Patent ID: 7484939

Claim:
A radial pump comprising a housing having a cavity with an axis there through and having a fluid inlet passage and a fluid outlet passage opening into the cavity; a first cylinder ring mounted within the cavity on a first pivot that engages the housing and having a first aperture within which a first cam surface is formed; a second cylinder ring mounted within the cavity on a second pivot that engages the housing on an opposite side of the axis from the first pivot, and the second cylinder ring having a second aperture within which a second cam surface is formed; a second pivot that is on an opposite side a cylinder block mounted for rotation about the axis within the first and second apertures and including a first plurality of radially extending cylinders and a second plurality of radially extending cylinders, wherein each cylinder has a port which communicates with the fluid inlet passage and the fluid outlet passage as the cylinder block rotates; a first plurality of pistons, each slideably received within a different one of the first plurality of cylinders and engaging the first cam surface of the first cylinder ring; a second plurality of pistons each slideably received within a different one of the second plurality of cylinders and engaging the second cam surface of the second cylinder ring; and an actuator mechanism operably coupled to move the first cylinder ring and the second cylinder ring and altering a spatial relationship between each cylinder ring and the cylinder block, which varies an amount that each piston moves upon rotation of the cylinder block.