Compact Constant Mesh Gearbox With Central Transverse Web
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing number of speed ratios in gear transmissions to achieve better acceleration and fuel economy leads to a larger transmission size, which is problematic for vehicle designers due to space constraints, and there is a need for a common base component to serve various vehicle types with different attributes.
Innovation Solution
A constant mesh gearbox with a symmetric arrangement of gear wheel pairs on either side of a central support plane, allowing for modular assembly and reduced size, incorporating a dual clutch transmission with co-axial input shafts and a central transverse web for improved stiffness and assembly efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of speed ratios is increased to achieve good acceleration and fuel economy, then the transmission performance is improved, but the transmission size increases which is problematic for vehicle designers
Solution Approach 1:
The transmission is divided into two separate casings: a first casing containing the input shaft and first layshaft with first gear wheel pairs, and a second casing containing the output shaft and second layshaft with second gear wheel pairs. This segmentation allows each casing to be optimized independently and reduces the overall volume by distributing components across separate housings.
Solution Approach 2:
The patent utilizes the longitudinal dimension by extending the transmission assembly across multiple casings arranged in series along the drive axis. The input shaft spans both casings, and gear wheel pairs are distributed along this longitudinal axis, effectively using length to accommodate more speed ratios without increasing radial or axial footprint in other dimensions.
2Adaptability or versatility
If a common base component is designed to serve various vehicle types, then the adaptability is improved, but the design complexity increases to accommodate different attributes
Solution Approach 1:
The transmission design provides multiple output locations through the second layshaft, allowing the same base transmission to serve different vehicle configurations (e.g., front-wheel drive, rear-wheel drive, four-wheel drive). The differential gears and output mechanisms can be selectively engaged to provide drive to different axles, making a single transmission design suitable for various vehicle types without requiring complete redesign.
Solution Approach 2:
By separating the transmission into two independent casings with distinct functional groups, the design allows selective configuration of each casing for different vehicle applications. The first casing with input and first layshaft can remain standard while the second casing is configured for specific drive types, reducing overall design complexity while maintaining versatility.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A constant mesh gear transmission has an input shaft (21, 22), two layshafts (31, 35) and an output shaft (23). Gear wheels are selectively connectable to shafts to provide forward and reverse speed ratios. A common central web (39) provides central support bearings for the shafts. The transmission is stiffened, and allows assembly of components from either end to the middle.