Multi-Speed Transmission With Planetary Gearsets
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Solution Overview
Problem
Current multiple speed transmissions face challenges in achieving a wide range of gear ratios with improved performance, cost efficiency, responsiveness, and packaging constraints, requiring innovative architectural designs.
Innovation Solution
The design incorporates multiple planetary gearsets and torque-transmitting mechanisms that are selectively engageable in combinations to establish at least eight forward and one reverse speed ratio, utilizing interconnecting members to optimize gear ratios and transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple planetary gearsets and torque-transmitting mechanisms are used to achieve eight or more forward speed ratios, then the gear ratio range and performance are improved, but the device complexity and packaging constraints worsen
Solution Approach 1:
The transmission system is divided into multiple planetary gearsets (first, second, third, and fourth planetary gearsets) each with distinct members (sun gears, ring gears, carrier members). This segmentation allows independent control and engagement of different gear elements through selective torque-transmitting mechanisms, enabling a wide range of speed ratios while maintaining manageable complexity through modular design
Solution Approach 2:
The planetary gearsets are configured with interconnecting members that allow each gearset to serve multiple functions. The same planetary gearset members can be engaged by different torque-transmitting mechanisms to achieve various speed ratios, and certain members (like the carrier members and ring gears) are continuously interconnected to multiple gearsets, enabling them to participate in multiple gear ratio configurations simultaneously
2Adaptability or versatility
If five torque-transmitting mechanisms are selectively engaged in combinations of at least three, then at least eight forward speed ratios and at least one reverse speed ratio are achieved, but the manufacturing cost and assembly difficulty increase
Solution Approach 1:
The torque-transmitting mechanisms are designed to be selectively engageable and disengageable, allowing dynamic reconfiguration of the transmission system. This dynamic engagement capability enables a single physical configuration to produce multiple speed ratios (at least eight forward and one reverse) by varying which mechanisms are active, rather than requiring separate physical pathways for each ratio
Solution Approach 2:
Multiple torque-transmitting mechanisms are combined within a unified planetary gearset architecture. The mechanisms share common structural elements (sun gears, ring gears, carrier members) and are integrated through interconnecting members, allowing them to be manufactured and assembled as a cohesive unit rather than separate subsystems, thereby reducing overall manufacturing complexity
3Productivity
If four planetary gearsets with multiple members are interconnected, then transmission efficiency and responsiveness are improved, but the packaging space and weight increase
Solution Approach 1:
The planetary gearsets are arranged in a nested or compact configuration where members of different gearsets are interconnected and share spatial relationships. The interconnecting members directly connect corresponding members (sun gears to sun gears, ring gears to ring gears, carrier members to carrier members) in a way that minimizes radial and axial dimensions, allowing the four planetary gearsets to be packed efficiently within a reduced volume
Solution Approach 2:
The transmission system utilizes multiple spatial dimensions for interconnecting members, arranging planetary gearsets and their connections in three-dimensional space rather than linear sequences. This dimensional arrangement allows efficient packing of four planetary gearsets with multiple members by optimizing spatial relationships in radial, axial, and longitudinal directions simultaneously
Data Source
AI summary
The present disclosure provides a multiple speed transmission having an input member, an output member, a plurality of planetary gearsets, a plurality of interconnecting members and a plurality of torque-transmitting mechanisms. The plurality of planetary gear sets includes first, second and third members. The input member is continuously interconnected with at least one member of one of the plurality of planetary gear sets, and the output member is continuously interconnected with another member of one of the plurality of planetary gear sets. At least eight forward speeds and one reverse speed are achieved by the selective engagement of the plurality of torque-transmitting mechanisms.