Marine Propulsion Motor Assembly With Rigid Conductor Coupling

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Solution Overview

Problem

Existing marine propulsion devices face challenges in efficiently electrically connecting and installing high-power electric motors due to the need for flexible conductors that are difficult to manage and prone to damage, especially with removable nose cones that increase complexity and risk of water ingress.

Innovation Solution

The method involves electrically coupling the motor assembly within the drive housing cavity without entering through the opposite end, using a connector body with threaded or compression mechanisms to secure inflexible conductors, ensuring alignment and secure connections, and utilizing a fixed nose cone design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flexible conductors are used to electrically connect high-power electric motors in marine propulsion devices, then electrical connectivity is achieved, but the conductors become difficult to manage and prone to damage

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidconductor management ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces flexible mechanical conductors with a rigid conductor assembly that includes a rigid conductor, positioning features, and alignment features. This substitution eliminates the management difficulties and damage susceptibility of flexible conductors while maintaining reliable electrical connectivity through precise mechanical positioning and alignment mechanisms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If removable nose cones are used in marine propulsion devices, then access to the cavity is improved, but the complexity and risk of water ingress increase

Engineering Contradiction:

Improvecavity access easeVSAvoidnose cone structure complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent divides the nose cone into a removable first portion and a fixed second portion. The first portion can be removed to provide access to the cavity for motor assembly installation, while the second portion remains fixed to maintain structural integrity and prevent water ingress. This segmentation allows easy access during assembly while avoiding the complexity of fully removable designs.

Inventive Principle:

Principle #1Segmentation

3Reliability

If inflexible conductors are used with threaded or compression mechanisms, then conductor damage risks are reduced, but the installation complexity increases

Engineering Contradiction:

Improveconductor durabilityVSAvoidinstallation ease

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent incorporates positioning features on the rigid conductor and corresponding alignment features on the motor assembly that automatically align the conductor with the electrical connection points during motor insertion. This preliminary positioning action eliminates the need for complex threaded or compression mechanisms during installation, reducing both conductor damage risks and installation complexity.

Inventive Principle:

Principle #10Preliminary action

4Ease of operation

If the conductor is moved in a vertical direction perpendicular to the longitudinal direction, then electrical coupling is achieved without entering the cavity, but the connection precision requirements increase

Engineering Contradiction:

Improveinstallation accessibilityVSAvoidconductor alignment precision

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent uses alignment features as intermediary elements between the conductor and the motor assembly electrical connection points. These alignment features guide the vertical movement of the conductor into precise engagement with the connector, reducing alignment precision requirements by providing mechanical guidance during the coupling process.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This approach allows for ergonomic and efficient installation of high-power motor assemblies, reducing damage risks and costs, while maintaining a watertight seal and improving maneuverability.

Implementation Method 1

a threaded opening in the connector body that receives the conductor

Methodology Applied

Scientific EffectThreaded engagement: Screw

Implementation Method 2

compression mechanisms to secure inflexible conductors

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentEP4169830B1Marine propulsion devices having electric motors and methods for making marine propulsion devices having electric motors

Publication Date: 2026.04.01 BRUNSWICK CORP

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AI summary

The invention relates to a method for making a marine propulsion device (1). The invention further relates to such marine propulsion device (1). The method includes providing a drive housing (2) that extends between a first end (5) and a second end (7), whereby drive housing (2) has a cavity (28) that extends inwardly from the second end (7). The method further includes positioning a conductor (14) within the drive housing (2), whereby the conductor (14) is configured to conduct power for the marine propulsion device (1). The method further includes inserting a motor assembly (30) into the cavity (28) and electrically coupling the motor assembly (30) and the conductor (14) while the motor assembly (30) is positioned in the cavity (28) and without entering the cavity (28) via the first end (5) of the drive housing (2).