Arc-Strut Vane Adjustment Lever for Lower Turbomachine Stress
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Solution Overview
Problem
Existing levers for adjusting variable vanes in turbomachines experience high mechanical stress and torque, leading to potential damage and inefficiencies, particularly in aircraft engines.
Innovation Solution
The introduction of an arc-shaped strut in the lever design that connects the adjusting and adjusting connection points, distributing force transmission primarily through normal forces, reducing material thickness and weight, and minimizing torque and shear forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional lever design is used for adjusting variable vanes, then the lever can transmit force from the connecting rod to the adjusting ring, but high mechanical stress and torque occur in the load and force arms, leading to potential damage and inefficiencies
Solution Approach 1:
The patent applies a curved strut connecting the load arm and force arm, replacing straight structural elements with curved geometry. This curvature redistributes the mechanical stress along the strut, converting concentrated bending moments in the arms into more evenly distributed normal forces, thereby reducing peak stresses and improving lever reliability
Solution Approach 2:
The patent introduces a third dimension by adding a curved strut that spans between the load arm and force arm, creating a three-dimensional braced structure. This additional structural dimension provides alternative load paths, reducing the bending moments and torque experienced by the individual arms while maintaining force transmission functionality
2Strength
If conventional lever design with thick arms is used to withstand high forces, then the lever can handle the mechanical loads, but the material usage increases and weight is reduced
Solution Approach 1:
The curved strut geometry allows for more efficient stress distribution, enabling the use of thinner arm sections while maintaining adequate strength. The curved shape naturally redirects forces along its length, reducing the need for massive cross-sections and allowing weight reduction through optimized material distribution
Solution Approach 2:
The patent segments the force transmission function across multiple structural elements: the load arm, the curved strut, and the force arm. This segmentation allows each component to be optimized for its specific function, with thinner arms compensated by the bracing effect of the strut, achieving overall strength without excessive weight in any single component
Data Source
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AI summary
The present invention relates to a lever for adjusting a variable displacement blade of a turbomachine (1), wherein the lever has a pivot point for rotatably mounting the lever about an axis of rotation, a first load arm with a first adjustment connection point for at least indirect connection with the variable displacement blade and a first force arm with a first actuating connection point for connection with an actuating device, wherein the lever further has a first strut which connects the first adjustment and first actuating connection points and extends in an arc shape about the axis of rotation.