A motor assembly that includes a motor having a motor casing, a rotatable shaft extending from said motor casing to a shaft length and a hub coupled to said rotatable shaft, the hub having a circumferential skid surface disposed immediately proximal to the motor casing and having a channel configured to seat a propeller, when a propeller is present, wherein a bending moment applied to the shaft through the hub results in the circumferential skid surface contacting said motor casing.

A motor assembly that includes a motor having a motor casing, a rotatable shaft extending from said motor casing to a shaft length and a hub coupled to said rotatable shaft, the hub having a circumferential skid surface disposed immediately proximal to the motor casing and having a channel configured to seat a propeller, when a propeller is present, wherein a bending moment applied to the shaft through the hub results in the circumferential skid surface contacting said motor casing.

A duct for a ducted-rotor aircraft may include an internal structure and an aerodynamic exterior skin that is adhesively bonded to the internal structure. The skin may include a leading-edge portion disposed at an inlet of the duct and an inner portion disposed along an interior of the duct. The inner portion of the skin may be bonded to the internal structure with a first bondline of adhesive and the leading-edge portion of the skin may be bonded to the inner portion of the skin with a second bondline of adhesive. One or both of the first and second bondlines of adhesive may be of non-uniform thickness to take up tolerance stackups between the inner portion of the skin, the leading-edge portion of the skin, and the internal structure.

A propulsion system of an unmanned aerial vehicle (UAV) includes a first and a second propulsion devices each including a rotor mount assembly including a base and a lock structure arranged at the base. The lock structure includes a protrusion protruding from the base. An angle between an extension direction of the protrusion and a rotation plane of the rotor mount assembly has an absolute value larger than 0° and smaller than 90°. Each of the first and second propulsion devices further includes a rotor blade assembly configured to be locked to the corresponding rotor mount assembly by the corresponding lock structure. The rotor mount assembly of the first propulsion device is configured to not allow the rotor blade assembly of the second propulsion device to be assembled to the rotor mount assembly of the first propulsion device.

A gimbaled rotor assembly for an aircraft. The gimbaled rotor assembly including a static mast; a spherical bearing comprising an inner component and an outer component pivotable relative to each other about a bearing focus, the inner component fixedly coupled to the static mast; a rotor hub rotatably coupled to the outer component, allowing for relative rotation of the rotor hub about a rotor axis and for pivoting together with the outer component about the bearing focus; and a primary hub spring coupling the outer component to the static mast and configured for opposing pivoting of the rotor hub about the bearing focus from a neutral position.

A gimbaled rotor assembly for an aircraft. The gimbaled rotor assembly including a static mast; a spherical bearing comprising an inner component and an outer component pivotable relative to each other about a bearing focus, the inner component fixedly coupled to the static mast; a rotor hub rotatably coupled to the outer component, allowing for relative rotation of the rotor hub about a rotor axis and for pivoting together with the outer component about the bearing focus; and a primary hub spring coupling the outer component to the static mast and configured for opposing pivoting of the rotor hub about the bearing focus from a neutral position.

A locking system for an electric propulsion system is disclosed. The system includes a propulsor configured to propel an electric vehicle and a motor operatively connected to the propulsor configured to power the propulsor. The motor includes a rotor connected to the propulsor and a stator configured to rotate the rotor. A propulsor sensor is configured to determine a motion parameter of the propulsor. A lock is configured to prevent a movement of the propulsor. A controller is configured to receive a signal from the propulsor sensor and control the motor as a function of the signal from the propulsor sensor, wherein controlling the motor includes allowing the propulsor to slow at a desired rate for parking.

A rotor-wing assembly includes a motor, a propeller, and a connection assembly connecting the propeller to the motor. The motor includes a rotating portion. The connection assembly includes a locking member and a reinforcing member arranged between the propeller and the motor. The locking member locks the propeller to the rotating portion. A first end of the reinforcing member is mounted at the rotating portion. A second end of the reinforcing member opposite to the first end is engaged with the locking member, to reinforce the locking member to lock the propeller to the rotating portion.

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.

A gimbaled rotor assembly for an aircraft. The gimbaled rotor assembly including a static mast; a spherical bearing comprising an inner component and an outer component pivotable relative to each other about a bearing focus, the inner component fixedly coupled to the static mast; a rotor hub rotatably coupled to the outer component, allowing for relative rotation of the rotor hub about a rotor axis and for pivoting together with the outer component about the bearing focus; and a primary hub spring coupling the outer component to the static mast and configured for opposing pivoting of the rotor hub about the bearing focus from a neutral position.