A propeller includes a bushing, a propeller body, and a propeller damper. The bushing includes a first cylinder portion surrounding the propeller shaft and a first projection protruding outwardly in a radial direction of the propeller from an outer peripheral surface of the first cylinder portion. The propeller body includes a second cylinder portion surrounding the bushing and a second projection protruding inwardly in the radial direction from an inner peripheral surface of the second cylinder portion. The first and second projections are arranged along a rotation direction of the propeller. The propeller damper includes first and second dampers side by side along an axial direction of the propeller between the first and second cylinders. The first and second dampers are separated from each other by a separation portion, and are individually elastically deformable.

A propeller includes a bushing, a propeller body, and a propeller damper. The bushing includes a first cylinder portion surrounding the propeller shaft and a first projection protruding outwardly in a radial direction of the propeller from an outer peripheral surface of the first cylinder portion. The propeller body includes a second cylinder portion surrounding the bushing and a second projection protruding inwardly in the radial direction from an inner peripheral surface of the second cylinder portion. The first and second projections are arranged along a rotation direction of the propeller. The propeller damper includes first and second dampers side by side along an axial direction of the propeller between the first and second cylinders. The first and second dampers are separated from each other by a separation portion, and are individually elastically deformable.

A propeller apparatus of a ship propulsion machine includes a tubular member inserted into an insertion hole so as to be movable in a circumferential direction with respect to a hub. First concave portions arranged in a circumferential direction are formed in an outer peripheral surface of the tubular member. Second concave portions arranged in the circumferential direction so as to respectively face the first concave portions are formed in an inner peripheral surface of the insertion hole. Each of the elastic bodies has a spherical or columnar shape, a first portion of each of the elastic bodies is disposed in each of the first concave portions, a second portion of each of the elastic bodies is disposed in each of the second concave portions, and the elastic bodies are rotatably held between the first concave portions and the second concave portions facing each other.

Systems and methods are provided for using an additively manufactured vehicle, such as an UUV, with additively manufactured modules. The vehicle may be configurable such that additively manufactured modules or components may be detachably connected to the vehicle by hand, without the use of tools. Such modules may include connectors adapted to securely attach additional modules that may be detached by hand, without the use of tools. The additively manufactured modules may include ball bearings for rotating modules such as propellers and thrusters, and clips or tabs for detachable connection. The modules may include optical components for communications between a swarm of unmanned vehicles. Such optical modules for underwater vehicles may utilize nephelometry and/or turbidimetry to improve communications parameters based on scattered light measurements.

A field configurable autonomous vehicle includes modular elements and attachable components. The vehicle can be assembled from these modular elements and components to meet desired mission and performance characteristics without the need to purchase specially designed vehicles for each mission. The main body of the vehicle is a spherical body.

A watercraft and a marine engine assembly for mounting to a watercraft are disclosed. The marine engine assembly includes an engine unit including: an engine unit housing being sealed such that water in which the engine unit housing is immersed is impeded from entering the engine unit housing; an engine in the housing; and an air intake assembly in the engine unit housing which forms a conduit between an exterior of the engine unit housing and the engine, the air intake assembly defining an inlet fluidly communicating with exterior air, the engine unit housing defining at least one aperture aligned with the inlet, the air intake assembly defining at least one outlet fluidly connected with the engine intake, the air intake assembly being sealed such that surrounding fluids within the engine unit housing are impeded from entering the air intake assembly; and a propulsion device operatively connected to the engine.

A watercraft and a marine engine assembly for mounting to a watercraft are disclosed. The marine engine assembly includes an engine unit including: an engine unit housing being sealed such that water in which the engine unit housing is immersed is impeded from entering the engine unit housing; an engine in the housing; and an air intake assembly in the engine unit housing which forms a conduit between an exterior of the engine unit housing and the engine, the air intake assembly defining an inlet fluidly communicating with exterior air, the engine unit housing defining at least one aperture aligned with the inlet, the air intake assembly defining at least one outlet fluidly connected with the engine intake, the air intake assembly being sealed such that surrounding fluids within the engine unit housing are impeded from entering the air intake assembly; and a propulsion device operatively connected to the engine.

A field configurable autonomous vehicle includes modular elements and attachable components. The vehicle can be assembled from these modular elements and components to meet desired mission and performance characteristics without the need to purchase specially designed vehicles for each mission. The vehicle can include a mechanisms that magnetically attach and release payloads such as cargo or ballast from the vehicle.

An unmanned aerial vehicle (UAV) includes a propeller, a driving device, and an elastic abutting member sleeve. The propeller includes a blade base, a blade mounted on the blade base, and a first installation foolproof member disposed on the blade base. The driving device includes a main body, a driving shaft rotatable relative to the main body, a locking member disposed on the main body, and a second installation foolproof member disposed on the locking member. The driving device is coupled with the propeller. The elastic abutting member is coupled with the driving shaft and disposed between the main body and the blade base and abuts against the main body and the blade base.

An unmanned aerial vehicle (UAV) includes a propeller, a driving device, and an elastic abutting member sleeve. The propeller includes a blade base, a blade mounted on the blade base, and a first installation foolproof member disposed on the blade base. The driving device includes a main body, a driving shaft rotatable relative to the main body, a locking member disposed on the main body, and a second installation foolproof member disposed on the locking member. The driving device is coupled with the propeller. The elastic abutting member is coupled with the driving shaft and disposed between the main body and the blade base and abuts against the main body and the blade base.