Actuator Sensor Arrangement With Non-Ferromagnetic Target

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Solution Overview

Problem

Conventional actuator-sensor arrangements in magnetic systems suffer from interference between the force-exerting magnetic field and the sensor system, which degrades signal quality and disrupts the force flow.

Innovation Solution

A sensor is placed within the force-transmitting magnetic flux between the coil and rotor, allowing it to detect movement without disturbing the magnetic field, and using eddy current or capacitive sensors with multiple coils and electrodes to measure deflections in various directions, including a non-ferromagnetic target to optimize signal integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sensor is placed in the force-transmitting magnetic flux to detect rotor movement, then measurement precision is improved, but the sensor disturbs the magnetic field and degrades signal quality

Engineering Contradiction:
Improvemeasurement precisionVSAvoidsignal quality
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A non-ferromagnetic target element is introduced as an intermediary between the rotor magnet and the sensor. This target element carries the magnet and serves as the measurement object for the sensor, while itself being unaffected by the magnetic field in a way that would interfere with sensor operation. The sensor measures position based on the target's position rather than directly on the magnet, eliminating the harmful interaction between the sensor and the force-exerting magnetic field.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a sensor is placed in the force-transmitting magnetic flux to detect rotor movement, then measurement precision is improved, but the sensor disrupts the force flow

Engineering Contradiction:
Improvemeasurement precisionVSAvoidforce flow
Core Design Contradiction:
Measurement precisionVSForce

Solution Approach 1:

The non-ferromagnetic target element acts as a mediator that transmits the magnetic force from the rotor magnet to the stator without being influenced by the sensor's magnetic field. Since the target is non-ferromagnetic, it does not distort the force-transmitting magnetic flux, allowing the sensor to measure position accurately while the force flow remains undisturbed.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The material property of the target element is changed to be non-ferromagnetic, which fundamentally alters its interaction with the magnetic field. This parameter change ensures that the target does not become magnetized or distorted by the sensor's field, thereby maintaining the integrity of the force flow while enabling precise measurement.

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

This arrangement minimizes interference between the actuator and sensor systems, maintaining signal quality and enabling precise measurement of relative positions and movements without affecting the magnetic field, even in vacuum or pressure-sealed environments.

Implementation Method 1

the coil generating a force-exerting magnetic field and thereby generating a force at least in one direction, for example in the Z-direction

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

the sensor is designed as an eddy current sensor with a flat design

Methodology Applied
Scientific EffectEddy current: Eddy Currents

Implementation Method 3

The sensor can be a capacitive sensor with a flat design

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3063504B1Actuator sensor arrangement and method for application with such an arrangement
Publication Date: 2017.08.30 MICRO EPSILON MESSTECHNIK GMBH & CO KG
  • EP3063504B1 patent drawingFigure 1
  • EP3063504B1 patent drawingFigure 2
  • EP3063504B1 patent drawingFigure 3

AI summary

An actuator sensor arrangement, comprising a magnetic actuator (1), which comprises at least one coil (3), preferably in the sense of an armature winding, and a magnet (2) used as a rotor, wherein the coil (3) generates a force-exerting magnetic field (4) and in this way a force acts on the rotor (2) at least in one direction, for example in the Z direction, is characterised in that a sensor (6) is arranged in the force-transmitting magnetic flux (7) between the coil (3) and the rotor, said sensor detecting the movement of the rotor in the at least one direction, for example in the Z direction (actuator-rotor spacing). A method is also claimed for the application of the actuator sensor arrangement according to the invention.