Concentric Double Wet Clutch Layout for Reduced Axial and Radial Size

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Solution Overview

Problem

Existing double wet clutch mechanisms face challenges in reducing both axial and radial size due to the bulk imposed by elastic washers and springs, leading to increased size and inefficiency in automotive transmission systems.

Innovation Solution

A compact double wet clutch mechanism is designed with concentrically nested elastic return devices and a guide bearing within the input disc carrier, utilizing a ball bearing guide bearing to manage axial forces without increasing axial size, and helical springs or annular washers for elastic return, allowing for reduced radial dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If elastic washers of Belleville type are used for each clutch, then sufficient force is generated to restore the actuator and clutch to initial configurations, but the axial size of the clutch mechanism increases

Engineering Contradiction:
Improverestoration forceVSAvoidaxial size
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The patent places the elastic return device (Belleville washers) inside the input disc carrier, nesting it within the existing clutch structure. This allows the restoration force function to be maintained while eliminating the need for additional axial space that would be required if the washers were positioned outside the carrier.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from a conventional axial arrangement of elastic washers to a radial arrangement within the input disc carrier. By utilizing the radial dimension and internal space of the carrier, the design maintains restoration force capability while reducing axial protrusion.

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

2Length of moving object

If elastic springs are located axially between friction faces and radially at the spline of input disc carrier, then axial size is reduced, but radial bulk increases leading to radial oversizing

Engineering Contradiction:
Improveaxial sizeVSAvoidradial size
Core Design Contradiction:
Length of moving objectVSArea of moving object

Solution Approach 1:

The patent nests the elastic return device within the input disc carrier's internal volume, utilizing the radial space already allocated for the carrier structure. This prevents radial oversizing by containing the elastic elements within the carrier's radial boundaries rather than allowing them to protrude outward.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The input disc carrier serves multiple functions: it transmits torque radially through splines and simultaneously houses the elastic return device axially. This multi-functionality allows the same radial structure to accommodate both torque transmission and elastic restoration without increasing radial dimensions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Volume of moving object

If elastic return devices and guide bearing are nested within input disc carrier, then axial and radial size are reduced, but device complexity increases

Engineering Contradiction:
Improveoverall sizeVSAvoidstructural complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The input disc carrier is designed to simultaneously perform torque transmission through its spline connection and house the elastic return device and guide bearing. This multi-functionality reduces overall complexity by eliminating the need for separate external components for these functions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the elastic return device and guide bearing into a single integrated assembly within the input disc carrier. This merging of components reduces the total number of separate parts and simplifies the overall structure while maintaining compact dimensions.

Inventive Principle:
Principle #5Merging (Combining)

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 achieves an axially compact and radially reduced clutch mechanism, effectively minimizing size while maintaining operational efficiency and force restoration capabilities.

Implementation Method 1

a guide bearing common to the first and second clutches arranged between the axial extension bearing and the input disc carrier

Methodology Applied
Scientific EffectBall bearing: Ball Bearing

Implementation Method 2

a first elastic return device for the first actuating piston arranged to bear on the input disc carrier, a second elastic return device for the second actuating piston arranged to bear on the input disc carrier

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3857090B1Compact double wet clutch mechanism
Publication Date: 2022.08.31 VALEO EMBRAYAGES SAS
  • EP3857090B1 patent drawingFigure 1
  • EP3857090B1 patent drawingFigure 2
  • EP3857090B1 patent drawingFigure 3~4

AI summary

The invention concerns a double wet clutch mechanism (1) for a motor vehicle transmission, comprising: - first and second clutches (E1, E2) respectively of the type with multiple discs rotating about an axis of rotation (O), controlled so as to selectively couple a drive shaft to a first driven shaft (A1) and to a second driven shaft (A2) via a common torque input disc carrier (10), the first clutch (E1) being arranged radially beyond the second clutch (E2); - a clutch control system (100) comprising first and second actuating pistons (110, 120) designed to control the first and second clutches (E1, E2); - first and second elastic return devices (60, 70) associated with the first and second actuating pistons arranged bearing on the input disc carrier, and - a guide bearing (80) supporting the input disc carrier (10) with respect to the actuation system (100), the clutches, the elastic return devices and the guide bearing being concentric.