Hairpin Winding Temperature Sensor Mounting for Accurate Coil Monitoring

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Solution Overview

Problem

Existing methods for attaching temperature sensors to electric machine coils face challenges in achieving good thermal connection, accessibility, and interchangeability, often resulting in inaccurate temperature measurements due to exposed sensor locations.

Innovation Solution

A method for producing a component for an electric machine that involves arranging U-shaped wire elements with bends in grooves of a laminated core, where a temperature sensor is attached to the tip of a bend, ensuring it is thermally connected and accessible, and using partial wire elements connected via welding points to form a stable and precise temperature measurement point.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the temperature sensor is attached to an exposed location on the coil, then accessibility for installation and maintenance is improved, but measurement precision deteriorates due to inaccurate temperature readings

Engineering Contradiction:
Improveaccessibility of temperature sensorVSAvoidtemperature measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces a temperature sensor holder as an intermediary component that bridges the exposed location and the winding. The holder includes a temperature sensor arrangement that can be attached to accessible wire elements (such as hairpin bends) while maintaining thermal connection to the winding through conductive coupling, thus mediating between accessibility requirements and measurement accuracy requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical attachment of the temperature sensor to the winding with a holder-based system. The holder provides both mechanical support for easy accessibility and thermal conduction for accurate measurement, substituting the need for direct sensor-to-winding mechanical contact while maintaining both accessibility and precision

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If the temperature sensor is attached directly to the winding, then measurement precision is improved, but ease of manufacture deteriorates due to complex installation processes

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidease of temperature sensor installation
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent segments the temperature sensor installation into two independent parts: the temperature sensor arrangement attached to the holder, and the holder itself attached to the wire element. This segmentation allows the sensor to be pre-mounted on the holder before final installation, simplifying the manufacturing process while maintaining measurement precision through the holder's thermal conduction design

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If the temperature sensor is placed in a position with good thermal connection to the winding, then measurement precision is improved, but accessibility for interchangeability deteriorates

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidinterchangeability of temperature sensor
Core Design Contradiction:
Measurement precisionVSEase of repair

Solution Approach 1:

The holder serves as a mediator that provides both thermal conduction for accurate measurement and mechanical accessibility for easy sensor replacement. The sensor can be attached to and removed from the holder without disturbing the holder's connection to the winding, enabling straightforward interchangeability while maintaining thermal connection precision

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 approach allows for precise temperature monitoring of the winding, preventing measurement distortion and ensuring good thermal connection, accessibility, and interchangeability of the temperature sensor, enhancing the reliability of temperature readings.

Implementation Method 1

a temperature sensor (16) is attached to a tip (50, 76) of a bend (6, 24, 48, 72) of at least one wire element (2, 20, 40, 70)... ensuring good thermal connection

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3716453B1Manufacturing method of a component and component of an electic maschine
Publication Date: 2024.06.19 AUDI AG
  • EP3716453B1 patent drawingFigure 1a~1c
  • EP3716453B1 patent drawingFigure 1d~2c
  • EP3716453B1 patent drawingFigure 3a~3c

AI summary

The manufacturing process of a component and the component itself of an electric machine, which has a laminated core with several slots, a central axis, and a winding. The winding consists of a plurality of wire elements (20). Each wire element (20) has two legs (22) that are connected to each other by a bend (24). Either one wire element is bent into a U-shape, or two wire elements are joined together to form a U-shape. At least the legs (22) of the wire elements (20) are arranged parallel to the axis in the slots, and the bend (24) is part of the winding head. A temperature sensor (26) is attached to the bend (24) of one of the wire elements (20).