Outboard Motor Cooling Egress Angled Discharge

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Solution Overview

Problem

The integration of a steerable lower gearcase in outboard motors creates backpressure conditions and restricts space for routing exhaust gases and cooling water, degrading engine power output and requiring efficient water egress systems to manage high temperatures and trapped water volumes.

Innovation Solution

A cooling water egress component with a mounting base and main body angled relative to the mounting base, directing cooling water flow away from the gearcase and propulsor assembly, and a gravity drain to rapidly drain trapped water, ensuring efficient heat exchange and water dispersion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a steerable lower gearcase is integrated into the outboard motor, then the propulsor can be steered to control direction, but backpressure conditions increase and space for routing exhaust gases and cooling water is restricted

Engineering Contradiction:

ImprovesteerabilityVSAvoidrouting complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The cooling water egress system is divided into separate functional components: an egress component with angled discharge path and a separate gravity drain component. This segmentation allows each component to be optimized independently - the egress component handles pressurized water discharge at an angle to avoid backpressure, while the gravity drain handles trapped water removal, simplifying the overall routing complexity despite the steerable gearcase integration.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If cooling water is discharged vertically downward, then the discharge path is simple, but water impacts the propulsor assembly and creates backpressure degrading engine power output

Engineering Contradiction:

Improvedischarge path simplicityVSAvoidengine power output

Core Design Contradiction:

Device complexityVSPower

Solution Approach 1:

The egress component is designed with an asymmetric angled discharge path rather than a symmetric vertical discharge. The main body of the egress component is angled relative to the mounting base, directing cooling water flow away from the gearcase and propulsor assembly. This asymmetric configuration eliminates water impact on the propulsor, preventing backpressure that would degrade engine power output, while maintaining a relatively simple discharge path structure.

Inventive Principle:

Principle #4Asymmetry

3Temperature

If cooling water flow rate is increased to manage high temperatures, then heat exchange efficiency improves, but trapped water volume in the cowling system increases requiring rapid drainage

Engineering Contradiction:

Improveheat exchange efficiencyVSAvoidtrapped water volume

Core Design Contradiction:

TemperatureVSQuantity of substance

Solution Approach 1:

The gravity drain component is positioned and configured to actively drain trapped water from the cowling system before it can accumulate to problematic levels. By providing a dedicated gravity-driven drainage path separate from the pressurized cooling water circulation system, trapped water is continuously removed in advance, preventing water accumulation that would occur if only high flow rate cooling were used. This preliminary drainage action allows the cooling system to operate at high flow rates for efficient heat exchange without concern for trapped water volume.

Inventive Principle:

Principle #10Preliminary action

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 solution enhances engine power output by reducing backpressure and efficiently manages high water volumes, achieving a target drain rate of 21 L/s and maintaining propulsive force while preventing cowling damage from trapped water.

Implementation Method 1

The egress component is configured to discharge the cooling water from the device at a discharge angle relative to a vertical axis

Methodology Applied

Scientific EffectFluid flow direction control:

Implementation Method 2

a gravity drain to rapidly drain trapped water, ensuring efficient heat exchange and water dispersion

Methodology Applied

Scientific EffectGravitation: Gravitation

Implementation Method 3

a cooling water circuit that conveys cooling water that exchanges heat with the engine

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentUS11572144B1Outboard motor cowling with cooling water egress system

Publication Date: 2023.02.07 BRUNSWICK CORP

AI summary

A marine propulsion device is provided. The device includes an engine, a driveshaft that is caused to rotate by the engine, a cowling system, a gearcase that supports a propulsor for imparting a propulsive force in a body of water, and a cooling water circuit that conveys cooling water that exchanges heat with the engine. The cooling water circuit includes an engine dump hose that extends from a first end to a second end. The first end is coupled to a cooling water outlet of the engine. The cooling water circuit further includes an egress component configured to discharge the cooling water from the device at a discharge angle relative to a vertical axis. The egress component extends through one or more components of the cowling system and is coupled to the second end of the engine dump hose.