Torque Angle Sensor Miniaturization via Integrated Magnetic Devices

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Solution Overview

Problem

Conventional torque and angle sensors in vehicle EPS systems are bulky due to multiple magnetic devices, leading to increased manufacturing costs and size, and suffer from angle non-linearity errors that require complex algorithms for error reduction.

Innovation Solution

A torque and angle sensor design that integrates multiple magnetic devices into a single package, reduces the number of teeth in main and sub-gears, and optimizes their arrangement to miniaturize the sensor, thereby reducing manufacturing costs and improving output linearity by increasing sub-gear revolutions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple magnetic devices are used to measure torque, then reliability is improved, but device complexity and volume increase

Engineering Contradiction:
Improvetorque measurement reliabilityVSAvoidsensor structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple magnetic devices (first and second magnetic devices) into a single integrated magnetic device package that detects both torque and angle simultaneously. This merging reduces the number of separate components while maintaining the reliability benefits of multiple detection elements, directly resolving the contradiction between reliability and device complexity.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If multiple magnetic devices are individually mounted, then measurement reliability is improved, but manufacturing cost and assembly complexity increase

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent integrates multiple magnetic devices into a single packaged unit that can be mounted as one component rather than requiring individual mounting of multiple magnetic devices. This reduces assembly steps and manufacturing complexity while maintaining the redundant measurement capability that ensures reliability.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If conventional gear ratios are used, then angle sensor functionality is achieved, but device volume increases

Engineering Contradiction:
Improveangle sensing functionalityVSAvoidsensor volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent changes the gear ratio parameter by using a main gear with fewer teeth (60 teeth) and sub-gears with specific tooth counts (20 and 15 teeth) to achieve a 3:1 revolution ratio. This parameter optimization reduces the overall gear size and sensor volume while maintaining the necessary angle sensing functionality through the modified gear relationship.

Inventive Principle:
Principle #35Parameter changes

4Measurement precision

If more teeth are used in main and sub-gears, then angle measurement precision is improved, but device volume and complexity increase

Engineering Contradiction:
Improveangle measurement precisionVSAvoidgear structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent optimizes the gear tooth parameters by selecting specific tooth counts (main gear: 60 teeth, sub-gears: 20 and 15 teeth) that provide sufficient angle measurement precision while minimizing the overall gear size and complexity. The 3:1 revolution ratio achieved through these parameter choices delivers adequate measurement precision without requiring excessive teeth.

Inventive Principle:
Principle #35Parameter changes

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 solution results in a more compact, cost-effective torque and angle sensor with reduced measurement errors, enhanced reliability, and simplified assembly processes, while maintaining accurate torque and angle measurements.

Implementation Method 1

a magnetic device recognizes a magnetic field of a magnet attached to the sub-gears meshed to the main gear and a rotational direction

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

the torque sensor is configured in such a manner that at least two magnetic devices are used to measure a torque applied to the steering column

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentEP2664906B1Torque angle sensor
Publication Date: 2021.07.28 LG INNOTEK CO LTD
  • EP2664906B1 patent drawingFigure 1~2
  • EP2664906B1 patent drawingFigure 3~4
  • EP2664906B1 patent drawingFigure 5~6

AI summary

A torque angle sensor according to an exemplary embodiment of the present disclosure includes a torque sensor unit and an angle sensor unit at a housing (1) centrally arranged with a rotation shaft (2), the torque sensor unit including a stator (10) installed inside the housing, a torque magnet (20) rotatably installed at a center of the stator (10) in conjunction with rotary operation of the rotation shaft (2), a collector (30) installed at the housing (1) to transmit a magnetic field of the torque magnet (20), a magnetic device module (40) formed with an individually operating first magnetic device and a second magnetic device in one package to detect the magnetic field transmitted by the collector (30), and a PCB (Printed Circuit Board) mounted with the magnetic device module (40), wherein the PCB is arranged to a direction perpendicular to an axial direction of the rotation shaft (2) and installed at a distal end with the magnetic device module (40).