Waterborne Vessel Propulsion Pod with External Transmission
Solution Overview
Problem
Conventional ship propulsion systems, particularly those using azimuth pod thrusters, occupy excessive space within vessels due to the need for long roller bearing assemblies, leading to reduced efficiency, increased noise, and vibration.
Innovation Solution
The use of a propulsion system with a rotatable outboard housing supported by plain bearing surfaces that are in slidable contact, allowing for a reduced overall height and space usage, combined with an external transmission unit and power unit configuration that positions the power unit towards the aft of the hull, reducing the need for forward motor placement and minimizing propeller shaft inclination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If roller bearing assemblies are used to support the azimuth pod thruster, then the thruster can rotate 360 degrees about a vertical axis, but the overall length of the bearing series increases, reducing the available area within the vessel
Solution Approach 1:
The patent extracts the transmission unit from the internal space and positions it externally on the transom of the vessel. This removes the need for long roller bearing assemblies inside the vessel, thereby preserving internal area while still enabling 360-degree thruster rotation through the external transmission mechanism
Solution Approach 2:
The patent moves the transmission system from the internal longitudinal dimension to the external transom dimension. By positioning the transmission unit outside the vessel on the transom, the bearing length requirement is shifted from consuming internal vessel area to occupying external space, resolving the area contradiction
2Ease of manufacture
If conventional transmission shafting and propellers with inclined shafts are used, then the propulsion system can be implemented, but the motor must be positioned forward in the boat, leading to large propeller shaft inclination and increased noise and vibration
Solution Approach 1:
The patent extracts the transmission unit from the internal vessel space and positions it externally on the transom. This allows the power unit to be positioned aft rather than forward, eliminating large propeller shaft inclination and the associated noise and vibration problems while maintaining propulsion functionality
Solution Approach 2:
The patent inverts the conventional arrangement by positioning the transmission unit externally on the transom rather than internally forward in the vessel. This reversal of the traditional layout allows the power unit to be placed aft, eliminating the need for inclined shafts and reducing noise and vibration
3Stability of the object's composition
If the power unit is positioned forward in the boat to avoid large propeller shaft inclination, then the shaft inclination can be minimized, but the overall height of the propulsion system increases due to the need for long roller bearing assemblies
Solution Approach 1:
The patent extracts the transmission unit from the internal space and positions it externally on the transom. This allows the power unit to be positioned aft with minimal shaft inclination while the external transmission housing contains the bearing assemblies, thereby minimizing both shaft inclination and the height occupation within the vessel
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 configuration reduces the overall height of the propulsion system, decreases noise and vibration, and provides more space within the vessel while improving maneuverability and efficiency by allowing the power unit to be positioned further back, enhancing acoustic conditions and simplifying assembly and maintenance.
Implementation Method 1
a first pair of plain bearing surfaces in slidable contact with each other, one plain bearing surface forming part of the rotatable outboard housing and the other plain bearing surface forming part of the hull structure
Data Source
AI summary
A propulsion system 2 for a waterborne vessel 4 having a hull structure 6, typically for a full or semi planing boat. The propulsion system 2 has a pod housing 8 having a front end 10 and a rear end 12, a propeller 14 and a propeller shaft 16. The propeller 14 is disposed externally at the front end 10 of the pod 8 and is rotatable about a longitudinal axis 18of the propeller shaft 16, the propeller shaft 16 being drivingly connected to a drive assembly. The drive assembly has a transmission unit 20 and a power unit 22 in the form of a diesel engine. In FIG. 1 the diesel engine is shown disconnected from the transmission unit 20. The power unit 22 is disposed within the structure of the hull 6 and, in this particular embodiment; the transmission unit 20 is disposed substantially outside the structure of the hull 6. The hull 6 is formed with a port 24 through which an interface unit 26 extends. The interface unit 26 provides structures for transmitting the torque of the power unit 22 to the transmission unit 20.