Automatic Transmission Radial Member Layout for Weight Reduction
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Solution Overview
Problem
Existing automatic transmissions face challenges in reducing weight and improving controllability due to increased inertia caused by thicker members required for high rigidity, which complicates multi-speed shifting and affects fuel economy.
Innovation Solution
The automatic transmission design positions the output side transfer members of the first and second input transfer clutches radially inward, allowing for smaller diameters and reduced weight, while also optimizing the placement of speed reduction transfer clutches and hydraulic servos to enhance torque transfer efficiency and controllability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If members are disposed radially outward to achieve higher rigidity for high-speed rotation, then rigidity is improved, but weight and inertia increase
Solution Approach 1:
The patent applies local quality by differentiating the radial positioning of members based on their rotational speed requirements. High-speed rotating members (output side transfer member of first input transfer clutch, output side transfer member of second input transfer clutch) are disposed radially inward where centrifugal force is lower, while members experiencing lower speeds can be positioned radially outward. This localized optimization allows each member to be positioned in the most favorable radial location for its specific operational requirements, achieving necessary rigidity without uniformly increasing weight across all members.
Solution Approach 2:
The patent resolves the rigidity-weight contradiction by utilizing the radial dimension strategically. Instead of increasing member thickness (one-dimensional solution) to achieve rigidity, the invention repositions members along the radial axis (adding dimensional consideration) to exploit the relationship between radial position and centrifugal force. Members are assigned to different radial zones based on their speed characteristics, transforming a thickness/rigidity problem into a spatial arrangement problem that reduces overall weight while maintaining necessary structural integrity.
2Strength
If members are disposed radially outward to achieve higher rigidity for high-speed rotation, then rigidity is improved, but controllability deteriorates
Solution Approach 1:
The patent applies local quality by differentiating the radial positioning of members based on their rotational speed requirements. High-speed rotating members (output side transfer member of first input transfer clutch, output side transfer member of second input transfer clutch) are disposed radially inward where centrifugal force is lower, while members experiencing lower speeds can be positioned radially outward. This localized optimization allows each member to be positioned in the most favorable radial location for its specific operational requirements, achieving necessary rigidity without uniformly increasing weight across all members.
Solution Approach 2:
The patent resolves the rigidity-weight contradiction by utilizing the radial dimension strategically. Instead of increasing member thickness (one-dimensional solution) to achieve rigidity, the invention repositions members along the radial axis (adding dimensional consideration) to exploit the relationship between radial position and centrifugal force. Members are assigned to different radial zones based on their speed characteristics, transforming a thickness/rigidity problem into a spatial arrangement problem that reduces overall weight while maintaining necessary structural integrity.
3Strength
If member thickness is increased to attain high rigidity, then rigidity is improved, but inertia increases
Solution Approach 1:
The patent applies local quality by differentiating the radial positioning of members based on their rotational speed requirements. High-speed rotating members (output side transfer member of first input transfer clutch, output side transfer member of second input transfer clutch) are disposed radially inward where centrifugal force is lower, while members experiencing lower speeds can be positioned radially outward. This localized optimization allows each member to be positioned in the most favorable radial location for its specific operational requirements, achieving necessary rigidity without uniformly increasing weight across all members.
Solution Approach 2:
The patent resolves the rigidity-weight contradiction by utilizing the radial dimension strategically. Instead of increasing member thickness (one-dimensional solution) to achieve rigidity, the invention repositions members along the radial axis (adding dimensional consideration) to exploit the relationship between radial position and centrifugal force. Members are assigned to different radial zones based on their speed characteristics, transforming a thickness/rigidity problem into a spatial arrangement problem that reduces overall weight while maintaining necessary structural integrity.
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 design reduces weight and inertia, improves controllability, and simplifies the transmission structure, enabling efficient multi-speed shifting and enhanced power transfer efficiency.
Implementation Method 1
a hydraulic servo that presses friction plates of the clutch together
Implementation Method 2
presses friction plates of the clutch together
Data Source
AI summary
An output side transfer member 103 of a second clutch C-2 extends around the outer circumferences of the output side transfer members 101, 102 of the third and first clutches C-3, C-1, the output side transfer member 104 (or 13, 101) of a fourth clutch C-4 and the output side transfer member 101 of a third clutch C-3 are linked to a sun gear S2, the output side transfer member 104 (or 13, 101) of a fourth clutch C-4, an output side transfer member 101 of a third clutch C-3, and a sun gear S2, which rotate integrally, are disposed radially inward with respect to the output side transfer member 102 of the first clutch C-1. Thereby, it becomes possible to reduce the diameter of the output side transfer member 104 (or 13, 101) of the fourth clutch C-4, to reduce the weight and inertia, and to improve the controllability of the automatic transmission 1.