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 fluid machine includes: a shaft portion; a shroud surrounding the shaft portion and including an inside surface that forms a flow path-forming surface defining a flow path with the shaft portion; a first propeller rotatably provided in the flow path; a second propeller rotatably provided on a downstream side of the first propeller in the flow path; and a motor including a rotor that is fixed to an outer circumferential portion of the second propeller and that is accommodated in the shroud, and a stator that surrounds the rotor via a clearance and that is fixed in the shroud. A portion of the flow path-forming surface on a downstream side of the second propeller decreases in diameter toward the downstream side, and the shroud includes an inlet flow path that is open at a portion between the first propeller and the second propeller of the flow path-forming surface.

A fluid machine includes: a shaft portion; a shroud surrounding the shaft portion and including an inside surface that forms a flow path-forming surface defining a flow path with the shaft portion; a first propeller rotatably provided in the flow path; a second propeller rotatably provided on a downstream side of the first propeller in the flow path; and a motor including a rotor that is fixed to an outer circumferential portion of the second propeller and that is accommodated in the shroud, and a stator that surrounds the rotor via a clearance and that is fixed in the shroud. A portion of the flow path-forming surface on a downstream side of the second propeller decreases in diameter toward the downstream side, and the shroud includes an inlet flow path that is open at a portion between the first propeller and the second propeller of the flow path-forming surface.

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.

A system for rotating an inner propeller shaft within a gearcase via a driveshaft. The system includes a stub shaft that extends between forward and aft ends and is rotatable within the gearcase. A forward gear is rotatably coupled to the stub shaft, where the forward gear meshes with 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, where the coupler has forward and aft ends, where the forward end of the coupler is engageable with the aft end of the stub shaft, and where the aft end of the coupler engageable with the inner propeller shaft. The coupler is torsional between the forward and aft ends such that shock is absorbable between the inner propeller shaft and the driveshaft.

A system for rotating inner and outer propeller shafts via a driveshaft. The system includes a stub shaft extending between forward and aft ends, the aft end having an engagement feature for engaging with the inner propeller shaft such that rotating the stub shaft rotates the inner propeller shaft. A reverse gear and a forward gear are each rotatably coupled to the stub shaft. The reverse gear and the forward gear mesh with the driveshaft and are engageable to become rotatably fixed to the stub shaft such that rotating the driveshaft rotates the stub shaft in reverse and forward directions, respectively. An outer driving gear is coupled to the inner propeller shaft to rotate therewith. An outer driven gear is coupled to the outer propeller shaft and a pinion rotatably coupling the outer driving gear to the outer driven gear such that rotation of the outer driving gear rotates the outer propeller shaft.

A coaxial contra-rotating circumferential thruster includes: an input end, a one-way commutator, a two-way deflector, a steering support and two output ends. The input end is connected to a power device. The one-way commutator converts one rotation into two rotations having the same rotation speed and opposite rotation directions. The two-way deflector respectively indirectly connects two shafts of a contra-rotating sleeve shaft to two output shafts thereof by means of two bevel gear pair. Two unidirectional deflecting torques respectively generated by the two bevel gear pairs have the same magnitude and opposite directions. By transferring by means of a bracket or an output sleeve shaft, the two unidirectional deflecting torques cancel each other. The two output ends are respectively connected to two propellers (or rotors). A turnaround control device controls the steering support to be turned around, the control torque required for co-rotating and contra-rotating is the same.

A system for adjusting the rotational timing between driveshafts rotated by an output shaft. The system includes a flange coupler configured to be coupled to a first of the driveshafts to prevent rotation therebetween. The flange coupler defines openings therein. A coupler input gear defines openings therein and is configured to rotatably mesh with a second input gear coupled to a second of the driveshafts. Fasteners are configured to the extend through the openings in the flange coupler and the openings in the coupler input gear to rotationally fix the flange coupler and the coupler input gear, which are fixable at multiple rotational orientations therebetween. The rotational timing between the driveshafts is adjustable by rotating the coupler input gear into different orientations of the multiple rotational orientations relative to the flange coupler prior to fixing the flange coupler to the coupler input gear.

A propulsion unit for a marine vessel is adapted to receive power from at least one power supply unit. The propulsion unit includes a stationary part adapted to be mounted to a hull of the marine vessel, and a movable part comprising one or more thrust generating devices adapted to transform the received power into a thrust by acting on water carrying the marine vessel. The propulsion unit is adapted to receive exhaust gases from at least two internal combustion engines, wherein the movable part is adapted to release the exhaust gases into the water.

There is provided a ship propulsion machine including: a drive shaft; a drive gear fixed to the drive shaft; a front gear meshed with the drive gear; a rear gear meshed with the drive gear; a rear propeller provided on an inner propeller shaft; a front propeller provided on an outer propeller shaft; a casing having a gear chamber; a second bearing that supports a front end side of the outer propeller shaft at a rear portion of the casing; a third bearing that supports the inner propeller shaft and the outer propeller shaft in a manner rotatable with respect to each other. The third bearing is disposed on an inner peripheral side of a shaft portion of the rear gear, and the second bearing is disposed on an outer peripheral side of the shaft portion of the rear gear.