Flexible Elastomer Housing for Rotational Speed Sensor Stress Absorption

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sensors for measuring variables like wheel speed in vehicles are prone to mechanical stress, leading to erroneous signals due to installation tolerances and temperature movements, which increase the air gap and tolerance range, limiting their reading range and accuracy.

Innovation Solution

A sensor design featuring a rigid measuring transducer housing made of synthetic resin, such as epoxy, and a flexible installation housing made of thermoplastic elastomer with a hardness of at least 80 Shore A, incorporating bending grooves and crushing ribs to absorb mechanical loads, ensuring the sensor is protected from stress and securely attached to the axle body, while maintaining a reduced air gap and increased reading range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid installation housing is used to protect the sensor from mechanical stress, then the sensor is protected from stress, but installation tolerances increase the air gap which increases the tolerance range of the sensor signal and restricts the reading range

Engineering Contradiction:
Improvesensor protection from mechanical stressVSAvoidinstallation tolerance and air gap
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The installation housing is made from a flexible material (elastomer with hardness of at least 80 Shore A) that can deform elastically to absorb mechanical loads from temperature movements and installation variations, while maintaining a constant, small air gap between the measuring sensor and transmitter element, thus resolving the contradiction between protection and precision

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The material properties of the installation housing are changed by selecting an elastomer with specific hardness (at least 80 Shore A), which provides the optimal balance between flexibility to absorb mechanical stress and rigidity to maintain precise positioning, thereby reducing both installation tolerance and air gap

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If installation tolerance is increased to facilitate mounting, then the mounting process is simplified, but the air gap between the measuring sensor and transmitter element increases which increases the tolerance range of the sensor signal and restricts the reading range

Engineering Contradiction:
Improvemounting simplicityVSAvoidair gap and reading range
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The flexible elastomer housing absorbs dimensional variations and misalignments during installation through elastic deformation, allowing simplified mounting procedures while maintaining a consistently small air gap between the sensor components, thus resolving the contradiction between ease of mounting and precision

Inventive Principle:
Principle #30Flexible shells and thin films

3Strength

If a rigid material like polyamide is used for the installation housing, then mechanical stress protection is provided, but the sensor must be fastened with predetermined installation tolerance which increases the air gap and restricts the reading range

Engineering Contradiction:
Improvemechanical stress resistanceVSAvoidinstallation tolerance and air gap
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The elastomer installation housing provides mechanical stress resistance through the material's inherent elasticity and damping properties, while simultaneously allowing tight tolerances to be maintained during installation, thus eliminating the need for predetermined installation tolerances that would increase the air gap

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The installation housing uses a composite approach by selecting an elastomer material that combines the mechanical strength needed for stress resistance with the flexibility required to maintain precise positioning, achieving both strength and manufacturing precision simultaneously

Inventive Principle:
Principle #40Composite materials

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 effectively reduces mechanical stress on the sensor, maintaining signal accuracy and extending the reading range by using a flexible installation housing to absorb mechanical loads, ensuring stable attachment and reduced installation tolerances.

Implementation Method 1

a flexible material that absorbs any mechanical loads that may occur as a result of the installation condition of the specified sensor

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

Thermoplastic elastomers can particularly preferably be used as the elastomer, which can be plastically processed to form the built-in housing from a certain temperature

Methodology Applied
Scientific EffectThermal softening: Melting

Data Source

PatentEP3084354B1Mechanically oversized assembly for rotational speed sensor
Publication Date: 2018.07.25 CONTINENTAL TEVES AG & CO OHG
  • EP3084354B1 patent drawingFigure 1
  • EP3084354B1 patent drawingFigure 2
  • EP3084354B1 patent drawingFigure 3

AI summary

A sensor for outputting a sensor signal which is dependent on a variable to be measured, including: —a measuring pickup which is connected electrically to a data line at a connecting point, is housed in a measuring pickup housing and is set up to feed the sensor signal which is dependent on the variable to be measured into the data line, with the result that the sensor signal can be output via the data line, an installation housing which houses the measuring pickup housing and the data line at least at the connecting point and is manufactured from a flexible material, and—a fastening element which is connected fixedly to the installation housing for fastening the installation housing to a sensor holder, wherein the measuring pickup housing; and the fastening element are arranged on two sides of the installation housing which lie opposite one another.