Dual Input Shaft Automated Manual Transmission for Multi-Stage Gear Shifts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional automated manual transmissions face challenges in increasing the number of gear steps beyond six forward speeds and one rearward speed due to limitations in their design, which restricts their operational efficiency and versatility.
Innovation Solution
The implementation of a dual input shaft system with multiple drive and driven gears, along with a synchronization mechanism, allows for the realization of eight forward speeds and one rearward speed by selectively engaging clutches and synchronizers to transmit and interrupt engine power effectively across multiple gear arrays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional automated manual transmission uses a single input shaft with multiple gears and a synchronization device, then the structure remains simple, but the number of gear steps is limited to six forward speeds and one rearward speed
Solution Approach 1:
The transmission is divided into two separate input shafts (first input shaft and second input shaft), each capable of independently receiving engine power through separate clutches. This segmentation allows multiple gear arrays to be formed by combining different drive gears from each input shaft with driven gears, thereby increasing the number of achievable gear steps beyond the conventional six forward speeds.
Solution Approach 2:
The patent introduces a dual-input-shaft configuration that adds a dimensional aspect to the traditional single-input-shaft design. By having two independent power transmission paths (first input shaft and second input shaft), the system creates multiple gear arrays through cross-combination of drive and driven gears, effectively expanding the gear step possibilities from a linear arrangement to a multi-dimensional gear selection matrix.
2Adaptability or versatility
If the number of gear steps is increased to eight forward speeds and one rearward speed, then operational versatility is enhanced, but the transmission size and weight increase
Solution Approach 1:
Multiple drive gears (first, second, third, and fourth drive gears) and driven gears (first through eighth driven gears) are merged into a compact arrangement where they share common mounting locations and spatial relationships. The synchronization device integrates multiple synchronization mechanisms that can simultaneously or sequentially engage different gear combinations, allowing eight forward speeds and one rearward speed to be achieved within a constrained volume, thereby limiting the increase in transmission weight.
Solution Approach 2:
The first and second input shafts serve multiple functions: each can independently transmit engine power, each can engage with multiple drive gears, and both work in conjunction with the synchronization device to achieve various gear ratios. This multi-functionality allows the transmission to realize eight forward speeds and one rearward speed without requiring separate dedicated components for each gear step, thus controlling the overall weight increase.
3Manufacturing precision
If multiple clutches and synchronization parts are installed to enable multi-stage gear shifts, then gear shift precision is improved, but the device complexity increases
Solution Approach 1:
The synchronization device is designed to pre-synchronize the rotational speeds of engaging gears before actual engagement occurs. The multiple clutches (first clutch and second clutch) are positioned and configured in advance to selectively engage with specific input shafts, and the synchronization mechanisms are pre-positioned to align with corresponding driven gears. This preliminary preparation ensures smooth and precise gear shifts when transitioning between eight forward speeds and one rearward speed.
Solution Approach 2:
The synchronization device acts as an intermediary mechanism between the clutches and the gear arrays. It mediates the power transmission by gradually equalizing the rotational speeds of meshing gears before full engagement, preventing shock loads and ensuring precise gear shifts. The multiple clutches serve as intermediaries that selectively connect the engine to either the first or second input shaft, enabling controlled power distribution across different gear arrays.
Data Source
AI summary
An automated manual transmission includes first and second power input shafts, a drive gear part, a clutch arranged to transmit or interrupt the power of the engine to the first or second input shaft, first and second power output shafts to which power is transmitted from the first or second input shaft, driven gearing including a plurality of driven gears on the first and second output shafts, and a synchronizer connecting or disconnecting the first output shaft or the second output shaft and the driven gear to provide multi-stage gear shift steps. The clutch includes first and second clutches installed at the first and second input shafts to transmit or interrupt input engine power. An example of such transmission having 8 forward speeds and one reverse speed is described.