Automatic Transmission Clutch Layout for Compact Axial and Radial Packaging
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Solution Overview
Problem
Automatic transmissions with multiple planetary gear sets face challenges in axial and radial dimension management, leading to potential interference with body components due to increased radial dimensions when clutches are aligned radially.
Innovation Solution
The configuration of automatic transmissions with one-side and other-side clutches aligned axially, where pistons penetrate friction plates in an overlapping manner, allowing for parallel arrangement of friction plates to reduce both axial and radial dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If clutches are aligned in the radial direction to reduce axial dimension, then the axial dimension is reduced, but the radial dimension increases causing interference with body components
Solution Approach 1:
The patent applies nesting by placing the piston of the other-side clutch inside the friction plate assembly of the one-side clutch. The piston penetrates through the friction plate in axial direction, allowing the piston to be nested within the friction plate structure. This nesting arrangement enables both clutches to share the same radial space while maintaining separate axial positions, thereby reducing the radial dimension of the transmission assembly.
Solution Approach 2:
The patent transitions from radial alignment to axial alignment of clutches, changing the dimension in which clutches are arranged. By aligning clutches in the axial direction and using overlapping piston-friction plate arrangement, the design moves the spatial organization to a different dimensional configuration, achieving compact radial dimensions while maintaining functional separation.
2Use of energy by moving object
If multiple planetary gear sets are added to improve fuel efficiency, then fuel efficiency improves, but the axial dimension of the transmission increases reducing mountability
Solution Approach 1:
The patent merges the structural elements of multiple clutches by aligning them axially and allowing pistons to penetrate friction plates of adjacent clutches. This merging approach consolidates what would otherwise be separate radial assemblies into a compact axial arrangement, enabling multiple planetary gear sets to be integrated without proportionally increasing the axial dimension.
Solution Approach 2:
By nesting pistons within friction plate assemblies of adjacent clutches, the patent reduces the overall axial space required for multiple clutch assemblies. The nested configuration allows multiple clutches to share common radial space while maintaining functional independence, thereby supporting multiple planetary gear sets with reduced axial growth.
3Area of moving object
If clutches are aligned in the axial direction to reduce radial dimension, then radial dimension is reduced, but the axial dimension increases
Solution Approach 1:
The patent resolves this contradiction by changing the dimensional organization from purely axial stacking to a hybrid arrangement where clutches are axially aligned but pistons penetrate into adjacent friction plates. This dimensional reorganization allows the system to achieve compact radial dimensions through axial alignment while using piston penetration to reduce the effective axial dimension required for each clutch assembly.
Data Source
AI summary
An automatic transmission has a one-side clutch and an other-side clutch in an axial direction, the one-side clutch and the other-side clutch being aligned in the axial direction on an axis of a power transmission shaft. These clutches respectively include: drum sections; hub sections; friction plates that are engaged in an axially slidable manner between the drum sections and the hub sections; and pistons that press the friction plates. The friction plates in the one-side and other-side clutches are arranged in parallel in the axial direction. The pistons in the one-side clutch and the other-side clutch are arranged on one sides in the axial direction of the friction plates and are arranged such that axial positions thereof overlap. The piston in the other-side clutch penetrates the friction plate in the one-side clutch in the axial direction.