Permanent Magnet Modules for Rotor Assembly
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Solution Overview
Problem
The assembly and maintenance of large electrical machines, such as wind turbine generators, are complicated by the need for numerous permanent magnets and extensive fastening materials, which can affect electromagnetic behavior and increase costs, especially in direct drive systems where access is difficult.
Innovation Solution
A permanent magnet module configuration featuring a metallic main body, a radially magnetized permanent magnet component, and a non-magnetic component that directs magnetic flux, reducing the number of magnets and fastening materials required, with a cover to secure the magnet and minimize extra material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a large number of permanent magnets are used in direct drive generators, then the electromagnetic performance is improved, but the assembly complexity and maintenance difficulty increase significantly
Solution Approach 1:
The rotor is divided into multiple modular segments, each containing a subset of permanent magnets. These modules can be independently assembled and maintained, transforming a single complex assembly into multiple manageable units. This segmentation reduces the overall assembly complexity while maintaining the required electromagnetic performance through the cumulative effect of all modules.
Solution Approach 2:
The permanent magnets are nested within modular carrier structures that are themselves nested within the rotor assembly. This hierarchical nesting allows for compact arrangement of numerous magnets while providing clear modular boundaries that simplify assembly procedures and maintenance access.
2Reliability
If extensive fastening materials are used to secure permanent magnets, then the fixation reliability is improved, but the electromagnetic behavior is negatively affected
Solution Approach 1:
Fastening materials are strategically positioned only at critical locations where mechanical strength is required, rather than uniformly distributed. The carrier structures use localized reinforcement zones with fasteners placed precisely where needed to secure magnets, minimizing the overall volume of non-magnetic materials in the electromagnetic field.
Solution Approach 2:
The fastening function is extracted from the electromagnetic active regions and concentrated in dedicated carrier structures. This separation allows fastening materials to be confined to specific non-active zones, preventing their interference with the electromagnetic field while maintaining reliable fixation.
3Strength
If numerous fastening elements are used to attach magnets to the rotor, then the mechanical strength is improved, but the manufacturing cost and assembly time increase
Solution Approach 1:
Multiple fastening operations are merged into single modular units. Each carrier structure is pre-assembled with its magnets and fastening elements as an integrated module, allowing the entire assembly to be installed in one operation rather than requiring sequential attachment of individual magnets. This merging dramatically reduces assembly time while maintaining the required mechanical strength through the combined fastening system.
Solution Approach 2:
The carrier structures are pre-assembled with permanent magnets and fastening elements before installation into the rotor. This preliminary preparation allows quality control and assembly verification to be performed on manageable modules rather than the complete rotor, accelerating the final assembly process while ensuring mechanical integrity.
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 configuration simplifies assembly and maintenance by reducing the number of magnets and fastening materials needed, improving electromagnetic efficiency and reducing costs while maintaining effective magnetic flux distribution.
Implementation Method 1
the magnets are normally arranged so as to cause magnetic flux that follows a path that crosses an air-gap between the rotor and a stator in such a manner that the stator is reached and is influenced by the magnetic flux
Implementation Method 2
The first permanent magnet component is arranged within the first receptacle of the metallic main body and is magnetized in such a way that, in use, the first permanent magnet component has a radial magnetization direction with respect to an axis of rotation of the rotor
Data Source
Figure 1
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AI summary
A permanent magnet module for a rotor is provided that is configured to be mounted to a rim (111) of the rotor and that comprises a metallic main body (100), a first permanent magnet component (101), and a first non-magnetic component (102). The metallic main body (100) forms a first partial pole piece (105) at a first lateral side of the permanent magnet module and forms a first receptacle. The first permanent magnet component (101) is arranged within the first receptacle of the metallic main body (100) and is magnetized in such a way that, in use, the first permanent magnet component (101) has a radial magnetization direction (115) with respect to an axis of rotation of the rotor. The first non-magnetic component (102) is arranged between the first partial pole piece (105) and the first permanent magnet component (101) according to a direction that, in use, is substantially tangential to the rotor rim (111).