Dual Clutch Actuation System with External Piston Arrangement

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Solution Overview

Problem

Existing dual clutch actuation systems face challenges in achieving a simple and robust design with easy assembly while ensuring functional reliability, particularly in maintaining independence of piston actuation and minimizing installation space and frictional influences.

Innovation Solution

The actuation system positions two pistons radially outside the guide sleeve, with rotational fixation on the guide sleeve, allowing for compact design and omission of breakouts, and uses overlapping functional elements to maintain axial and radial installation space, along with external lever designs and end stops for independent actuation and reduced friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the pistons are arranged radially inside the guide sleeve, then the installation space is reduced, but the guide sleeve requires breakouts and recesses which reduce structural stability and increase friction

Engineering Contradiction:
Improveinstallation spaceVSAvoidstructural stability
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent inverts the conventional arrangement by positioning the pistons radially outside the guide sleeve instead of inside. This inversion eliminates the need for breakouts and recesses in the guide sleeve, maintaining its structural integrity and static stability while still achieving compact installation space through the external positioning of pistons.

Inventive Principle:
Principle #13The other way round (Inversion)

2Volume of moving object

If the pistons are arranged radially inside the guide sleeve, then the installation space is compact, but the lever penetrations create friction influences and wear

Engineering Contradiction:
Improveinstallation spaceVSAvoidfriction and wear
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent extracts the pistons from the internal space of the guide sleeve and positions them externally. This extraction eliminates the need for lever penetrations through the guide sleeve wall, thereby removing the source of friction and wear associated with such penetrations and improving the reliability of the actuation system.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If the guide sleeve is designed with breakouts for internal piston accommodation, then the pistons can be actuated independently, but the guide sleeve becomes statically unstable

Engineering Contradiction:
Improveindependent actuationVSAvoidstatic stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

By inverting the piston arrangement to external positioning, the guide sleeve maintains its complete, closed cylindrical structure without breakouts. This preserves the static stability of the guide sleeve while independent actuation is still achieved through the external lever connection points on the pistons.

Inventive Principle:
Principle #13The other way round (Inversion)

4Strength

If the pistons are arranged radially outside the guide sleeve, then the guide sleeve can be designed without breakouts for high mechanical requirements, but the installation space may increase

Engineering Contradiction:
Improvemechanical strengthVSAvoidinstallation space
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

The patent utilizes the radial dimension outside the guide sleeve to position the pistons, allowing the guide sleeve to maintain its full structural strength without internal compromises. The external piston arrangement is configured to minimize space occupation by utilizing the available radial and axial dimensions efficiently.

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

Data Source

PatentEP2201258B2Clutch actuation system
Publication Date: 2015.02.25 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP2201258B2 patent drawingFigure 1~2
  • EP2201258B2 patent drawingFigure 3~7
  • EP2201258B2 patent drawingFigure 8~10

AI summary

The invention relates to an actuation system for a double clutch, comprising a guide sleeve disposed around the transmission input shafts of a double-clutch transmission connected downstream, two pistons being disposed on said sleeve axially displaceably by an actuator unit, each for actuating the clutches. The pistons can be displaced independently from each other, are locked into position, and overlap each other.