Tri-Wedge Vane Arm for Gas Turbine Torque Stress
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Solution Overview
Problem
Current vane arm geometries in gas turbine engines face challenges in meeting stress requirements due to increased vane stem torque associated with higher engine temperatures and pressures, particularly in variable vane systems where the angle of attack of vane airfoils relative to airflow needs to be adjusted.
Innovation Solution
A vane arm design featuring a tri-wedge circular pocket with specific groove configurations on its vertical surfaces, limiting rotation to 1° or less, and utilizing titanium or titanium alloys to enhance structural integrity and stress distribution, thereby addressing the torque-related stress issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If current vane arm geometries (e.g., claw feature) are used, then the design is simple, but the stress requirements associated with increased vane stem torque cannot be met
Solution Approach 1:
The vane arm incorporates a tri-wedge circular pocket with non-uniform geometry that concentrates structural reinforcement precisely where hoop stress is highest (at the vane stem aperture), rather than uniformly thickening the entire component. This localized geometric modification optimizes stress distribution while minimizing additional material and complexity.
Solution Approach 2:
The invention transitions from a conventional two-dimensional cross-sectional view of the vane arm to a three-dimensional tri-wedge circular pocket geometry that adds radial and angular dimensions to the stress management approach, creating a more effective stress distribution pattern throughout the component volume.
2Stress or pressure
If the vane arm aperture diameter is increased to reduce stress, then stress distribution improves, but the rotation control precision deteriorates
Solution Approach 1:
The tri-wedge circular pocket creates localized geometric features (wedge faces and vertical surfaces) that simultaneously manage hoop stress distribution across the aperture while providing precise rotational positioning through the interaction between these localized features and corresponding features on the vane stem.
Solution Approach 2:
The tri-wedge geometry introduces asymmetric features into the otherwise circular aperture, creating specific contact points and rotational stops that precisely control vane arm rotation while the overall circular form maintains efficient stress distribution. The asymmetric wedge faces provide rotational positioning without compromising the symmetric stress management benefits of a circular geometry.
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
A vane arm (140) may comprise a first end (141) having a first surface (148) and a second surface (151) opposite the first surface (148). A vane stem aperture (146) may be formed through the first end (141) of the vane arm (140). The first surface (148) may define a first perimeter (160) of the vane stem aperture (146). The second surface (151) may define a second perimeter (162) of the vane stem aperture (146). The second perimeter (162) may comprise a circular or elliptical shape. A first wedge face (174) and second wedge face (176) may define a portion of the vane stem aperture (146).