Marine Propulsion Drive Switching With Retry Control for Gear Meshing

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Solution Overview

Problem

Marine propulsion devices with both internal combustion engines and electric motors face challenges in smooth drive source switching due to space constraints and strength issues, leading to potential noise and excessive load on actuators during synchronization.

Innovation Solution

A drive source switching system with a controller that manages the movement of driven members to ensure smooth engagement and disengagement with driving members, temporarily interrupting switching attempts when alignment issues occur to prevent collisions and excessive load, allowing for repeated attempts when conditions are favorable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a synchronizing mechanism is installed to synchronize the number of revolutions of protrusions with the gear, then smooth meshing between protrusions and gear is achieved, but the device complexity increases and space requirements are not met

Engineering Contradiction:

Improvesmooth meshingVSAvoidmechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the traditional synchronizing mechanism from the system. Instead of adding a separate synchronization device, the invention directly engages the protrusions with the gear teeth through a simplified direct coupling mechanism, thereby eliminating the complexity and space requirements of the synchronizing mechanism while maintaining reliable engagement.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical synchronizing mechanism with a control-based approach. The controller coordinates the rotation of the first and second driving members to achieve synchronization without requiring a separate mechanical synchronization device, thus reducing device complexity while maintaining smooth meshing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If taper processing is applied to the edges of protrusions and gear edges to facilitate meshing, then ease of operation is improved, but the strength of the protrusions and gear is reduced

Engineering Contradiction:

Improvemeshing facilitationVSAvoidprotrusion strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The controller performs preliminary synchronization of the rotation speeds and positions of the first and second driving members before engagement occurs. This preliminary action ensures that the protrusions and gear teeth are already aligned when engagement begins, eliminating the need for taper processing while maintaining smooth meshing and full structural strength.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If the actuator continues to move the shift slider for multiple attempts to mesh protrusions and gear, then the drive source switching is completed, but a large load is applied to the actuator motor

Engineering Contradiction:

Improveswitching completionVSAvoidactuator load

Core Design Contradiction:

ProductivityVSForce

Solution Approach 1:

The controller continuously monitors the positions and rotation speeds of the first and second driving members, and provides feedback control to adjust their synchronization. This feedback mechanism ensures that engagement occurs at the optimal moment with minimal force required, preventing excessive load on the actuator motor while completing the drive source switching efficiently.

Inventive Principle:

Principle #23Feedback

4Volume of moving object

If miniaturization of protrusions and motor driven gear is performed for retrofitting electric motor, then space constraints are satisfied, but manufacturing precision requirements increase

Engineering Contradiction:

Improvecomponent sizeVSAvoidmeshing precision

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent replaces mechanical tolerance-based engagement with controller-based synchronization. The controller precisely controls the rotation speeds and positions of the miniaturized components, compensating for the reduced size and ensuring accurate meshing without requiring extremely tight manufacturing tolerances on the miniaturized protrusions and gear.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11560209B2Drive source switching system for marine propulsion device including multiple drive sources, and method of switching drive sources of marine propulsion device

Publication Date: 2023.01.24 YAMAHA MOTOR CO LTD

AI summary

A drive source switching system for a marine propulsion device includes a first drive source, a second drive source, a propeller shaft, a first driving member, a second driving member, a first driven member, and a second driven member that are movable in an axial direction of the propeller shaft, and a controller. The first driven member transmits a drive force generated by the first drive source to the propeller shaft when engaged with the first driving member. The second driven member transmits a drive force generated by the second drive source to the propeller shaft when engaged with the second driving member. When the controller moves the first driven member that is not engaged with the first driving member toward the first driving member, the controller moves the first driven member back when the first driven member fails to be engaged with the first driving member.