Adaptive Marine Propulsion Mount Using Magnetorheological Fluid

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Solution Overview

Problem

Current elastomeric mounts for marine propulsion systems have functional limitations that lead to engineering compromises in noise, vibration, and harshness characteristics, and are not adjustable or vessel-specific, failing to adapt to changing conditions during marine vessel travel.

Innovation Solution

A system with elastic mounts containing electromagnetic fluid, where the electromagnet's electricity control adjusts the shear strength to adapt the mount's elasticity based on sensed conditions, such as oscillation, acceleration, and steering angle, to improve handling and reduce the likelihood of impact with adjacent structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional elastomeric mounts are used, then the propulsion device can be mounted, but the noise, vibration, and harshness characteristics deteriorate and the mount cannot adapt to changing conditions

Engineering Contradiction:

Improveadaptability to changing conditionsVSAvoidnoise, vibration, and harshness

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the mount's elasticity adjustable in real-time based on operating conditions. The elastic mount includes an electromagnet that can vary the shear strength of electromagnetic fluid, allowing the mount to transition from a static to a dynamic system that adapts its characteristics based on sensed parameters such as oscillation, acceleration, and steering angle.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter of the mount's elasticity by using electromagnetic fluid whose shear strength can be modified by applying different amounts of electricity to the electromagnet. This allows the mount to change its elastic properties dynamically, resolving the contradiction between maintaining low noise/vibration and adapting to varying operating conditions.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the mount elasticity is fixed, then the structure is simple, but the mount cannot adapt to oscillation and impact conditions

Engineering Contradiction:

Improveresponse to oscillation and impactVSAvoidmount structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical adjustment mechanisms with an electromagnetic system. Instead of using complex mechanical linkages or adjustable components, the invention uses an electromagnet to control the shear strength of electromagnetic fluid, providing a more compact and controllable system for adapting mount elasticity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses electromagnetic fluid, which is a fluid-based system, to provide the elastic mounting function. By controlling the shear strength of this fluid through electromagnetic fields, the system achieves adaptive elasticity without requiring complex mechanical structures, combining the benefits of fluid systems with electromagnetic control.

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Object-generated harmful factors

If the mount is made stiffer to reduce oscillation, then vibration is reduced, but the likelihood of impact with adjacent structures increases

Engineering Contradiction:

ImproveoscillationVSAvoidimpact with adjacent structures

Core Design Contradiction:

Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using sensors to detect oscillation, acceleration, and steering angle, then using this information to control the electromagnet's power input. This closed-loop system automatically adjusts the mount's elasticity in response to actual operating conditions, reducing oscillation when necessary while preventing excessive stiffness that could cause impact.

Inventive Principle:

Principle #23Feedback

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 solution enhances noise, vibration, and harshness characteristics, allowing for increased power, speed, and acceleration while maintaining tighter transom packaging and reducing the risk of collisions during varying operating conditions.

Implementation Method 1

The elastic mount contains an electromagnetic fluid. An electromagnet is configured so that increasing an amount of electricity applied to the electromagnet increases the shear strength of the electromagnetic fluid

Methodology Applied

Scientific EffectElectromagnetic fluid shear strength adjustment: Magnetorheological Fluid

Data Source

PatentUS10967946B1Systems and methods for mounting a propulsion device with respect to a marine vessel

Publication Date: 2021.04.06 BRUNSWICK CORP

AI summary

A system comprises an elastic mount configured to support a propulsion device with respect to a marine vessel. The elastic mount contains an electromagnetic fluid. An electromagnet is configured so that increasing an amount of electricity applied to the electromagnet increases the shear strength of the electromagnetic fluid in the elastic mount and thereby decreases elasticity of the elastic mount, and so that decreasing the amount of electricity applied to the electromagnet decreases the shear strength of the electromagnetic fluid in the elastic mount and thereby increases the elasticity of the elastic mount. A controller automatically adapts the amount of electricity applied to the electromagnet based on one or more sensed conditions so as to improve performance and/or handling of the marine vessel.