Ten-speed transmission using nested planetary gear sets
Solution Overview
Problem
Current multiple speed transmissions face challenges in achieving improved performance, efficiency, responsiveness, smoothness, reduced size, and weight, particularly in achieving a compact ten-speed configuration while maintaining cost-effectiveness.
Innovation Solution
The transmission employs four planetary gear sets and a plurality of torque transmitting devices, including clutches and brakes, with specific interconnecting members and mechanisms to achieve ten or more speeds, utilizing a combination of sun gears, ring gears, and carrier members for efficient gear ratio progression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a multiple speed transmission uses a combination of friction clutches, planetary gear arrangements and fixed interconnections to achieve a plurality of gear ratios, then the transmission can provide multiple speed ratios, but the size and weight of the transmission increase
Solution Approach 1:
The patent combines multiple planetary gear sets (first, second, third, and fourth planetary gear sets) with shared components and interconnections to achieve ten forward speeds in a single integrated transmission system, rather than using separate gear sets for each ratio
Solution Approach 2:
The transmission uses six torque transmitting mechanisms that can selectively interconnect various members of the planetary gear sets with each other and with stationary members, allowing the same mechanical components to serve multiple functions across different gear ratios
2Adaptability or versatility
If a multiple speed transmission uses a combination of friction clutches, planetary gear arrangements and fixed interconnections to achieve a plurality of gear ratios, then the transmission can provide multiple speed ratios, but the packaging space required increases
Solution Approach 1:
The patent arranges planetary gear sets in a nested configuration where members of different planetary gear sets are interconnected and share common mounting structures, allowing compact packaging of ten speed ratios in a reduced volume
Solution Approach 2:
The transmission uses multiple interconnecting members that link planetary gear sets across different spatial dimensions, enabling compact three-dimensional packaging of the gear train while maintaining all ten forward speeds
3Adaptability or versatility
If the transmission uses six torque transmitting mechanisms selectively engageable to interconnect members with stationary members, then the transmission achieves ten forward and one reverse speed, but the device complexity increases
Solution Approach 1:
The patent divides the transmission into four distinct planetary gear sets, each with specific functions, and uses six dedicated torque transmitting mechanisms to control connections between them, allowing systematic management of complexity through modular segmentation
Data Source
AI summary
A transmission is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices include clutches and brakes.