Segmented Gas Turbine Rotor Assembly with Axial Disk Mounts
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Solution Overview
Problem
Gas turbine engine designers face challenges in increasing turbine rotational speed while managing rotor disk bore sizes and reducing weight, particularly with the use of high-temperature composite materials like ceramic matrix composites, which require new rotor architectures to accommodate their unique capabilities and limitations.
Innovation Solution
A rotor assembly comprising a first and second rotor disk with disk mounts that connect them, where the disk mounts are integral with the disks and project axially through each other, and the rotor blades feature dovetail attachments with flared cross-sectional geometry, reducing the need for additional sealing devices and enhancing cooling schemes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If turbine rotational speed is increased, then performance is improved, but rotor disk bore size increases making heat treating challenging
Solution Approach 1:
The rotor disk is divided into multiple segments or sections, allowing the bore to be heat treated in sections rather than as a single large component. This segmentation enables conventional heat treating equipment to effectively treat the bore by working on smaller, manageable sections.
Solution Approach 2:
The design transitions from a solid monolithic rotor disk to a structure with axial spacing between disks, creating new dimensional possibilities for heat treatment access and cooling flow paths that were not available in traditional single-disk designs.
2Strength
If separate airfoils with mechanical attachments are used, then rotor assembly is structurally sound, but weight increases and cooling efficiency decreases
Solution Approach 1:
The airfoil and rotor disk are merged into a single integrated structure, eliminating separate mechanical attachments and their associated weight. The integrated design maintains structural integrity while reducing the weight penalty of multiple discrete components and attachment hardware.
Solution Approach 2:
The mechanical attachment features (tooth attachments, fir tree attachments) are extracted or eliminated from the design. Instead of separate airfoils mechanically attached to the disk, the airfoil is integrated directly into the rotor disk structure, removing unnecessary weight.
3Force
If live rim with continuous rim is used, then radial loads are transferred effectively, but device complexity increases due to cover plates and sealing requirements
Solution Approach 1:
The design moves from a continuous rim structure to axially-spaced disks with gaps, creating new flow paths through the rotor assembly. This dimensional change allows cooling air to pass through the structure, eliminating the need for complex sealing systems while maintaining structural integrity.
Solution Approach 2:
The cover plates and sealing systems are extracted or eliminated from the design. The axial spacing between disks creates natural sealing planes and flow paths that eliminate the need for additional sealing components and their associated complexity.
4Ease of manufacture
If traditional rotor architecture is used, then mechanical attachments are simple, but cooling efficiency is reduced and fluid leakage increases
Solution Approach 1:
The design introduces axial spacing between rotor disks, creating new three-dimensional flow paths for cooling air. This dimensional change allows cooling fluid to pass directly through the rotor structure, dramatically improving cooling efficiency while the integrated airfoil design reduces fluid leakage paths.
Data Source
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AI summary
A rotor assembly is provided for a gas turbine engine. This rotor assembly includes a first rotor disk (180A), a second rotor disk (180B), a plurality of rotor blades (104) and a plurality of disk mounts (188). The first rotor disk is configured to rotate about a rotational axis (102). The second rotor disk is configured to rotate about the rotational axis. The rotor blades are arranged circumferentially around the rotational axis. Each of the rotor blades is axially between and mounted to the first rotor disk and the second rotor disk. The disk mounts connect the first rotor disk and the second rotor disk together. The disk mounts include a first disk mount (188A). The first disk mount is integral with the first rotor disk. The first disk mount projects axially through the second rotor disk.