Nested Planetary Transmission Architecture for Compact Multi-Gear Vehicles
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Solution Overview
Problem
Existing agricultural and industrial commercial vehicle transmissions require excessive installation space due to numerous shafts and gearwheel 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, efficient, and adaptable powertrain architecture with a sufficient number of gear ratios, reducing installation space and complexity while improving torque transmission and fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional power shift transmissions with multiple shafts and gearwheel sets are used, then sufficient gear ratios and speed ranges can be achieved, but the transmission requires excessive installation space
Solution Approach 1:
The patent employs nested planetary gear sets where smaller planetary gear sets are positioned within the planetary gear sets of larger sizes. This nesting arrangement allows multiple gear reduction stages to be compacted into a single transmission unit, achieving sufficient gear ratios while minimizing the transmission's axial length and overall installation space.
Solution Approach 2:
The patent transitions from traditional parallel shaft arrangements to a coaxial planetary gear configuration. By stacking planetary gear sets along the same axis and utilizing radial space, the transmission achieves multiple gear ratios without increasing the footprint area, thereby reducing installation space while maintaining adaptability.
2Adaptability or versatility
If traditional transmissions with numerous shafts and gearwheel sets are used, then sufficient gear ratios can be achieved, but the transmission becomes complex in technical and constructive terms
Solution Approach 1:
The patent merges multiple gear reduction functions into a single integrated planetary gear set structure. Instead of using separate shafts and gearwheel sets for each reduction stage, the nested planetary gears combine multiple stages in one compact unit, reducing the number of components and simplifying the transmission's technical and constructive complexity.
Solution Approach 2:
The planetary gear sets serve multiple functions simultaneously: they provide gear reduction, torque multiplication, and compact space utilization. The same structural elements (planetary gears, sun gears, ring gears) perform multiple roles across different reduction stages, eliminating the need for separate dedicated components and reducing overall complexity.
3Adaptability or versatility
If traditional transmissions with many shifting elements are used, then sufficient gear ratios can be achieved, but production costs increase
Solution Approach 1:
The patent combines multiple shifting functions into fewer shifting elements by using the nested planetary gear structure. The synchronized design of the planetary sets allows a single shifting mechanism to control multiple gear stages simultaneously, reducing the total number of shifting elements required and thereby lowering production costs.
Solution Approach 2:
The patent eliminates redundant shifting elements that would be required in traditional multi-shaft transmissions. By using the planetary gear nesting approach, the design recovers space and component count, discarding unnecessary shafts, bearings, and shifting mechanisms that would increase manufacturing complexity and cost.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed transmission system achieves a more compact and efficient design with a higher number of gear ratios, reducing installation space, production costs, and improving driving comfort and fuel efficiency, while minimizing wear and complexity.
Implementation Method 1
The primary transmission unit has at least three planetary gear sets, and the intermediate gearbox has at least one planetary gear set, and the reversing unit has at least one planetary gear set
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.