Parallel Double Clutch Layout With Selective Axial Cooling
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Solution Overview
Problem
The challenge of limited axial and radial space within a vehicle for a double clutch assembly, particularly in sports car transaxles, combined with high torque transfer requirements and the need for ease of assembly and disassembly, is addressed by the configuration of a double clutch unit with parallel clutch packs and axial liquid distribution.
Innovation Solution
The double clutch unit features parallel arranged engine and gearbox friction clutch packs flanking a common clutch reaction plate, with torque transmission via fixed drive plates, and an axial liquid distributor system that selectively provides cooling and balancing fluid to each clutch pack through non-overlapping conduits on the clutch input shaft and stator, allowing for compact design and efficient cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If two clutches are disposed in parallel arrangement to reduce axial space, then radial space is reduced, but torque transfer capability and cooling requirements increase
Solution Approach 1:
The patent transitions from conventional axial stacking of clutch packs to a parallel radial arrangement, effectively changing the spatial dimension used for clutch pack configuration. This allows the clutch packs to be positioned side-by-side rather than one above the other, reducing axial length while maintaining functional separation through radial positioning relative to the input shaft
Solution Approach 2:
The clutch transmission system is segmented into two independent parallel clutch packs (odd and even gear clutches) that operate simultaneously but independently. Each clutch pack has its own piston, friction plates, and hydraulic control, allowing separate torque transfer paths that collectively handle high torque loads while maintaining compact axial dimensions
2Length of moving object
If clutch packs are disposed in parallel arrangement, then axial compactness is improved, but assembly and disassembly complexity increases
Solution Approach 1:
The clutch assembly is divided into modular clutch packs that can be independently assembled and disassembled. Each clutch pack functions as a self-contained unit with standardized interfaces to the input shaft and reaction plate, allowing maintenance personnel to service individual clutch packs without disassembling the entire transmission assembly
Solution Approach 2:
The common reaction plate and input shaft serve both clutch packs simultaneously, providing universal support structures that simplify the overall assembly architecture. This shared infrastructure reduces the number of unique components and assembly steps compared to completely separate clutch assemblies
3Temperature
If cooling liquid is provided to both clutch packs simultaneously, then thermal management is improved, but fluid distribution complexity and energy loss increase
Solution Approach 1:
The cooling liquid distribution system dynamically adapts to actual thermal needs by providing cooling only to actively slipping clutch packs. The hydraulic control system detects which clutch is currently engaged and directs cooling fluid accordingly, rather than continuously cooling both clutches, thereby reducing unnecessary energy consumption and fluid circulation requirements
Solution Approach 2:
Cooling liquid is delivered selectively to specific localized areas (individual clutch packs) based on their immediate thermal requirements. Each clutch pack has dedicated cooling channels that receive fluid only when needed, creating a localized cooling response rather than a global cooling system that wastes energy on already-cooled components
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 configuration enhances axial compactness, facilitates easy assembly and disassembly, and optimizes cooling by directing fluid only to the clutch pack needing it, thereby improving performance and reducing complexity and costs.
Implementation Method 1
an axial liquid distributor (90), ALD (90), configured for transport of at least one liquid in an axial direction between the (E) side of the clutch input shaft and a location towards the (G) side of the clutch input shaft (60)
Implementation Method 2
one or more GS cooling channels (74c) for providing cooling liquid to the GS clutch pack (30)
Data Source
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AI summary
Provided is double clutch unit (100) for a transmission comprising: an engine (E) side friction clutch pack, ES clutch pack (40), and a gearbox (G) side friction clutch pack, GS clutch pack (30); a clutch input shaft (60) having an axis (A-A') of rotation; an axial liquid distributor (90), ALD (90), configured for transport of at least one liquid in an axial direction between the (E) side of the clutch input shaft and a location towards the (G) side of the clutch input shaft (60); wherein - a first ALD conduit (24c) of the plurality of ALD conduits services both an ES clutch pack piston balancing chamber (450) and one or more GS cooling channels (74c) for providing cooling liquid to the GS clutch pack (30); and a second ALD (24d) of the plurality of ALD conduits, different from the first ALD conduit (24c), services both a GS clutch pack piston balancing chamber (350) and one or more ES cooling channels (74d) for providing cooling liquid to the ES clutch pack (40).