Stator Temperature Sensing for Dense Hairpin Windings

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Solution Overview

Problem

Conventional temperature sensors are difficult to integrate with densely wound hairpin or bar wave windings due to limited space, leading to inefficient temperature detection and inability to compensate for manufacturing and operational tolerances.

Innovation Solution

A temperature measuring device with a holding device that engages behind the windings, using positioning and locking parts to secure a sensor device externally, ensuring a consistent thermal connection and compensating for manufacturing and operational movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional temperature sensor is inserted between stator winding sections, then temperature detection is possible, but the sensor cannot be inserted in densely wound hairpin or bar wave windings due to very small spaces

Engineering Contradiction:
Improvetemperature detectionVSAvoidsensor insertion
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

Instead of inserting the temperature sensor inside the stator between windings as in conventional designs, the patent inverts the approach by placing the sensor device outside the stator and using locking parts that extend through the stator wall to engage with the windings from the outside, thereby avoiding the space constraint problem while maintaining temperature measurement capability

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If a temperature sensor is arranged inside the stator, then thermal connection to windings is achieved, but manufacturing and material tolerances and operational movements cannot be compensated

Engineering Contradiction:
Improvethermal connectionVSAvoidtolerance compensation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent employs resilient locking parts that can deform elastically to accommodate manufacturing tolerances and operational movements. The locking parts are designed with spring elements that allow dynamic adjustment of the sensor device position, maintaining consistent thermal contact with the windings despite dimensional variations or vibrations during operation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resilient locking parts change their physical state (deformation) in response to manufacturing tolerances and operational movements, automatically adjusting the sensor device position to maintain optimal thermal contact. This parameter change allows the system to adapt to varying conditions without requiring precise initial positioning

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a holding device with locking parts is used to secure the sensor externally, then tolerance compensation and stable connection are achieved, but the device complexity increases

Engineering Contradiction:
Improveconnection stabilityVSAvoidholding device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The holding device integrates multiple functions into a single component structure: the locking parts serve both to mechanically secure the sensor device to the stator and to provide resilient tolerance compensation. The positioning parts simultaneously guide the locking parts during assembly and maintain the sensor device in the correct position, reducing the need for separate adjustment mechanisms

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

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

Provides a cost-effective, simple, and reliable method for temperature measurement in hairpin or bar wave windings, maintaining a stable connection despite manufacturing and operational variations.

Implementation Method 1

the at least one locking part has a spring element which is arranged between the first and second ends of the locking part in order to press the sensor device against a winding or an insulating paper with a spring force

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

the alignment element is made of an elastomer material. In this way, a consistent thermal connection of the sensor device to a hairpin or bar wave winding can be ensured

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

ensures a consistent thermal connection of the sensor device to a hairpin or bar wave winding

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3970265B1Temperature measuring apparatus for a stator of an electrical machine having hairpin wave windings or bar wave windings
Publication Date: 2025.10.08 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP3970265B1 patent drawingFigure 1~2
  • EP3970265B1 patent drawingFigure 3~4
  • EP3970265B1 patent drawingFigure 5~6

AI summary

The invention relates to a temperature measuring apparatus (1) for a stator (31) of an electrical machine (30) having hairpin wave windings or bar wave windings (32, 33, 34) and for measuring the temperature of the stator (31), said apparatus comprising: - a sensor device (2) for measuring the temperature of the stator (31), - a holding device (3) for holding the sensor device (2) on a winding (32) of the stator (31), - wherein the holding device (3) is designed to engage behind and latch onto at least one winding (33, 34) of the stator (31). The invention also relates to an electrical machine (30) comprising hairpin wave windings or bar wave windings and comprising a temperature measuring apparatus (1).