Outboard Motor Shift Device Housing Configuration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing outboard motors have a large shift device that increases the height dimension and traveling resistance due to the positioning of the dog clutch between the upper and lower bevel gears.
Innovation Solution
The outboard motor design includes a power transmission mechanism between the upper and lower shafts, a shift device with a cam mechanism and a dog clutch that moves in the upper-lower direction, and a housing with a widened portion for the power transmission mechanism and a narrowed portion for the shift device, reducing the front projection area and traveling resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the dog clutch is positioned between the upper and lower bevel gears, then the shift device can operate the power transmission mechanism, but the height dimension and traveling resistance increase
Solution Approach 1:
The patent repositions the dog clutch from a vertical arrangement (between upper and lower bevel gears) to a horizontal arrangement (between the bevel gear and drive shaft). This dimensional change allows the shift device to be accommodated in the front-rear direction rather than increasing height, thereby reducing the height dimension while maintaining operational functionality
Solution Approach 2:
The patent inverts the traditional power transmission arrangement by placing the dog clutch horizontally adjacent to the drive shaft rather than vertically between gears. This inversion of the spatial relationship allows the shift device to be compact in height while still achieving the required power transmission control
2Reliability
If the shift device components are enlarged to accommodate the dog clutch positioning, then the power transmission mechanism can function, but the front projection area and traveling resistance increase
Solution Approach 1:
The patent changes the spatial arrangement from a vertical stacking configuration to a horizontal linear configuration. By positioning the dog clutch horizontally between the bevel gear and drive shaft, the components can be compactly arranged in the front-rear direction, reducing the front projection area while maintaining reliable power transmission functionality
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design reduces the size of the shift device and power transmission mechanism, minimizing the front projection area of the housing and thereby reducing traveling resistance and improving acceleration.
Implementation Method 1
a cam mechanism configured to convert rotation of the shift shaft into upper-lower movement of an operation portion
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, a shift device that operates the transmission mechanism, and a housing. 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 that is moved in the upper-lower direction to operate the transmission mechanism; and a connector pin coupling the shift slider and the dog clutch. The housing includes an anti-cavitation plate provided above the propeller, widened and narrowed portions provided above and below the anti-cavitation plate. The transmission mechanism is accommodated in the widened portion, and at least the shift slider of the shift device is accommodated in the narrowed portion.