11-Speed DCT with Nested Planetary Gears
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power transmission systems for vehicles, such as double clutch transmission (DCT), face limitations in achieving a high number of forward and reverse speed stages while maintaining fuel economy and minimizing component count and weight.
Innovation Solution
The integration of two planetary gear sets and two synchronizers into a DCT system allows for the realization of eleven forward speed stages and one reverse speed stage, simplifying the interior layout and reducing the number of components, thereby improving fuel economy and enabling smooth shifting by alternately operating the clutches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple planetary gear sets are added to increase the number of speed stages, then the number of forward and reverse speed stages is improved, but the device complexity and component count increase
Solution Approach 1:
The patent combines two planetary gear sets (first and second planetary gear sets) into a single integrated transmission system where the first sun gear, first planet carrier, and first ring gear of the first planetary gear set are directly connected to the second sun gear, second planet carrier, and second ring gear respectively. This merging approach enables eleven forward speed stages and one reverse speed stage to be achieved while minimizing component count and avoiding rotational interference between input shafts.
2Use of energy by moving object
If more synchronizers and planetary gear sets are integrated, then fuel economy is improved through higher speed stages, but the weight of the power transmission apparatus increases
Solution Approach 1:
The patent employs a nested configuration where the first input shaft is disposed inside the second input shaft, and the first planetary gear set is integrated within the second planetary gear set. The first sun gear is positioned at the center of the second sun gear, and the first planet carrier is disposed inside the second planet carrier. This nested arrangement achieves eleven forward speed stages and one reverse speed stage while minimizing the overall size and weight of the transmission apparatus.
3Ease of operation
If two input shafts are used to enable selective torque reception, then shifting smoothness is improved, but the length and interior layout complexity increase
Solution Approach 1:
The patent implements a nested dual input shaft configuration where the first input shaft is disposed inside the second input shaft without rotational interference. This nested arrangement allows two input shafts to be integrated in a compact space, enabling smooth shifting through selective clutch operation while minimizing the overall length and interior layout complexity of the transmission apparatus.
Data Source
AI summary
A power transmission apparatus may include an first shifting member receiving the torque of the engine from the second input shaft, changing the torque of the engine into first and second preliminarily shifted torques, and outputting the first and second preliminarily shifted torques; a second shifting member receiving the torque of the engine from the third input shaft, changing the torque of the engine into third and fourth preliminarily shifted torques, and outputting the third and fourth preliminarily shifted torques; and a third shifting member changing the torque of the engine selectively transmitted from the first input shaft and the first preliminarily shifted torque to the fourth preliminarily shifted torque selectively transmitted from the first shifting member or the second shifting member into eleven forward speed stages and one reverse speed stage, and outputting the eleven forward speed stages and the one reverse speed stage.