Modular Hydromechanical CVT Layout for Compact Machine Packaging
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Solution Overview
Problem
Existing continuously variable transmissions (CVTs) are not compact enough for smaller machines with restrictive space limitations, limiting their application in smaller machines and more compact designs.
Innovation Solution
A modular gear arrangement for CVTs, including a differential module with a first planetary gear arrangement, a range module with a second planetary gear arrangement, and a drop box module, along with selectively engageable clutch assemblies, allows for compact packaging by providing variable rotational power and directional control through a combination of power source paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing CVT designs are used, then the transmission can provide continuous variable gear ratios, but the transmission structure becomes large and long, making it unsuitable for smaller machines with space limitations
Solution Approach 1:
The transmission is divided into three separate modules: a differential module containing a first planetary gear arrangement, a range module containing a second planetary gear arrangement, and a drop box module. These modules can be selectively associated and coupled together, allowing the transmission to be compacted while maintaining functionality. The segmentation enables each module to be optimized independently and allows for flexible configuration in smaller machine applications.
2Volume of moving object
If the transmission is made more compact, then it can fit smaller machines, but the complexity of coupling multiple modules increases
Solution Approach 1:
The clutch assemblies serve multiple functions: they selectively engage different planetary gear arrangements, couple different modules together, and provide directional control for power flow. This multi-functionality reduces the need for separate components for each function, thereby reducing overall complexity despite the modular architecture.
Solution Approach 2:
The transmission employs selectively engageable clutch assemblies that can dynamically configure the power flow paths between modules. This dynamic reconfiguration capability allows the same modular structure to adapt to different operational requirements without requiring physical reassembly, simplifying the coupling process while maintaining versatility.
3Adaptability or versatility
If multiple planetary gear arrangements are used to provide variable rotational power, then the gear ratio range is improved, but the transmission becomes more complex and larger
Solution Approach 1:
The first planetary gear arrangement in the differential module and the second planetary gear arrangement in the range module are merged through selective coupling via clutch assemblies. This merging allows the combined system to achieve a wider gear ratio range than either arrangement alone, while the modular structure prevents the complexity from becoming unmanageable by keeping the arrangements in separate, standardized modules.
Data Source
AI summary
A continuously variable transmission (CVT) may include differential and range modules that include planetary gear arrangements, a plurality of selectively engageable clutch assemblies, and a drop box module with a final output member. First and second power source paths may provide power to a same end of the differential module. The clutch assemblies may be selectively engageable to provide variable rotational power from the differential module to the range module, and from the range module to the drop box module in a plurality of directional ranges. The drop box module may adapt the variable rotational power provided in the selected range for connection in a given application.