Variable displacement vane pump

A variable displacement vane pump, comprising:

• a ported casing having a pair of relatively rotatable complementary cams, each having a surface shaped to provide a curvilinear annular track,
• a rotor rotatably mounted in said casing;
• and
• a first and second plurality of vanes mounted to be axially slidable upon said rotor, each of said vanes being sized and positioned to engage a corresponding one of said pair of cams, the vanes of the first plurality engaging one of the cams, the vanes of the second plurality engaging the other of the cams, and said vanes being grouped into a plurality of circumferentially spaced pairs, one from each of the first and second plurality, the vanes within each pair being positioned adjacently.

A variable displacement vane pump comprising:

• a ported casing having a pair of relatively rotatable complementary cams, each having a surface shaped to provide a curvilinear annular track, with each of said cams having along its annular track a thickness that varies circumferentially but not radially;
• a rotor rotatably mounted in said casing;
• and
• a first and second plurality of vanes slideably mounted to be axially slidable upon said rotor, each of said vanes being sized and positioned to engage a corresponding one of said pair of cams, the vanes of the first plurality engaging one of the cams, the vanes of the second plurality engaging the other one of the cams.

A variable displacement vane pump comprising:

• a casing having at least one port and having a pair of complementary cams relatively rotatable in opposite directions with respect to said one port, and each having a surface shaped to provide a curvilinear annular track;
• a rotor rotatably mounted in said casing;
• and
• a first and second plurality of vanes slidably mounted upon said rotor, each of said vanes being sized and positioned to engage a corresponding one of said pair of cams, the vanes of the first plurality engaging one of the cams, the vanes of the second plurality engaging the other one of the cams.

A variable displacement vane pump comprising:

• a casing having a pair of relatively rotatable complementary cams, each having a surface shaped to provide a curvilinear annular track, said casing having at least one inlet and outlet port and wherein said annular track has a thickness that various periodically in a circumferential direction;
• a rotor rotatably mounted in said casing;
• and
• a first and second plurality of vanes slideably mounted upon said rotor, each of said vanes being sized and positioned to engage a corresponding one of said pair of cams, the vanes of the first plurality engaging one of the cams, the vanes of the second plurality engaging the other one of the cams.