Gas Turbine Variable Guide Vane Bushing Ring and Biasing Member
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas turbine engines face challenges in improving flow conditions and reducing energy losses in the compressor section, particularly due to limitations in variable guide vane assemblies, which affect the operable range and aerodynamic loading on rotors.
Innovation Solution
The use of a bushing ring with a biasing member, such as a U-seal or W-seal made of elastomeric material, to securely engage and rotate variable guide vanes within the compressor section, reducing part count and weight while maintaining tight tolerances and sealing to minimize leakage and vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If variable guide vanes are used in the compressor section, then flow conditions and aerodynamic loading are improved, but device complexity increases due to additional components and assembly requirements
Solution Approach 1:
The patent combines multiple functions into the bushing ring component: it serves as both a sealing element and a bearing support for the variable guide vane stems. The biasing member is integrated into the same assembly, creating a compact unit that reduces the number of separate parts while maintaining the ability to control flow conditions and reduce aerodynamic loading issues.
Solution Approach 2:
The bushing ring performs multiple functions simultaneously: it provides sealing between components, supports the rotational movement of variable guide vane stems, and works with the biasing member to maintain proper positioning. This multi-functionality improves compressor performance without proportionally increasing device complexity.
2Productivity
If tight manufacturing tolerances are applied to variable guide vane assemblies, then flow conditions improve, but manufacturing precision requirements and cost increase
Solution Approach 1:
The biasing member is designed to apply axial force that compensates for manufacturing variations and wear. By changing the mechanical parameter of applying continuous axial force, the system can maintain proper clearance and sealing without requiring extremely tight manufacturing tolerances on the bushing ring and stem interfaces.
Solution Approach 2:
The biasing member pre-compresses the sealing interface between the bushing ring and adjacent components, creating a cushioning effect that compensates for manufacturing tolerances. This beforehand cushioning ensures consistent sealing and flow conditions even when manufacturing precision varies within reasonable limits.
3Reliability
If traditional sealing methods are used in variable guide vane assemblies, then sealing is provided, but energy losses increase due to leakage
Solution Approach 1:
The biasing member is made of elastomeric material, which is a flexible polymer. This flexible material deforms to conform to the mating surface, creating an effective seal that prevents gas leakage. The flexibility allows the seal to maintain contact under varying operational conditions, reducing energy losses while providing reliable sealing.
Solution Approach 2:
The use of elastomeric material changes the physical parameter of the sealing element from rigid to flexible. This material property change allows the seal to adapt to surface irregularities and maintain effective sealing, thereby reducing leakage losses while ensuring reliable sealing performance.
4Ease of manufacture
If multiple separate components are used in the variable guide vane assembly, then ease of manufacture is improved, but weight and device complexity increase
Solution Approach 1:
The patent merges the sealing function, bearing support function, and biasing function into a single integrated assembly (bushing ring with integrated biasing member). This consolidation reduces the total number of parts, thereby reducing the overall weight of the moving components in the variable guide vane assembly while maintaining manufacturability.
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
This configuration enhances the performance of gas turbine engines by improving flow conditions, reducing energy losses, and extending the operable range of the compressor, while also reducing the need for strict manufacturing tolerances and minimizing axial movement and vibrations.
Implementation Method 1
a biasing member received within the annular recess and disposed axially between the ring and the downstream inner wall of the component, the biasing member exerting a force against the ring in an axial direction
Implementation Method 2
the biasing member is a sealing member... the sealing member extends circumferentially all around the central axis... the sealing member is made of an elastomeric material
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A gas turbine engine (10) includes first and second components (28, 32) respectively defining first and second gaspath surfaces (22a, 32a) that are axially spaced apart from one another by an annular recess (28d). A bushing ring (44) is disposed within the annular recess (28d) and defines stem pockets (44e) therein. Variable guide vanes (42) are pivotable about respective vane axes (A) extending between first and second stems (42d, 42f). A biasing member (50) is received within the annular recess (28d) and disposed axially between the bushing ring (44) and one of the first component and the second component (28, 32). The biasing member (50) exerts a force against the bushing ring (44) in an axial direction relative to the central axis (11) and towards the other of the first component and the second component (28, 32).