Modular Switched Reluctance Motor Layout for Lower Unaligned Induction

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Solution Overview

Problem

Existing synchronous reluctance motors face challenges in torque production and power conversion efficiency due to unaligned induction, complex winding strategies, and inadequate cooling, particularly in axial-flux and radial-flux motors, which necessitate a more efficient and simpler design that reduces unaligned induction and enhances cooling.

Innovation Solution

A hybrid axial-flux and radial-flux switched reluctance motor design with modular rotor-stator assemblies and forced air-cooling systems, featuring minimal ferromagnetic material between stator poles and circumferential windings, along with vacuum cavities to minimize unaligned induction and enhance cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional axial-flux or radial-flux synchronous reluctance motors are used, then magnetic flux can be generated, but unaligned induction occurs reducing torque production and power conversion efficiency

Engineering Contradiction:
Improveunaligned induction lossVSAvoidtorque production
Core Design Contradiction:
Loss of energyVSPower

Solution Approach 1:

The motor is divided into modular rotor-stator assemblies with discrete magnetic circuits for each phase, allowing independent optimization of each segment's magnetic path to minimize unaligned induction while maintaining torque production

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Ferromagnetic material is removed from regions between stator poles where it would create unwanted magnetic flux paths during unaligned positions, eliminating the source of unaligned induction losses

Inventive Principle:
Principle #2Taking out (Extraction)

2Power

If complex winding strategies are employed to improve torque, then torque production increases, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvetorque productionVSAvoidwinding strategy complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

Ferromagnetic material is strategically placed only in specific locations where it is needed for magnetic flux conduction, with minimal material between stator poles, optimizing magnetic circuit efficiency without requiring complex windings

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The motor utilizes changes in magnetic reluctance as the rotor rotates, exploiting the natural variation in magnetic circuit impedance to generate torque through simple windings rather than complex configurations

Inventive Principle:
Principle #35Parameter changes

3Temperature

If adequate cooling systems are added to improve heat dissipation, then temperature control improves, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveheat dissipationVSAvoidcooling system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The motor structure itself provides cooling pathways through its modular rotor-stator assembly design, allowing air to flow naturally through internal channels and dissipate heat without requiring separate complex cooling systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The motor incorporates ferromagnetic material with controlled porosity or structured geometry that facilitates air flow and heat dissipation while maintaining magnetic circuit integrity

Inventive Principle:
Principle #31Porous materials

4Loss of energy

If minimal ferromagnetic material is used between stator poles, then unaligned induction is reduced, but magnetic flux conduction path may be compromised

Engineering Contradiction:
Improveunaligned induction lossVSAvoidmagnetic flux conduction
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

Ferromagnetic material is placed precisely where needed to conduct magnetic flux during aligned positions, with strategic gaps or reduced material in regions that would create unaligned induction, achieving both goals through localized optimization

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The magnetic circuit is designed to dynamically adapt its effective path as the rotor rotates, providing strong flux conduction when aligned and minimal coupling when unaligned, exploiting the rotational position to optimize performance

Inventive Principle:
Principle #15Dynamics

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 35% increase in torque and power conversion efficiency, with improved saliency ratio and responsiveness, while simplifying assembly and maintenance, and reducing manufacturing costs.

Implementation Method 1

a machine that transforms electric power into mechanical power (and vice versa) via the exclusive principle of magnetic reluctance

Methodology Applied
Scientific EffectMagnetic reluctance: Magnetic Reluctance

Implementation Method 2

The novel motor architecture enables a powerful and effective air-based cooling of the internal components, encompassing the electric windings plus rotor and stator

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 3

the electrical winding is coiled in a circular manner circumferential around the said axis of rotation

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4583367A1Magnetic reluctance turbine/motor for future ground- , flight-, and space-based electric vehicles
Publication Date: 2025.07.09 TEIA DOS SANTOS MENDES GOMES LUIS DANIEL
  • EP4583367A1 patent drawingFigure 1A
  • EP4583367A1 patent drawingFigure 1B
  • EP4583367A1 patent drawingFigure 1C

AI summary

The invention relates to a switched reluctance motor that includes two identical modules interconnected in parallel, each composed of a rotor assembly and two joined halves of a stator assembly. The two rotor assemblies are mounted and locked onto the same shaft such that when one is aligned with the stator, the other is unaligned. More particularly, the rotor assemblies are composed of a non-ferromagnetic shaft-mounted and rotational-locked disc, with slotted ferromagnetic blades forming the rotor poles. Two pairs of windings, located at either side of said rotor assembly, are enclosed within each stator's half and are coiled circumferentially around the engine axis, to facilitate assembly and maintenance. Each module has the same number of stator and rotor poles. Thus, the stator's cross section at the rotor midsection (during alignment) forms two vertically-mirrored O-shaped magnetic loops, where the flux exists the rotor vertically to the stator at the tip, travels around the windings on either side, down radially via the stator's poles, and enters axially back into the rotor blade. Electrically, each motor module is activated in an alternating way. Forced-air cooling is driven through the motor via rotating wings embodied into the rotor blades, and also via shaft mounted side fans. Two covers connect on either side of the two linked modules representing all together the static part of the motor, while bearings provide rotational interface between said covers and the shaft plus rotor assemblies. The vehicle and/or load-bearing machine's transmission axle slides inside, and is geared to, the shaft via inner teeth. The stator design minimizes coil exposure to ferromagnetic material during unalignment, effectively reducing unaligned induction. In another embodiment of the novel motor, the rotor gaps in between blades are filled with vacuum blades that, due to their absence of magnetic permeability, break completely the unaligned magnetic circuit, thus drastically enhancing this unaligned induction effect. The collective end outcome is a boost in torque production and power conversion capacity, including a readily available internal air-cooling ability.