The ongoing electrification revolution, originating in the automotive industry, has now expanded into the marine sector. This transition from internal combustion engines to electric motors necessitates careful adjustments due to the unique characteristics of electric motors, notably their high starting force. In the context of watercraft, where structural modifications are undesirable, this disclosure introduces a drive system fixation unit. This unit effectively redirects the sterndrive force from the stern wall to the sturdy structural base of the watercraft, ensuring a seamless integration of electric propulsion without compromising the vessel's integrity.

A marine propulsion system for shallow waters, swamps, savannahs and the like includes a rotating propeller shaft supporting a propeller. An anti-cavitation body defines a partial cylinder having a longitudinal axis adjacent to the propeller. The propeller generates a vacuum between the anti-cavitation body and a surface of a water body. First and second wings adjacent to edges of the anti-cavitation body are generally planar and operatively angled towards the bottom of a water body. The first and second wings are adjusted to run below the water body surface and seal the anti-cavitation body to maintain generated vacuum. A first thread is cut in a first helical direction at an end of the rotating propeller shaft adjacent the propeller, and slightly more distal therefrom a second thread is cut in a second helical direction opposed to the first thread helical direction. The second thread drives matter away from the bearing.

A marine propulsion system for shallow waters, swamps, savannahs and the like includes a rotating propeller shaft supporting a propeller. An anti-cavitation body defines a partial cylinder having a longitudinal axis adjacent to the propeller. The propeller generates a vacuum between the anti-cavitation body and a surface of a water body. First and second wings adjacent to edges of the anti-cavitation body are generally planar and operatively angled towards the bottom of a water body. The first and second wings are adjusted to run below the water body surface and seal the anti-cavitation body to maintain generated vacuum. A first thread is cut in a first helical direction at an end of the rotating propeller shaft adjacent the propeller, and slightly more distal therefrom a second thread is cut in a second helical direction opposed to the first thread helical direction. The second thread drives matter away from the bearing.

A sealing arrangement is used when mounting a thruster in a well box attached to a hull of a marine vessel. The well box has an axis, a bottom flange, a top flange, an annular wall therebetween and hoisting pipes fastened parallel with the axis to the bottom flange radially outside the annular wall. Both the well box and a mounting flange have at least one surface acting as a sealing surface between the well box and the thruster. At least one of the surfaces has a groove for a seal for preventing water from entering the well box. The well box has a rotationally symmetric wall with an internal guide surface and the mounting flange of the thruster has an axially extending rotationally symmetric part provided with an outer surface having means for sealing the mounting flange in relation to the well box.

In a stern tube sealing device, slurry contained in outboard water is suppressed from depositing on sliding portions between a wall surface of a seal ring chamber or an outer peripheral surface of a propeller shaft and a sealing surface of a seal ring. A first seal ring (121) is arranged in a first seal ring chamber (111), and a second seal ring (122) is arranged in a second seal ring chamber (112) which is formed at an inboard side of the first seal ring chamber. The first seal ring chamber and the second seal ring chamber are in communication with each other through the sliding portions between a wall surface of the first seal ring chamber and a sealing surface (121a) of the first seal ring. Outboard water is filled into the first seal ring chamber, and clear water is filled into the second seal ring chamber.

In a stern tube sealing device, slurry contained in outboard water is suppressed from depositing on sliding portions between a wall surface of a seal ring chamber or an outer peripheral surface of a propeller shaft and a sealing surface of a seal ring. A first seal ring (121) is arranged in a first seal ring chamber (111), and a second seal ring (122) is arranged in a second seal ring chamber (112) which is formed at an inboard side of the first seal ring chamber. The first seal ring chamber and the second seal ring chamber are in communication with each other through the sliding portions between a wall surface of the first seal ring chamber and a sealing surface (121a) of the first seal ring. Outboard water is filled into the first seal ring chamber, and clear water is filled into the second seal ring chamber.

A method and an arrangement for sealing a propeller shaft. The propeller shaft is rotatably supported with a bearing arrangement inside a pod that is suspended at a hull of the marine vessel. The bearing arrangement includes at least two seal rings axially spaced apart from each other such that at least one lubricant seal chamber is delimited. The arrangement includes a lubrication arrangement for conducting lubricant to and from said bearing arrangement. The lubrication arrangement includes an additional lubrication circulation line for conducting a part of said flow of lubricant to and from said at least one lubricant seal chamber. The lubrication arrangement being additionally configured to create a flow of lubricant in the additional lubricant circulation line and in said at least one lubricant seal chamber.

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 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.

An input shaft for the torque-transmitting connection of motor and propeller of a ship drive has input-side and output-side interfaces and a composite hollow shaft made of fiber composite material arranged therebetween. The input shaft has a section which is arranged between the input-side and output-side interfaces, is connected to the composite hollow shaft, and is made of non-flammable material. A ship includes a hull, a bulkhead running transversely to the longitudinal axis of the hull, a motor, a propeller and an input shaft described above. The input shaft of the ship is fed through the bulkhead and has the non-flammable section arranged in the region of the feedthrough through the bulkhead.