Outboard Motor Shift Mechanism That Bypasses Intermediate Gear Wear
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Solution Overview
Problem
The intermediate gear in outboard motors experiences high abrasion due to constant rotation during both forward and backward movements, leading to reduced durability and efficiency.
Innovation Solution
The outboard motor incorporates a shift mechanism with a first gear, second gear, third gear, and clutches to reverse rotation direction, allowing the intermediate gear to be bypassed during one direction of movement, thereby reducing abrasion by not transmitting rotation through it during that direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the intermediate gear is constantly used for transmitting rotation in both forward and backward movements, then the shift mechanism can maintain a simple structure, but the abrasion resistance of the intermediate gear deteriorates
Solution Approach 1:
The patent applies the dynamics principle by making the gear transmission path changeable based on operation mode. The shift mechanism dynamically selects between two different transmission paths: one using the intermediate gear for forward movement, and another bypassing the intermediate gear for backward movement. This dynamic adaptation resolves the contradiction by reducing the intermediate gear's rotation count during backward movement, thereby enhancing its abrasion resistance while maintaining structural simplicity through the use of existing gears and clutches.
2Adaptability or versatility
If the intermediate gear is constantly rotated during both forward and backward movements, then the gear can serve multiple functions, but its lifespan deteriorates due to high abrasion
Solution Approach 1:
The patent applies segmentation by dividing the gear transmission function into separate paths for forward and backward movements. Instead of using the intermediate gear for both directions, the system segments the transmission paths so that the intermediate gear is primarily used for forward movement while backward movement uses an alternative path. This segmentation reduces the intermediate gear's usage frequency and abrasion, thereby extending its lifespan while maintaining the versatility of the shift mechanism.
3Device complexity
If the dog clutch is engaged with the intermediate gear for backward movement, then the transmission path is simplified, but the intermediate gear experiences excessive wear
Solution Approach 1:
The patent applies the taking out principle by extracting the intermediate gear from the backward movement transmission path. Instead of having the dog clutch engage with the intermediate gear for backward movement, the system creates a separate transmission path that bypasses the intermediate gear. This extraction eliminates the harmful abrasion effect on the intermediate gear during backward movement while maintaining a relatively simple transmission structure through the use of existing gears and the dog clutch in its original position.
Data Source
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AI summary
When a shift member is set in a first position, a first clutch couples a second drive shaft to a first drive shaft. When the shift member is set in the first position, a second clutch decouples a first gear from the first drive shaft. When the shift member is set in the first position, a third clutch decouples a second gear from the second drive shaft.