Clutch Mechanism Asymmetrical Retaining Ring Reduces Axial Force

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The assembly of a clutch mechanism in motor vehicles is challenging due to the difficulty in engaging the clutch thrust bearing, which requires significant axial force and can lead to bearing cup cracking or snapping issues, especially in heavy vehicles where the attachment ring's eccentricity affects the alignment and positioning.

Innovation Solution

A clutch mechanism with a support cup and an improved snap ring design featuring asymmetrical openings and inclined support surfaces, which reduces play and eccentricity, allowing for reliable engagement with low axial force and correct positioning of the attachment ring regardless of the angular position relative to the engine's axis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clutch thrust bearing is engaged using a conventional attachment ring, then the clutch mechanism can be assembled, but significant axial force is required which can cause bearing cup cracking or snapping issues

Engineering Contradiction:
Improvereliability of bearing engagementVSAvoidaxial force required for engagement
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The attachment ring features asymmetrical openings instead of symmetrical ones. The first opening has a major axis and the second opening has a minor axis, creating an asymmetric geometry that reduces play and eccentricity during engagement. This asymmetric design allows the attachment ring to self-align and engage with reduced axial force while maintaining reliability.

Inventive Principle:
Principle #4Asymmetry

2Adaptability or versatility

If the attachment ring has freedom along the vertical axis, then the attachment ring can adjust to angular positions, but the attachment ring becomes offset under gravity affecting engagement accuracy

Engineering Contradiction:
Improveadaptability to angular positionVSAvoidpositioning precision of attachment ring
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The asymmetrical openings create a preferred orientation for the attachment ring. The major axis of the first opening and minor axis of the second opening establish a specific angular position that the attachment ring naturally assumes, reducing random offset under gravity while maintaining adaptability to the required angular positions during operation.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The attachment ring is pre-positioned during assembly using the asymmetrical opening geometry. The asymmetric shape guides the attachment ring into the correct orientation before the clutch mechanism is fully assembled, ensuring precise positioning is achieved during the preliminary engagement phase rather than requiring perfect alignment during final assembly.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If the attachment ring is offset due to gravity, then the attachment ring can accommodate angular variations, but the engagement becomes difficult and requires significant axial force

Engineering Contradiction:
Improveaccommodation of angular variationVSAvoidease of bearing engagement
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The asymmetrical openings are designed to accommodate the expected angular variations while maintaining ease of engagement. The major and minor axes of the openings are oriented to work with the gravitational offset, allowing the attachment ring to engage smoothly without requiring excessive axial force, thus combining adaptability with operational ease.

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

Facilitates the assembly of the clutch release bearing with reduced axial force requirements and improved reliability, ensuring secure attachment and preventing bearing cup damage, even in critical eccentricity positions.

Implementation Method 1

an elastically deformable hooking ring inserted at the inside of the socket of the support cup

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

each having a support surface capable of retaining the hooking ring when the hooking ring is offset with respect to the support cup

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3677808B1Clutch mechanism for a motor vehicle and clutch comprising such a clutch mechanism
Publication Date: 2021.04.07 VALEO EMBRAYAGES SAS
  • EP3677808B1 patent drawingFigure 1
  • EP3677808B1 patent drawingFigure 2
  • EP3677808B1 patent drawingFigure 3~4

AI summary

Clutch mechanism (10) for a motor vehicle clutch, comprising: - a cover (11), - a diaphragm (20) having a central bore (21), - a support cup (30) comprising: - an annular collar (34) bearing against the diaphragm (20), - a cylindrical bushing (35) with axis (○) inserted into the central bore (23) of the diaphragm (20), - first and second openings (31, 32) formed on the bushing (35), and - a passage orifice (33a, 33b) formed on the bushing (35), - an elastically deformable retaining ring (40) inserted inside the bushing (35) of the support cup, said retaining ring (40) comprising two bosses (42) engaged in the first and second openings of the bushing, the first and second openings being of the form asymmetrical and each presenting a bearing surface (31d, 32d) capable of retaining the retaining ring when the retaining ring is offset from the bearing cup.