Rotor with cut-outs

1. A gerotor device comprising:

a stator having n+1 lobes;

a rotor having n teeth, the rotor teeth and the stator lobes cooperating with one another to define expanding and contracting fluid pockets as the rotor rotates and orbits with respect to the stator, each tooth being divided by an axis and including a first inner recess formed in a peripheral surface on a first side of the axis, a second inner recess formed in a peripheral surface on a second side of the axis, a first outer recess formed in a peripheral surface on the first side of the axis, a second outer recess formed in a peripheral surface on the second side of the axis, wherein each edge of each recess is generally defined by a respective line of action; and wherein at least one of the first and second inner recess being configured to permit fluid communication between the maximum volume transition pocket and an adjacent expanding fluid pocket as the maximum volume transition pocket approaches maximum volume and at least one of the first and second outer recess being configured to permit fluid communication between the minimum volume transition pocket and an adjacent contracting fluid pocket as the minimum volume transition pocket approaches minimum volume.

2. The gerotor device of claim 1 , wherein each edge of each recess is offset a distance from a respective line of action.

3. The gerotor device of claim 1 , wherein each tooth includes an intermediate recess disposed between the inner recess and the outer recess.

4. The gerotor device of claim 3 , wherein the intermediate recess extends from an end face of the rotor into the rotor about 20% of the depth of the rotor.

5. The gerotor device of claim 1 , wherein each inner recess and at least one outer recess extends the entire depth of the rotor.

6. The gerotor device of claim 1 , wherein at least one inner recess and at least one outer recess extends a portion of the entire depth of the rotor.

7. The gerotor device of claim 1 , wherein each axis bisects a respective tooth.

8. The gerotor device of claim 1 , wherein the lobes are rollers each having a circular cross section having no points of inflection.

9. The gerotor device of claim 8 , wherein each tooth includes an apex and a valley that defines a profile for the rotor and the rotor has only one point of inflection in each valley.

10. A hydraulic device comprising:

a gerotor device comprising a rotor having n teeth and a stator having n+1 lobes, the rotor teeth and the stator lobes cooperating with one another to define expanding and contracting fluid pockets as the rotor rotates with respect to the stator, each tooth being divided by an axis and including a first inner recess formed in a peripheral surface on a first side of the axis, a second inner recess formed in a peripheral surface on a second side of the axis, a first outer recess formed in a peripheral surface on the first side of the axis, a second outer recess formed in a peripheral surface on the second side of the axis, each tooth including an apex and a valley that define a profile for the rotor; wherein at least one of the first and second inner recess being configured to permit fluid communication between the maximum volume transition pocket and an adjacent expanding fluid pocket as the maximum volume transition pocket approaches maximum volume and at least one of the first and second outer recess being configured to permit fluid communication between the minimum volume transition pocket and an adjacent contracting fluid pocket as the minimum volume transition pocket approaches minimum volume.

11. The device of claim 10 , wherein n teeth include a first tooth and a second tooth adjacent the first tooth, at an instant during the movement of the rotor with respect to the stator at least one of the fluid pockets is generally defined between an inner edge of the first outer recess of the first tooth and an outer edge of the first inner recess of the second tooth.

12. The device of claim 11 , wherein n teeth include a third tooth adjacent the second tooth, at an instant during the movement of the rotor with respect to the stator at least one of the fluid pockets is generally defined between an outer edge of the first inner recess of the second tooth and an inner edge of the first inner recess of the third tooth.

13. The device of claim 12 , wherein n teeth including a fourth tooth adjacent the third tooth, at an instant during the movement of the rotor with respect to the stator at least one of the fluid pockets is generally defined between an inner edge of the first inner recess of the third tooth and an inner edge of the second inner recess of the fourth tooth.

14. The device of claim 10 , wherein n teeth include a first tooth, at an instant during the movement of the rotor with respect to the stator an outer edge of the first outer recess of the first tooth and an outer edge of the second outer recess of the first tooth both generally define a closed fluid pocket.

15. A gerotor device comprising a rotor and a stator, the rotor including a plurality of teeth defining a profile and the stator including a plurality of lobes, the rotor teeth and the stator lobes cooperating with one another to define expanding and contracting fluid pockets that include minimum volume transition pockets and maximum volume transition pockets as the rotor rotates with respect to the stator, each tooth being divided by a tooth axis and including a first recess and a second recess spaced from the first recess along the profile on the same side of the tooth axis, the first recesses being configured to permit fluid communication between the maximum volume transition pocket and an adjacent expanding fluid pocket as the maximum volume transition pocket approaches maximum volume, the second recesses being configured to permit fluid communication between the minimum volume transition pocket and an adjacent contracting fluid pocket as the minimum volume transition pocket approaches minimum volume.

16. The gerotor device of claim 15 , wherein the first recess is disposed closer to the tooth axis along the profile as compared to the second recess.

17. The gerotor device of claim 15 , further comprising an intermediate recess disposed between the first recess and the second recess.

18. The gerotor device of claim 17 , wherein the intermediate recess extends into the rotor from a face only a portion of the entire depth of the rotor.

19. The gerotor device of claim 15 , wherein the recesses extend only a portion of the axial dimension of the rotor.

20. The gerotor device of claim 15 , wherein the recesses extend at least substantially the entire axial dimension of the rotor.