Rotation Sensor Hub Unit Radial Positioning Structure

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Solution Overview

Problem

Existing rotation detecting sensor mounting constructions face challenges in maintaining sensor stability and accuracy due to radial dislocation and deflection issues, particularly under external forces and thermal changes, which affect the reliability of wheel rotation detection.

Innovation Solution

A hub unit with an annular cover element and a resilient piece that guides and secures the sensor head portion, using swelling portions and receiving portions to prevent radial dislocation and deflection, along with a reinforcement member to maintain fixation stability over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the head portion of the sensor is pushed into the holding portion and fixed by the resilient piece, then the sensor can be easily positioned in the radial direction, but the head portion becomes easy to fall (to be inclined) under axial external force, leading to radial dislocation

Engineering Contradiction:
Improveease of positioningVSAvoidstability against radial dislocation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention adds axial positioning features (protrusions and recesses) to complement the existing radial positioning, thereby preventing the sensor head from falling in the axial direction while maintaining radial positioning accuracy

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

Solution Approach 2:

The resilient piece is designed with curved surfaces that conform to the sensor head portion, providing continuous contact and support to prevent inclination and falling while maintaining easy positioning

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Manufacturing precision

If the distal end face of the head portion is brought into abutment with the inner surface of the resilient base portion, then the head portion is positioned in the radial direction, but deflection or torsion is generated in the head portion, reducing rotation detecting accuracy

Engineering Contradiction:
Improveradial positioning precisionVSAvoidrotation detecting accuracy
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The invention extracts the positioning function from the resilient base portion inner surface and relocates it to dedicated protrusions and recesses, eliminating the harmful abutment contact that causes deflection while preserving radial positioning

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The protrusions and recesses act as intermediary elements between the sensor head and resilient piece, providing precise positioning without creating the harmful contact that causes deflection or torsion

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the resilient piece is pressed from the vehicle inner side to engage with the engagement portion, then the sensor is securely fixed, but thermal changes cause the resilient piece to expand or contract, affecting fixation stability

Engineering Contradiction:
Improvefixation stabilityVSAvoidthermal expansion effect
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention designs the resilient piece with controlled elasticity parameters that allow thermal expansion and contraction without compromising the engagement force, maintaining stable fixation across temperature variations

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The resilient piece is pre-designed to accommodate thermal changes through its elastic properties, cushioning the effects of thermal expansion and contraction before they can affect fixation stability

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 positions and secures the sensor head, preventing radial dislocation and deflection, ensuring high accuracy in rotation detection and maintaining stability despite external forces and thermal changes.

Implementation Method 1

a resilient piece (a clip portion) which is formed on the holding portion is brought into engagement of an engagement portion (a locking groove) of the head portion so as to press and fix the head portion

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2133699B1Rotation sensor installation structure and hub unit
Publication Date: 2020.02.19 JTEKT CORP
  • EP2133699B1 patent drawingFigure 1
  • EP2133699B1 patent drawingFigure 2
  • EP2133699B1 patent drawingFigure 3(a)~3(d)

AI summary

End faces in a push-in direction of swelling portions which swell from both side portions of a head portion are received by flat surfaces formed on receiving portions of a resilient piece. By the distal end faces of the swelling portions being received by the flat surfaces of the receiving portions, the head portion is positioned in a radial direction by a holding portion, whereby a pressing action (a resilient action) of the resilient piece can be applied forwards towards the head portion from a position lying further rearwards than the receiving positions. By this configuration, a radial positioning of the head portion and the prevention of radial dislocation of the head portion are facilitated.