Marine Drive Gearcase Nose Caps for Cooling Water Pressure

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Solution Overview

Problem

In marine drives mounted high on a vessel, water flow into the cooling cavity can be reduced, leading to decreased water pressure, which affects performance.

Innovation Solution

A gearcase assembly with a removable nose cap and retainer device that allows for easy reconfiguration of water flow into the cooling cavity, using interchangeable nose caps with varying through-bores to adjust water flow and pressure based on operational conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the marine drive is mounted high on the vessel, then the marine drive is positioned for optimal performance and accessibility, but water flow into the cooling cavity is reduced leading to decreased water pressure

Engineering Contradiction:

Improvemounting position accessibilityVSAvoidwater pressure in cooling cavity

Core Design Contradiction:

Ease of operationVSStress or pressure

Solution Approach 1:

The nose cap is designed as a removable component with interchangeable through-bores, allowing the water flow characteristics to be dynamically adjusted based on operational conditions. This enables optimization of water pressure in the cooling cavity while maintaining high mounting position accessibility.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

By providing interchangeable nose caps with varying through-bore configurations, the patent allows changing the physical parameters of water flow (cross-sectional area, flow pattern) to compensate for reduced water pressure caused by high mounting position, thereby maintaining optimal cooling performance.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a fixed nose cap design is used, then the structure is simple and reliable, but the water flow and pressure cannot be adjusted for different operational conditions

Engineering Contradiction:

Improvestructural reliabilityVSAvoidwater flow adjustability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The nose cap is segmented as a removable component that can be interchangeably replaced with different designs. This segmentation allows the system to maintain structural reliability through standardized interfaces while achieving adaptability by selecting different nose cap variants for different operational conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The removable nose cap design creates a universal interface that can accommodate multiple through-bore configurations. This single design approach provides multi-functionality, allowing the same mounting structure to support different water flow characteristics as needed for various operational scenarios.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12491977B1Gearcase assemblies for marine drives having torpedo plugs

Publication Date: 2025.12.09 BRUNSWICK CORP

AI summary

A gearcase assembly for a marine drive has a gearcase having a torpedo housing, a torpedo plug in the torpedo housing, the torpedo plug separating a lubricant cavity containing lubricant for the gearcase and a water cavity containing cooling water for the marine drive, and a shift actuator configured to actuate a shift clutch in the gearcase. The shift actuator retains the torpedo plug in place relative to the torpedo housing.