Outboard Motor Shift Device Layout Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing outboard motor shift devices are large in size and have limited flexibility in component layout due to the positioning of the dog clutch between the upper and lower bevel gears.
Innovation Solution
The outboard motor design includes an upper shaft and a lower shaft with a power transmission mechanism featuring an upper gear, a lower gear, and an intermediate gear. A shift device with a shift shaft, cam mechanism, shift slider, dog clutch, and connector pin operates the power transmission mechanism to reversely rotate the propeller, allowing the shift slider to be positioned offset in the height direction, thereby reducing the size of the shift device and improving component layout flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the dog clutch is positioned between the upper bevel gear and the lower bevel gear, then the shift device can achieve forward and reverse gear switching, but the shift device becomes large in size and has limited flexibility in component layout
Solution Approach 1:
The patent repositions the shift slider from a vertical arrangement between the upper and lower bevel gears to a horizontal arrangement offset in the height direction. This dimensional change allows the dog clutch to be coupled to the lower shaft in an integrally rotatable manner while maintaining the shift function, thereby reducing the overall shift device size and improving component layout flexibility.
Solution Approach 2:
The patent employs a cam mechanism that converts rotational movement of the shift shaft into upper-lower movement of the operation portion, enabling dynamic positioning of the dog clutch. This dynamic mechanism allows the shift slider to be positioned above the upper gear or below the lower gear, providing flexibility in component layout while maintaining the shift function.
2Volume of moving object
If the shift slider is positioned above the upper gear or below the lower gear, then the shift device size is reduced and component layout flexibility is improved, but the mechanism becomes more complex
Solution Approach 1:
The patent introduces a connector pin as an intermediary element that couples the shift slider and the dog clutch. This connector pin simplifies the overall mechanism by providing a direct coupling between the shift slider and the dog clutch, eliminating the need for additional complex linkage mechanisms while enabling the shift slider to be positioned offset in the height direction.
Solution Approach 2:
The lower shaft is designed to support both the lower gear in a relatively rotatable manner and the dog clutch in an integrally rotatable manner. This multi-functional design of the lower shaft reduces the need for separate support structures, thereby simplifying the overall mechanism while enabling the shifted device to achieve compact layout.
Data Source
AI summary
An outboard motor includes upper and lower shafts extending from an engine toward a propeller, a transmission mechanism interposed between the upper and lower shafts, and a shift device that operates the transmission mechanism. The transmission mechanism includes an upper gear fixed to the upper shaft, a lower gear rotatably supported by the lower shaft, and an intermediate gear meshing with the upper and lower gears. The shift device includes a shift shaft extending downward from an actuator, a cam mechanism that converts rotation of the shift shaft into upper-lower movement of an operation portion, a shift slider coupled to the operation portion, a dog clutch coupled to the lower shaft and connectable to the upper or lower gear, and a connector pin coupling the shift slider and the dog clutch. The shift slider is positioned above the upper gear or below the lower gear.