Sleeve Bleed Valve Pressure Balancing to Reduce Wear and Leakage
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Solution Overview
Problem
Conventional high-pressure bleed valves for gas turbine engines face inefficiencies and wear due to high pressure differentials, leading to leakage and reduced performance in maintaining constant pressure supply for secondary aircraft systems.
Innovation Solution
A full-area piston bleed valve design with angled surfaces and a solenoid pressure control system, utilizing an intermediate-pressure source and solenoid pressure valve to manage high-pressure fluid flow, minimizing leakage and wear through a compact, symmetrical configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If conventional high-pressure bleed valve design is used, then the valve can handle high-pressure fluid flow, but the valve experiences increased wear and leakage due to high pressure differentials
Solution Approach 1:
The patent introduces an intermediate-pressure chamber between the high-pressure inlet and low-pressure outlet. This intermediary chamber reduces the pressure differential across the piston by staging the pressure reduction in two steps: first from high-pressure to intermediate-pressure, then from intermediate-pressure to low-pressure. This eliminates direct exposure to extreme pressure differentials, reducing wear and leakage while maintaining high-pressure handling capability
Solution Approach 2:
The patent employs pneumatic pressure balancing through the full-area piston design where pressurized fluid acts on both sides of the piston. The intermediate-pressure chamber provides counter-pressure to balance the high-pressure force, creating a controlled pressure environment that reduces mechanical stress and wear on moving parts while enabling high-pressure operation
2Device complexity
If conventional bleed valve design is used, then the valve structure is simple, but the valve is heavy and less efficient
Solution Approach 1:
The patent segments the valve into modular components: inlet housing, outlet housing, end cap, and piston assembly. The hollow shaft is divided into sections with mounting points for each component. This segmentation allows for optimized material distribution and reduced overall weight while maintaining structural integrity and functional complexity for high-pressure operation
3Productivity
If conventional bleed valve design is used, then the valve can maintain pressure supply, but the valve experiences reduced performance and increased leakage
Solution Approach 1:
The intermediate-pressure chamber acts as an intermediary that enables controlled pressure regulation. By staging the pressure reduction process, the system maintains efficient pressure supply to the secondary system while minimizing energy loss through leakage. The controlled pressure environment reduces the driving force for leakage paths
Solution Approach 2:
The full-area piston design provides inherent feedback control where the intermediate-pressure chamber pressure acts back on the piston to balance forces. This self-regulating mechanism maintains optimal valve positioning for efficient pressure supply while minimizing leakage, as any pressure imbalance automatically adjusts the valve state
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a lightweight, efficient, and reliable high-pressure bleed valve that maintains constant pressure supply with reduced wear and leakage, suitable for high-temperature and high-pressure environments, improving the performance and efficiency of gas turbine engine systems.
Implementation Method 1
An intermediate pressure of the first pressure chamber is for driving the piston into the closed position
Implementation Method 2
A solenoid pressure of the second pressure chamber is for driving the piston into the open position
Implementation Method 3
The outer sleeve of the piston can include a high-pressure seal ring at an interface between an outer diameter surface of the outer sleeve of the piston and an inner diameter surface of the inlet housing
Data Source
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AI summary
A bleed valve (100) includes inlet and outlet housings (102, 104), a hollow shaft (106) defining a valve axis (A), and a full-area piston (116). The shaft (106) includes a first end (108) mounted to an inner diameter portion (112) of the inlet housing (102) and a second end (110) mounted to an end cap (114) of the outlet housing (104). The piston (116) is slidably mounted to the shaft (106). A first chamber (118) is defined between an upstream side (120) of the piston (116) and the inner diameter portion (112) of the inlet housing (102). A second chamber (124) is defined between a downstream side (126) of the piston (116) and the end cap (114) of the outlet housing (104). An area of an upstream surface (132) of the piston (116) at an angle with respect to the valve axis (A) is in fluid communication with the first chamber (118), and is substantially equal to an area of a downstream surface (134) of the piston (116) at an angle with respect to the valve axis (A) and in fluid communication with the second chamber (124).