Multiturn Angle Measuring Device Using Mechanical Magnetic Storage

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Solution Overview

Problem

Existing angle measuring devices require continuous power supply for multiturn detection, leading to limited service life and high costs, especially in battery-operated systems, and are not suitable for low-cost applications due to dependency on ambient temperature and complex electrical measures.

Innovation Solution

A mechanical angle measuring device using a rotatable field element with offset axes of rotation and a sensor array to detect magnetic field changes, allowing for mechanical storage of absolute angle without power, utilizing a permanent magnet for cost-effectiveness and independence from electricity, with a planetary gear for compact and scalable multiturn detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If battery-operated or self-sufficient detection systems are used for multiturn detection, then the system can operate without continuous external power supply, but the service life is limited and the system becomes dependent on ambient temperature

Engineering Contradiction:
Improvepower supply requirementVSAvoidservice life and temperature dependency
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent replaces electrical storage mechanisms (batteries, capacitors) with a mechanical storage system using a permanent magnet and gear mechanism. The permanent magnet generates a magnetic field that is mechanically stored in the gear system, allowing multiturn detection without electrical power. This mechanical substitution eliminates battery replacement needs and reduces temperature dependency while maintaining continuous operation capability.

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

2Reliability

If complex electrical measures are used to detect angle changes in switched-off state, then multiturn detection is enabled, but the device complexity and cost increase

Engineering Contradiction:
Improvemultiturn detection capabilityVSAvoidelectrical system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex electrical detection circuits with a simple mechanical gear-based magnetic field storage system. The permanent magnet combined with gear mechanisms provides a straightforward mechanical means to store and detect angle information without requiring complex electrical measures, thereby reducing device complexity and cost while maintaining reliable multiturn detection.

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

Solution Approach 2:

The permanent magnet automatically generates the magnetic field required for detection without needing external power supply or complex electrical circuitry. The system serves itself by using the mechanical rotation to both store and trigger the detection signal, eliminating the need for external electrical assistance and simplifying the overall device design.

Inventive Principle:
Principle #25Self-service

3Device complexity

If a single field element is used for multiturn detection, then the device is simplified and cost-effective, but the measurement range and resolution may be limited

Engineering Contradiction:
Improvenumber of field elementsVSAvoidmeasurement range and resolution
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces a second dimension to the measurement system by adding a gear mechanism that rotates in a different plane or with a different transmission ratio. This allows the single field element to measure both small angular displacements (through direct magnetic field detection) and large rotational movements (through the gear mechanism), effectively extending the measurement range without adding multiple field elements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The single field element serves multiple functions: it detects both the primary angular position and, through interaction with the gear mechanism, the cumulative rotational count. This multi-functionality allows one field element to provide both high-resolution angular measurement and multiturn detection capability, avoiding the need for additional specialized sensors.

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

Enables precise and cost-effective multiturn detection without power supply, extending the measurement range and avoiding 'overflow' issues, while maintaining high resolution and accuracy, suitable for both rotary and position encoders.

Implementation Method 1

A permanent magnet (2) which generates a magnetic field is provided

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP3907473B1Angle measuring device for single and multiturn measurement
Publication Date: 2022.08.24 BAUMER ELECTRIC AG
  • EP3907473B1 patent drawingFigure 1
  • EP3907473B1 patent drawingFigure 2
  • EP3907473B1 patent drawingFigure 3

AI summary

A multi-turn angle measuring device (1) is proposed, comprising a field element (2) that generates a magnetic field and is rotatably mounted about a first axis of rotation (7), wherein the field element (2) is rotatably mounted about a second axis of rotation (6) that is offset from the first axis of rotation (7), such that the field element (2) rotates in a plane of rotation (8) about the second axis of rotation (6), with a sensor array having at least two sensors (10, 11, 12, 13, 14, 15) that are positioned offset from the plane of rotation (8), wherein the sensor array is configured to determine the position of the field element (2) in the plane of rotation (8) and its orientation with respect to its north-south pole orientation by measuring the magnetic field generated by the field element (2) as a function of the position of the field element (2) in the plane of rotation (8) and/or as a function of the north-south pole orientation of the field element (2) about the first axis of rotation (7). The axis of rotation (7) is measured.