A coupling is disclosed for connecting a propeller to a motor in an aircraft such as a rotary wing aircraft and the like. The coupling comprises a propeller hub having an inner propeller hub bore defining an axial keyway. A rotatable shaft has an internal shaft bore connected for rotation with the motor. A radial key is slidably located in a radial aperture extending through the rotatable shaft. An actuator is slidably mounted within the internal shaft bore of the rotatable shaft. The radial key is received with the axial keyway for securing the propeller hub to the rotatable shaft. A depression of the actuator retracting the radial key relative to an outer surface of the rotatable shaft for permitting the propeller hub bore to be introduced onto the rotatable shaft.

A system for retaining a folded proprotor blade in flight. The system includes a mounting plate, a first arm coupled to the mounting plate at an acute angle relative to the mounting plate, and a first deformable pad affixed to the first arm and adapted to contact the folded proprotor blade.

A system for retaining a folded proprotor blade in flight. The system includes a mounting plate, a first arm coupled to the mounting plate at an acute angle relative to the mounting plate, and a first deformable pad affixed to the first arm and adapted to contact the folded proprotor blade.

A propeller blade assembly comprises a propeller blade having a blade root for attaching the propeller blade to a hub. The blade root has a radially outer surface. The assembly further comprises a collar mounted to the blade root. The collar comprises at least two collar segments assembled around the radially outer surface of the blade root. Each collar segment has a radially inner surface, an opposed radially outward surface and first and second circumferential end lugs. The lugs receive fasteners for coupling the collar segments together to form the collar. The collar segments are formed from a flexible plastics material and the radially inner surface of each collar segments engages the radially outer surface of the blade root only over a limited circumferential extent of the collar segment.

An aerial vehicle including a housing, an outrunner motor including a stator mechanically coupled to the housing and a rotor rotationally coupled to the stator, and a propeller removably coupled to the rotor, the propeller including a hub and a plurality of propeller blades. A rotor, a propeller including a hub and a propeller blade, a radial alignment mechanism, a rotational retention mechanism, and an axial retention mechanism.

Methods and apparatus to retain a rotor blade are disclosed herein. An example apparatus includes a rotor blade coupled to a rotatable hub of an engine system. The rotor blade includes a root, a flange and a blade. The root and the flange are disposed inside a cowling, and the blade is disposed outside of the cowling. The example apparatus also includes a retainer disposed inside the cowling adjacent the flange. The flange is to engage the retainer to retain the rotor blade with the engine system.

Methods and apparatus to retain a rotor blade are disclosed herein. An example apparatus includes a rotor blade coupled to a rotatable hub of an engine system. The rotor blade includes a root, a flange and a blade. The root and the flange are disposed inside a cowling, and the blade is disposed outside of the cowling. The example apparatus also includes a retainer disposed inside the cowling adjacent the flange. The flange is to engage the retainer to retain the rotor blade with the engine system.

A propulsion system comprises a propeller and a driving device coupled with the propeller. The propeller comprises a hub having a receiving hole, a plurality of blades connected to the hub, and a connecting surface. The driving device comprises a body portion, an elastic abutting member disposed on the body portion and configured to abut against the connecting surface, and a lock portion disposed on the body portion and including a first snap-fitting portion. A second snap-fitting portion is arranged on an inner wall of the receiving hole and is configured to snap with the first snap-fitting portion.

A propulsion system comprises a propeller and a driving device coupled with the propeller. The propeller comprises a hub having a receiving hole, a plurality of blades connected to the hub, and a connecting surface. The driving device comprises a body portion, an elastic abutting member disposed on the body portion and configured to abut against the connecting surface, and a lock portion disposed on the body portion and including a first snap-fitting portion. A second snap-fitting portion is arranged on an inner wall of the receiving hole and is configured to snap with the first snap-fitting portion.

A propeller blade retention arrangement having a propeller blade comprising in radial sequence an aerofoil portion, a shank portion and a root portion. The root portion having first cross-sectional area close to the shank portion and second cross-sectional area at the end distal to the aerofoil portion, wherein the second cross-sectional area is greater than the first cross-sectional area. At least two cheeks each having an inner surface arranged to abut the root portion, an outer surface that is threaded and edge surfaces that abut another of the at least two cheeks; wherein the at least two cheeks are arranged to surround the root portion in circumferential abutment. A collar having a threaded inner surface arranged to threadingly engage the outer surfaces of the at least two cheeks.