Sail Drive Refrigerant Flow Switching for Orientation Changes

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Solution Overview

Problem

When the arrangement direction of the upper unit with respect to the lower unit in a sail drive is changed, the flow passage of lubricating oil is altered, leading to insufficient cooling and potential overheating of the sail drive.

Innovation Solution

A sail drive configuration with a lower unit, an upper unit, and an intermediate unit that switches the refrigerant flow passage between them, ensuring continuous circulation and cooling even when the upper unit's arrangement direction is changed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the arrangement direction of the upper unit with respect to the lower unit is changed to improve mountability, then versatility is improved, but the refrigerant flow passage is altered causing insufficient cooling and overheating

Engineering Contradiction:
ImprovemountabilityVSAvoidcooling efficiency
Core Design Contradiction:
Adaptability or versatilityVSTemperature

Solution Approach 1:

The intermediate unit incorporates a flow passage switching mechanism that can dynamically change the refrigerant flow path configuration. This allows the system to adapt the flow passage arrangement according to the upper unit's orientation, ensuring effective cooling regardless of whether the upper unit is arranged in the original direction or reversed. The switching mechanism enables the system to maintain optimal cooling performance while supporting flexible mounting configurations.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the upper unit arrangement direction is changed, then ease of installation is improved, but the refrigerant circulation becomes less effective

Engineering Contradiction:
Improveease of installationVSAvoidrefrigerant circulation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The intermediate unit acts as an intermediary component between the lower unit and the upper unit, providing a flow passage switching mechanism that mediates the refrigerant flow. This intermediary structure enables the system to accommodate different upper unit orientations while maintaining reliable refrigerant circulation through appropriate flow path selection, thus decoupling the installation flexibility from cooling performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a fixed refrigerant flow passage is used, then device complexity is reduced, but adaptability to different arrangement directions is limited

Engineering Contradiction:
Improveflow passage structureVSAvoidarrangement direction flexibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

Rather than implementing multiple fixed flow passages for different orientations, the invention uses a dynamic flow passage switching mechanism in the intermediate unit. This single mechanism can reconfigure the flow path according to the upper unit's arrangement direction, achieving adaptability without proportionally increasing overall system complexity.

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

Prevents overheating of the sail drive by maintaining effective refrigerant circulation and cooling, regardless of the upper unit's orientation relative to the lower unit.

Implementation Method 1

lubricating oil circulates to ensure lubrication and heat exchange to components (e.g. gears) of the propulsion unit

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 2

cooling of the lubricating oil in the lower unit becomes insufficient

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP4707158A1Sail drive and ship
Publication Date: 2026.03.11 YANMAR HLDG CO LTD
  • EP4707158A1 patent drawingFigure 1
  • EP4707158A1 patent drawingFigure 2
  • EP4707158A1 patent drawingFigure 3

AI summary

[Problem] To provide a technique capable of avoiding overheating of a sail drive even when an arrangement direction of an upper unit with respect to a lower unit is changed. [Solution] The sail drive includes a lower unit, an upper unit that is disposed above the lower unit such that an arrangement direction can be changed with respect to the lower unit, and an intermediate unit that is disposed between the lower unit and the upper unit. A refrigerant flowing between the lower unit and the upper unit via the intermediate unit is cooled in the lower unit. The intermediate unit switches a flow passage of the refrigerant.