Nutating Electric Motor for High-Torque Traction Drive

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Solution Overview

Problem

Conventional electric motors face challenges in achieving high torque density, as the radial pressure generated is not effectively harnessed for smooth power transmission, leading to inefficiencies in torque production.

Innovation Solution

The electric motor design incorporates a rotor-stator configuration with nutating traction interfaces, where the rotor nutates with respect to the stator, creating a dynamic air gap and utilizing magnetic fields to generate torque through a series of windings that sequentially activate to tilt the rotor, allowing for efficient torque transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional motor designs are used, then basic motor functions are achieved, but efficiency is low and cooling is insufficient

Engineering Contradiction:
Improvemotor efficiencyVSAvoidcooling performance
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The patent merges the cooling function with the motor housing structure by integrating cooling channels directly into the housing. This combination allows the housing to serve dual purposes: structural support and thermal management, thereby improving cooling performance without compromising motor efficiency

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a cooling medium (fluid) as an intermediary to transfer heat from the motor internal components through the cooling channels in the housing to the external environment. This mediator enables efficient heat dissipation while maintaining the motor's operational temperature and efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If motor housing is designed for basic protection, then structural integrity is maintained, but heat dissipation is insufficient

Engineering Contradiction:
Improvehousing structural integrityVSAvoidheat dissipation
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent applies local quality by designing cooling channels specifically in regions of the housing where heat generation is highest. The housing structure maintains its overall structural integrity while incorporating localized cooling features that enhance heat dissipation precisely where needed without compromising strength

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If simple housing structure is used, then manufacturing is easy, but cooling channels cannot be effectively integrated

Engineering Contradiction:
Improvehousing manufacturing simplicityVSAvoidcooling channel integration
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent incorporates cooling channels into the housing design from the outset, during the initial manufacturing process. By performing the cooling channel integration as a preliminary action rather than a subsequent modification, the housing can be manufactured with built-in cooling capabilities using standard manufacturing techniques, maintaining ease of manufacture while achieving effective cooling

Inventive Principle:
Principle #10Preliminary action

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 high torque density by effectively harnessing radial pressure, providing smooth power transmission and efficient torque generation, suitable for applications requiring high torque output.

Implementation Method 1

a cooling channel (17) formed in the motor housing (10)

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP3797470B1Electric motor
Publication Date: 2026.04.22 TAU MOTORS INC
  • EP3797470B1 patent drawingFigure 1
  • EP3797470B1 patent drawingFigure 2
  • EP3797470B1 patent drawingFigure 3

AI summary

An electric motor has a stator mechanically coupled to the rotor by a nutating traction interface, such that during nutation of the rotor with respect to the stator a tilt axis of the rotor progresses about the axis of rotation of the output shaft. The rotor and a surface of the stator bound a dynamic gap across which a magnetic field is produced by electrical activation of the motor to generate a force between the rotor and the stator. The traction interface and the gap are arranged such that, in a plane containing the axis of rotation of the output shaft, the traction interface is angled with respect to the stator surface bounding the gap. The rotor is connected to the output shaft by a tiltable connection such as a gimbal.