Turbine engine air control valve

1. A turbine engine air control valve comprising:

a valve body having a fluid flow passage;

a valve member disposed in the valve body, the valve member being configured to rotate about a rotation axis between a maximum flow position and a minimum flow position;

wherein the valve member includes a vane and a floating member operatively coupled to the vane; and

wherein the floating member is configured to float relative to the vane and the floating member has an outer diameter which is less than an inner diameter of the fluid flow passage at the position of the floating member, such that when the valve member is in the minimum flow position, the floating member is spaced apart from the valve body to form an annular flow gap that provides a controlled amount of minimum fluid flow across the valve member as the fluid flows through the annular flow gap.

2. The air control valve according to claim 1 , wherein the vane is configured as a disc-shaped plate.

3. The air control valve according to claim 1 , wherein the control valve is configured as a butterfly valve and the vane is configured as a butterfly plate.

4. The air control valve according to claim 1 , wherein the vane has a circumferential edge having a circumferential groove, and the floating member includes an annular ring disposed in the circumferential groove.

5. The air control valve according to claim 4 , wherein the annular ring is continuous, or includes a split, or includes a plurality of discrete segments circumferentially disposed about the vane.

6. The air control valve according to claim 1 , wherein the valve member further comprises a resilient member radially interposed between the floating member and the vane, the resilient member being configured to engage the floating member to restrict movement of the floating member relative to the vane.

7. The air control valve according to claim 6 , wherein the resilient member is a centering spring.

8. The air control valve according to claim 1 , wherein the valve member further comprises one or more coupling members configured to floatably couple the floating member to the vane, wherein the one or more coupling members are configured to restrict radially outward movement of the floating member to prevent the floating member from engaging the valve body.

9. The air control valve according to claim 8 , wherein the one or more coupling members each include a pin extending through the vane and into an elongated slot of the floating member.

10. The air control valve according to claim 9 , wherein the elongated slot of the floating member is radially or circumferentially elongated.

11. The air control valve according to claim 1 , wherein the valve member is configured to modulate the flow of air through the fluid flow passage based on an angular position of the valve member within the flow passage.

12. The air control valve according to claim 11 ,

wherein the fluid flow passage extends along a longitudinal axis;

wherein the valve member is rotated to extend toward a direction parallel to the longitudinal axis in the maximum flow position; and

wherein the valve member is rotated to extend toward a direction perpendicular to the longitudinal axis in the minimum flow position.

13. The air control valve according to claim 1 , wherein the control valve further comprises a rotatable shaft extending through the valve body;

wherein the valve member is secured to the rotatable shaft so that rotation of the shaft causes the valve member to rotate about the rotation axis between the maximum flow position and the minimum flow position.

14. The air control valve according to claim 13 ,

wherein the rotatable shaft is rotatable about a shaft axis that is inclined to a plane perpendicular to a longitudinal axis of the valve body, and

wherein the valve member has a major surface that extends along a plane that is inclined relative to the shaft axis.

15. An airflow control system for a gas turbine engine comprising:

an airflow supply passage configured to convey air therethrough;

a butterfly valve operatively disposed in the airflow supply passage, the butterfly valve comprising:

a valve body having a fluid flow passage that defines at least a portion of the airflow supply passage;

a rotatable shaft extending through the valve body;

a valve member disposed in the valve body and secured to the rotatable shaft such that rotation of the shaft causes the valve member to rotate about a rotation axis between a maximum flow position and a minimum flow position;

wherein the valve member includes a vane and a floating member operatively coupled to the vane; and

wherein the floating member is configured to float relative to the vane and the floating member has an outer diameter which is less than an inner diameter of the fluid flow passage at the position of the floating member, such that when the valve member is in the minimum flow position, the floating member is spaced apart from the valve body to form an annular flow gap that provides a controlled amount of minimum fluid flow across the valve member as the fluid flows through the annular flow gap;

the airflow control system further comprising an actuator operatively coupled to the rotatable shaft for selectively rotating the valve member between the maximum and minimum flow positions.

16. The airflow control system according to claim 15 , wherein the airflow control system further comprises:

a position sensor having an output signal associated with an angular position of the valve member in the valve body; and

a controller operatively coupled to the position sensor and to the actuator;

wherein the controller is configured to receive the output signal from the position sensor and is configured to control the actuator to rotate the rotatable shaft and thereby the valve member to a selected position between the maximum and minimum flow positions.

17. The airflow control system according to claim 15 ,

wherein the valve body has an upstream inlet opening and a downstream outlet opening, the valve member being disposed in the valve body between the inlet and outlet openings;

wherein the airflow supply passage has an upstream portion upstream of the inlet opening of the valve body, the upstream portion being in fluid communication with a bypass flow passage of an aircraft engine; and

wherein the airflow supply passage has a downstream portion downstream of the outlet opening of the valve body, the downstream portion being in fluid communication with a turbine section of the aircraft engine.

18. A butterfly valve comprising:

a valve body having a fluid flow passage;

a valve member disposed in the valve body, the valve member being configured to rotate about a rotation axis between a maximum flow position and a minimum flow position;

wherein the valve member includes a vane and a floating member operatively coupled to the vane, wherein the vane has a circumferential edge having a circumferential groove, and the floating member includes an annular ring disposed in the circumferential groove; and

wherein the floating member is configured to float relative to the vane and the floating member has an outer diameter which is less than an inner diameter of the fluid flow passage at the position of the floating member, such that when the valve member is in the minimum flow position, the floating member is spaced apart from the valve body to form an annular flow gap that provides a controlled amount of minimum fluid flow across the valve member as the fluid flows through the annular flow gap.