An electrically powered aerial vehicle includes at least one motor where each motor includes a stator and a rotor, a motor housing having an inlet opening and a discharge opening for airflow, a plurality of rotor blades rotatable by the rotor, each of the plurality of rotor blades having a cavity running from a proximal end of the rotor blade towards a distal end of the rotor blade, and a blade hub coupled to the rotor blades at the proximal end of each rotor blade and coupled to the motor housing at the discharge opening. A chamber is defined in the blade hub and is in fluid communication with the discharge opening of the motor housing and the cavity of each rotor blade. The airflow is centrifugally drawn in from the motor housing through the discharge opening and transported through the chamber and into the cavities of the rotor blades when the rotor blades are rotating.

An electrically powered aerial vehicle includes at least one motor where each motor includes a stator and a rotor, a motor housing having an inlet opening and a discharge opening for airflow, a plurality of rotor blades rotatable by the rotor, each of the plurality of rotor blades having a cavity running from a proximal end of the rotor blade towards a distal end of the rotor blade, and a blade hub coupled to the rotor blades at the proximal end of each rotor blade and coupled to the motor housing at the discharge opening. A chamber is defined in the blade hub and is in fluid communication with the discharge opening of the motor housing and the cavity of each rotor blade. The airflow is centrifugally drawn in from the motor housing through the discharge opening and transported through the chamber and into the cavities of the rotor blades when the rotor blades are rotating.

A brush wear indicating arrangement is provided. The brush wear indicating arrangement includes an insert, a first electrically conductive brush, and a wear indicator. The insert is disposed within a brush block housing and defines a first aperture. The first electrically conductive brush is movably engaged within the first aperture. The electrically conductive brush is configured to move outward from the first aperture as a wear surface of the first electrically conductive brush wears. The wear indicator is coupled to the first electrically conductive brush. The wear indicator is configured to extend beyond a first insert face of the insert as wear condition of the wear surface of the first electrically conductive brush exceeds a wear threshold.

The invention comprises an improved nut for securing a propeller to a drive shaft of a vehicle engine. The invention further comprises a nut that may be securely fastened to the end of the drive shaft of a trolling motor engine without the use of separate tools, such as wrenches or drivers. The invention even further comprises a nut with an exterior portion and a shaft portion that communicates along an axis of the drive shaft of a marine engine against the propeller assembly, the shaft portion having elastomeric materials to interface with the propeller assembly and at least one channel which together absorb vibration, heat and sound from the propeller assembly.

The invention comprises an improved nut for securing a propeller to a drive shaft of a vehicle engine. The invention further comprises a nut that may be securely fastened to the end of the drive shaft of a trolling motor engine without the use of separate tools, such as wrenches or drivers. The invention even further comprises a nut with an exterior portion and a shaft portion that communicates along an axis of the drive shaft of a marine engine against the propeller assembly, the shaft portion having elastomeric materials to interface with the propeller assembly and at least one channel which together absorb vibration, heat and sound from the propeller assembly.

A modeling method for a fan assembly includes constructing non-axially symmetric end wall curved surfaces in a cascade channel. Constructing the non-axially symmetric end wall curved surfaces in the cascade channel includes: determining, using a flow path design method for a dual flow path of a blade end area, an initial axially symmetric curve radius and a recessed curve lowest point radius of non-axially symmetric curved surfaces; and constructing the non-axially symmetric end wall curved surfaces in the cascade channel according to the initial axially symmetric curve radius and the recessed curve lowest point radius. The modeling method constructs the non-axially symmetric end wall curved surfaces in the cascade channel using the flow path design method for a dual flow path of a blade end area, to implement the control of flow directions by the non-axially symmetric curved surfaces, thereby reducing end wall loss.

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.

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.

A diverter duct for a propeller includes a second duct element having a semi-annular wedge shape, which is pivotably coupled to the first duct element, a first drive structure configured to drive a pivoting of the second duct element relative to the first duct element and a second drive structure configured to drive a rotation of the first and second duct elements about an axis of rotation of the propeller.

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.