Patent ID: 7811064

Claim:
A variable displacement reciprocating pump comprising: a power source; a central shaft driven by said power source; an intermediate shaft, said intermediate shaft driven by said power source and said intermediate shaft is parallel to said central shaft; a first shaft driven by said power source, said first shaft positioned between said intermediate shaft and said power source whereby power transmits from said power source through said first shaft to said intermediate shaft; a rotating rotary actuator positioned between said first shaft and said central shaft, whereby power transmits from said first shaft through said rotating rotary actuator to said central shaft; at least one outer cam rotationally carried by said central shaft; a pump plunger connected to said outer cam; a pair of driving gears carried by each outer cam, said driving gears driven by at least one gear carried by said intermediate shaft such that rotation of said intermediate shaft rotates said driving gears thereby rotating said outer cams and driving said pump plunger; and, at least one inner cam carried by said central shaft wherein said inner cam is secured to said central shaft such that said inner cam rotates with said central shaft whereby rotation of said central shaft by said rotating rotary actuator changes the relative position of said inner cam to said outer cam.