Dual-Rotor Axial Flux Machine With Claw-Pole Segmentation
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Solution Overview
Problem
Rotating electrical machines with axial flux face challenges in achieving compactness and high power efficiency while minimizing material usage and magnetic flux leaks, particularly in adjusting field winding flux and reducing torque ripples and harmonics.
Innovation Solution
A rotating electrical machine design featuring a stator with teeth and windings arranged parallel to the axis of rotation, paired with two coaxial cylindrical rotor armatures and claw-poles, utilizing a toroidal excitation coil for global excitation, and optional permanent magnets to minimize flux leaks, which allows for adjustable magnetic flux and reduced material consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single stator and two rotors configuration is used, then power density and compactness are improved, but magnetic flux leaks increase
Solution Approach 1:
The machine is segmented into a single stator and two rotors configuration, where the stator is divided into two independent axial air gaps. This segmentation allows the magnetic flux to be contained within each air gap separately, reducing cross-flux leaks while maintaining high power density in a compact structure.
Solution Approach 2:
One rotor is nested within the stator, and the second rotor is nested within the stator on the opposite side, creating a concentric arrangement. This nesting configuration maximizes the use of magnetic flux within the available space, improving power density while the stator structure acts as a flux containment barrier.
2Stability of the object's composition
If claw-poles are arranged in alternation on coaxial armatures, then torque ripples and harmonics are reduced, but device complexity increases
Solution Approach 1:
The claw-poles on the two coaxial rotor armatures are arranged in alternating polarity sequences that are asymmetric relative to each other. This asymmetric alternating arrangement creates complementary magnetic fields that cancel out torque ripples and harmonics, providing smooth torque output despite the increased structural complexity.
3Ease of operation
If global excitation with toroidal coil is used, then ease of operation is improved, but manufacturing precision requirements increase
Solution Approach 1:
The toroidal excitation coil serves multiple functions: it provides global excitation to both rotors simultaneously, acts as a flux containment structure, and enables independent control of magnetic flux in both air gaps. This multi-functionality simplifies operation through a single control mechanism while the modular design accommodates manufacturing tolerances.
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
The design achieves a compact, powerful machine with reduced material usage, high rotation speeds, and minimized torque ripples and harmonics, enabling efficient magnetic flux adjustment and operation without the need for rotating power supplies.
Implementation Method 1
Each of the rotors may further comprise a fixed ferromagnetic ring arranged so as to be passed through radially by the field winding magnetic flux. The excitation coil makes it possible to generate a magnetic flux in the cylindrical and coaxial rotor armatures and in the claw-poles
Implementation Method 2
each bearing claw-poles arranged to interact magnetically with the teeth of the stator, notably with passage of the magnetic flux in a direction parallel to the axis of rotation of the machine
Data Source
AI summary
The present invention relates to a rotating electrical machine including at least one stator and at least two rotors, which are arranged on either side of the stator along an axis of rotation of the machine,said at least one stator including teeth and windings arranged on the teeth, andeach of said at least two rotors including two mutually coaxial rotor armatures, each bearing claw-poles arranged to interact magnetically with the teeth of the stator, the claw-poles of an armature being arranged circumferentially in alternation with the claw-poles of the other armature.