Torque Sensor Stator Tooth Overlap for Magnetic Flux Isolation

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Solution Overview

Problem

Existing torque sensors in electronic power systems are affected by external magnetic fields, leading to inaccurate measurement of torsion in torsion bars due to magnetic flux interference, which is exacerbated by increasing electronic equipment in vehicles.

Innovation Solution

A sensing device with a stator and rotor configuration featuring first, second, and third stator teeth, where the magnet is positioned between these teeth, and a collector is placed between the stator teeth to minimize magnetic field interference, with the second and third teeth having smaller diameters than the first, and being concentrically disposed to overlap and charge differently, reducing magnetic flux leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a collector is used to measure magnetic flux in a torque sensor, then torque measurement capability is enabled, but external magnetic fields interfere with the measurement accuracy

Engineering Contradiction:
Improvetorque measurement accuracyVSAvoidexternal magnetic field interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The stator teeth are divided into three distinct groups (first, second, and third stator teeth) with different diameters and positions. This segmentation allows each group to serve specific functions in guiding and differentiating magnetic flux paths, thereby improving measurement accuracy while reducing external field interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different stator teeth groups are positioned at specific locations with different diameters to create localized magnetic field characteristics. The first stator teeth are positioned to guide external magnetic fields away from the collector, while the second and third stator teeth create specific flux patterns that enhance measurement accuracy.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If multiple stator teeth with different diameters are used to reduce magnetic field interference, then measurement accuracy improves, but device complexity increases

Engineering Contradiction:
Improvemagnetic flux measurement accuracyVSAvoidstator structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The multiple stator teeth groups serve multiple functions simultaneously: they guide magnetic flux, differentiate between external and internal magnetic fields, and provide structural support. This multi-functionality reduces the need for additional separate components, thereby managing device complexity while improving measurement accuracy.

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

This configuration effectively prevents or minimizes magnetic field interference from external sources, enhancing the accuracy of torque measurement by reducing the impact of external magnetic fields on the sensor, thereby improving the reliability of torsion measurement in electronic power systems.

Implementation Method 1

a magnet disposed between the plurality of first teeth and the plurality of third teeth and disposed between the plurality of first teeth and the plurality of second teeth

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP3940358B1Sensing device
Publication Date: 2023.09.06 LG INNOTEK CO LTD
  • EP3940358B1 patent drawingFigure 1
  • EP3940358B1 patent drawingFigure 2
  • EP3940358B1 patent drawingFigure 3

AI summary

An embodiment may provide a sensing device comprising: a stator comprising stator teeth; and a rotor comprising magnets, wherein: the stator teeth comprise a first stator tooth and a second stator tooth arranged to overlap the first stator tooth in the radial direction from the center of the stator; the first stator tooth comprises multiple first teeth and multiple third teeth, and the second stator tooth comprises multiple second teeth; one of the multiple first teeth is arranged to overlap one of the multiple second teeth in the radial direction; and the magnets are disposed between the multiple first teeth and the multiple third teeth, respectively.