Clutch Disc Support Axial Flexibility Design

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Solution Overview

Problem

Existing clutch discs for friction clutches, particularly in motor vehicle transmissions, face issues with axial flexibility and production simplicity, leading to problems such as clutch chattering and squealing, especially in robotized gearboxes.

Innovation Solution

A clutch disc design featuring a support with increased axial flexibility, achieved by a radial offset between the spacer and friction lining, allowing the radially inner edge of the spacer to be at a greater distance from the hub axis than the friction lining, which increases the radial dimension of the support portion not in contact with the flange or spacer, without altering the friction surfaces or torque transmission performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the support is made rigid to ensure structural strength, then strength is improved, but axial flexibility deteriorates leading to clutch chattering and squealing

Engineering Contradiction:
Improvestructural strengthVSAvoidaxial flexibility
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The support is segmented into multiple radial portions (first, second, third portions) with different flexibility characteristics. The first radial portion has high axial flexibility to prevent clutch chattering and squealing, while the second and third portions maintain structural strength. This segmentation allows each portion to be optimized for its specific function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the support are given different local properties. The first radial portion (radially inner region) is designed with high axial flexibility through specific geometric features, while the second and third portions (radially outer regions) maintain higher rigidity. This local quality differentiation resolves the contradiction between overall flexibility and local strength requirements.

Inventive Principle:
Principle #3Local quality

2Reliability

If the radial dimension of the support portion between flange and spacer is increased to improve axial flexibility, then axial flexibility is improved, but the friction surface area is reduced

Engineering Contradiction:
Improveaxial flexibilityVSAvoidfriction surface area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The solution moves the flexibility enhancement from the radial dimension to the axial dimension. By creating axial offsets between the friction lining, intermediate piece, and flange, the first radial portion is given increased axial flexibility without reducing the radial extent of the friction surfaces. This dimensional shift allows flexibility improvement while preserving friction surface area.

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

Solution Approach 2:

The support is designed with dynamic flexibility in the axial direction through the first radial portion, allowing it to deform axially under load variations. This dynamic capability is achieved through geometric features in the first portion while maintaining the static friction surface geometry in the second and third portions.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If the clutch disc design is simplified to reduce production cost, then ease of manufacture is improved, but axial flexibility deteriorates

Engineering Contradiction:
Improveproduction simplicityVSAvoidaxial flexibility
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The support is divided into functional segments that can be manufactured using standard processes. The first, second, and third radial portions are defined by conventional geometric features (offsets, thickness variations) that can be produced with typical machining or forming operations, avoiding complex specialized manufacturing while achieving the desired flexibility gradient.

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 reduces clutch chattering and squealing by enhancing axial flexibility while maintaining torque transmission performance, and can be produced relatively simply and inexpensively.

Implementation Method 1

the support has a portion in which it is neither in direct contact with the flange nor in direct contact with the spacer. It is desirable that this portion of the support has a certain axial flexibility

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the friction surfaces capable of coming into contact with the pressure or reaction plate of the clutch

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3212951B1Clutch disc for a friction clutch
Publication Date: 2020.02.26 VALEO MATERIAUX DE FRICTION
  • EP3212951B1 patent drawingFigure 1
  • EP3212951B1 patent drawingFigure 2~3
  • EP3212951B1 patent drawingFigure 4~5

AI summary

A clutch disc (1) for a friction clutch, comprising: - a hub (3) extending along a longitudinal axis (X), - a flange (6) coupled to the hub (3), - a support (10) rigidly coupled to the flange (6) and extending radially beyond the flange (6), - a friction lining (12) rigidly connected to the support (10), and - a spacer (11) disposed axially between the support (10) and the friction lining (12), the portion of the radially inner edge (20) of the spacer (11) in contact with the support (10) being separated from the axis X of the hub (3) by a distance greater than the distance between said axis (X) and the radially inner edge (21) of the friction lining (12).