Generator Rotor Wedge Radial Support Design
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Solution Overview
Problem
In high-speed generators, the centrifugal loading on the main field lamination stack often requires a compromise between magnetic properties and geometry due to the need for radial support of the rotor wedges, which affects the performance of both the lamination stack and the windings.
Innovation Solution
A triangular-shaped wedge with flat surfaces is used in the generator rotor, extending radially outward to provide support for both the windings and the lamination stack, eliminating the need for the lamination stack to provide radial support, and a containment sleeve is force-fit around the assembly to offer additional radial support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the main field lamination stack provides radial support for the rotor wedges, then the structural integrity is maintained, but the magnetic properties and lamination geometry must be compromised
Solution Approach 1:
The radial support function is extracted from the main field lamination stack and transferred to dedicated wedge retention structures. The lamination stack is relieved of the mechanical burden of supporting wedges, allowing it to be optimized purely for magnetic performance while the extracted support structures handle mechanical loads.
Solution Approach 2:
The rotor structure is segmented into distinct functional zones: the main field lamination stack for magnetic function, and separate wedge retention structures (including wedge blocks and containment sleeves) for mechanical support. This segmentation allows each component to be optimized for its specific purpose without compromise.
2Reliability
If the lamination stack geometry is optimized for magnetic properties, then magnetic performance improves, but the ability to provide radial support for wedges deteriorates
Solution Approach 1:
The radial support function is extracted from the lamination stack geometry, allowing the stack to be designed purely for magnetic optimization. Dedicated wedge retention structures assume the mechanical support role, enabling the lamination geometry to be tailored for magnetic performance without structural compromise.
Solution Approach 2:
Wedge retention structures act as intermediary elements between the lamination stack and the windings/wedges. These intermediaries provide the necessary mechanical support interface, allowing the lamination stack to maintain its magnetic-optimized geometry while still enabling proper wedge retention through the intermediary structures.
3Device complexity
If conventional wedge retention methods are used, then the structure is simple, but the centrifugal loading causes compromise in lamination material selection
Solution Approach 1:
The structure is segmented into simple, modular components: standard wedges, wedge blocks, and containment sleeves. While the overall system has multiple parts, each component remains relatively simple in design, allowing use of conventional materials and manufacturing methods while achieving reliable wedge retention under centrifugal loading.
Solution Approach 2:
The wedge retention system effectively creates a composite structure where the containment sleeve (outer layer) and wedge blocks (inner support elements) work together to provide enhanced mechanical support. This composite approach distributes centrifugal loads across multiple components rather than relying on a single compromised lamination material.
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 design allows the lamination stack to be optimized for magnetic properties alone, reducing material compromises and enhancing the robustness of radial support for the windings and stack, thereby improving the generator's efficiency and performance.
Implementation Method 1
A containment sleeve is force-fit around the wedges and the main lamination stack to provide radial support for the wedges
Data Source
AI summary
A wedge for use in a generator rotor includes a wedge body having a generally triangular shape with flat surfaces, and such that when the wedge is placed in a generator rotor, the flat surfaces will define circumferential extents of the wedge body relative to a rotational axis of the rotor, and said flat surfaces extending to a radially outermost extent of the wedge body. A wedge and winding combination, a generator rotor, a generator and a method all using the wedges are disclosed and claimed.