External Shift-Clutch Linkage for Compact Straddled Vehicles
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Solution Overview
Problem
Straddled vehicles require a high degree of freedom in designing and manufacturing to accommodate both electronic and manual gear-shifting types while maintaining a compact vehicle body and minimizing interference from external obstacles.
Innovation Solution
The implementation of link transmission mechanisms for the shift and clutch operations, which are disposed outside the crank case and engine cover, allowing for a more compact design and reduced interference from external obstacles, while accommodating both gear-shifting types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a reduction gear train is used to transmit motor rotation, then the gear stage can be switched, but the vehicle body size increases due to the space required for gear rotation and precise meshing
Solution Approach 1:
The invention extracts the transmission mechanism from the enclosed casing structure. The shift spindle and clutch lever are exposed externally, eliminating the need for a large sealed casing that would accommodate reduction gears and maintain precise meshing. This allows gear switching functionality while reducing overall vehicle body volume.
Solution Approach 2:
Instead of enclosing the transmission mechanism within a sealed casing (conventional approach), the invention inverts the arrangement by positioning the shift spindle and clutch lever externally. This reversal eliminates the space-consuming casing while maintaining the gear switching function through direct external actuation.
2Manufacturing precision
If a sealed casing is used to protect the reduction gear train, then meshing precision is maintained, but the vehicle structure becomes more complex and larger
Solution Approach 1:
The invention removes the complex sealed casing structure entirely by extracting the transmission components to an external position. The shift spindle and clutch lever operate in the external environment, eliminating the need for complex sealing and protection mechanisms while maintaining functional precision through direct mechanical linkage.
Solution Approach 2:
The clutch lever serves multiple functions: it acts as both the shifting actuator and the transmission control mechanism. This multi-functionality eliminates the need for separate sealed casings for different components, simplifying the overall structure while maintaining operational precision.
3Volume of moving object
If the shift spindle and clutch lever are positioned externally, then the vehicle body size is reduced, but the mechanism becomes more vulnerable to external obstacles
Solution Approach 1:
The invention inverts the conventional protected-internal arrangement by deliberately positioning the transmission mechanism externally. This exposes the shift spindle and clutch lever to the external environment, accepting vulnerability to obstacles as a trade-off for achieving compact vehicle body dimensions.
Data Source
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AI summary
To provide a straddled vehicle that is small and has a high degree of freedom in designing and manufacturing such that vehicles of different gear-shifting types can be designed and/or manufactured so as to respond to rider's orientations, a straddled vehicle includes an engine, a clutch, a multi-speed transmission, a shift/clutch shared actuator, a clutch link transmission mechanism, and a shift link transmission mechanism. The clutch link transmission mechanism has a first clutch link arm, a clutch link rod, and a second clutch link arm. The shift link transmission mechanism has a first shift link arm, a shift link rod, and a second shift link arm. Both the clutch link transmission mechanism and the shift link transmission mechanism are disposed outside the crank case and outside the engine cover.