Elastic Joint Rim Structure to Prevent Pad Radial Creep

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Solution Overview

Problem

The existing elastic joints in motor vehicles experience material degradation over time, leading to reduced elasticity and permanent deformation of elastomeric pads, which results in ineffective shock absorption and vibration filtering due to radial creep of the pads away from the abutment face.

Innovation Solution

The elastic articulation features a stop face with a peripheral rim that extends axially and surrounds the bearing face, preventing radial creep of the pads, and includes a radial cup with water evacuation orifices to maintain contact and functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If elastomeric buffers are used for shock absorption and vibration filtering, then the joint provides flexibility and comfort, but the buffers creep radially outwards over time causing permanent deformation and loss of functionality

Engineering Contradiction:
Improveshock absorption functionalityVSAvoidbuffer position stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary anti-action by designing a peripheral rim on the abutment face that proactively prevents radial outward creep of the buffers before permanent deformation occurs. The rim creates a mechanical constraint that counteracts the creping tendency of the elastomeric material under repeated compression cycles, maintaining buffer position and functionality throughout the service life of the joint.

Inventive Principle:
Principle #9Preliminary anti-action

2Force

If buffers are designed to project axially for permanent contact with the abutment face, then shock absorption is effective, but repeated crushing causes the buffers to move outwards and lose contact

Engineering Contradiction:
Improveshock absorption forceVSAvoidpermanent contact maintenance
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The patent applies local quality by modifying the local geometry of the abutment face through the addition of a peripheral rim. This localized structural feature creates a specific constraint zone that prevents radial displacement of the buffers while maintaining the overall axial compression function. The rim is positioned specifically at the periphery where creep occurs, providing targeted restraint without interfering with the central shock absorption function.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the abutment face is designed with a simple flat surface, then manufacturing is simple, but the buffers cannot be prevented from creeping radially outwards

Engineering Contradiction:
Improveabutment face fabricationVSAvoidbuffer position stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies segmentation by dividing the abutment face into two functional zones: a central bearing surface for shock absorption and a peripheral rim for creep prevention. This segmentation allows each zone to perform its specific function independently - the flat central area maintains ease of manufacture for load bearing, while the added peripheral rim provides the necessary geometric constraint to prevent radial creep without significantly complicating the overall manufacturing process.

Inventive Principle:
Principle #1Segmentation

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 design ensures permanent contact between the pads and the abutment face, maintaining effective shock absorption and vibration filtering over time, thereby enhancing the durability and performance of the elastic joint.

Implementation Method 1

the repeated crushing and releasing phases of the buffers causes the elastomer material to creep radially outwards

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The buffers allow shock absorption, vibration absorption and participation in the elastic return of the elastic joint to its resting state

Methodology Applied
Scientific EffectShock absorption: Damping

Implementation Method 3

the abutment face has a peripheral rim which extends axially in projection and which surrounds the bearing face in order to prevent the pads from creeping radially outwards

Methodology Applied
Scientific EffectMechanical constraint: Physical Containment

Data Source

PatentEP4421336A1Elastic joint for connecting a ground-engaging element to a motor vehicle chassis
Publication Date: 2024.08.28 RENAULT SA
  • EP4421336A1 patent drawingFigure 1
  • EP4421336A1 patent drawingFigure 2
  • EP4421336A1 patent drawingFigure 3

AI summary

The invention relates to an elastic joint (14) of a motor vehicle comprising: - an outer ring (16) having a main axis (A); - an inner ring (20) mounted concentrically in the outer ring; - an elastic sleeve (22) interposed radially between the inner ring and the outer ring, the elastic sleeve comprising at least one deformable pad (28) which extends axially in projection relative to the outer ring; - a fixed orthogonal stop face (24) relative to the inner ring and against an annular support area (30) of which the pads are mounted axially clamped, characterized in that the stop face comprises a peripheral rim (32) which extends axially in projection and which surrounds the support face in order to prevent the pads from creeping radially outwards.