Multi-Speed Planetary Transmission With Selective Coupler Reconfiguration
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Solution Overview
Problem
Current multi-speed transmissions face limitations in achieving a sufficient number of forward and reverse speed ratios using planetary gearsets and selective couplers, as they often require complex configurations and additional elements to meet the desired gear ratio requirements.
Innovation Solution
A multi-speed transmission design incorporating multiple planetary gearsets and selective couplers, including clutches and brakes, which are actively or passively controlled to achieve at least nine forward speed ratios and one reverse speed ratio by varying the engagement of these components to optimize gear interconnections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple planetary gearsets and selective couplers are used to achieve more forward and reverse speed ratios, then the number of speed ratios is improved, but the device complexity increases
Solution Approach 1:
The transmission system is divided into multiple independent planetary gearsets (first, second, third, and fourth planetary gearsets) that can be selectively engaged through individual selective couplers. This segmentation allows each gearset to contribute specific speed ratios while maintaining independent control, enabling the achievement of multiple forward and reverse speed ratios without requiring a single complex gear arrangement
Solution Approach 2:
The transmission system employs selectively engageable couplers that dynamically connect or disconnect planetary gearsets based on the desired speed ratio. This dynamic reconfiguration allows the transmission to adapt its gear train composition in real-time, providing multiple speed ratios while maintaining a relatively simple base structure that only becomes complex when all components are considered together
2Adaptability or versatility
If additional elements are added to achieve sufficient speed ratios, then the speed ratio requirements are met, but the transmission structure becomes more complex
Solution Approach 1:
Each selective coupler is designed to perform multiple functions: it can connect different planetary gearsets, engage different gear configurations, and enable both forward and reverse speed ratios through the same component. This multi-functionality reduces the need for dedicated components for each specific ratio, thereby meeting speed ratio requirements while limiting structural complexity
Data Source
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AI summary
A multi-speed transmission (100) including a plurality of planetary gearsets (108, 110, 112, 114) and a plurality of selective couplers (162, 164, 166, 168, 170, 172) to achieve at least nine forward speed ratios is disclosed. The plurality of planetary gearsets may include a first planetary gearset (108), a second planetary gearset (110), a third planetary gearset (112), and a fourth planetary gearset (114). The plurality of selective couplers (162, 164, 166, 168, 170, 172) may include a number of clutches (166, 168, 170, 172) and a number of brakes (162, 164). The multi-speed transmission (100) may have four planetary gearsets (108, 110, 112, 114) and six selective couplers (162, 164, 166, 168, 170, 172). The six selective couplers (162, 164, 166, 168, 170, 172) may include four clutches (166, 168, 170, 172) and two brakes (162, 164).