Coil Insulator Recess for Temperature Sensor Mounting

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Solution Overview

Problem

Existing electrical machines face challenges in efficiently installing and securely positioning temperature sensors within the stator coils, which can lead to inaccurate temperature measurements due to the presence of a water cooling circuit, potentially resulting in under-evaluation of winding temperatures.

Innovation Solution

A coil insulator with a flexible hollow tab that forms a housing for the temperature sensor, providing elastic retention and maintaining contact with the coil, while also allowing for easy installation and potential use of thermally conductive resin for improved heat transfer and electrical insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a temperature sensor is installed inside the stator coil to measure winding temperature, then measurement precision is improved, but the device complexity increases due to the need for additional housing structures and installation mechanisms

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidcoil insulator structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the temperature sensor housing with the coil insulator into a single integrated component. The insulator body incorporates a recess that directly receives and positions the temperature sensor, eliminating the need for separate housing structures. This merging approach maintains precise temperature measurement capability while reducing overall device complexity by consolidating functional elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coil insulator is designed to serve multiple functions: electrical insulation, mechanical support for the coil, and housing for the temperature sensor. The insulator body integrates these diverse functions into a single component, with the recess providing both structural support and sensor positioning. This multi-functionality approach improves measurement precision while avoiding additional dedicated structures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If a rigid housing structure is used to position the temperature sensor, then measurement precision is maintained, but ease of manufacture deteriorates due to increased manufacturing steps and assembly complexity

Engineering Contradiction:
Improvesensor positioning accuracyVSAvoidcoil insulator manufacturing ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The housing for the temperature sensor is merged with the coil insulator body, forming a single integrated component. The recess is directly formed in the insulator during the molding process, eliminating separate housing parts and assembly steps. This approach maintains precise sensor positioning while significantly improving ease of manufacture through single-step fabrication.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes the molding process parameters to directly form the recess with precise dimensions and geometry. By controlling the mold cavity parameters, the recess is created with the exact specifications needed for accurate sensor positioning, eliminating the need for secondary machining or assembly operations. This parameter control approach maintains precision while simplifying manufacturing.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the temperature sensor is positioned away from the coil to avoid water cooling circuit interference, then measurement reliability is improved, but temperature measurement accuracy deteriorates due to increased thermal distance

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidtemperature measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent creates a localized thermal environment for the temperature sensor by positioning it in a recess within the coil insulator that places it in direct contact with the coil winding. This local positioning ensures the sensor measures the actual winding temperature despite the presence of water cooling circuits elsewhere in the stator. The recess geometry is specifically designed to maximize thermal contact with the coil while maintaining electrical insulation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The coil insulator acts as an intermediary structure that enables direct thermal contact between the temperature sensor and the coil winding. The recess in the insulator body provides a controlled interface that facilitates heat transfer from the coil to the sensor while maintaining electrical isolation. This intermediary approach allows the sensor to accurately measure coil temperature even in the presence of cooling circuits.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If a flexible tab structure is used to retain the temperature sensor, then ease of operation is improved for sensor installation and removal, but reliability may deteriorate due to potential sensor displacement

Engineering Contradiction:
Improvesensor installation easeVSAvoidsensor positioning stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent employs a flexible tab formed from the insulator material that can be elastically deformed to facilitate sensor installation. The tab acts as a flexible retaining element that can be pushed aside during assembly to allow sensor insertion, then returns to its original position to secure the sensor. This flexible structure provides easy installation while maintaining reliable sensor retention through elastic recovery.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The retaining tab is designed with dynamic characteristics, allowing it to change position during installation and then stabilize in a fixed position during operation. The tab can be temporarily displaced to accommodate sensor insertion, then elastically returns to engage and secure the sensor. This dynamic behavior provides ease of operation during assembly while ensuring reliable, stable sensor positioning during machine operation.

Inventive Principle:
Principle #15Dynamics

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 ensures accurate temperature measurement by maintaining sensor contact with the coil, avoiding under-evaluation of winding temperatures and enhancing reliability through dual sensor placement for redundancy.

Implementation Method 1

the lug (301) exerting an elastic action against the temperature sensor (303) so as to keep it in contact with the coil

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

potential use of thermally conductive resin for improved heat transfer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2896116B1Coil insulator capable of receiving a temperature sensor, and corresponding stator interconnector and bearing for temperature sensor
Publication Date: 2022.01.26 VALEO EQUIP ELECTRIC MOTEUR
  • EP2896116B1 patent drawingFigure 1~2a
  • EP2896116B1 patent drawingFigure 2b~2c
  • EP2896116B1 patent drawingFigure 3a

AI summary

The invention relates to a coil insulator (20) to be provided around the tooth of a stator of an electric machine. Said coil insulator has a body comprising walls forming a frame as well as a front rim (203) and a rear rim (204) defining, together with the walls of the frame, a mounting groove for winding a coil (19), characterized in that said coil insulator comprises a recess (302, 331', 401) for receiving a temperature sensor. The invention also relates to an interconnector for the stator of the electric machine as well as to a bearing for the corresponding temperature sensor.