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.

A propulsion unit (1) for a marine vessel, comprising a shell structure (2), a shaft (4) rotatably coupled to a propulsion motor (3) inside the shell structure (2), and a propeller (5) coupled to the shaft (4) outside the shell structure (2). A shaft seal arrangement (6) is provided to engage the shaft (4), such that at least a first seal chamber (6a) is delimited between adjacent seal lips (6′) and the shaft (4). A first lubrication arrangement is provided for circulating a first lubricant through the first seal chamber (6a). The first lubrication arrangement (7) further comprises a first lubricant heat exchanger (7e) arranged at least partly outside of the shell structure (2) for conducting the first lubricant therethrough and for transferring heat from the first lubricant to an outside environment of the shell structure (2). A propulsion unit for a marine vessel, including a shell structure, a shaft rotatably coupled to a propulsion motor inside the shell structure, and a propeller coupled to the shaft outside the shell structure. A shaft seal arrangement is provided to engage the shaft, such that at least a first seal chamber is delimited between adjacent seal lips and the shaft. A first lubrication arrangement is provided for circulating a first lubricant through the first seal chamber. The first lubrication arrangement further includes a first lubricant heat exchanger arranged at least partly outside of the shell structure for conducting the first lubricant therethrough and for transferring heat from the first lubricant to an outside environment of the shell structure.

A propulsion unit includes a housing supported on a vessel. A propeller shaft extends in the housing. The propeller shaft is rotatably supported with a first bearing and a second bearing. A propeller is attached to at least one end of the propeller shaft. The first bearing includes a first radial bearing and a first thrust bearing. The first radial bearing is a sliding bearing positioned axially inside the first thrust bearing. The first bearing is positioned at the first end of the housing and the second bearing being positioned at the second end of the housing or vice a versa.

A method and an arrangement for sealing a propeller shaft located under water. The propeller shaft is arranged at a pod of a ship and an air chamber is provided circumferentially around the propeller shaft. The method includes supplying compressed air from a compressed air source to the air chamber, discharging compressed air from the air chamber in an air return line and colleting liquid present in the compressed air discharged from the air chamber in an intermediate leakage tank that is provided in the air return line. The method includes closing the air return line upstream of the intermediate leakage tank, and supplying compressed air to the intermediate leakage tank to effect flowing of liquid present in the intermediate leakage tank to a leakage tank.

A clamping mechanism is provided. The mechanism includes a male clamping body. The mechanism also includes a female clamping body configured to mate with the male clamping body. The mechanism further includes tightening bolts structured to connect the male clamping body to the female clamping body. The mechanism includes connecting spans connected to the male clamping body and the female clamping body. The mechanism also includes integral positioning ring halves connected to the male clamping body and the female clamping body, wherein the positioning rings are designed to fit into a positioning groove of a drive shaft and to provide a backstop to a support ring. Also, the connecting spans, the male clamping body, and the female clamping body have inner diameters that are identical and are arranged to securely fit onto an outer surface of the drive shaft when the tightening bolts are tightened.

A system for rotating a propeller shaft within a gearcase via a driveshaft. A stub shaft is rotatable within the gearcase. A forward gear is rotatably coupled to the stub shaft. The forward gear is rotatable by the driveshaft and is engageable to become rotatably fixed to the stub shaft such that rotating the driveshaft rotates the stub shaft. A shock absorbing coupler is positioned within the gearcase. The shock absorbing coupler couples the stub shaft to the propeller shaft and is torsional such that shock is absorbable between the propeller shaft and the driveshaft.

An outboard motor includes a drive source, a drive shaft, a propeller shaft, a first case, a second case, a third case, a bearing, and a bearing housing. The drive shaft extends downward from the drive source. The propeller shaft is connected to the drive shaft and extends in a front-rear direction of the outboard motor. The first case houses the drive source. The second case houses the propeller shaft. The third case is between the first case and the second case in a vertical direction of the outboard motor. The bearing rotatably supports the drive shaft. The bearing is between the first case and the second case in the vertical direction and outside the third case. The bearing housing supports the bearing. The bearing housing is between the first case and the second case in the vertical direction and outside the third case.

An arrangement and a method for sealing a propeller shaft of a marine vessel. The arrangement including a shaft seal arrangement and a lubrication arrangement including a lubricant circulation line for conducting lubricant to and from the shaft seal arrangement and a lubricant circulator. The lubricant circulation line includes a connection line that is connected in fluid connection with the lubricant circulation line downstream of the lubricant circulator and upstream of the shaft seal arrangement, and that is connected in fluid connection with a second part of the lubricant circulation line so as to selectively conduct a part of the flow of lubricant past the shaft seal arrangement. At least one hydraulically operated pressure relief means is configured to control the flow of lubricant in the connection line.

An arrangement and a method for sealing a propeller shaft of a marine vessel. The arrangement includes a propeller shaft rotatable supported with at least one bearing, a bearing arrangement, a first lubrication arrangement including a first lubricant circulation line for conducting first lubricant to and from the bearing arrangement, a shaft seal arrangement for sealing the propeller shaft against sea water, and a second lubrication arrangement including a second lubricant circulation line for conducting second lubricant to and from the shaft seal arrangement. A first heat exchanger is in thermal contact with the first lubricant circulation line and in thermal contact with the second lubricant circulation line.

A boat and a propeller assembly for a boat. The propeller assembly includes a propeller and a thrust bearing, and the thrust bearing is made of a harder material than the propeller. The boat may also include a hull, a drive shaft, and a motor. The motor may be positioned within the hull and configured to rotate the drive shaft. The drive shaft may extend through a hull bottom of the hull and the propeller assembly may be positioned forward of a transom of the hull and beneath the hull bottom. The propeller may include a central hub having a hole capable of having the drive shaft inserted therethrough. The thrust bearing may be located in the hole of the central hub and secured to the propeller such that the thrust bearing and the propeller form a unified assembly.