Rotary Electrical Machine with Segmented Rotor Magnets
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Solution Overview
Problem
Conventional rotary electrical machines face challenges in manufacturing magnet rows with N-poles facing each other, increased magnetic reluctance due to oblique magnetic flux crossing air gaps, and magnetic flux interference between neighboring poles, making it difficult to achieve high torque at low speeds.
Innovation Solution
A rotary electrical machine design featuring a rotor disc with rectangular magnets whose polarities differ and are positioned to cross the rotation direction, with armature cores sandwiching the magnets and a winding wound between them, allowing for reduced magnetic flux leakage and optimized magnetic flux distribution by adjusting the angle between armature cores.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If magnets are disposed with N-poles facing each other in a conventional sandwiched rotor, then the rotor structure is simplified, but magnetic reluctance increases and magnetic flux interference occurs between neighboring magnetic poles
Solution Approach 1:
The patent applies asymmetry by alternating the polarity arrangement of magnets in different radial layers. Specifically, in one radial layer N-poles face each other while in adjacent radial layers S-poles face each other. This asymmetric arrangement across layers prevents magnetic flux interference and reduces magnetic reluctance while maintaining the simplified sandwiched rotor structure.
2Ease of manufacture
If magnets are disposed with N-poles facing each other, then manufacturing is simplified, but magnetic flux must obliquely cross air gaps increasing magnetic reluctance
Solution Approach 1:
The patent transitions from a two-dimensional single-layer magnet arrangement to a three-dimensional multi-layer radial structure. By distributing magnets across multiple radial layers with alternating polarity patterns, the magnetic flux path is optimized to cross air gaps more perpendicularly, reducing magnetic reluctance while maintaining manufacturing simplicity.
3Device complexity
If conventional magnet arrangement is used, then device complexity is reduced, but torque ripple increases and low-speed high-torque performance is compromised
Solution Approach 1:
The patent segments the rotor magnet structure into multiple independent radial layers, each with its own polarity pattern. This segmentation allows independent optimization of magnetic flux paths in each layer, reducing torque ripple and enabling high torque output at low speeds while keeping the overall device complexity manageable through modular layer construction.
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 reduces magnetic flux leakage, enabling higher torque production at low speeds while minimizing torque ripple, allowing for more compact designs and efficient low-speed operation.
Implementation Method 1
The rotor disc is configured in such a manner that plural rectangular magnets whose longitudinal direction crosses the direction of rotation are disposed on the rotor disc, and that the polarities of neighboring magnets differ from each other. The armature is configured in such a manner that plural armature cores are disposed to sandwich the magnets
Implementation Method 2
a winding is commonly wound between the armature cores
Data Source
AI summary
When a conventional technology is employed, it is difficult to manufacture a magnet row because magnets are disposed so that N-poles face each other while S-poles face each other. Further, magnetic reluctance is increased because a generated magnetic flux obliquely crosses an air gap in which the magnets are disposed. Furthermore, the conventional technology is at a disadvantage in that magnetic flux interference occurs between neighboring magnetic poles. The present invention has been made to address the above problems and provide a rotary electrical machine capable of generating high torque at low speed. The rotary electrical machine includes a rotor disc and an armature. The rotor disc is configured so that plural rectangular magnets whose longitudinal direction crosses the direction of rotor disc rotation are disposed on the rotor disc, and that the polarities of neighboring magnets differ from each other. The armature is configured so that plural armature cores are disposed to sandwich the magnets, which are mounted on the rotor disc and provided with a particular magnetic pole, and that a winding is commonly wound between the armature cores.