Folding Propeller with Adjustable Pivot Pins
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Solution Overview
Problem
Folding propellers for boats face issues with corrosion, fouling, and the inability to adjust blades for wear and production tolerances, leading to inefficiencies and increased drag when changing direction.
Innovation Solution
A folding propeller design featuring pivot pins with locking means that allow for adjustable clearance between blades and hub, using lightweight polymer materials for the hub and metal alloys for blades, with integrated links and shock absorbers to manage centrifugal forces and corrosion, and a method for adjusting the propeller to maintain optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional folding propeller design is used, then the propeller can fold to minimize drag and noise, but the blades cannot be adjusted for wear and production tolerances
Solution Approach 1:
The patent introduces adjustable pivot pins with locking mechanisms that allow the propeller blades to be dynamically repositioned relative to the hub. This enables adaptation to wear and production tolerances while maintaining reliable performance through secured blade positions during operation.
Solution Approach 2:
The patent enables change in the geometric parameters of the propeller by allowing adjustment of blade angles and positions through the adjustable pivot pin system, while maintaining structural integrity through the locking mechanism that secures these parameter changes.
2Strength
If metal materials are used for propeller parts, then strength and durability are improved, but corrosion resistance deteriorates
Solution Approach 1:
The patent employs composite material construction, specifically using corrosion-resistant alloys such as stainless steel or titanium for propeller parts that require both strength and corrosion resistance, creating a material solution that satisfies both requirements simultaneously.
Solution Approach 2:
The patent incorporates sacrificial anodes made of less expensive, more corrosion-prone materials that can be replaced periodically to protect the main propeller structure from galvanic corrosion, extending the service life of critical components.
3Strength
If heavy materials are used for propeller hub, then structural strength is improved, but moment of inertia increases
Solution Approach 1:
The patent applies local quality optimization by using heavier materials only in specific high-stress areas of the hub structure where strength is critical, while using lighter materials in low-stress areas to minimize overall moment of inertia, creating a non-uniform material distribution that optimizes both strength and weight.
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
The design enhances corrosion resistance, reduces noise and drag, allows for blade adjustment to compensate for wear, and uses lightweight materials to minimize inertia, resulting in improved operational efficiency and reduced maintenance.
Implementation Method 1
the mechanism for taking up the forces acting on the propeller when operated, comprises a closed mechanical system
Implementation Method 2
shock absorber means being arranged at one or more blade roots
Data Source
AI summary
A folding propeller for a boat, e.g., for a sailboat or a multihull yacht, and a method for installing and/or adjusting such a folding propeller, where said folding propeller has a hub for directly or indirectly fastening at a driveshaft connected to a motor, where said folding propeller further has at least two individual blades, where each of said blades has a root arranged to pivot around a pivot pin at said hub to be either in a first, operative position, where the blades are pointing mainly in a radial direction, and in a second, inoperative position, where the blades are pointing mainly in an axial direction, where said hub has one or more cut outs for said blades roots and further has a first set of holes for installing said pivot pins and a second set of holes for installing a locking device for engagement with said pivot pins.