Pump

1. A pump comprising:

a double-stroke delivery contour, the delivery contour having at least one rise zone, at least one large circle region, at least one fall zone, and at least one small circle region, and, a rotor within the delivery contour, the rotor having radially displaceable vanes in radial rotor slots,

an angular range of the large circle region of the delivery contour being lengthened, wherein the large circle region is greater than the fall zone.

2. The pump as recited in claim 1 wherein the pump is a transmission pump.

3. The pump as recited in claim 1 wherein the pump is a 10 vane pump and the large circle region of the delivery contour on one side is between 48 and 51 degrees.

4. The pump as recited in claim 3 wherein the large circle region on one side extends 49 degrees.

5. The pump as recited in claim 1 wherein the pump is a 12 vane pump and the large circle region of the delivery contour on one side is between 51 and 55 degrees.

6. The pump as recited in claim 5 wherein the large circle region on one side extends 52 degrees.

7. The pump as recited in claim 1 wherein a length of a suction region is not lengthened.

8. The pump as recited in claim 1 wherein the pump is a 12 vane pump, and turning points of a displacement contour function in a direction from a suction region to a pressure region are spaced apart by approximately 105 degrees.

9. The pump as recited in claim 1 wherein the pump is a 10 vane pump, and turning points of a displacement contour function in a direction from a pressure region to a suction region are spaced apart by approximately 90 degrees.

10. The pump as recited in claim 1 wherein the pump is a 10 vane pump, turning points of a displacement contour function being shifted by approximately 3° in direction of rotation.

11. The pump as recited in claim 1 wherein turning points of a displacement contour function are not spaced evenly about the delivery contour.