Magnetic Incremental Encoder for Frictionless Multi-Axis Detenting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current aeronautical encoders face challenges with compactness, multi-turn capabilities, incrementation, and detenting, often resulting in complex assemblies with friction, wear, and reliability issues due to mechanical components, which limit their lifespan and performance.

Innovation Solution

An incremental magnetic encoder design featuring a fixed and movable body with magnetic rings and detectors that minimize mechanical contact, allowing for frictionless and wear-free operation, enabling simultaneous coding and detenting in multiple directions using the same magnetic effect, thus reducing the number of parts and assembly complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical notching and optical detection are used, then encoding and detenting functions are achieved, but friction and wear occur limiting device lifespan

Engineering Contradiction:
Improveencoder reliability and lifespanVSAvoidfriction and wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical notching system with a magnetic field-based system. Magnets arranged in alternating polarity patterns on the rotating element interact with magnetic sensors to provide both encoding and detenting functions without mechanical contact, thereby eliminating friction and wear associated with traditional mechanical notching mechanisms.

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

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the rotating element and the detection system. The magnetic field serves as a non-contact mediator that transmits positional and detent information from the rotating element to the sensors, replacing direct mechanical interaction and eliminating the harmful effects of friction and wear.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple mechanical components are used for encoding and detenting, then functional capabilities are achieved, but assembly complexity increases

Engineering Contradiction:
Improvemulti-directional encoding and detenting capabilityVSAvoidnumber of parts and assembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the encoding and detenting functions into a single integrated magnetic field system. The same arrangement of magnets on the rotating element that provides encoding information also generates the detent forces, eliminating the need for separate mechanical notching components and reducing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The magnetic field system serves multiple functions simultaneously: it provides rotational encoding, translational encoding, and detenting forces for both rotational and translational movements. This multi-functionality is achieved through the versatile interaction between the magnet arrangement and the magnetic sensors, which can detect both position and force information.

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

The solution provides a reliable, compact, and long-lasting encoder that can perform multi-turn rotations and translations without friction or wear, meeting high reliability and safety standards while simplifying assembly and reducing the risk of part misalignment.

Implementation Method 1

a first ring extending in a first longitudinal direction coincident with the encoder axis and a first circumferential direction perpendicular to the first longitudinal direction, the first longitudinal direction corresponding to the first coding direction, the first ring defining a magnetic alternation in the first coding direction

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Implementation Method 2

at least one first notching tooth made of ferromagnetic or magnetic material arranged opposite the first ring to create a notch during a movement of the mobile body in the first coding direction

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 3

a first pair of magnetic detectors arranged opposite the first ring and configured to quantify each movement of the mobile body in the first coding direction

Methodology Applied
Scientific EffectMagnetic detection: Magnetic Field

Data Source

PatentEP4279872B1Incremental magnetic encoder
Publication Date: 2024.08.28 THALES SA
  • EP4279872B1 patent drawingFigure 1
  • EP4279872B1 patent drawingFigure 2
  • EP4279872B1 patent drawingFigure 3

AI summary

The present invention relates to an incremental magnetic encoder (10) defining an encoder axis (X) and comprising a fixed body and a movable body relative to the fixed body along at least one first encoding direction (C1). One of the bodies, referred to as the first body (21), comprises a first ring extending along a first longitudinal direction coinciding with the encoder axis (X) and a first circumferential direction perpendicular to the first longitudinal direction, and defining a magnetic alternation along the first encoding direction (C1). The other body, referred to as the second body (22), comprises at least one first notching tooth made of ferromagnetic or magnetic material disposed opposite the first ring, and a first pair of magnetic detectors disposed opposite the first ring and configured to quantify each movement of the movable body along the first encoding direction (C1).