Dual-Clutch Transmission Power-Shifting via Nested Shafts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing double-clutch group transmissions in commercial vehicles face challenges with gear changes in the range group, which are not traction-assisted, leading to noticeable interruptions and discomfort for the driver.
Innovation Solution
A double-clutch group transmission design with a splitter group and a main group in countershaft design, combined with a range group in planetary design, featuring a direct connection between the transmission input shaft and the main shaft, and an additional hollow shaft for independent operation of the planetary carrier, allowing gear changes without traction interruption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the range group is switched between two gear ranges using conventional design, then the transmission provides a large number of gears with corresponding gear spread, but the switching process is not assisted by traction and takes comparatively long time causing noticeable interruptions
Solution Approach 1:
The transmission is divided into two independent input shafts (first and second transmission input shafts) that can operate separately. The first input shaft handles gears in the first gear range while the second input shaft handles gears in the second gear range, allowing independent switching without affecting the other range and enabling traction-assisted switching.
Solution Approach 2:
A synchronization device is introduced as an intermediary mechanism between the input shafts and the planetary gear set. This synchronization device coordinates the switching between the two input shafts, ensuring smooth transitions and enabling traction-assisted switching by maintaining continuous power flow during range changes.
2Ease of operation
If a direct connection between transmission input shaft and main shaft is implemented, then gear changes can be power-shiftable, but the transmission shaft length increases
Solution Approach 1:
The first and second transmission input shafts are arranged coaxially, with one shaft nested within the other. This nested arrangement allows direct connection for power-shiftable capability while minimizing the overall length of the transmission system by utilizing the same axial space for both input paths.
Solution Approach 2:
Instead of extending the transmission shafts axially to provide direct connection, the patent uses a radial arrangement with two input shafts positioned at different radial locations but sharing the same axial position. This dimensional reorganization enables power-shiftable capability without increasing the overall axial length of the transmission.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a dual-clutch group transmission, having a splitter group (GV), a main group (HG) and a range group (GP), in which dual-clutch group transmission the splitter group (GV) and the main group (HG) are configured as a transfer box transmission and the range group (GP) is configured as a planetary gear transmission with an internal gear (27), a sun gear (26) and a planetary gear set (28) which is guided by a planetary carrier (29), having an inner transmission input shaft (22) which is connected to a first clutch (C1), having an outer transmission input shaft (23) which is connected to a second clutch (C2), having a transmission main shaft (24) and having shifting apparatuses (S1, S2, S3, S4, S5, S6) for shifting gears or producing non-positive connections, and to a method for actuating said dual-clutch group transmission. In order to make power-shift gear changes during a shift of the range group (GP) possible, the inner transmission input shaft (22) can be connected directly to the transmission main shaft (24) via a shifting apparatus (S2), and in addition an additional hollow shaft (25) is arranged coaxially on the transmission main shaft (24), on which at least one movable gear (18) of a forward gear (1G) of the main group (HG) is mounted rotatably, which movable gear (18) can be connected fixedly via a shifting apparatus (S4) to the hollow shaft so as to rotate with it, wherein the hollow shaft (25) can be connected via a shifting apparatus (S3, S5) to the transmission main shaft (24) and via a shifting apparatus (S5) to the planetary carrier (29).