Three-Planetary Transmission Layout for Equal Dual Output Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current motor vehicle transmissions lack the ability to efficiently generate two approximately equal-sized output torques greater than the input torque while maintaining a compact and efficient design, which is essential for improved power density and efficiency.
Innovation Solution
A transmission system comprising three planetary gear sets with specific rotational fixings and connections, including radially nested gear sets and a common ring or sun gear configuration, to achieve torque conversion and differential functions, allowing for efficient power distribution to both wheels of a motor vehicle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a transmission system uses multiple planetary gear sets to generate two equal-sized output torques greater than input torque, then power density and efficiency are improved, but device complexity increases
Solution Approach 1:
The patent combines three planetary gear sets into a single integrated transmission system where the gear sets share common components (input shaft, coupling shafts, output shafts). This merging approach enables the system to generate two equal-sized output torques greater than input torque while maintaining a compact structure, thereby improving power density without proportionally increasing device complexity
Solution Approach 2:
The transmission system performs multiple functions simultaneously: it acts as a torque converter (generating two output torques greater than input torque), a differential (distributing power to two output shafts), and a speed reducer. This multi-functionality is achieved through the specific configuration of three planetary gear sets with shared components, improving overall system efficiency while consolidating functions into a single device
2Power
If a transmission system uses three planetary gear sets with specific rotational fixings, then torque conversion capability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent employs a nested configuration where planetary gear sets are arranged radially and share common shafts and components. The first, second, and third planetary gear sets are integrated such that they share the input shaft, coupling shafts, and output shafts, creating a compact nested structure that facilitates torque conversion while simplifying manufacturing compared to separate gear sets
Solution Approach 2:
The transmission system is segmented into three distinct planetary gear sets, each with specific rotational fixings (first element fixed to input shaft, second element fixed to coupling shaft, third element fixed to output shaft or stationary component). This segmentation allows for modular manufacturing and assembly, where each planetary gear set can be manufactured and tested separately before integration, thereby improving torque conversion capability while managing manufacturing complexity
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
The proposed transmission system effectively generates two equal-sized output torques greater than the input torque, enhancing power density and efficiency while maintaining a compact design, suitable for electric vehicles and all-wheel drive systems.
Implementation Method 1
The transmission has a first planetary gear set, a second planetary gear set and a third planetary gear set, wherein each planetary gear set includes a first element, a second element and a third element
Data Source
AI summary
A transmission for a motor vehicle includes a first, a second, and a third planetary gear set, an input shaft, a first and a second output shaft, and a first and a second coupling shaft. Respective elements of the first planetary gear set are rotationally fixed to the input shaft, rotationally fixed to the first coupling shaft, and rotationally fixed to the second coupling shaft. Respective elements of the second planetary gear set are rotationally fixed to the first coupling shaft, rotationally fixed to a stationary component, and rotationally fixed to the second output shaft. Respective elements of the third planetary gear set are rotationally fixed to the second coupling shaft, rotationally fixed to the first output shaft, and rotationally fixed to the second output shaft.