Stator Winding Termination for Motor Heat Sink

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Solution Overview

Problem

Electric motors with built-in electronic circuitry face challenges in effectively absorbing excess heat and maintaining reliable electrical connections due to difficulties in achieving good thermal contact and mechanical connections within a sealed enclosure, often relying on unreliable sliding contacts which are prone to wear and vibration issues.

Innovation Solution

The method involves using elastic coupling means, such as springs, to securely connect the electronic circuit to the stator and heat sink, allowing for effective heat exchange while maintaining a reliable electrical connection through flexible portions of the electric terminations that can move and absorb vibrations, ensuring the circuit is pressed against the heat sink and maintaining a secure connection to the stator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If sliding contacts are used to connect electronic circuitry to motor and terminal strip, then the assembly can be closed with cover, but reliability deteriorates due to contact wear, vibrations, and operating temperature

Engineering Contradiction:
Improveease of closing assemblyVSAvoidreliability of electrical connection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent removes sliding contacts from the system entirely. Instead, rigid electrical connections are established through leads that extend through the cover to connect the electronic circuitry to the terminal strip, eliminating the sliding contact interface that caused reliability issues.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces leads as intermediary elements that pass through the cover structure. These leads provide a rigid mechanical and electrical connection between the electronic circuitry mounted on the cover and the terminal strip, serving as a reliable mediator without requiring sliding contacts.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If electronic circuitry is rigidly connected to cover to optimize heat exchange, then thermal contact improves, but electrical connection reliability to motor deteriorates due to assembly tolerances

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidelectrical connection stability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent segments the electrical connection function from the thermal management function. The electronic circuitry is rigidly mounted to the cover for optimal heat exchange, while separate leads provide flexible electrical connections to the motor, allowing each function to be optimized independently without compromise.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Leads serve as intermediary elements between the rigidly mounted electronic circuitry and the motor. These leads provide the necessary flexibility to accommodate assembly tolerances while maintaining reliable electrical connections, decoupling the thermal and electrical connection requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If electronic circuitry is effectively connected to motor by soldering, then electrical connection reliability improves, but heat exchange with cover deteriorates on account of closing tolerances

Engineering Contradiction:
Improveelectrical connection strengthVSAvoidthermal contact effectiveness
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent separates the electrical connection function from the thermal management function. Soldering is used to create reliable electrical connections between leads and circuitry, while the circuitry remains rigidly mounted to the cover for optimal heat exchange, allowing both requirements to be satisfied simultaneously through functional segmentation.

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If at least one sliding contact is provided to enable assembly closing, then assembly can be closed with cover, but excess heat absorption deteriorates because circuitry cannot be effectively pressed against heat sink

Engineering Contradiction:
Improveease of assembly closingVSAvoidheat absorption efficiency
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The patent removes sliding contacts from the assembly, enabling the electronic circuitry to be rigidly mounted directly to the cover without requiring sliding contact mechanisms. This extraction of the sliding contact element allows for direct, effective thermal contact between the circuitry and heat sink.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution enhances the reliability and efficiency of heat absorption and electrical connections within the motor, providing a secure and efficient assembly that maintains performance under varying conditions, including high temperatures, by using elastic elements to ensure effective heat exchange and secure electrical connections.

Implementation Method 1

elastic coupling means, such as springs, to securely connect the electronic circuit to the stator and heat sink, allowing for effective heat exchange while maintaining a reliable electrical connection

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2804298B1Method of winding an electric machine stator
Publication Date: 2019.03.27 SPAL AUTOMOTIVE
  • EP2804298B1 patent drawingFigure 1
  • EP2804298B1 patent drawingFigure 2
  • EP2804298B1 patent drawingFigure 3

AI summary

A method for making a rotary electric machine comprises the steps of: preparing a core (18) having a plurality of pole expansions and a plurality of windings (100, 200, 300) made of electrically conductive material on the pole expansions, where at least a part of the windings (100, 200, 300) is made from a conductor wire having a free end (14) that can be connected electrically to a mains power supply; stably coupling to each other at least two free ends (14) of different windings (100, 200, 300) so as to connect them to a single power supply terminal; twisting the coupled ends (14) together to form a single electrical termination (5, 6, 7) twisted along a principal line of extension of the electrical termination (5, 6, 7).