Cathodic protection and anti-fouling arrangement and method

Patent metadata

Field	Value
Publication number	US-12291315-B2
Application number	US-201917754981-A
Country	US
Kind code	B2
Filing date	Oct 18, 2019
Priority date	Oct 18, 2019
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

An anti-fouling arrangement in a marine vessel with a marine propulsion system, the propulsion system comprising at least one driveline housing, a torque transmitting drive shaft extending out of the driveline housing, and at least one propeller mounted on the drive shaft. The at least one propeller is electrically isolated from its drive shaft, wherein each electrically isolated propeller is connected to a positive terminal of a direct current power source, and each metallic component to be protected against fouling is connected to a negative terminal of the direct current power source. A control unit is arranged to regulate the voltage and current output from the direct current power source.

First claim

The invention claimed is:

1. A marine vessel comprising a cathodic protection and anti-fouling arrangement and a marine propulsion system, the marine propulsion system comprising;
at least one driveline housing at least partially submerged in water;
a torque transmitting drive shaft extending out of the driveline housing;
at least one propeller mounted on the drive shaft;
the arrangement being wherein
the at least one propeller is electrically isolated from the drive shaft the at least one propeller is mounted on;
the at least one electrically isolated propeller to be protected against fouling is connected to a positive terminal of a direct current power source;
at least one metallic component of the marine vessel to be protected against corrosion is connected to a negative terminal of the direct current power source; and that
a control unit is arranged to regulate the voltage and current output from the direct current power source.

2. Marine vessel according to claim 1 , wherein the arrangement is an impressed current cathodic protection arrangement and that the at least one propeller is an anode.

3. Marine vessel according to claim 1 , wherein the at least one propeller is made from an inert metallic anode material.

4. Marine vessel according to claim 1 , wherein the metallic component to be protected is the at least one driveline housing.

5. Marine vessel according to claim 1 , wherein the metallic component to be protected is at least one trim tab.

6. Marine vessel according to claim 1 , wherein the metallic component to be protected is a metal portion of the vessel hull.

7. Marine vessel according to claim 1 , wherein a torque transmitting electrically isolating component is mounted between the at least one propeller and the drive shaft.

8. Marine vessel according to claim 7 , wherein the torque transmitting electrically isolating component is made from an elastic material.

9. Marine vessel according to claim 8 , wherein the elastic material is a natural or synthetic rubber.

10. Marine vessel according to claim 1 , wherein a reference electrode is at least partially submerged in water and is connected to the control unit in order to provide a ground reference value.

11. Marine vessel according to claim 1 , wherein a dielectric shield is provided between the at least one propeller and the drive shaft.

12. Marine vessel according to claim 11 , wherein the dielectric shield comprises a layer of dielectric material extending along the drive shaft over at least the entire axial extension of the propeller hub.

13. Marine vessel according to claim 1 , wherein the propeller is connected to the positive terminal of the direct current power source by wiring extending through a hollow portion of the drive shaft.

14. A method for protecting a marine vessel with a marine propulsion system against corrosion and fouling, the propulsion system comprising;
at least one driveline housing at least partially submerged in water;
a torque transmitting drive shaft extending out of the driveline housing;
at least one propeller mounted on the drive shaft;
the method comprising:
providing electrical power from a direct current power source;
causing at least one metallic component of the vessel to act as a cathode, and
causing the at least one propeller of said marine propulsion system to act as an anode in a galvanic circuit which comprises the at least one metallic component, the at least one propeller and water, in which water the metallic component and the propeller are at least partially submerged, and
electrically connecting said anode to the direct current power source and directing a direct current flow through said galvanic circuit.

15. A method according to claim 14 , further comprising controlling the direct current flow through said galvanic circuit using a reference electrode at least partially submerged in water to provide a ground reference value for the control unit.

Assignees

• Volvo Penta Corp

Inventors

• Räftegård Viktor

Classifications

• B63H20/00

  Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels · CPC title

• B63B59/00

  Hull protection specially adapted for vessels; Cleaning devices specially adapted for vessels {(inhibiting corrosion of metals by anodic or cathodic protection C23F13/00)} · CPC title

• B63B39/061

  by using trimflaps, i.e. flaps mounted on the rear of a boat, e.g. speed boat · CPC title

• C23F2213/31

  Immersed structures, e.g. submarine structures · CPC title

• C23F13/06 Primary

  Constructional parts, or assemblies of cathodic-protection apparatus · CPC title