| 摘要 |
PURPOSE:To facilitate designing and always obtain the absorbing softening action for the vibrational force of a propeller by forming a gas sealed space which can absorb and soften the variable water pressure onto the bottom part of a stern hull and adjusting the internal pressure in the gas sealed space. CONSTITUTION:A gas sealed space S is constituted by closing the lower opened port of a recessed part 7 formed onto the bottom part of a stern hull 2 directly above a screw propeller 1 by a plate-shaped elastic body 8. Further, the air having a set pressure is introduced inside the gas sealed space S through a pressurized air feeding pipe 11 equipped with an electromagnetic opening/closing valve 9 and an air pump 10. A controller 12 controls the power of the air pump 10 to a proper value according to the variation of the input number of revolution of the propeller 1, and opening-operates the electromagnetic opening/closing valve 9 and sets the internal pressure of the space S to the proper value corresponding to the number of revolution of the propeller, and then closes the valve 9. |
