Marine Outdrive Vertical Thrust Point Adjustment
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Solution Overview
Problem
Conventional outdrives for inboard watercraft have a fixed and immovable propeller shaft location, which complicates adjustments, affects handling and stability, and limits performance, especially in racing and maneuvering scenarios, as the thrust point is not effectively adjustable relative to the watercraft's bottom.
Innovation Solution
An outdrive system that allows the propeller and its shaft to move vertically relative to the watercraft's bottom while under power, featuring a standoff box with a transfer shaft and secondary shaft that rotate to adjust the propeller's position, enabling vertical movement and tilt adjustments without disassembly, using components like ball splines and transfer gears for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the propeller shaft location is fixed relative to the watercraft bottom, then the outdrive structure is simple, but the thrust point cannot be adjusted to optimize performance under varying loads and conditions
Solution Approach 1:
The patent implements a dynamic adjustment mechanism that allows the propeller shaft to move vertically relative to the watercraft bottom while maintaining rotational capability. The drive unit is positioned on a movable platform that can adjust its vertical position, transforming the fixed shaft location into an adjustable one without requiring complete disassembly of the outdrive system.
Solution Approach 2:
The outdrive system is divided into separable modules: the drive unit, the movable platform, and the adjustment mechanism. This segmentation allows the thrust point adjustment function to be added as a modular component rather than redesigning the entire outdrive system, thereby managing complexity through functional decomposition.
2Ease of operation
If the engine is mounted higher within the hull to mount the standard drive at the surface, then the drive installation is simplified, but the center of gravity is raised affecting stability and handling
Solution Approach 1:
The movable platform acts as an intermediary between the fixed engine mounting and the adjustable propeller shaft location. This intermediary component allows the drive to be mounted at the surface for ease of installation while the platform can lower the propeller shaft to optimize the center of gravity and improve watercraft stability.
3Adaptability or versatility
If the propeller shaft location is fixed, then the outdrive assembly is simpler, but adjustments require disassembly which is time-consuming and expensive
Solution Approach 1:
The adjustment mechanism is designed to be self-contained within the outdrive system, allowing users to adjust the propeller shaft location without requiring external tools or complete disassembly. The system provides its own adjustment capability through the movable platform and associated mechanisms, enabling quick modifications while the watercraft is under power or at dock.
4Productivity
If the propeller shaft is at a fixed position, then the manufacturing and installation process is simpler, but performance is limited in racing and maneuvering scenarios
Solution Approach 1:
The system transitions from a static propeller shaft position to a dynamic one, allowing the shaft to move vertically to optimize performance for different operating conditions such as racing, maneuvering, and varying load scenarios. This dynamic capability enables performance optimization without requiring complex complete redesign of the outdrive system.
Data Source
AI summary
An outdrive for a marine vessel, such as a watercraft having an inboard engine, is provided. The outdrive can include a standoff box joined with a drive unit having a driveshaft that rotates in response to rotation of an input shaft coupled to an engine within a hull of the watercraft. The drive unit includes a propeller shaft that rotates in response to rotation of the driveshaft, and an associated propeller. The drive unit is vertically movable from a raised mode to a lowered mode, in which the propeller shaft is a preselected distance from a bottom of the boat hull, thereby lowering a thrust point produced by the propeller, all while the watercraft is moving through water and while the propeller is producing thrust. A related method and standoff box are also provided.