Rotatable Screw Unit for Planing Boat Maneuverability

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Solution Overview

Problem

Existing planing boats with fixed jet propulsion devices are limited in steering angle and cannot make sudden direction changes for small-radius turns.

Innovation Solution

A planing boat with a rotatable screw unit and a direction change mechanism that allows the expulsion direction of the water current to vary by 360 degrees, enabled by a turning drive force source, allowing for easy maneuverability and reduced weight and cost compared to multiple screw units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a jet propulsion device is fixed to the hull, then the structure is simple and stable, but the steering angle is limited and sudden direction changes cannot be made

Engineering Contradiction:
Improvesteering angle rangeVSAvoidpropulsion system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The screw unit is made rotatable with respect to the hull, allowing the expulsion direction to change dynamically. The direction change mechanism enables the screw unit to rotate 360 degrees, transforming the fixed propulsion system into a dynamic one that can adapt to various steering requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The propulsion system is divided into separate functional components: the screw unit that can rotate independently from the hull, and the direction change mechanism that controls its orientation. This segmentation allows the screw unit to change direction without moving the entire hull or propulsion system.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If multiple screw units are provided to enable 360-degree direction change, then maneuverability is improved, but weight and cost increase

Engineering Contradiction:
ImprovemaneuverabilityVSAvoidboat weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

A single screw unit performs multiple functions by rotating to different orientations. The same screw unit can propel the boat forward, backward, or turn in any direction by changing its expulsion angle, eliminating the need for multiple dedicated screw units for different maneuvers.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The single screw unit dynamically changes its orientation to achieve different propulsion directions. By rotating the screw unit 360 degrees, the system achieves the maneuverability of multiple fixed screw units while using only one movable propulsive element.

Inventive Principle:
Principle #15Dynamics

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

Enables the planing boat to make small-radius turns and improve maneuverability by changing the expulsion direction of the water current with a single screw unit, reducing weight and cost while maintaining efficient propulsion.

Implementation Method 1

a screw unit (2) having a screw (20), and configured to be rotatable with respect to the hull (1) so that the expulsion direction of a water current by the screw (20) can vary by 360 degrees

Methodology Applied
Scientific EffectJet propulsion: Jet

Data Source

PatentEP3760527B1Planing boat
Publication Date: 2024.04.24 YANMAR POWER TECH CO LTD
  • EP3760527B1 patent drawingFigure 1
  • EP3760527B1 patent drawingFigure 2A
  • EP3760527B1 patent drawingFigure 2B

AI summary

A planing boat including: a hull 1 having a boarding area 10; a screw unit 2 having a screw 20, and configured to be rotatable with respect to the hull 1 so that the expulsion direction BD of a water current by the screw 20 can vary by 360 degrees; and a direction change mechanism 3 having a turning drive force source 30, and configured to change the expulsion direction BD by rotating the screw unit 2 with respect to the hull 1 with a drive force of the turning drive force source 30.