Hybrid Vessel Propulsion for Rapid Emergency Reverse Thrust
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Solution Overview
Problem
Existing emergency stop methods for water vessels, particularly those with high-speed sailboats, are inefficient and slow due to reliance on combustion engines, which have lag and lower acceleration compared to electric motors, and propeller efficiency decreases when reversing rotation direction.
Innovation Solution
A hybrid propulsion system with a combustion engine and an electric machine, allowing the propeller shaft to pivot 180 degrees and utilize the electric machine for immediate reverse thrust, optionally supported by the combustion engine, to achieve rapid emergency stops with enhanced efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a combustion engine is used for emergency stop, then the system has simple structure, but the stop time and stop distance are increased due to engine lag and lower acceleration
Solution Approach 1:
The patent combines a combustion engine and an electric machine in a hybrid propulsion system. The electric machine is permanently connected to the propeller shaft and can independently provide emergency stop thrust without waiting for combustion engine response, thereby reducing emergency stop time while maintaining structural simplicity through integrated design
Solution Approach 2:
The electric machine is pre-connected to the propeller shaft and kept ready to provide immediate torque. When emergency stop is requested, the electric machine can instantly deliver full power in reverse direction without the startup lag characteristic of combustion engines, achieving preliminary preparation for rapid response
2Power
If the propeller shaft is pivoted 180 degrees for emergency stop, then thrust efficiency is improved, but the system complexity increases
Solution Approach 1:
The propeller shaft is made pivotable by at least 180 degrees about a vertical axis, allowing dynamic reorientation of the propeller. This enables the system to achieve optimal thrust efficiency by positioning the propeller in the reverse direction while maintaining forward rotation, converting a static limitation into a dynamic solution
Solution Approach 2:
The pivotable propeller shaft mechanism serves multiple functions: normal propulsion in forward direction, emergency stop in reverse direction, and potential maneuvering capabilities. This multi-functionality justifies the added structural complexity by providing versatile operational capabilities from a single integrated system
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 method enables quick emergency stops with increased thrust efficiency, reducing the stop distance and time, especially for sailboats, by leveraging the electric machine's rapid acceleration and combining it with the combustion engine's power for enhanced torque.
Implementation Method 1
The electric machine can be permanently connected to the propeller shaft... setting the electric machine to maximum drive power
Implementation Method 2
at least one propeller which is mounted to a propeller shaft... The at least one propeller can be driven by the combustion engine in a forward and reverse direction
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method for an emergency stop of a water vessel (100), wherein the water vessel comprises a propulsion system (1) with a combustion engine (2) as a first prime mover and an electric machine (3) as a second prime mover. The method comprising the following steps: • receiving (S1) an emergency stop request signal, • checking (S2) an on/off status of the combustion engine (2) and o if the combustion engine (2) is on, slowing down (S2a) combustion engine (2) to an idle mode and disengage the forward transmission clutch (6), o if the combustion engine (2) is off, starting (S2b) the combustion engine (2), • pivoting (S3) the propeller shaft (5) by approximately 180 degrees in a reverse direction, • engaging (S4) the forward transmission clutch (6), • setting (S5) the electric machine (3) to maximum drive power and the combustion engine (2) to full throttle. The invention is further related to a control unit (110), a propulsion system (1) and a water vessel (100) being configured to carry out such a method.