Motor Coil Cross-Sectional Area Gradient for Heat Dissipation

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Solution Overview

Problem

Existing motor designs face inefficiencies due to non-uniform heat distribution and radiation in coils, leading to reduced motor performance and increased losses from Joule heat accumulation.

Innovation Solution

The motor design features a stator with teeth protruding from the stator core, where coils are wound in a non-uniform manner, with the first turn having a larger cross-sectional area adjacent to the motor center, gradually reducing in size, enhancing heat radiation effects and refrigerant flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If coils are made uniform in cross-sectional area through molding or forming, then uniform resistance is achieved, but heat radiation effects are concentrated and heat accumulation occurs

Engineering Contradiction:
Improveuniform resistanceVSAvoidheat accumulation
Core Design Contradiction:
Manufacturing precisionVSTemperature

Solution Approach 1:

The patent applies local quality by making the cross-sectional area of coil turns non-uniform along the radial direction. Specifically, coil turns closer to the center of the motor have larger cross-sectional areas, while those farther away have smaller areas. This localized variation optimizes heat radiation effects in different regions, allowing better heat dissipation near the center where refrigerant flows, while maintaining appropriate resistance characteristics overall.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If the space factor of coils is increased to suppress current loss, then motor efficiency is improved, but heat generation increases requiring better heat management

Engineering Contradiction:
Improvecurrent lossVSAvoidheat generation
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The patent applies parameter changes by varying the cross-sectional area parameter of coil turns along the radial direction. This creates a gradient structure where the space factor is optimized to suppress current loss, while simultaneously managing heat generation through the non-uniform geometry that enhances heat radiation effects in critical regions.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If heat radiation effects are increased through non-uniform coil configuration, then motor efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveheat radiation efficiencyVSAvoidcoil structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements local quality by creating non-uniform cross-sectional areas in specific regions of the coils rather than making the entire coil structure complex. The variation is applied systematically along the radial direction, with larger areas near the center and smaller areas outward, simplifying the manufacturing approach while achieving improved heat radiation efficiency.

Inventive Principle:
Principle #3Local quality

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 significantly increases heat radiation, preventing heat accumulation and achieving a highly efficient motor with improved performance and reduced losses.

Implementation Method 1

the cross-sectional area of a part lying adjacent to the center of the motor is greater in each of the coils, further increasing heat radiation effects due to the coils with respect to the refrigerant flowing adjacent to the center of the motor

Methodology Applied
Scientific EffectHeat radiation: Thermal Radiation

Implementation Method 2

When Joule heat is generated, heat easily accumulates in coils

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3588744B1motor
Publication Date: 2022.09.07 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3588744B1 patent drawingFigure 1A
  • EP3588744B1 patent drawingFigure 1B
  • EP3588744B1 patent drawingFigure 1C

AI summary

A motor includes a stator core, teeth respectively protruding from the stator core, and coils respectively wound onto the teeth n (n is an integer of 2 or greater) turns including first to n-th turns. Within each of ranges respectively wound with the coils onto the teeth in directions of protrusion of the teeth from the stator core, the first turn of each of the coil lies adjacent to a center of the motor. A k-th (k is an integer, 1 < k ≤ n) turn of each of the coils lies opposite to the center of the motor. The first turn when each of the coils is cut in a corresponding one of the directions of protrusion of the teeth from the stator core is greater in cross-sectional area than each of the k-th turn and the n-th turn.