Symmetrical Sensor Element With Three-Point Support

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Solution Overview

Problem

Existing contactless distance or position sensors, such as inductive and capacitive displacement transducers, face measurement errors due to environmental disturbances like temperature gradients, humidity changes, pressure, and vibrations, which are not adequately compensated by differential signal evaluation, leading to asymmetrical influences on the sensor elements.

Innovation Solution

A mechanically symmetrical sensor design is achieved by arranging measuring elements symmetrically within the sensor, using multi-layer substrates and a three-point support system with non-metallic balls to minimize thermal and mechanical asymmetries, ensuring that environmental influences affect both sides equally, thus compensating for disturbances through differential evaluation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a half-bridge arrangement with two identical measuring elements is used, then disturbances such as temperature changes can be compensated, but local temperature gradients and asymmetrical environmental influences still cause measurement errors

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidtemperature gradients and environmental disturbances
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry in reverse - it deliberately creates a symmetrical arrangement where both measuring elements are positioned at identical distances from the housing surface, one in front and one at the back. This symmetrical design ensures that environmental influences like temperature gradients and humidity changes affect both elements equally, allowing the differential evaluation to effectively compensate for these disturbances and maintain measurement precision.

Inventive Principle:
Principle #4Asymmetry

2Strength

If the sensor element is mechanically mounted in a housing, then structural support is provided, but mechanical strains and compressions cause non-deterministic displacements and deformations

Engineering Contradiction:
Improvestructural supportVSAvoidmechanical tolerances and sensor element deformation
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies local quality by providing structural support only at specific discrete locations (three mounting points) rather than continuous contact across the sensor element. This localized support approach maintains structural stability while minimizing the area subject to mechanical strains and compressions, thereby reducing non-deterministic displacements and deformations that would affect measurement precision.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If measuring elements are positioned close to the housing surface for compact design, then device size is reduced, but asymmetrical environmental influences affect the measurements

Engineering Contradiction:
Improvesensor housing sizeVSAvoidmeasurement accuracy
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent resolves this contradiction by creating a symmetrical configuration where both measuring elements are positioned at identical distances from the housing surface. This symmetrical arrangement ensures that environmental influences affect both elements equally, enabling effective differential compensation. The elements can be positioned close to the housing surface for compact design while maintaining measurement precision through this symmetrical geometry.

Inventive Principle:
Principle #4Asymmetry

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 approach results in precise and stable measurements by ensuring symmetrical environmental effects on the sensor elements, reducing measurement errors caused by temperature, pressure, and other non-deterministic changes, and allowing for easier replacement and reduced mechanical tolerances.

Implementation Method 1

inductively operating sensor, in particular for distance or position measurement

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

capacitive displacement transducers

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3308106B1Sensor and sensor element
Publication Date: 2021.01.20 MICRO EPSILON MESSTECHNIK GMBH & CO KG
  • EP3308106B1 patent drawingFigure 1
  • EP3308106B1 patent drawingFigure 2
  • EP3308106B1 patent drawingFigure 3

AI summary

The invention relates to a sensor which operates in a contactless manner, in particular an inductively or capacitively operating sensor, preferably for distance or position measurement of an object, comprising an inductive or capacitive sensor element, wherein measuring elements of the sensor element are embedded in a multi-layer ceramic and form together with the ceramic the sensor element. The invention is characterized in that the sensor element has a geometrically and/or electrically symmetrical design with respect to its measuring elements and that a bearing is provided at a distance with respect to a holder, which has the smallest possible contact surfaces on the sensor element. The invention further relates to a sensor element, such as used in the sensor according to the invention.