Provided is a ship propelling apparatus including a rotation shaft on which a rear propeller is fixed; a front propeller rotatably supported on the rotation shaft in front of the rear propeller; and a counter-rotating device through which the rotation shaft passes, which includes a gear box including therein a plurality of gears configured to reverse rotation of the rotation shaft and transfer the reversed rotation to the front propeller, and which is installed in an installation space formed at the rear of a ship. The rotation shaft includes a measurement hole formed to pass through a center of the rotation shaft for centering of the counter-rotating device installed in the installation space; and an individual lubricant path separated from the measurement hole.

A strut mounted gear box for counter rotating propellers. The gear box is strut mounted for securement to the hull of a boat. A main input shaft is coupled to a propulsion component of a boat with a distal end secured to an idler gear cage assembly located within the gear box. The main input shaft transfers torque and rotation from the propulsion component to an idler gear cage assembly. An inner tail shaft is coupled to the main input shaft and arranged to rotate the inner tail shaft in a first direction. A counter shaft is coupled to the idler gear cage assembly and arranged to rotate the counter shaft in a second direction. A first propeller is secured to the inner tail shaft providing rotation in the first direction; and a second propeller is secured to the counter shaft allowing rotation in the second direction.

Provided is a ship propelling apparatus including a rotation shaft on which a rear propeller is fixed; a front propeller rotatably supported on the rotation shaft in front of the rear propeller; and a counter-rotating device through which the rotation shaft passes, which includes a gear box including therein a plurality of gears configured to reverse rotation of the rotation shaft and transfer the reversed rotation to the front propeller, and which is installed in an installation space formed at the rear of a ship. The rotation shaft includes a measurement hole formed to pass through a center of the rotation shaft for centering of the counter-rotating device installed in the installation space; and an individual lubricant path separated from the measurement hole.

Provided are a propulsion device for a ship and a ship including the same. The propulsion device for the ship includes: a rear propeller fixed to a rotation shaft; a front propeller that is rotatably supported on the rotation shaft in the front of the rear propeller; at least one bearing interposed in at least one of spaces between a hub of the front propeller and the rotation shaft and between the rotation shaft and a ship body; and an inverse rotation unit that inverts rotation of the rotation shaft, transfers the inverted rotation to the front propeller and includes a gearbox that is accommodated in an installation space formed in a tail of the ship body in a state in which a plurality of gears for implementing inversion of the front propeller are embedded, wherein at least one measurement unit for measuring operating states of the at least one bearing is mounted to the rotation shaft.

Disclosed are a propulsion system for a ship, a method of assembling the same, and a method of disassembling the same. The propulsion system for the ship includes: a rear propeller fixed to a rotary shaft; a front propeller that is rotatably supported on the rotary shaft in front of the rear propeller; a contra-rotating device that is mounted in an installation space at a rear end of a hull so as to reverse the rotation of the rotary shaft and transmit the reversed rotation to the front propeller; a propeller connecting member that connects the contra-rotating device and the front propeller to transmit a rotational force; and a thrust supporting device that is provided between the contra-rotating device and the propeller connection member to support thrust of the front propeller.

A tapered counter rotating propeller hub assembly for a stern drive marine propulsion assembly. The propeller hub assembly having aligned forward and aft tapered hubs with a predetermined slope.

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.

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.

Provided is a pod propulsion system including first and second counter rotating propellers for propelling a marine vessel first and second propeller modules, each including an electric motor having a driving-end configured to rotate the first and second propellers, respectively. Also included are first and second gondolas, each (i) for housing a respective one of the first and second electric motors and (ii) including a boltable interface formed along a lengthwise direction of an extremity of the gondola. A strut (i) connects the first and second gondolas to a hull of the marine vessel (ii) including first and second boltable interfaces. Each of the boltable interfaces of the strut is configured to form a bolted joint interface with a corresponding one of boltable interfaces of the first and second gondolas.