Dual-Clutch Transmission Layout for Low-Loss Agricultural Shifting
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Solution Overview
Problem
Current dual-clutch transmission architectures for agricultural vehicles suffer from high energy dissipation and inertia during gear shifting, leading to inefficient fuel consumption and increased weight, which affects performance and comfort across all working speed ranges.
Innovation Solution
The proposed dual-clutch transmission architecture features a staggered arrangement of clutches and gears, with axially offset even and odd clutches, and an intermediate shaft with wheels that split torque paths, allowing for efficient gear shifting with reduced weight and manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If big wet clutches are used to allow shift between range gears, then gear shifting capability is improved, but energy dissipation increases
Solution Approach 1:
The transmission is divided into multiple stages (input stage, gear ratio stage, range gear ratio stage) with separate clutch assemblies for each function. Range clutches and gear clutches are independently controlled, allowing selective engagement without requiring large clutches to handle all shifting operations simultaneously.
Solution Approach 2:
The patent employs a staggered axial arrangement of clutches where range clutches and gear clutches are positioned at different axial locations. This spatial separation allows independent torque paths and reduces the size requirements for individual clutches while maintaining full shifting capability.
2Adaptability or versatility
If traditional DCT architecture is used, then powershift capability is provided, but weight increases
Solution Approach 1:
Multiple clutch assemblies (range clutches and gear clutches) are merged into a single integrated clutch housing structure. The shared housing and mounting infrastructure reduces overall weight compared to separate clutch assemblies while maintaining all powershift functions.
Solution Approach 2:
The clutch housing serves multiple functions: it houses both range clutches and gear clutches, provides mounting for all clutch assemblies, and acts as a structural element for the entire transmission. This multi-functionality reduces the need for additional separate components and reduces overall weight.
3Adaptability or versatility
If traditional DCT architecture is used, then powershift transmission is achieved, but manufacturing time increases
Solution Approach 1:
The integrated clutch housing combines multiple clutch assemblies into a single manufacturable unit. This allows for more efficient production through unified casting or machining operations rather than assembling multiple separate housings, thereby reducing manufacturing time.
4Loss of energy
If staggered clutch arrangement is used, then torque path efficiency is improved, but device complexity increases
Solution Approach 1:
The clutch assembly employs an asymmetric staggered arrangement where range clutches and gear clutches are positioned at different axial locations rather than symmetrically. This asymmetric layout optimizes torque path length and reduces energy loss while the standardized clutch component design keeps manufacturing complexity manageable.
Data Source
Figure 1
Figure 1A
Figure 2
AI summary
Architecture for a dual clutch transmission (1) for an off road vehicle provided with an input stage (A), a gear ratio stage (B) and a range gear ratio stage (C) operatively connected in series one to the other with respect to an input shaft (2) and an output shaft (3), the transmission (1) comprises selection elements (17) configured to selectively couple gears (14, 15,22) of gear ratio stage (B) and range gear ratio stage (C) to the respective first and second shafts (11, 12) and support shaft (23).