JPS62260080A - Corrosion preventive device for propulsion system of ship - Google Patents

Abstract

PURPOSE:To execute corrosion prevention, etc., of the stern tube of a water-sealed propulsion shaft system or the crank journal sliding parts of an engine based on a potential difference to be generated between a ship and the propulsion system without any trouble by applying electric energy to the propulsion shaft system without contact by an electromagnetic coupling effect thereby eliminating the above-mentioned potential difference. CONSTITUTION:An AC power source is supplied to a coil 20 wound on a magnetic iron core material 19. A coil 13 which is wound on the propulsion shaft 7 and is juxtaposed with the coil 20 and the coil 20 are then coupled by magnetic lines 22 of force even during the rotation of the shaft 7. The induced voltage is converted to a DC voltage by a current rectifying element 14. The above-mentioned voltage is impressed through a lead wire 15 and an insoluble anode 16 at the top end in a boss part 6 of a propeller 4 to the propeller 4 via the sea water. The potential of the propeller 4 is controlled to about the same degree as the hull potential by the current applied to the propeller 4. The applied current passes the shaft 7 and returns to the one side of the coil 13, thus forming a circuit. The current value is controllable in the tap position on the secondary side of a variable voltage controller 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a corrosion protection device applied to a marine vessel propulsion system such as a propeller, a propulsion shaft casket tube, or a crank journal.

[Conventional technology]

Conventionally, the hull of a ship is made of steel, and its propulsion device is made of a copper alloy. For this reason, so-called cathodic protection is carried out in which zinc anodes are attached to the hull shell plates to protect the hull and propulsion equipment from galvanic corrosion. During cruising, the rotation of the propeller causes insufficient contact between the hull and propulsion system, creating a potential difference between the two. This potential difference causes insufficient corrosion protection of the propeller, corrosion of water-lubricated hull tubes, The sliding surface of the crank journal for driving the propulsion shaft is corroded. To prevent this, a short circuit device such as a carbon brush was installed between the propulsion shaft and the hull to eliminate the potential difference.

[Problem that the invention seeks to solve]

However, conventional short-circuit devices used to prevent the aforementioned various problems caused by potential differences between the propulsion system and the ship's hull during navigation require maintenance of the sliding surfaces due to mechanical contact action. Care must be taken to prevent wear and tear on the brushes, oil stains on the sliding surfaces, and maintenance of contact pressure, etc., and in today's era of trying to keep engine room occupants as clean as possible, highly reliable products are required. Also, by installing this short-circuit device, the consumption of zinc for corrosion protection on the hull outer plate attached to the hull increases, which necessitates the installation of additional zinc, resulting in problems such as an increase in the propulsion resistance of the hull.

The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide a ship propulsion system corrosion protection device that uses electrical energy supplied to the propulsion shaft system to make the potentials of the propulsion shaft system and the hull the same.

[Means for solving problems]

Therefore, the corrosion protection device for a marine propulsion system of the present invention is a corrosion protection device for a propulsion shaft system consisting of a propeller and a propulsion shaft of a ship, which has zinc anodes on the hull and rudder. A coil to be wound around the coil, a coil to be wound on a magnetic iron core material placed parallel to the coil and connected to an AC power supply, and one end connected to the coil on the propulsion shaft and the other end to the propeller boss. The present invention is characterized by comprising a lead wire and a rectifying element disposed at an intermediate portion of the lead wire.

[Effect]

With the above configuration, electrical energy is supplied to the propulsion shaft system in a non-contact manner by electromagnetic coupling, and this electrical energy is used to energize the propeller and maintain the propeller potential at the same potential as the hull, thereby creating a potential difference between the hull and the propeller (propulsion system). Eliminate.

〔Example〕

Fig. 1 is an embodiment of the ship propulsion system corrosion protection device of the present invention, and shows a side view of the ship's propulsion system showing the ship's propulsion system.
' indicates the hull outer plate of the vessel 1, and 2 indicates the sea water line. The hull 1 of the ship 1 is made of steel and painted, but a zinc anode 5 is attached to prevent corrosion below the water line 2. 3 is the rudder, which is painted the same as ship 1 and has a zinc anode 5 attached to it. A propeller 4 is generally made of copper alloy, and the propeller 4 is connected to a propulsion shaft 7 at a root boss 6. Although not shown, it is driven by an engine and rotates together with the propulsion shaft 7 to propel the ship. The propulsion shaft 7 is made of steel, and one side is joined by a flange 8, another propulsion shaft 10, and a flange 11. A narrow hole 9 is provided in the propulsion shaft 7 in the axial direction, and a suitable groove is also cut in the flange 8.11 at right angles to the axis, through which the lead wire 15 is passed. 12 indicates a propulsion shaft bearing. Reference numeral 13 denotes a wire ring attached to the propulsion shaft 7, one side of which is electrically contacted with the propulsion shaft 7, and the other wire connected to the lead wire 15 through the rectifying element 14.

The lead wire 15 passes through the groove of the flange 8.11 and connects to the propulsion shaft 7.
A cap-shaped insoluble anode 16 at the tip of the boss 6 is connected through the small hole 9 and the boss 6 to, for example, a titanium base plated with platinum metal on the side facing the seawater.

Reference numeral 17 denotes a variable voltage regulator for adjusting the alternating voltage. The alternating current voltage regulator 17 is connected to a wire ring 20 wound around a magnetic iron core material 19 by a lead wire 21 via an ammeter 18, for example.

With such a device, if AC power is supplied, the propulsion shaft 70
Even during rotation, the wire wheels 20 and 13 are coupled by magnetic lines of force 22, and the induced voltage is converted into a DC voltage by the rectifier 14 and applied to the propeller 4 through the lead wire 15 and the insoluble anode 16 through seawater.

This additional current to the propeller 4 adjusts the potential of the propeller 4 to approximately the same level as the hull potential. The additional current returns to one side of the wire ring 13 through the propulsion shaft 7, forming a circuit. The current value at this time is measured by an ammeter 18, and the magnitude can be adjusted by the position of the secondary tap of the variable transformer 7.

When at anchor, the propulsion bearing 12 is in metal contact and the hull of the propeller 4 is short-circuited and held at approximately the same potential, so the supply of current from the variable transformer 17 is not necessarily required. Therefore, a sequence of power supply vn and off may be incorporated in accordance with the start and stop of the ship. However, in reality, if a constant voltage is supplied, it will have the effect of suppressing the current flowing from the zinc 5 to the propeller 4 (the bearing device 12 short-circuits the hull and propeller) when at anchor, reducing wear and tear on valuable metals. It is effective from the top. Which one to select depends on the size of the ship, the size of the propeller, and the frequency of starting and stopping the ship.

[Effects of the Invention] As detailed above, the ship propulsion system corrosion protection device of the present invention can apply electrical energy to the rotating body without contact and eliminate the potential difference generated between the ship body and the propulsion system. It has the effect of resolving problems caused by the generation of potential differences, such as (1) preventing corrosion of the pedestal tube of the water seal propulsion shaft system, and (2) preventing corrosion of the engine crank journal sliding part.

[Brief explanation of drawings]

FIG. 1 is a side view of a ship's propulsion system, which is an embodiment of the ship propulsion system corrosion protection device of the present invention. 1... Ship, 3... Rudder, 4... Propeller, 5...
Anode zinc, 6... Boss part, 7... Propulsion shaft, 10...
・Propulsion shaft, 13... Line wheel, 14... Rectifying element, 15
... Lead wire, 16 ... Insoluble anode, 17 ... Variable voltage regulator, 19 ... Magnetic iron core material, 20 ... Wire ring

Claims (1)

[Claims] In a corrosion protection device for a propulsion shaft system consisting of a propulsion shaft and a propeller of a ship having zinc anodes on the ship's part and rudder, a wire ring wrapped around any propulsion shaft of the propulsion shaft system, and A wire ring wound around a magnetic iron core material which is connected to an AC power supply installed, a lead wire whose one end is connected to the wire ring on the propulsion shaft and the other end to the propeller boss, and an intermediate portion of the lead wire. A ship propulsion system corrosion protection device characterized by comprising a rectifying element arranged in a ship propulsion system.