The invention relates to a method for controlling a water jet propulsion device for the propulsion of a marine vessel, the water jet propulsion device comprising: a conduit extending between an inlet and an outlet; an impeller in the conduit; and a mechanical power provider arranged to deliver power to the impeller; the method comprising receiving a plurality of thrust commands, and controlling a thrust level of the water jet propulsion device in dependence the thrust commands, wherein controlling the thrust level comprises adjusting a position of a deflector arranged to deflect water flowing out of the outlet, characterised by coordinating the adjustment of the position of the deflector with a level of engagement of a clutch, arranged to adjust the delivery of power from the power provider to the impeller, so that the thrust level is substantially continuous in a thrust command domain.

A marine vessel maneuvering system includes a jet propulsion device to jet a water current out from a jetting port and obtain a propulsive force from a recoil of the jetted water current, a handle to change a direction of the jetting port, a reverse bucket to open and close the jetting port, and a controller configured or programmed to change the direction of the jetting port in accordance with a rotation angle of the handle. In a state in which the reverse bucket covers at least a portion of the jetting port and when the rotation angle of the handle exceeds a first threshold, the controller is configured or programmed to execute a turning assist control to reduce an amount by which the reverse bucket covers the jetting port.

A marine vessel maneuvering system includes a jet propulsion device to jet a water current out from a jetting port and obtain a propulsive force from a recoil of the jetted water current, a handle to change a direction of the jetting port, a reverse bucket to open and close the jetting port, and a controller configured or programmed to change the direction of the jetting port in accordance with a rotation angle of the handle. In a state in which the reverse bucket covers at least a portion of the jetting port and when the rotation angle of the handle exceeds a first threshold, the controller is configured or programmed to execute a turning assist control to reduce an amount by which the reverse bucket covers the jetting port.

A built-in propulsion system includes an engine, a diversion unit with a diversion base and an exhaust pipe, and a propulsion unit. The diversion base is connected to the engine, having a water inlet, a water outlet, a diversion channel in communication between the water inlet and the water outlet, a shaft hole above the water inlet and an exhaust chamber behind the shaft hole. The exhaust pipe is fixed on the outer periphery surface of the diversion base in communication with the exhaust chamber. The propulsion unit includes a transmission shaft inserted through the shaft hole and connected to the engine, and an impeller located in the diversion channel and connected to the transmission shaft. The exhaust pipe is used to exhaust the exhaust gas of the engine to the outside of the diversion base to avoid the interference of the exhaust gas and the water flow.

A water-jet propulsion unit includes a body, an impeller for moving water, the impeller disposed in an impeller tunnel, an impeller shaft for driving the impeller, a first bearing housing to support the impeller shaft on the body, and a jet nozzle for forming a water jet. The body comprises a shaft opening for the impeller, a flow duct having a first contact surface, an inlet opening, and an outlet opening, the planes of which are at an angle α relative to each other. The impeller tunnel has a first end comprising a planar second contact surface and a second end comprising a planar third contact surface to seal the impeller tunnel between the body and the jet nozzle. The second and third planar contact surfaces of the impeller tunnel are arranged at an angle relative to each other. The impeller shaft is adapted for alternative types of installation by turning the impeller tunnel through 180° about the rotational axis of the impeller shaft. Support equipment supports the impeller shaft on the body in the alternative positions.

A water-jet propulsion unit includes a body, an impeller for moving water, the impeller disposed in an impeller tunnel, an impeller shaft for driving the impeller, a first bearing housing to support the impeller shaft on the body, and a jet nozzle for forming a water jet. The body comprises a shaft opening for the impeller, a flow duct having a first contact surface, an inlet opening, and an outlet opening, the planes of which are at an angle α relative to each other. The impeller tunnel has a first end comprising a planar second contact surface and a second end comprising a planar third contact surface to seal the impeller tunnel between the body and the jet nozzle. The second and third planar contact surfaces of the impeller tunnel are arranged at an angle relative to each other. The impeller shaft is adapted for alternative types of installation by turning the impeller tunnel through 180° about the rotational axis of the impeller shaft. Support equipment supports the impeller shaft on the body in the alternative positions.

One embodiment of the invention comprises a method for controlling a marine vessel having a first steerable propulsor, a corresponding first reversing device, a second steerable propulsor and a corresponding second reversing device. The method comprises receiving a first vessel control signal corresponding to a rotational movement and no translational movement command, generating at least a first actuator control signal and a second actuator control signal in response to the first vessel control signal, coupling the first actuator control signal to and controlling the first steerable propulsor and the second steerable propulsor, and coupling the second actuator control signal to and controlling the first reversing device and to the second reversing device. The method creates rotational forces on the marine vessel with substantially no translational forces on the marine vessel.

One embodiment of the invention comprises a method for controlling a marine vessel having a first steerable propulsor, a corresponding first reversing device, a second steerable propulsor and a corresponding second reversing device. The method comprises receiving a first vessel control signal corresponding to a rotational movement and no translational movement command, generating at least a first actuator control signal and a second actuator control signal in response to the first vessel control signal, coupling the first actuator control signal to and controlling the first steerable propulsor and the second steerable propulsor, and coupling the second actuator control signal to and controlling the first reversing device and to the second reversing device. The method creates rotational forces on the marine vessel with substantially no translational forces on the marine vessel.

A water-jet propulsion unit includes a body, an impeller for moving water, the impeller disposed in an impeller tunnel, an impeller shaft for driving the impeller, a first bearing housing to support the impeller shaft on the body, and a jet nozzle for forming a water jet. The body comprises a shaft opening for the impeller, a flow duct having a first contact surface, an inlet opening, and an outlet opening, the planes of which are at an angle α relative to each other. The impeller tunnel has a first end comprising a planar second contact surface and a second end comprising a planar third contact surface to seal the impeller tunnel between the body and the jet nozzle. The second and third planar contact surfaces of the impeller tunnel are arranged at an angle relative to each other. The impeller shaft is adapted for alternative types of installation by turning the impeller tunnel through 180° about the rotational axis of the impeller shaft. Support equipment supports the impeller shaft on the body in the alternative positions.

A water-jet propulsion unit includes a body, an impeller for moving water, the impeller disposed in an impeller tunnel, an impeller shaft for driving the impeller, a first bearing housing to support the impeller shaft on the body, and a jet nozzle for forming a water jet. The body comprises a shaft opening for the impeller, a flow duct having a first contact surface, an inlet opening, and an outlet opening, the planes of which are at an angle α relative to each other. The impeller tunnel has a first end comprising a planar second contact surface and a second end comprising a planar third contact surface to seal the impeller tunnel between the body and the jet nozzle. The second and third planar contact surfaces of the impeller tunnel are arranged at an angle relative to each other. The impeller shaft is adapted for alternative types of installation by turning the impeller tunnel through 180° about the rotational axis of the impeller shaft. Support equipment supports the impeller shaft on the body in the alternative positions.