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EP-4493457-B1 - A CAVITATION CONTROLLED RUDDERLESS PROPULSION SYSTEM

EP4493457B1EP 4493457 B1EP4493457 B1EP 4493457B1EP-4493457-B1

Inventors

  • GONCA, Guven

Dates

Publication Date
20260506
Application Date
20230315

Claims (4)

  1. A cavitation controlled rudderless propulsion system for use in sea vehicles, configured to perform the propulsion and manoeuvring of the vehicle without the need for a rudder, and comprising: a main propulsion propeller (1), a starboard auxiliary propeller (2), a port auxiliary propeller (3), an upper auxiliary propeller (4), a lower auxiliary propeller (5), a starboard auxiliary propeller connection (6), a port auxiliary propeller connection (7), an upper auxiliary propeller connection (8), a lower auxiliary propeller connection (9), and a propeller shaft (10), comprising: · an angle adjustment mechanism (11) that is positioned between the entire propeller system and the stern, that allows the propellers to get rid of cavitation by adjusting the angle of the propeller shaft (10) and the immersion level of the main propeller (1), the starboard auxiliary propeller (2), the port auxiliary propeller (3), the upper auxiliary propeller (4), and the lower auxiliary propeller (5) and calculates whether cavitation occurs or not by using the pressure and ship speed information received from a pressure sensor (12), • the pressure sensor (12) that is located on an upper auxiliary propeller (4) blade and transfers the pressure data to the electronic control unit (13), and transfers the pressure and ship speed it senses to the angle adjustment mechanism (11), • an electronic control unit (13) that controls the angle adjustment mechanism (11) to prevent cavitation, ensures that the propeller shaft (10) reaches the appropriate angle, constantly checks whether the angle is sufficient and adjusts the angle according to the pressure, and • an engine driven starboard auxiliary propeller reducer (14), a port auxiliary propeller reducer (15), an upper auxiliary propeller reducer (16) and a lower auxiliary propeller reducer (17) that connect the starboard auxiliary propeller (2), the port auxiliary propeller (3), the upper auxiliary propeller (4) and the lower auxiliary propeller (5) to the propeller shaft (10) connected to the main propeller (1).
  2. A cavitation controlled rudderless propulsion system according to Claim 1, wherein the angle adjustment mechanism (11) provides downward rotation of the propeller shaft (10) up to 30 degrees from the horizontal axis to prevent cavitation.
  3. A cavitation controlled rudderless propulsion system according to Claim 1, wherein the electronic control unit (13) enables the ship to be kept on the sea surface by increasing the angle in an emergency in which the ship is damaged in the stern.
  4. A cavitation controlled rudderless propulsion system according to Claim 1, wherein the angle adjustment mechanism (11) ensures that the angle is maximized, and the ship is prevented from sinking if the ship is damaged from the stern and is sinking towards the stern.

Description

Technical field of the invention The invention relates to a rudderless propulsion system with cavitation control that has been developed for use in sea vehicles, performs the propulsion and manoeuvring of the vehicle without the need for a rudder, and comprises main propulsion propeller, starboard auxiliary propeller, port auxiliary propeller, upper auxiliary propeller, lower auxiliary propeller, starboard auxiliary propeller connection, port auxiliary propeller connection, upper auxiliary propeller connection, lower auxiliary propeller connection, propeller shaft, angle adjustment mechanism, pressure sensor and electronic control unit. State of the Art The rudders are the dynamic parts of air and sea vehicles that serve to steer the vehicle. They are elements made of steel sheet, which are used to change the course of the ship while cruising and to facilitate the movements of the manoeuvring ship. When the rudder is directed to starboard or port, it tries to turn the ship with a water force depending on the cruising speed of the ship. If the rudder is turned at a low angle, the boat turns slowly. If the boat is desired to turn quickly or strongly, the rudder angle should be enlarged. The ship's rudder is turned by an electrical and hydraulic system called rudder gear. The current rudder system used in vessels today causes additional resistance at the rear of the vessel. In addition, the initial installation cost of these rudder systems is high. The total production and propulsion cost of the ship increases due to the rudder systems. In addition, in existing vessels, the probability of sinking is high when the vessel receives a major injury. In the studies carried out, it is tried to reduce the appendage resistance of the ship by lightening the rudder system and using the rudder form that causes less resistance. Although the total resistance is tried to be reduced by arranging the rudder form and propeller track, the rudder system itself always causes some resistance. In order to eliminate this resistance, a more efficient manoeuvring propulsion system should be put in place of the rudder. During the rotation of the ship's propellers, a vacuum is created. This vacuum falls under the evaporation pressure of sea water and initiates the formation of vapour. This fact causes the formation of bubbles filled with water vapour. When the bubbles hit the impeller surface, they burst and cause damage to the material forming the propeller. This situation, which is stated as one of the biggest problems seen in ship propellers, is the formation of cavitation due to the decrease in pressure. Vibrations caused by cavitation are felt more especially when there is no load on the ship. Vibrations felt may negatively affect the comfort of the ship's personnel, as well as cause deterioration of electronic equipment. Another undesirable result of cavitation in the propeller is the uneven force applied to the shaft to which the propeller is attached. This creates capillary cracks in the shaft and can create problems that are difficult to repair over time. In addition, cavitation is one of the most important factors affecting the life of the propeller. When cavitation progresses, unusual sounds can be heard from the stern of the ship. In particular, the periodic change in the size of the layer cavitation on the propeller blades causes non-constant propeller forces and vibration, and noise generation under water and within the ship. The invention that is the subject of the patent no "TR 2017/18567" in the state of the art is related to a propeller system that enables ships and similar vessels to manoeuvre without using a rudder. In particular, the invention relates to a propeller system developed for use in vessels, which eliminates the need for a rudder, as it contains one main propeller that provides the propulsion of the vessel and four auxiliary propellers that provide manoeuvring. However, in this propeller system, there is no improvement in preventing abnormal sounds from the stern of the ship, non-continuous propeller forces and vibration, and noise that may occur underwater and within the ship. The invention that is the subject of the patent no "JPS5747295A" in the state of the art relates to an apparatus developed to prevent cavitation wear. This structure has an air injection port near the rear end of a ring-like structure in front of a spiral propeller at the stern of a ship. The ring-like structure is mounted on the front of the propeller. A side surface of the structure takes the shape where the length of the upper part is longer and narrows towards the lower part. A plurality of air ducts are arranged in an upper part of the ring-shaped structure, and the injection zones at the end parts open towards the impeller. The invention that is the subject of the patent no "CN1440346A" in the state of the art relates to a marine propeller, particularly to a cavitation prevention device that can increase the efficiency of the