Cantilevered Stator Vane Fixture for Precision Tip Machining
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Solution Overview
Problem
Conventional methods for machining cantilevered stator vanes in gas turbine engines are time-consuming and costly, requiring the use of wax or plastic for assembly and disassembly, which complicates achieving tight tolerances between vane tips and rotor structures.
Innovation Solution
A fixture and insert assembly that applies a progressive force to simulate the operational positioning of cantilevered stator vanes, allowing for accurate machining of vane tips to achieve desired tolerances without the need for wax or plastic, thereby reducing assembly and disassembly time and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wax or plastic is used to encapsulate stators for vane tip machining, then the vanes can be retained and machined, but the assembly and disassembly process becomes time-consuming and costly
Solution Approach 1:
The invention extracts the retention function from consumable materials (wax/plastic) and transfers it to a reusable mechanical fixture system. The fixture with clamping mechanisms directly holds the stator assembly during machining, eliminating the need for encapsulation materials and their associated time-consuming application and removal processes.
Solution Approach 2:
The fixture acts as an intermediary device between the machining operation and the stator assembly. It provides a stable, reusable interface that secures the vanes in the correct position for machining without requiring consumable materials, thereby reducing both time and cost while maintaining precision.
2Manufacturing precision
If wax or plastic is used to retain vanes during machining, then the vanes can be held in position, but additional materials must be procured and disposed of
Solution Approach 1:
The fixture is designed to be self-retaining through its mechanical clamping mechanisms. Once assembled, the fixture securely holds the stator assembly without requiring additional consumable materials. The system serves itself by using its own structural elements for retention, eliminating the need for external wax or plastic materials.
Solution Approach 2:
The invention recovers and reuses the fixture across multiple machining operations. Instead of discarding consumable wax or plastic materials after a single use, the durable fixture can be reused numerous times, significantly reducing material loss and associated costs while maintaining consistent machining precision.
3Ease of manufacture
If conventional machining methods are used without simulating operational positioning, then the machining process is simpler, but the desired tolerances between vane tips and rotor structures cannot be achieved
Solution Approach 1:
The fixture is configured to pre-position the stator assembly in the exact operational orientation and location relative to the rotor structure before machining begins. This preliminary positioning ensures that when the vane tips are machined, they will achieve the desired tolerances for clearance with the rotor, eliminating the need for complex post-machining adjustments.
Solution Approach 2:
The fixture replicates the actual operational geometry and positioning of the engine assembly. By creating a simplified copy of the operational environment, the fixture allows vanes to be machined in their exact running position, ensuring that clearance tolerances are achieved without requiring the full complexity of the actual engine assembly.
Data Source
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AI summary
An assembly includes a fixture, first and second vanes, and an insert. The first vane and the second vane are retained within the fixture and are spaced at a distance from one another. The insert is disposed between the first vane and the second vane and the insert includes a spring that exerts a force that is applied to both the first vane and the second vane.