Motorized Clutch Layout for Compact Straddled Vehicle Transmissions
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Solution Overview
Problem
The challenge is to downsize the multistage transmission device in straddled vehicles, particularly the clutch motor, while maintaining efficient control of the starting and gear-shifting clutch, which is affected by heat and vibration, and requires a dedicated motor for precise control.
Innovation Solution
The operation power transmission mechanism is disposed between the crankcase and crankcase cover, reducing the distance between the clutch motor and starting clutch, allowing for a compact design and heat/vibration protection, with a dedicated clutch motor for precise control of the starting clutch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the operation power transmission mechanism is disposed outside the crankcase (conventional arrangement), then the clutch motor and transmission mechanism can be separately positioned, but the overall device size increases and space efficiency decreases
Solution Approach 1:
The operation power transmission mechanism is merged with the crankcase by disposing it inside the crankcase rather than outside. This integration reduces the overall device volume while maintaining the functional separation between the clutch motor and transmission components through internal spatial arrangement.
Solution Approach 2:
The transmission mechanism is repositioned from an external three-dimensional arrangement to an internal configuration within the crankcase. This dimensional reorganization utilizes the internal space of the crankcase, reducing the external footprint while preserving component functionality.
2Length of moving object
If the distance between the clutch motor and starting clutch is reduced, then the device becomes more compact, but the transmission mechanism becomes more complex to accommodate
Solution Approach 1:
The transmission mechanism is segmented into distinct functional components (worm gear, sector gear, coupling members, lever member) that can be independently positioned and optimized. This segmentation allows for compact arrangement within the crankcase while maintaining clear functional relationships between components.
Solution Approach 2:
The sector gear acts as an intermediary element between the worm gear and the coupling members, enabling efficient power transmission in a compact space. This intermediary component facilitates the transmission of operation power through a reduced distance while maintaining mechanical advantage.
3Measurement precision
If the clutch motor is positioned closer to the starting clutch within the crankcase, then heat and vibration from the engine are increased, but precise control of the clutch is improved
Solution Approach 1:
The clutch motor and transmission mechanism are nested within the crankcase structure, which provides both proximity to the starting clutch for precise control and a degree of thermal and vibrational management through the engine housing.
Solution Approach 2:
The clutch motor replicates the control function of the starting clutch with high precision, allowing for accurate clutch engagement and disengagement despite the challenging thermal and vibrational environment within the crankcase.
Data Source
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AI summary
Provided is a straddled vehicle with which the whole of a multistage transmission device including a clutch motor can be downsized. The straddled vehicle of the present teaching includes an engine, a multistage transmission device, and a driving wheel. The multistage transmission device includes an input shaft, an output shaft, a clutch, a clutch motor, and an operation power transmission mechanism. The operation power transmission mechanism is configured to transmit operation power from the clutch motor to the clutch, and is disposed so as to be at least partially included in a space between the crankcase and the crankcase cover.