Rocket thruster comprising load-balanced pintle valve

1. A rocket thruster assembly comprising:

a nozzle providing an internal passageway-defining surface structure for receiving and expelling combustion products, the internal passageway-defining structure comprising a converging region that converges in cross section into a throat region, and a diverging region located aft of the throat region and extending radially outwardly;

a valve subassembly comprising a pintle with a head portion, the head portion having a truncated substantially conical surface region terminating at an aft truncated portion coaxial with the throat region, the truncated substantially conical surface region facing the converging region and the throat region to provide a variable effective throat area therebetween, the truncated portion having a bleed passageway opening in communication with a passage leading through the head portion to a bleed cavity located on an opposite side of the head portion relative to the throat region for receiving and expelling the combustion products to counterbalance the pintle; and

a thrust control subassembly operatively coupled to the pintle for moving the pintle axially back and forth relative to the throat region to a plurality of axial positions and for selectively retaining the pintle at the plurality of axial positions for changing the effective throat area;

wherein the thrust control subassembly further comprises an actuator operatively coupled to the pintle for moving the pintle axially back and forth relative to the throat region and retaining the pintle at a plurality of open positions in which the pintle is spaced from the converging region and the throat region, and at a closed position in which the pintle contacts the internal passageway-defining surface structure to close at least one of the throat region and the converging region.

2. A rocket thruster assembly according to claim 1 , wherein the internal passageway-defining surface structure comprises an insert structure.

3. A rocket thruster assembly according to claim 1 , wherein the internal passageway-defining surface structure comprises an insert structure defining the converging region and the throat region, the insert structure comprising at least one refractory material selected from the group consisting of rhenium, tungsten, rhenium alloys, and tungsten alloys.

4. A rocket thruster assembly according to claim 1 , wherein the converging and diverging regions and the throat region are coaxially aligned with each other.

5. A rocket thruster assembly according to claim 1 , wherein the truncated portion has an outer edge defining the bleed passageway opening.

6. A rocket thruster assembly according to claim 1 , wherein the pintle further comprises a stem portion integral with the head portion, the stem portion being surrounded by the bleed cavity.

7. A rocket thruster assembly according to claim 1 , wherein the head portion comprises a refractory material comprising at least one material selected from the group consisting of rhenium, tungsten, a rhenium alloy, and a tungsten alloy.

8. A rocket thruster assembly according to claim 1 , wherein the truncated substantially conical surface region has a bi-angular cross section.

9. A rocket thruster assembly according to claim 1 , wherein the truncated substantially conical surface region is concentric with the throat region and the converging region.

10. A rocket thruster assembly comprising:

a nozzle providing an internal passageway-defining surface structure for receiving and expelling combustion products, the internal passageway-defining structure comprising a converging region that converges in cross section into a throat region, and a diverging region located aft of the throat region and extending radially outwardly;

a valve subassembly comprising a pintle with a head portion, the head portion having a truncated substantially conical surface region terminating at an aft truncated portion coaxial with the throat region, the truncated substantially conical surface region facing the converging region and the throat region to provide a variable effective throat area therebetween, the truncated portion having a bleed passageway opening in communication with a passage leading through the head portion to a bleed cavity located on an opposite side of the head portion relative to the throat region for receiving and expelling the combustion products to counterbalance the pintle; and

a thrust control subassembly operatively coupled to the pintle for moving the pintle axially back and forth relative to the throat region to a plurality of axial positions and for selectively retaining the pintle at the plurality of axial positions for changing the effective throat area;

wherein the thrust control subassembly further comprises an actuator operatively coupled to the pintle for moving the pintle axially back and forth relative to the throat region and retaining the pintle at a plurality of open positions in which the pintle is spaced from the converging region and the throat region, the effective throat area being different for each of the open positions.

11. A rocket thruster assembly according to claim 10 , wherein the internal passageway-defining surface structure comprises an insert structure.

12. A rocket thruster assembly according to claim 10 , wherein the internal passageway-defining surface structure comprises an insert structure defining the converging region and the throat region, the insert structure comprising at least one refractory material selected from the group consisting of rhenium, tungsten, rhenium alloys, and tungsten alloys.

13. A rocket thruster assembly according to claim 10 , wherein the converging and diverging regions and the throat region are coaxially aligned with each other.

14. A rocket thruster assembly according to claim 10 , wherein the truncated portion has an outer edge defining the bleed passageway opening.

15. A rocket thruster assembly according to claim 10 , wherein the pintle further comprises a stem portion integral with the head portion, the stem portion being surrounded by the bleed cavity.

16. A rocket thruster assembly according to claim 10 , wherein the head portion comprises a refractory material comprising at least one material selected from the group consisting of rhenium, tungsten, a rhenium alloy, and a tungsten alloy.

17. A rocket thruster assembly according to claim 10 , wherein the truncated substantially conical surface region has a bi-angular cross section.

18. A rocket thruster assembly according to claim 10 , wherein the truncated substantially conical surface region is concentric with the throat region and the converging region.

19. A rocket thruster assembly comprising:

a nozzle providing an internal passageway-defining surface structure for receiving and expelling combustion products, the internal passageway-defining structure comprising a converging region that converges in cross section into a throat region, and a diverging region located aft of the throat region and extending radially outwardly;

a valve subassembly comprising a pintle with a head portion, the head portion having a truncated substantially conical surface region terminating at an aft truncated portion coaxial with the throat region, the truncated substantially conical surface region facing the converging region and the throat region to provide a variable effective throat area therebetween, the truncated portion having a bleed passageway opening in communication with a passage leading through the head portion to a bleed cavity located on an opposite side of the head portion relative to the throat region for receiving and expelling the combustion products to counterbalance the pintle; and

a thrust control subassembly operatively coupled to the pintle for moving the pintle axially back and forth relative to the throat region to a plurality of axial positions and for selectively retaining the pintle at the plurality of axial positions for changing the effective throat area;

wherein the thrust control subassembly is continuously variable, the thrust control subassembly comprises an actuator operatively coupled to the pintle for moving the pintle axially relative to the throat region and retaining the pintle at any position between a maximum open position and a closed position.

20. A rocket thruster assembly according to claim 19 , wherein the internal passageway-defining surface structure comprises an insert structure.

21. A rocket thruster assembly according to claim 19 , wherein the internal passageway-defining surface structure comprises an insert structure defining the converging region and the throat region, the insert structure comprising at least one refractory material selected from the group consisting of rhenium, tungsten, rhenium alloys, and tungsten alloys.

22. A rocket thruster assembly according to claim 19 , wherein the converging and diverging regions and the throat region are coaxially aligned with each other.

23. A rocket thruster assembly according to claim 19 , wherein the truncated portion has an outer edge defining the bleed passageway opening.

24. A rocket thruster assembly according to claim 19 , wherein the pintle further comprises a stem portion integral with the head portion, the stem portion being surrounded by the bleed cavity.

25. A rocket thruster assembly according to claim 19 , wherein the head portion comprises a refractory material comprising at least one material selected from the group consisting of rhenium, tungsten, a rhenium alloy, and a tungsten alloy.

26. A rocket thruster assembly according to claim 19 , wherein the truncated substantially conical surface region has a bi-angular cross section.

27. A rocket thruster assembly according to claim 19 , wherein the truncated substantially conical surface region is concentric with the throat region and the converging region.

28. A rocket thruster assembly comprising:

a nozzle providing an internal passageway-defining surface structure for receiving and expelling combustion products, the internal passageway-defining structure comprising a converging region that converges in cross section into a throat region, and a diverging region located aft of the throat region and extending radially outwardly;

a valve subassembly comprising a pintle with a head portion, the head portion having a truncated substantially conical surface region terminating at an aft truncated portion coaxial with the throat region, the truncated substantially conical surface region facing the converging region and the throat region to provide a variable effective throat area therebetween, the truncated portion having a bleed passageway opening in communication with a passage leading through the head portion to a bleed cavity located on an opposite side of the head portion relative to the throat region for receiving and expelling the combustion products to counterbalance the pintle; and

a thrust control subassembly operatively coupled to the pintle for moving the pintle axially back and forth relative to the throat region to a plurality of axial positions and for selectively retaining the pintle at the plurality of axial positions for changing the effective throat area;

wherein the passage comprises a central entrance bore and a plurality of radial bleed passageways, the central entrance bore extending from the bleed passageway opening and terminating in the pintle, the radial bleed passageways each having a respective first end intersecting the central entrance bore and a respective second end terminating at the bleed cavity, the second ends of the radial bleed passageways being spaced circumferentially from each other.

29. A rocket thruster assembly according to claim 28 , wherein the internal passageway-defining surface structure comprises an insert structure.

30. A rocket thruster assembly according to claim 28 , wherein the internal passageway-defining surface structure comprises an insert structure defining the converging region and the throat region, the insert structure comprising at least one refractory material selected from the group consisting of rhenium, tungsten, rhenium alloys, and tungsten alloys.

31. A rocket thruster assembly according to claim 28 , wherein the converging and diverging regions and the throat region are coaxially aligned with each other.

32. A rocket thruster assembly according to claim 28 , wherein the truncated portion has an outer edge defining the bleed passageway opening.

33. A rocket thruster assembly according to claim 28 , wherein the pintle further comprises a stem portion integral with the head portion, the stem portion being surrounded by the bleed cavity.

34. A rocket thruster assembly according to claim 28 , wherein the head portion comprises a refractory material comprising at least one material selected from the group consisting of rhenium, tungsten, a rhenium alloy, and a tungsten alloy.

35. A rocket thruster assembly according to claim 28 , wherein the truncated substantially conical surface region has a bi-angular cross section.

36. A rocket thruster assembly according to claim 28 , wherein the truncated substantially conical surface region is concentric with the throat region and the converging region.

37. A rocket thruster assembly comprising:

a nozzle providing an internal passageway-defining surface structure for receiving and expelling combustion products, the internal passageway-defining structure comprising a converging region that converges in cross section into a throat region, and a diverging region located aft of the throat region and extending radially outwardly;

a valve subassembly comprising a pintle with a head portion, the head portion having a truncated substantially conical surface region terminating at an aft truncated portion coaxial with the throat region, the truncated substantially conical surface region facing the converging region and the throat region to provide a variable effective throat area therebetween, the truncated portion having a bleed passageway opening in communication with a passage leading through the head portion to a bleed cavity located on an opposite side of the head portion relative to the throat region for receiving and expelling the combustion products to counterbalance the pintle; and

a thrust control subassembly operatively coupled to the pintle for moving the pintle axially back and forth relative to the throat region to a plurality of axial positions and for selectively retaining the pintle at the plurality of axial positions for changing the effective throat area, wherein:

the pintle further comprises a retention sleeve movable axially in unison with the pintle head, the retention sleeve having an outer surface region;

the valve subassembly further comprises at least one split ring insulator surrounding the retention sleeve, the split ring insulator having at least one slit that faces the outer surface region of the retention sleeve to define a secondary bleed passageway;

the thrust control subassembly comprises a piston for axially sliding the pintle relative to the split ring insulator to move the pintle head portion toward and away from the throat region, movement of the pintle head toward the throat region establishing a secondary cavity at an area from which the piston was moved; and

the secondary bleed passageway connects the bleed cavity to the secondary cavity.

38. A rocket thruster assembly according to claim 37 , wherein the internal passageway-defining surface structure comprises an insert structure.

39. A rocket thruster assembly according to claim 37 , wherein the internal passageway-defining surface structure comprises an insert structure defining the converging region and the throat region, the insert structure comprising at least one refractory material selected from the group consisting of rhenium, tungsten, rhenium alloys, and tungsten alloys.

40. A rocket thruster assembly according to claim 37 , wherein the converging and diverging regions and the throat region are coaxially aligned with each other.

41. A rocket thruster assembly according to claim 37 , wherein the truncated portion has an outer edge defining the bleed passageway opening.

42. A rocket thruster assembly according to claim 37 , wherein the pintle further comprises a stem portion integral with the head portion, the stem portion being surrounded by the bleed cavity.

43. A rocket thruster assembly according to claim 37 , wherein the head portion comprises a refractory material comprising at least one material selected from the group consisting of rhenium, tungsten, a rhenium alloy, and a tungsten alloy.

44. A rocket thruster assembly according to claim 37 , wherein the truncated substantially conical surface region has a bi-angular cross section.

45. A rocket thruster assembly according to claim 37 , wherein the truncated substantially conical surface region is concentric with the throat region and the converging region.

46. A rocket thruster assembly comprising:

a nozzle providing an internal passageway-defining surface structure for receiving and expelling combustion products, the internal passageway-defining structure comprising a converging region that converges in cross section into a throat region, and a diverging region located aft of the throat region and extending radially outwardly;

a valve subassembly comprising a pintle with a head portion, the head portion having a truncated substantially conical surface region terminating at an aft truncated portion coaxial with the throat region, the truncated substantially conical surface region facing the converging region and the throat region to provide a variable effective throat area therebetween, the truncated portion having a bleed passageway opening in communication with a passage leading through the head portion to a bleed cavity located on an opposite side of the head portion relative to the throat region for receiving and expelling the combustion products to counterbalance the pintle; and

a thrust control subassembly operatively coupled to the pintle for moving the pintle axially back and forth relative to the throat region to a plurality of axial positions and for selectively retaining the pintle at the plurality of axial positions for changing the effective throat area, wherein:

the pintle further comprises a stem portion integral with the head portion, the stem portion having an outer surface region, the head portion and the stem portion each comprising a refractory material comprising at least one refractory metal; and

the valve subassembly further comprises:

a pintle retainer surrounding the stem portion and adjacent the outer surface region of the stem portion, the pintle retainer having an outer surface region and comprising an insulation material;

a pintle retention sleeve surrounding the pintle retainer and adjacent the outer surface portion surrounding the pintle retainer, the pintle retention sleeve comprising at least one refractory metal; and

at least one ring insulator surrounding the pintle retention sleeve, the ring insulator comprising a material suitable for use as a heat sink.

47. A rocket thruster assembly according to claim 46 , wherein the refractory metal comprises at least one member selected from the group consisting of rhenium, tungsten, a rhenium alloy, and a tungsten alloy.

48. A rocket thruster assembly according to claim 46 , wherein the internal passageway-defining surface structure comprises an insert structure.

49. A rocket thruster assembly according to claim 46 , wherein the internal passageway-defining surface structure comprises an insert structure defining the converging region and the throat region, the insert structure comprising at least one refractory material selected from the group consisting of rhenium, tungsten, rhenium alloys, and tungsten alloys.

50. A rocket thruster assembly according to claim 46 , wherein the converging and diverging regions and the throat region are coaxially aligned with each other.

51. A rocket thruster assembly according to claim 46 , wherein the truncated portion has an outer edge defining the bleed passageway opening.

52. A rocket thruster assembly according to claim 46 , wherein the pintle further comprises a stem portion integral with the head portion, the stem portion being surrounded by the bleed cavity.

53. A rocket thruster assembly according to claim 46 , wherein the head portion comprises a refractory material comprising at least one material selected from the group consisting of rhenium, tungsten, a rhenium alloy, and a tungsten alloy.

54. A rocket thruster assembly according to claim 46 , wherein the truncated substantially conical surface region has a bi-angular cross section.

55. A rocket thruster assembly according to claim 46 , wherein the truncated substantially conical surface region is concentric with the throat region and the converging region.