Brushless DC Motor Insulator Heat Dissipating Plate

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Solution Overview

Problem

In brushless DC motors, heat generated in the coil and iron core is transferred to the heat dissipating plate, which can hinder the effective dissipation of heat from the switching element, leading to potential overheating issues.

Innovation Solution

The heat dissipating plate is attached to an insulator that is less thermally conductive than the iron core, preventing heat transfer from the iron core and allowing for improved heat dissipation of the switching element, while ensuring the sensor remains stationary relative to the stator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heat dissipating plate is attached to the iron core, then the sensor can be fixed stationary relative to the stator, but heat generated in the coil and iron core transfers to the heat dissipating plate, preventing effective heat dissipation from the switching element

Engineering Contradiction:

Improvesensor stabilityVSAvoidheat dissipation efficiency

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent introduces an insulator as an intermediary component between the iron core and the heat dissipating plate. This insulator prevents direct thermal contact while allowing the heat dissipating plate to remain attached to the stator assembly, thereby maintaining sensor stability while blocking harmful heat transfer from the iron core to the heat dissipating plate.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the thermal pathways by separating the heat dissipating plate from direct contact with the iron core. The heat dissipating plate is attached to the insulator rather than the iron core, creating distinct thermal zones that allow the switching element heat to be dissipated independently from the coil and iron core heat.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If feet of the heat dissipating plate contact the iron core, then the structure is simplified, but heat transfer from the iron core to the heat dissipating plate occurs, hindering heat dissipation from the switching element

Engineering Contradiction:

Improvestructural simplicityVSAvoidheat dissipation efficiency

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The insulator serves as a mediator that replaces direct feet-to-iron-core contact. Instead of simplifying the structure by direct contact, the insulator is introduced as a thin intermediary layer that maintains structural simplicity while eliminating the harmful thermal conduction pathway from the iron core to the heat dissipating plate.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If the circuit board is attached directly to the iron core, then attachment is simplified, but heat from the iron core transfers to the circuit board, causing overheating of the switching element

Engineering Contradiction:

Improveattachment simplicityVSAvoidheat transfer to circuit board

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The insulator acts as a thermal barrier intermediary between the iron core and the circuit board. The circuit board is attached to the insulator surface rather than directly to the iron core, simplifying the attachment process while the insulator material blocks heat transfer from the hot iron core to the temperature-sensitive circuit board and switching element.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances the heat dissipation of the switching element and maintains the sensor's stability by preventing heat transfer from the iron core to the heat dissipating plate, thereby improving the motor's operational efficiency and reducing the risk of overheating.

Implementation Method 1

The insulator includes an electrically insulating material having a lower rate of heat transfer than a material included in the iron core

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

circuit board 404 is attached so as to be in contact with main body 403a of heat dissipating plate 403 to dissipate heat

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS10530224B2Motor and electric tool equipped with the same

Publication Date: 2020.01.07 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A motor includes: a stator; a rotor axially aligned with the stator; a circuit board; and a heat dissipating plate. The stator includes: an iron core including teeth; an insulator covering one end surface, in the axial direction, of the iron core; and a coil wound around the teeth. The insulator includes an electrically insulating material having a lower rate of heat transfer than a material included in the iron core. The heat dissipating plate is attached to the insulator in a state in which the heat dissipating plate is in contact with the insulator without being in contact with the iron core, and the circuit board is attached to the heat dissipating plate in a state in which the circuit board is in contact with the heat dissipating plate without being in contact with the iron core.