The present invention relates to a fluid resistance reduction apparatus for a ship, and more particularly, to an apparatus for reducing fluid resistance of a ship, the apparatus capable of significantly reducing wave-making resistance as well as frictional resistance caused by seawater during navigation of a ship, thus improving the speed, allowing stable navigation, and saving fuel, wherein the fluid resistance reduction apparatus is disposed below the draft line of the hull and allows the ship to proceed while seawater is introduced through the bow due to rotation of a propeller disposed on the hull and is discharged through the back of the stern, thereby significantly reducing frictional resistance and wave-making resistance of seawater.

A fluid machine includes: a shaft portion; a shroud having an inside surface with a diameter decreasing from an upstream side toward a downstream side, a flow path being formed between the shroud and the shaft portion and having a flow path cross-sectional area decreasing toward the downstream side; a propeller rotatably provided about an axis between the shaft portion and the shroud and configured to pump a fluid from the upstream side toward the downstream side; and a motor provided to correspond to the propeller and including a rotor having a ring-like shape fixed to an outer circumference portion of the propeller and accommodated in the shroud and a stator having a ring-like shape surrounding the rotor and fixed in the shroud, in which a plurality of the propellers are provided to be spaced apart in the axis direction, the motors are provided in an identical number to the propellers to correspond to each of the propellers, and of a plurality of motors, the rotor of the motor positioned more on the downstream side has a smaller average outside diameter.

Propulsion unit (11) for propulsion and maneuvering of a maritime vessel, which includes a nozzle (12) exhibiting a curved following edge (12) at outlet of the nozzle (12), which results in that length of the nozzle (12) is longer in upper part of the nozzle (12) and shortest at the outermost points of a horizontal central axis through the nozzle (12), when the nozzle (12) is seen from behind.

Implementations of a boat propulsion and guidance system are provided. In some implementations, the boat propulsion and guidance system comprises one or more conduits and propulsion devices. In some implementations, the boat propulsion and guidance system may further comprise one or more valve devices. In some implementations, the boat propulsion and guidance system may further comprise a controller. In some implementations, a method of using the boat propulsion and guidance system comprises installing the boat propulsion and guidance system to a boat and operating the boat propulsion and guidance system to move (e.g., steer, maneuver, and/or otherwise propel) the boat in one or more directions. In some implementations, the method may further comprise operating the boat propulsion and guidance system to dynamically anchor the boat to remain in a desired position in the water.

Implementations of a boat propulsion and guidance system are provided. In some implementations, the boat propulsion and guidance system comprises one or more conduits and propulsion devices. In some implementations, the boat propulsion and guidance system may further comprise one or more valve devices. In some implementations, the boat propulsion and guidance system may further comprise a controller. In some implementations, a method of using the boat propulsion and guidance system comprises installing the boat propulsion and guidance system to a boat and operating the boat propulsion and guidance system to move (e.g., steer, maneuver, and/or otherwise propel) the boat in one or more directions. In some implementations, the method may further comprise operating the boat propulsion and guidance system to dynamically anchor the boat to remain in a desired position in the water.

A propulsion system for a vessel includes an engine propulsion unit that provides a propulsive force to a hull by using an engine as a power source, an electric propulsion unit that provides a propulsive force to the hull by using an electric motor as a power source, a storing mechanism that is displaced from an actuating position to actuate the electric propulsion unit to a storing position to store the electric propulsion unit and performs a storing operation to store the electric propulsion unit, and an interlock controller that interlocks a storing operation of the storing mechanism with generation of a propulsive force by the engine propulsion unit.

A propulsion system for a vessel includes an engine propulsion unit that provides a propulsive force to a hull by using an engine as a power source, an electric propulsion unit that provides a propulsive force to the hull by using an electric motor as a power source, a storing mechanism that is displaced from an actuating position to actuate the electric propulsion unit to a storing position to store the electric propulsion unit and performs a storing operation to store the electric propulsion unit, and an interlock controller that interlocks a storing operation of the storing mechanism with generation of a propulsive force by the engine propulsion unit.

The present invention relates generally to propulsion systems and, more specifically, to propulsion systems configured to vector and provide directional thrust such as those that may be used in aircraft or watercraft. Such propulsion systems may be used in connection with unmanned aerial vehicles, other aircraft, or various watercraft including submersibles.

A fluid machine includes: a shaft portion extending in an axis direction; a shroud provided to surround the shaft portion, and forming a flow path between the shroud and the shaft portion, the flow path having one side in the axis direction serving as an upstream side and another side in the axis direction serving as a downstream side; a first propeller provided rotatably around the axis between the shaft portion and the shroud; a second propeller provided rotatably around the axis between the shaft portion and the shroud on the downstream side of the first propeller; an outer periphery driving motor provided in the shroud and configured to rotationally drive the first propeller; and an inner periphery driving motor provided in the shaft portion and configured to rotationally drive the second propeller in a direction opposite to the rotational direction of the first propeller.

A fluid machine includes: a shaft portion extending in an axis direction; a shroud provided to surround the shaft portion and having a diameter decreasing from an upstream side on one side in the axis direction toward a downstream side on another side in the axis direction, a flow path being formed between the shroud and the shaft portion and having a flow path cross-sectional area decreasing toward the downstream side; a propeller rotatably provided about an axis between the shaft portion and the shroud and configured to pump a fluid from the upstream side toward the downstream side; and a motor provided to correspond to the propeller, the motor including a rotor having a ring-like shape and being fixed to an outer circumference portion of the propeller and accommodated in the shroud and a stator having a ring-like shape surrounding the rotor and being fixed in the shroud, in which the motor is a conical motor in which diameters of the rotor and the stator decrease from the upstream side toward the downstream side.