An unmanned aerial vehicle includes a propulsion system including a driving device having a main body, a driving shaft rotatable relative to the main body, and a locking member disposed on the main body. The locking member includes at least one snap-fitting member. The propulsion system also includes a propeller coupled with the driving device, the propeller including a blade base and a blade mounted on the blade base. The at least one snap-fitting member is configured to snap-fit with the propeller. The propulsion system also includes an elastic abutting member sleeve coupled with the driving shaft, a first installation foolproof member disposed on the blade base, and a second installation foolproof member disposed on the locking member.

A propeller hub assembly for a marine drive having a propeller shaft is provided. The propeller hub assembly includes a first hub portion having a first main body and multiple propeller blades extending radially therefrom, a second hub portion, wherein the second hub portion is coupled to the first hub portion, and a damper hub portion, wherein the damper hub portion is coupled to the second hub portion. The propeller hub assembly further includes multiple pendulum masses located within the damper hub portion. The first hub portion, the second hub portion, and the damper hub portion are configured to engage the propeller shaft such that rotation of the propeller shaft causes rotation of the first hub portion, the second hub portion, and the damper hub portion. Oscillations of the pendulum masses relative to the damper hub portion are configured to dampen torsional vibrations of the propeller hub assembly.

A propeller hub assembly for a marine drive having a propeller shaft is provided. The propeller hub assembly includes a first hub portion having a first main body and multiple propeller blades extending radially therefrom. The first main body is substantially cone-shaped and tapers inwardly from a first keyed end proximate the multiple propeller blades. The propeller hub assembly further includes a second hub portion having a second keyed end. The first hub portion is coupled to the second hub portion such that the first keyed end is mated to the second keyed end, and the first hub portion and the second hub portion are configured to engage the propeller shaft such that rotation of the propeller shaft causes rotation of the first hub portion and the second hub portion.

A propeller unit of a marine propulsion apparatus includes: an inner hub; an outer hub arranged coaxially with the inner hub, connected to the inner hub, and provided with a plurality of blades on its outer circumferential surface; and a bushing having a hollow shaft member provided with ribs on an outer circumferential surface and connected to the propeller shaft, and a damper formed of an elastic member and arranged to cover an outer circumferential surface of the hollow shaft member between the outer circumferential surface of the hollow shaft member and the inner circumferential surface of the inner hub, wherein the bushing is spline-coupled to the propeller shaft through spline teeth formed on an inner circumferential surface of a front half or rear half of a longitudinal direction of the hollow shaft member, and has a breakable portion provided in a part corresponding to the non-spline-toothed portion.

The portable pedal system for kayaks and other watercraft is a propulsion device. The portable pedal system for kayaks and other watercraft removably attaches to a vessel. The portable pedal system for kayaks and other watercraft is manually powered. The portable pedal system for kayaks and other watercraft comprises a belt drive, a transmission structure, and a vessel. The belt drive and the transmission structure removably attach to the vessel. The belt drive attaches to the transmission structure. A client manually powers the rotation of the belt drive. The rotation of the belt drive rotates the transmission structure which propels the vessel through the water.

A field configurable vehicle includes bladders located interior of the vehicle hull walls. One or more of the bladders can be filled with fluids of varying densities to manage the buoyancy, mass properties, and thermal heat dissipation of the vehicle.

A propeller unit of a marine propulsion apparatus includes: an inner hub; an outer hub arranged coaxially with the inner hub, connected to the inner hub, and provided with a plurality of blades on its outer circumferential surface; and a bushing having a hollow shaft member provided with ribs on an outer circumferential surface and connected to the propeller shaft, and a damper formed of an elastic member and arranged to cover an outer circumferential surface of the hollow shaft member between the outer circumferential surface of the hollow shaft member and the inner circumferential surface of the inner hub, wherein the bushing is spline-coupled to the propeller shaft through spline teeth formed on an inner circumferential surface of a front half or rear half of a longitudinal direction of the hollow shaft member, and has a breakable portion provided in a part corresponding to the non-spline-toothed portion.

Provided is a ship propelling apparatus including a rotation shaft on which a rear propeller is fixed; a front propeller rotatably supported on the rotation shaft in front of the rear propeller; and a counter-rotating device through which the rotation shaft passes, which includes a gear box including therein a plurality of gears configured to reverse rotation of the rotation shaft and transfer the reversed rotation to the front propeller, and which is installed in an installation space formed at the rear of a ship. The rotation shaft includes a measurement hole formed to pass through a center of the rotation shaft for centering of the counter-rotating device installed in the installation space; and an individual lubricant path separated from the measurement hole.

The present device relates to boatbuilding, and more particularly to screw propellers with safety couplings, intended for use in outboard motors and/or marine screw propellers. A screw propeller with a safety coupling comprises a screw propeller body-cum-hub, a drive coupling, a driven coupling, and a dowel pin. The driven coupling is disposed for rotation on a spacer bushing, said spacer bushing being a tail bushing of the driving coupling. The driven coupling is partially or completely disposed in an opening in the screw propeller body-cum-hub and transmits torque to the screw propeller body-cum-hub by means of a longitudinal dowel pin and/or longitudinal grooves and a spline coupling. A common opening for the dowel pin in the driving and/or the driven coupling is configured as a through opening, and/or the blind end of the opening for the dowel pin is connected by a transverse opening to the outside surface.

Provided are a propulsion device for a ship and a ship including the same. The propulsion device for the ship includes: a rear propeller fixed to a rotation shaft; a front propeller that is rotatably supported on the rotation shaft in the front of the rear propeller; at least one bearing interposed in at least one of spaces between a hub of the front propeller and the rotation shaft and between the rotation shaft and a ship body; and an inverse rotation unit that inverts rotation of the rotation shaft, transfers the inverted rotation to the front propeller and includes a gearbox that is accommodated in an installation space formed in a tail of the ship body in a state in which a plurality of gears for implementing inversion of the front propeller are embedded, wherein at least one measurement unit for measuring operating states of the at least one bearing is mounted to the rotation shaft.