Nested Variable Field Motor for Compact EV Propulsion

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Solution Overview

Problem

Existing cross-drive propulsion systems for electric vehicles require multiple PM motors, leading to increased space consumption and width, making them cumbersome and less suitable for compact applications.

Innovation Solution

The development of a compact dynamoelectric machine with nested variable field permanent magnet motors, where a central element allows for axial and radial nesting of propulsion and steering motors, reducing overall dimensions and enabling efficient power transfer between tracks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple PM motors are used for cross-drive propulsion systems, then propulsion and steering functions are achieved, but space consumption and width increase

Engineering Contradiction:

Improvepropulsion and steering functionsVSAvoidspace consumption

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent implements a nested motor configuration where a first PM motor and a second PM motor are arranged concentrically around a central element. The first rotor shaft rotates about the central axis while the second rotor shaft rotates about the first rotor shaft, creating a compact nested structure that provides both propulsion and steering functions without requiring separate motor housings, thereby reducing overall space consumption and width.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Adaptability or versatility

If multiple PM motors are stacked axially or radially, then cross-drive propulsion is achieved, but the system becomes cumbersome

Engineering Contradiction:

Improvecross-drive propulsion capabilityVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges two separate PM motors into a single integrated assembly by arranging them concentrically around a shared central element. Both motors share common structural components and mounting arrangements, reducing the number of separate housings, bearings, and support structures needed. This unified configuration provides both propulsion and steering functions while simplifying the overall system architecture and reducing mechanical complexity.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If additional axial length is provided for motor housing, then magnet and conductive wires can be drawn apart for variable field operation, but overall motor length increases

Engineering Contradiction:

Improvevariable field operation capabilityVSAvoidaxial length

Core Design Contradiction:

Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The patent transitions from axial displacement to radial displacement for variable field operation. Instead of drawing the magnet and conductive wires apart axially, the nested configuration allows the first and second magnetic drive elements to be positioned at different radial distances from the central axis. This radial arrangement enables variable field operation while maintaining a compact axial length, as the adjustment occurs in the radial dimension rather than extending the axial dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 the axial length and circumference of the motor system, allowing for more space in vehicles and maintaining compatibility with roadways, while providing redundant propulsive power and efficient torque and speed characteristics, thus optimizing space usage and power distribution.

Implementation Method 1

PM motors convert electrical energy to kinetic energy by exploiting the electromagnetic relationship between a magnet and an electric field

Methodology Applied

Scientific EffectElectromagnetic relationship: Electromagnetic Induction

Implementation Method 2

PM generators convert kinetic energy to electrical energy using the inverse of the electromagnetic relationship

Methodology Applied

Scientific EffectElectromagnetic relationship: Electromagnetic Induction

Data Source

PatentUS7642684B2Nested variable field dynamoelectric machine

Publication Date: 2010.01.05 HAMILTON SUNDSTRAND CORP

AI summary

A dynamoelectric machine comprises a first rotor shaft, a second rotor shaft and a central element. The first rotor shaft rotates about a central axis of the machine and has a first magnetic drive element disposed about an outer circumference of the first rotor shaft. The second rotor shaft rotates about the first rotor shaft and has a second magnetic drive element disposed about an inner circumference of the second rotor shaft. The central element is disposed between the first rotor shaft and the second rotor shaft and is configurable to remain stationary while the first rotor shaft and the second rotor shaft rotate about the central axis. The central element also includes a third magnetic drive element for interacting with the first magnetic drive element, and a fourth magnetic drive element for interacting with the second magnetic drive element.