Vehicle Generator Terminal Device Thermal Management

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Solution Overview

Problem

High current output in vehicle AC generators leads to heat generation and temperature rise in semiconductor elements and insulating bushes, causing thermal deterioration and loosening of fastening forces in output terminals.

Innovation Solution

A rotating electric machine with a terminal device featuring a resin body of high thermal conductivity and electrical insulation, integrating the output terminal, cylindrical body, and heat sink to suppress temperature rise and maintain fastening force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If high current flows through the output terminal to achieve high output power, then the power output is improved, but the output terminal generates heat causing temperature rise of semiconductor elements and insulating bush

Engineering Contradiction:

Improveoutput powerVSAvoidtemperature of output terminal and internal devices

Core Design Contradiction:

PowerVSTemperature

Solution Approach 1:

A resin body with high thermal conductivity is introduced as an intermediary substance between the output terminal and the surrounding environment. This resin body serves as a thermal mediator that conducts heat away from the output terminal and semiconductor elements, effectively reducing the temperature rise caused by high current flow while maintaining the high power output capability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite material approach by using a resin body with specifically engineered high thermal conductivity properties. This composite material combines the electrical insulation properties of resin with enhanced thermal conduction capabilities, allowing simultaneous management of electrical and thermal characteristics in the terminal device

Inventive Principle:

Principle #40Composite materials

2Strength

If the output terminal is firmly fixed integrally with an insulating bush made of resin, then the fastening strength is improved, but the heat generation causes thermal deterioration and thermal contraction of the resin bush leading to loosening of the fastened nut

Engineering Contradiction:

Improvefastening forceVSAvoidthermal stability of resin bush

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The patent changes the thermal parameter of the resin material by selecting a resin body with high thermal conductivity. This parameter change allows the resin to dissipate heat more effectively, preventing thermal deterioration and thermal contraction that would otherwise cause the fastened nut to loosen, thereby maintaining fastening strength under high temperature conditions

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful effect of heat generation into a beneficial outcome by using the high thermal conductivity resin body to actively manage and dissipate the heat. The heat that would normally cause thermal contraction and loosening is instead channeled through the resin to cooler regions, preventing the harmful thermal effects while maintaining the integral fastening structure

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

Effectively reduces temperature increase at the output terminal, prevents thermal deterioration, and maintains the fastening force between the output terminal and external device, enhancing durability and assembly efficiency.

Implementation Method 1

a resin body having electrical insulating property and high thermal conductivity, for integrally covering the output terminal except at least for a portion to be connected to the terminal portion

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9906089B2Rotating electric machine

Publication Date: 2018.02.27 MITSUBISHI ELECTRIC CORP

AI summary

Provided is a rotating electric machine capable of suppressing an increase in temperature of an output terminal (26) to suppress a temperature rise of an internal device, and preventing lowering of a force for fastening the output terminal and a terminal portion of an external device. The rotating electric machine for a vehicle includes a rectifier provided inside a casing, and a terminal device projecting outward through an opening portion of the casing to connect the internal device and the external device. The terminal device includes the output terminal (26) projecting outward through the opening portion to be connected to the terminal portion of the external device by fastening, and a resin body (37) having electrical insulating property and high thermal conductivity, for integrally covering the output terminal (26) except at least for a portion to be connected to a harness-side terminal (35).