Abstract: Disclosed are a propulsion device for a ship and a ship having the same. The propulsion device may include a rotational shaft, a rear propeller fixed to the rotational shaft, a front propeller rotatably supported by the drive shaft in front of the rear propeller, a counter rotation unit disposed in an installation space of a stern of a ship body and including a plurality of gears configured to reverse rotation of the rotational shaft and transmit the reversed rotation to the front propeller and a gear box configured to receive the plurality of gears, a coupling unit configured to separably connect the rotational shaft with the counter rotation unit and cut off power transmission from the rotational shaft to the counter rotation unit upon disconnection therebetween, and a rotation preventing unit configured to prevent rotation of the front propeller when the coupling unit is separated.

Abstract: Disclosed are a propulsion device for a ship and a ship having same. The propulsion device, according to an embodiment of the present invention, comprises: a rear propeller fixed to a driveshaft; a front propeller positioned in front of the rear propeller, and supported rotably on the driveshaft; and a counter rotation device for reversing and transmitting the rotation of the driveshaft to the front propeller; a motor for rotating the driveshaft; and an housing, which extends from to the lower part of the hull, and which is installed so as to envelope the counter rotation device and the motor.

Abstract: Disclosed are a propulsion device for a ship and a ship having the same. The propulsion device, according to an embodiment of the present invention, includes a rotational shaft, a rear propeller fixed to the rotational shaft, a front propeller rotatably supported by the drive shaft in front of the rear propeller, a counter rotation unit disposed in an installation space of a stern of a ship body and including a plurality of gears configured to reverse rotation of the rotational shaft and transmit the reversed rotation to the front propeller and a gear box configured to receive the plurality of gears, a coupling unit configured to separably connect the rotational shaft with the counter rotation unit and cut off power transmission from the rotational shaft to the counter rotation unit upon disconnection therebetween, and a rotation preventing unit configured to prevent rotation of the front propeller when the coupling unit is separated.

Abstract: Disclosed are a ship propulsion device and a ship having the same. According to one embodiment of the present invention, the ship propulsion device includes a rear propeller fixed on a drive shaft; a front propeller supported on a drive shaft of the front of the rear propeller to be rotated; and a reverse rotary device having a plurality of gears which are provided on a rear side of the ship, and transmits rotation of the drive shaft after reversing the rotation to the front propeller.

Abstract: Disclosed are a propulsion device for a ship and a ship having same. The propulsion device, according to an embodiment of the present invention, comprises: a rear propeller fixed to a driveshaft; a front propeller positioned in front of the rear propeller, and supported rotably on the driveshaft; and a counter rotation device for reversing and transmitting the rotation of the driveshaft to the front propeller; a motor for rotating the driveshaft; and an housing, which extends from to the lower part of the hull, and which is installed so as to envelope the counter rotation device and the motor.

Abstract: Disclosed are a propulsion device for a ship and a ship having same. The propulsion device, according to an embodiment of the present invention, comprises: a rear propeller fixed to a first driveshaft; a front propeller positioned in front of the rear propeller and supported rotably on the first driveshaft; a counter rotation device, which penetrates the hull, and which counter-rotates the front propeller and the rear propeller on the basis of the rotation of a second driveshaft, which is installed perpendicular to the first driveshaft; and a housing installed so as to envelope the second driveshaft and the counter rotation device.

Abstract: Disclosed is an excitation force reducing type ship. An excitation force reducing type ship according to one embodiment of the present invention comprises: a hull having a rear end with a propeller; and an excitation force reducing module which forms an air layer for generating reflected waves on a surface of the hull neighboring the propeller during an operation of the propeller so as to reduce the excitation force in the direction of the hull, wherein the excitation force reducing module can be arranged eccentrically with respect to a center line penetrating through the center of the axis of rotation of the propeller in a vertical direction of the hull.

Abstract: Disclosed are a ship propulsion device and a ship having the same. According to one embodiment of the present invention, the ship propulsion device includes a rear propeller fixed on a drive shaft; a front propeller supported on a drive shaft of the front of the rear propeller to be rotated; and a reverse rotary device having a plurality of gears which are provided on a rear side of the ship, and transmits rotation of the drive shaft after reversing the rotation to the front propeller.

Abstract: A flow control mechanism is provided for controlling a stern flow field disturbed by cooling water discharged from the cooling water outlet of a ship. The flow control mechanism is located within a distance, which corresponds to three times the diameter of the cooling water outlet, from the cooling water outlet, is installed at an angle from 16° to 30° with respect to the horizontal plane of a hull, and has a vertical height, which is within a range from 0.2 times to 0.6 times the diameter of the cooling water outlet in a vertical direction of the hull, and a horizontal width, which is within a range from 0.5 times to 1.3 times the diameter of the cooling water outlet in a horizontal direction of the hull. Thereby, the flow control mechanism restores the distribution of wake flow that encounters a propeller so that the distribution of the wake flow is symmetrical around the central axis of the hull, and reduces the generation of a cavity.

Abstract: A flow control mechanism, for improving pressure resistance and hull vibration, includes a lower fin and an upper fin. The lower fin is disposed between a second station and a fourth station in a length direction of a ship and between 10% and 20% of a design draft from a bottom of the ship in a height direction of the ship, the lower fin being inclined at an angle of 20 to 40 degrees with respect to a design draught (or base) line. The upper fin is disposed between the second station and the fourth station in the length direction of the ship and between 30% and 60% of the design draft from the bottom of the ship in the height direction of the ship, the upper fin being inclined at an angle of 10 to 30 degrees with respect to the design draught (or base) line.

Abstract: A flow control mechanism is provided for controlling a stern flow field disturbed by cooling water discharged from the cooling water outlet of a ship. The flow control mechanism is located within a distance, which corresponds to three times the diameter of the cooling water outlet, from the cooling water outlet, is installed at an angle from 16° to 30° with respect to the horizontal plane of a hull, and has a vertical height, which is within a range from 0.2 times to 0.6 times the diameter of the cooling water outlet in a vertical direction of the hull, and a horizontal width, which is within a range from 0.5 times to 1.3 times the diameter of the cooling water outlet in a horizontal direction of the hull. Thereby, the flow control mechanism restores the distribution of wake flow that encounters a propeller so that the distribution of the wake flow is symmetrical around the central axis of the hull, and reduces the generation of a cavity.

Abstract: A flow control mechanism, for improving pressure resistance and hull vibration, includes a lower fin and an upper fin. The lower fin is disposed between a second station and a fourth station in a length direction of a ship and between 10% and 20% of a design draft from a bottom of the ship in a height direction of the ship, the lower fin being inclined at an angle of 20 to 40 degrees with respect to a design draught (or base) line. The upper fin is disposed between the second station and the fourth station in the length direction of the ship and between 30% and 60% of the design draft from the bottom of the ship in the height direction of the ship, the upper fin being inclined at an angle of 10 to 30 degrees with respect to the design draught (or base) line.