Axially Magnetized Torque Sensor Stator Segmentation

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Solution Overview

Problem

Conventional torque sensors for power steering systems face challenges in efficiently measuring torque due to weak magnetic signals and complex stator structures, which complicate the detection process and reduce productivity.

Innovation Solution

A torque sensor design featuring axially magnetized ring-shaped magnets and stators with ring-shaped plated bodies and vertically penetrating holes, allowing for simplified magnetic flux measurement and improved control over dimensions and shapes, enhancing detection accuracy and productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional stators with bent lug pieces are used to detect magnetic field changes, then torque measurement is enabled, but the stator structure becomes complex and magnetic detection efficiency decreases

Engineering Contradiction:
Improvetorque measurement accuracyVSAvoidstator structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The stator is segmented into multiple independent holes penetrating the stator body, with each hole containing a magnetic sensor. This segmentation allows each sensor to independently detect magnetic field changes at specific locations, simplifying the overall structure while maintaining measurement accuracy through distributed sensing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The conventional mechanical bent lug pieces are replaced with a simplified stator body containing holes. The magnetic sensors positioned in these holes detect magnetic field changes directly, eliminating the need for complex mechanical bending and positioning of lug pieces, thus reducing structural complexity while preserving measurement capability.

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

2Measurement precision

If bent surfaces of stators are prepared and separate collectors are arranged to collect magnetization values, then magnetic field detection is achieved, but the structure becomes complicated and productivity decreases

Engineering Contradiction:
Improvemagnetic signal detection accuracyVSAvoidmanufacturing efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The stator body and magnetic sensor housing are merged into a single integrated structure. The holes are directly formed in the stator body during manufacturing, eliminating the need for separate bent surface preparation and separate collector components. This integration significantly simplifies the manufacturing process and improves productivity while maintaining detection accuracy.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If lug pieces are arranged with equal gaps to maintain uniform magnetic detection, then measurement consistency is improved, but the arrangement and positioning become difficult and time-consuming

Engineering Contradiction:
Improvemagnetic detection consistencyVSAvoidarrangement and positioning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The holes are pre-formed in the stator body at precisely positioned locations during the manufacturing process, rather than requiring subsequent arrangement and positioning of separate lug pieces. This preliminary action ensures uniform spacing and consistent magnetic detection across all sensors while eliminating the time-consuming manual or automated positioning process.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If axially magnetized ring-shaped magnets are used with simplified stators, then magnetic detection efficiency is improved and structure is simplified, but manufacturing precision requirements increase

Engineering Contradiction:
Improvemagnetic detection efficiencyVSAvoidhole positioning and magnet alignment precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The axially magnetized ring-shaped magnets generate a magnetic field that naturally aligns with the axial orientation of the holes in the stator body. This self-aligning property reduces the stringency of manufacturing precision requirements, as the magnetic field geometry inherently guides the sensors to detect changes along the correct axis, compensating for minor variations in hole positioning or magnet alignment.

Inventive Principle:
Principle #25Self-service

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

The design improves magnetic detection efficiency, simplifies the stator structure, and enhances productivity by concentrating magnetic changes in an axial direction, leading to more accurate torque measurement and operational reliability.

Implementation Method 1

measurement of magnetic change is performed by a magnetic flux formed in an axial direction

Methodology Applied
Scientific EffectMagnetic flux: Magnetic Field

Implementation Method 2

a ring-shaped stator including an upper stator and a lower stator... measurement of magnetic change is performed by a magnetic flux formed in an axial direction

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentEP2511683B1Torque sensor
Publication Date: 2017.11.22 LG INNOTEK CO LTD
  • EP2511683B1 patent drawingFigure 1~3
  • EP2511683B1 patent drawingFigure 4

AI summary

The present disclosure relates to a torque sensor configured to axially magnetize a magnet and simplify a stator structure facing the magnet, whereby dimensions and shapes of members capable of collecting magnetism can be easily controlled to provide a torque sensor excellent in operational reliability, the torque sensor including a ring-shaped and axially-magnetized magnet connected to one of an input shaft of a steering wheel and an output shaft; and a stator including a ring-shaped body axially discrete from the magnet and a plurality of holes vertically penetrating the body, whereby structure of the torque sensor is simplified to enhance a concentrated efficiency of magnetic change.