| 摘要 |
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. |
