS AND SAID GUIDE SHOES ABOUT THE AXIS OF SAID CYLINDERS; GUIDE MEANS IN SAID CASING HAVING CYLINDRICAL GUIDE SURFACES SUBSTANTIALLY CONFORMINGLY ENGAGEABLE WITH SAID ARCUATE GUIDE SURFACE MEANS TO RECIPROCATE SAID PISTONS AND SAID GUIDE SHOES, SAID GUIDE MEANS HAVING AN ECCENTRICITY RELATIVE TO SAID BODY; SAID GUIDE SHOES PIVOTING RELATIVE TO THE RESPECTIVE CONNECTED PISTONS, DURING MOVEMENT OF SAID BODY, IN ACCORDANCE WITH THE ECCENTRICITY OF SAID GUIDE MEANS, WHEREBY FORCES ACTING TANGENTIALLY THERETO ARE IMPOSED ON THE RESPECTIVE PISTONS; THE OUTER LATERAL SURFACE OF EACH PISTON AND THE INNER SURFACE OF THE ASSOCIATED CYLINDER CONJOINTLY DEFINING AT LEAST ONE RECESS THEREBETWEEN; AND MEANS SELECTIVELY OPERABLE TO CONNECT EACH RECESS TO THE CYLINDER SPACE BENEATH THE ASSOCIATED PISTON TO SUPPLY FLUID TO THE RECESS AT A PRESSURE SUBSTANTIALLY PROPORTIONAL TO SAID TANGENTIAL FORCES IMPOSED ON THE RESPECTIVE PISTON, AND IN A DIRECTION TO COMPENSATINGLY OPPOSE SUCH FORCES.