Clutch Cover Subassembly With Elastic Ring for Wear-Resistant Articulation

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Solution Overview

Problem

Clutch mechanisms in heavy-duty vehicles experience significant wear in the articulation of the diaphragm with the lid, leading to reduced stroke and incomplete disengagement, making it difficult to change gear ratios due to the use of low-wear-resistant steel and assembly challenges with separate annular rings.

Innovation Solution

A sub-assembly featuring a cover with a circular housing and an open elastic ring that can transition between a free and constrained state, using additional retaining means to secure the elastic ring within the cover, made from high-wear-resistant materials, simplifying assembly and ensuring correct positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a toroidal surface is formed directly into the cover by stamping, then the articulation means are made of the same material as the cover (stamping steel with low carbon content), but wear resistance is insufficient leading to peening and wear after large number of clutch disengagements

Engineering Contradiction:
Improveease of manufactureVSAvoidwear resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The articulation means are divided into two separate components: the cover and the annular ring. The ring is a distinct element that can be made of wear-resistant material while the cover maintains its original material properties, allowing each part to be optimized independently for its specific function and manufacturing process

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clutch mechanism uses composite construction by combining the cover (made of stamping steel) with an annular ring (made of wear-resistant material such as spheroidal graphite cast iron or steel). This allows the articulation surface to have superior wear resistance while the overall structure maintains its original manufacturing advantages

Inventive Principle:
Principle #40Composite materials

2Reliability

If a separate annular ring is used for articulation means, then wear resistance is improved, but assembly difficulties arise due to positioning challenges during clutch assembly

Engineering Contradiction:
Improvewear resistanceVSAvoidease of assembly
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The annular ring is pre-positioned on the cover before the diaphragm is installed. The spacers are also pre-positioned to define the correct location. This preliminary arrangement of components simplifies the final assembly process and ensures proper positioning without requiring complex adjustment procedures

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Spacers are introduced as intermediary elements to facilitate the positioning of the annular ring on the cover. The spacers act as mediators that define the correct location and orientation of the ring, making the assembly process easier and more reliable

Inventive Principle:
Principle #24Intermediary (Mediator)

3Duration of action of moving object

If the diaphragm joint wears against the cover, then play develops between the joint and diaphragm, but this reduces the stroke of the periphery of the diaphragm and prevents complete disengagement

Engineering Contradiction:
Improveservice lifeVSAvoiddisengagement completeness
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The articulation means use composite construction by combining the cover (made of stamping steel) with an annular ring (made of wear-resistant material such as spheroidal graphite cast iron or steel). This allows the articulation surface to have superior wear resistance while the overall structure maintains its original manufacturing advantages

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The wear-resistant annular ring acts as a protective element that prevents wear before it can affect the diaphragm joint. By placing this protective ring in advance at the articulation surface, the design prevents the development of play and maintains complete disengagement capability throughout the service life of the clutch

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 reduces wear and ensures complete disengagement by maintaining the elastic ring in a constrained state, enhancing the reliability and durability of the clutch mechanism while simplifying assembly and maintaining the elastic ring's secure positioning.

Implementation Method 1

an open elastic ring (20) inserted into said circular housing (13) of said cover (12)... The open elastic ring (20) is defined by two operating states: a free state, in which an outer diameter of the ring is greater than a diameter of the housing (13), and a constrained state, in which the outer diameter of the ring is contained within the diameter of the housing (13)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3628884B1Subassembly for clutch mechanism and clutch mechanism comprising such a subassembly
Publication Date: 2021.07.14 VALEO EMBRAYAGES SAS
  • EP3628884B1 patent drawingFigure 1
  • EP3628884B1 patent drawingFigure 2
  • EP3628884B1 patent drawingFigure 3A~3B

AI summary

Subassembly (10) for clutch mechanism (1), comprising: - a cover (12) having a circular housing (13) with axis (O) of revolution, - an open elastic ring (20) inserted in the circular housing (13), the open elastic ring (20) being defined by two operating states: a free state, in which the outside diameter (dA) of the ring (20) is greater than the diameter (dL) of the housing (13), and a constrained state, in which the outside diameter (dA) of the ring (20) is inscribed in the diameter (dL) of the housing (13).