Planetary Multi-Speed Transmission With 8-Speed Clutch Layout
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Solution Overview
Problem
Current multiple speed transmissions face challenges in achieving different gear ratios with improved performance, cost efficiency, responsiveness, and packaging constraints, limiting their effectiveness.
Innovation Solution
The design incorporates a system with four planetary gearsets and five selectively engageable torque-transmitting mechanisms, including brakes and clutches, controlled by an electro-hydraulic system and transmission control circuit to achieve eight forward and one reverse speed ratio, optimizing gear shifting and torque transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple speed transmissions use a number of friction clutches or brakes, planetary gearsets, shafts, and other elements to achieve a plurality of gear or speed ratios, then the transmission can achieve multiple speed ratios, but the device complexity increases and packaging constraints are worsened
Solution Approach 1:
The transmission system is divided into four distinct planetary gearsets (first, second, third, and fourth), each capable of independent operation. This segmentation allows the system to achieve multiple speed ratios by selectively engaging different planetary gearsets and their associated torque-transmitting mechanisms, rather than using a single complex gearset configuration.
Solution Approach 2:
The patent introduces interconnecting members that create additional dimensional connections between planetary gearsets. These interconnecting members allow torque and motion to be transferred between different planetary gearsets, adding a new dimension of complexity management that enables multiple speed ratios without proportionally increasing overall system complexity.
2Adaptability or versatility
If five torque-transmitting mechanisms are selectively engageable to establish eight forward speed ratios and one reverse speed ratio, then the transmission achieves multiple speed ratios, but the device complexity and packaging constraints worsen
Solution Approach 1:
Each torque-transmitting mechanism is designed to perform multiple functions. For example, the first torque-transmitting mechanism can engage to provide direct drive, while also serving as a foundation for achieving reverse ratios when combined with other mechanisms. This multi-functionality allows five mechanisms to control eight forward and one reverse speed ratio without requiring additional dedicated components for each ratio.
Solution Approach 2:
The patent merges the functions of multiple torque-transmitting mechanisms through shared planetary gearset components. The interconnecting members allow different torque-transmitting mechanisms to work in combination, where the engagement of two or more mechanisms simultaneously achieves complex speed ratios, thereby reducing the total number of mechanisms needed compared to traditional designs.
3Ease of manufacture
If the transmission architecture is determined based on cost, size, packaging constraints, and desired ratios, then the transmission can be optimized for specific applications, but the adaptability to different conditions is limited
Solution Approach 1:
The transmission system employs dynamic engagement and disengagement of torque-transmitting mechanisms through friction clutches and brakes. This dynamic capability allows the transmission to adapt to different operating conditions in real-time, shifting between various speed ratios as needed, while maintaining a compact architecture optimized for cost and packaging constraints.
Data Source
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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 five torque-transmitting mechanisms.