Controlled porting for a pressure transformer

A pressure transformer for the conversion of hydraulic power from a first fluid flow having a first fluid pressure into the hydraulic power of a second fluid flow having a second pressure by controlling a third fluid flow having a third pressure, the hydraulic pressure transformer having a housing with three port connections, a rotating group having a barrel with a face surface and a plurality of piston assemblies each slideably disposed in respective cylinders that have cylinder ports defined in the barrel and opening to the face surface, each of the cylinder ports are spaced from one another around a predetermined circumference, a displacement control mechanism operatively associated with the respective piston assemblies to control the volume of fluid within each cylinder between a minimum and a maximum volume as the rotating group rotates, and an adjustable port plate having a face surface with three arcuate slots defined therein spaced from one another around a predetermined circumference that is substantially equal to the predetermined circumference of the cylinder ports, the face surface of the adjustable port plate being in mating contact with the face surface of the rotating group and each of the three arcuate slots being in communication with respective ones of the three ports in the housing, the pressure transformer comprising:

• each cylinder port having a leading edge, a trailing edge, and first and second spaced apart circumferential sides, the leading edge and the trailing edge of each cylinder port being spaced from one another a predetermined circumferential distance;
• each arcuate slot having a leading edge, a trailing edge, and first and second spaced apart circumferential sides, the trailing edge of one of the arcuate slots and the leading edge of an adjacent slot being spaced from one another a predetermined circumferential distance along the predetermined circumference, the predetermined distance between the adjacent slots being less than the predetermined distance between the leading edge and the trailing edge of the respective cylinder slots;
• and
• during relative rotation between the barrel and the port plate, the leading edge of the respective cylinder ports is in an open overlapping relationship with one of the arcuate slots and the trailing edge of the same cylinder port is in an open overlapping relationship with the second one of the arcuate slots.