Nested Planetary Transmission Layout for More Gears in Less Space
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing agricultural and industrial commercial vehicle transmissions require excessive installation space due to numerous shafts and gear sets, leading to insufficient gear ratios, high production costs, and complexity, which limits their efficiency and adaptability.
Innovation Solution
A transmission system incorporating multiple planetary gear sets, shifting elements, and a reversing unit to provide a compact, modular design with a high number of gear ratios, reducing installation space and complexity while improving efficiency and adaptability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional power shift transmissions are used with multiple shafts and gear sets, then the transmission can provide multiple gear ratios, but the installation space requirement increases significantly
Solution Approach 1:
The patent employs nested planetary gear sets where smaller planetary gears are positioned within the annulus of larger planetary gears. Specifically, a first planetary gear set is nested within a second planetary gear set, allowing multiple gear ratios to be achieved in a compact radial arrangement. This nesting principle enables the transmission to provide diverse gear ratios without proportionally increasing the overall transmission size, directly resolving the contradiction between gear ratio diversity and installation space requirements.
2Adaptability or versatility
If more shafts and gear sets are added to increase gear ratios, then the transmission becomes more versatile, but the device complexity increases
Solution Approach 1:
The patent merges multiple planetary gear sets into a single integrated transmission unit where the first and second planetary gear sets share common components such as the sun gear, planet carrier, and annulus. This merging approach allows the transmission to achieve multiple gear ratios through a unified structure rather than separate gear trains, thereby reducing overall device complexity while maintaining versatility. The combined planetary sets enable smooth transitions between gear ratios without requiring additional shafts or independent gear mechanisms.
3Adaptability or versatility
If traditional transmissions are designed to fit existing power train architectures, then compatibility is maintained, but the transmission requires excessive installation space
Solution Approach 1:
The patent transitions from traditional linear shaft-based gear arrangements to a radial planetary gear configuration. By organizing gears in concentric circles around a central sun gear rather than along a linear shaft, the transmission achieves multiple gear ratios in a two-dimensional radial layout. This dimensional change allows the transmission to maintain compatibility with existing power train architectures while significantly reducing the axial length and overall volume required, directly addressing the contradiction between architectural compatibility and transmission volume.
Data Source
AI summary
A transmission includes a drive element, a first output element, a primary transmission unit, a reversing unit, and an intermediate gearbox. At least two of the at least five shifting elements of the primary transmission unit, at least one of the at least two shifting elements of the reversing unit, and at least one of the at least two shifting elements of the intermediate gearbox are activatable in combinations of at least four shifting elements so as to establish at least twelve forward gears between the drive element and the first output element.