Switched Reluctance Motor Torque Tunnel Without Permanent Magnets

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Solution Overview

Problem

Conventional electric motors rely on permanent magnets, which are costly and dependent on rare earth metals, and they are inefficient in terms of energy consumption and torque production.

Innovation Solution

The development of switched reluctance motors (SRM) that operate without permanent magnets, using a magnetic toroidal cylinder and a coil winding assembly to generate torque through magnetic reluctance, rather than magnetic fields.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If permanent magnets are used in conventional electric motors, then magnetic field strength and torque production are improved, but material costs increase due to rare earth metal dependency

Engineering Contradiction:

Improvetorque productionVSAvoidmaterial cost

Core Design Contradiction:

ForceVSEase of manufacture

Solution Approach 1:

The patent removes permanent magnets from the motor system entirely, extracting the problematic component that causes high material costs and rare earth metal dependency. The motor achieves torque production through electromagnetic induction in the rotor bars instead of permanent magnets, eliminating the cost issue while maintaining force generation capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive permanent magnets with simple copper or aluminum rotor bars that are much cheaper to manufacture. These rotor bars serve as temporary magnetic field carriers through electromagnetic induction, providing a cost-effective alternative to permanent rare earth magnets.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Force

If permanent magnets are used in conventional electric motors, then magnetic field strength is improved, but energy efficiency deteriorates

Engineering Contradiction:

Improvemagnetic field strengthVSAvoidenergy consumption

Core Design Contradiction:

ForceVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic electromagnetic induction in the rotor bars, where the rotating magnetic field from the stator continuously induces currents in the rotor bars. This periodic action creates a rotating magnetic field in the rotor that interacts with the stator field to produce torque, achieving efficient energy conversion without the energy losses associated with permanent magnets.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The invention replaces the static magnetic field of permanent magnets with a dynamically induced magnetic field through electromagnetic induction. This substitution transforms the magnetic field generation from a passive permanent magnet system to an active electromagnetic induction system, improving energy efficiency by only generating magnetic fields when needed through current flow.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If switched reluctance motors without permanent magnets are used, then material costs and energy consumption are reduced, but torque density may be compromised

Engineering Contradiction:

Improvematerial cost and energy efficiencyVSAvoidtorque density

Core Design Contradiction:

Ease of manufactureVSForce

Solution Approach 1:

The patent optimizes various parameters including rotor bar geometry, stator winding configuration, air gap dimensions, and magnetic circuit design to maximize torque density. By carefully adjusting these parameters, the motor achieves high torque output despite using simpler rotor construction without permanent magnets, balancing cost efficiency with performance requirements.

Inventive Principle:

Principle #35Parameter changes

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

SRMs achieve efficient energy conversion, reduced material costs, and increased torque density compared to conventional motors, while also minimizing vibration and noise.

Implementation Method 1

The coil winding assembly is configured so that there is at least one coil within each of the reluctance tunnel segments. The rotor core assemblies are adapted to rotate to a position that minimizes the reluctance of the SRM when the coils are sequentially energized.

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

switched reluctance motors (SRM) that operate without permanent magnets, using a magnetic toroidal cylinder and a coil winding assembly to generate torque through magnetic reluctance, rather than magnetic fields

Methodology Applied

Scientific EffectMagnetic reluctance: Magnetic Reluctance

Data Source

PatentUS20250175065A1Switched reluctance machines without permanent magnets

Publication Date: 2025.05.29 LINEAR LABS

AI summary

Disclosed are various embodiments for switched reluctance machines having a rotor comprising a plurality of rotor core assemblies configured to form a reluctance torque tunnel having at least a first reluctance tunnel segment and a second reluctance tunnel segment and a stator having a plurality of coils configured to form a coil winding assembly, the coil winding assembly positioned within the reluctance torque tunnel, such that at least one of the plurality of coils is surrounded by the first reluctance tunnel segment or the second reluctance tunnel segment, alternatively the rotor may be the coil winding assembly and the stator may be the reluctance torque tunnel.