Ship Rudder Stock Segmentation for Bending Force Isolation
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Solution Overview
Problem
Existing rudder designs for ships require the rudder stock to absorb both bending and torsional forces, leading to inefficiencies and increased manufacturing complexity, as well as limitations in size and cost due to the need for a single, long, forged rudder stock.
Innovation Solution
The rudder blade is mounted on the trunk pipe via two external bearings that absorb only radial forces, allowing the rudder stock to transmit torsional forces without absorbing bending forces, thus eliminating the need for the rudder stock to be directly supported on the trunk pipe and enabling a more efficient, cost-effective, and slimmer design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the rudder stock is directly supported on the trunk tube, then the rudder assembly is structurally stable, but the rudder stock must absorb both bending and torsional forces, increasing manufacturing complexity and cost
Solution Approach 1:
The patent segments the force transmission functions by introducing separate bearing elements that handle bending forces independently from the rudder stock. The rudder stock is divided into an upper part and lower part that can be manufactured separately and assembled, reducing manufacturing complexity while maintaining structural stability through the bearing support system.
2Strength
If the rudder stock is made as a single long forged piece, then structural integrity is ensured, but manufacturing cost and complexity increase significantly
Solution Approach 1:
The rudder stock is segmented into an upper part and a lower part that can be manufactured separately using more economical processes and then assembled together. The bearing support system ensures that this segmented construction maintains structural integrity comparable to a single forged piece, while significantly reducing manufacturing cost and complexity.
3Strength
If the rudder stock absorbs bending forces, then the rudder assembly is structurally sound, but the rudder blade design becomes less hydrodynamically efficient
Solution Approach 1:
The patent extracts the bending force absorption function from the rudder stock by introducing dedicated bearing elements. This allows the rudder stock to be optimized solely for torsional force transmission, enabling a slimmer, more hydrodynamically efficient rudder blade design while maintaining structural soundness through the bearing support system.
4Force
If the rudder stock is supported on the trunk tube, then bending forces are absorbed, but the rudder stock cannot be designed to be slimmer and lighter
Solution Approach 1:
The patent extracts the bending force absorption function from the rudder stock and assigns it to the bearing elements supported on the trunk tube. This allows the rudder stock to be designed as a lighter, slimmer component optimized for torsional force transmission only, while the bearings handle the bending forces, reducing overall weight while maintaining force absorption capability.
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 allows for the complete separation of bending and torsional force absorption, simplifying the rudder stock's manufacturing, reducing costs, and enabling the use of lighter, more hydrodynamically favorable rudder blades, particularly in large ships, by allowing the rudder stock to be designed in multiple parts and using lighter materials like plastic for the upper trunk pipe.
Implementation Method 1
The bearings are designed as plain bearings that absorb exclusively radial forces, so that they transmit lateral bending forces acting on the rudder blade in a radial direction into the coker tube
Implementation Method 2
The rudder stock serves solely to introduce a torsional force into the rudder blade for positioning the rudder blade
Data Source
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AI summary
The invention relates to a rudder for ships, comprising a rudder blade that is rotatably mounted on the hull of the ship, a rudder post connected to the rudder blade, and a rudder trunk which lies on the hull of the ship and which extends into a recess of the rudder blade with a trunk pipe that receives the rudder post. The rudder blade (11) is supported on the trunk pipe (200) by a lower support (21) and by an upper support (22), which is offset to the lower support (21) along the trunk pipe (200). In this manner a rudder for ships is provided, said rudder enabling the absorption of bending forces exclusively by the trunk pipe so that the rudder post must not absorb any bending forces.