A power transmission device includes an electromagnet, a rotor, an armature and a hub. The hub couples the armature to a shaft of a drive-subject device. The hub includes: an outer hub that is coupled to the armature; a boss portion that is coupled to the shaft; an inner side plate-shaped portion that extends from the boss portion toward a radially outer side; and an inner plate that is placed between the outer hub and the inner side plate-shaped portion. The inner side plate-shaped portion and the inner plate are formed integrally in one piece. At least one of the inner side plate-shaped portion and the inner plate is formed by a member that is configured to deform or melt with heat generated by friction between the rotor and the armature when the shaft of the drive-subject device is locked at a time of energizing the electromagnet.

A power transmission device includes an electromagnet, a rotor, an armature and a hub. The hub couples the armature to a shaft of a drive-subject device. The hub includes: an outer hub that is coupled to the armature; a boss portion that is coupled to the shaft; an inner side plate-shaped portion that extends from the boss portion toward a radially outer side; and an inner plate that is placed between the outer hub and the inner side plate-shaped portion. The inner side plate-shaped portion and the inner plate are formed integrally in one piece. At least one of the inner side plate-shaped portion and the inner plate is formed by a member that is configured to deform or melt with heat generated by friction between the rotor and the armature when the shaft of the drive-subject device is locked at a time of energizing the electromagnet.

An aircraft includes an engine and an electric power system. The electric power system includes a permanent magnet machine. The permanent magnet machine includes a stator and a rotor configured to rotate relative to the stator.

A method and disconnector for disconnecting a drive shaft of a drive mechanism from rotating equipment, upon a failure of the drive mechanism or rotating equipment, includes a housing, an arm extending from the housing and movable relative to the housing between a first position and a second position, and a parting tool on a distal end of the arm.

A method and disconnector for disconnecting a drive shaft of a drive mechanism from rotating equipment, upon a failure of the drive mechanism or rotating equipment, includes a housing, an arm extending from the housing and movable relative to the housing between a first position and a second position, and a parting tool on a distal end of the arm.

A power transmission device that transmits a rotational driving force outputted from a driving source to a target device to be driven includes: a driving rotor rotated by the rotational driving force; a driven rotor that rotates with a rotary shaft of the target device; and a connection member. The connection member has a plate shape extending perpendicular to the rotary shaft. The connection member is connected at least one of the driving rotor and the driven rotor, and is capable of connecting the driving rotor and the driven rotor to each other. The connection member has a through hole, and the driven rotor has an overlapping portion disposed overlapping with the through hole when viewed in the axial direction of the rotary shaft.

A thermal fuse is covered with a case that has a slit. A capacity of the case is larger than a volume of the thermal fuse, and the case has a space that is formed between an inner wall surface of the case and the thermal fuse. The slit is formed in the case introduce radiant heat, which is generated at a friction surface of a rotor, into an inside of the case. Thereby, the radiant heat, which is inputted into the inside of the case through the slit, can be reflected by the inner wall surface of the case and thereafter can be absorbed by the thermal fuse.

A drive shaft assembly includes an outer shaft, an inner shaft, and an interface medium. The outer shaft defines a central channel. The inner shaft extends into the central channel and defines a clearance gap between an interior surface of the outer shaft and an exterior surface of the inner shaft. The interface medium is disposed in the clearance gap and rotationally couples the outer shaft and the inner shaft in an operational state of the drive shaft assembly. In response to a temperature of the drive shaft assembly exceeding a threshold temperature, the interface medium at least partially melts and rotationally uncouples the outer shaft and the inner shaft in a fault state of the drive shaft assembly.

A drive shaft assembly includes an outer shaft, an inner shaft, and an interface medium. The outer shaft defines a central channel. The inner shaft extends into the central channel and defines a clearance gap between an interior surface of the outer shaft and an exterior surface of the inner shaft. The interface medium is disposed in the clearance gap and rotationally couples the outer shaft and the inner shaft in an operational state of the drive shaft assembly. In response to a temperature of the drive shaft assembly exceeding a threshold temperature, the interface medium at least partially melts and rotationally uncouples the outer shaft and the inner shaft in a fault state of the drive shaft assembly.

An assembly for a gas turbine engine comprising an accessory gearbox comprising a drive gear and pinion gear and a starter/generator mechanically mounted to the accessory gearbox. The starter/generator comprising a housing and a portion of a rotatable shaft with a safety disconnect where the safety disconnect is located within the housing of the starter/generator.