An electric motor includes a housing, a stator assembly disposed in the housing, a rotor assembly rotatably disposed in the stator assembly, and an impeller configured to be rotated by the rotor assembly and to generate a flow of air. The stator assembly defines an inner flow path configured to guide a part of the air to pass through an inside of the stator assembly. The housing defines a bypass flow path at an outside of the stator assembly, where the bypass flow path is configured to guide another part of the air to bypass the stator assembly.

A motorized hand tool such as a cordless ratchet wrench that has a motor, and a housing that encloses or houses the motor. The motor includes one or more exhaust ports that expel exhaust air out of the motor. The housing includes one or more exhaust ports and inwardly projecting protrusions or deflectors that extend around the exhaust ports. The inwardly projecting protrusions/deflectors extend in a direction towards the motor exhaust ports, and/or are at least partially disposed in the motor exhaust ports to direct exhaust air out of the housing and prevent exhaust air from recirculating near the motor and electronic components of the tool.

A motorized hand tool such as a cordless ratchet wrench that has a motor, and a housing that encloses or houses the motor. The motor includes one or more exhaust ports that expel exhaust air out of the motor. The housing includes one or more exhaust ports and inwardly projecting protrusions or deflectors that extend around the exhaust ports. The inwardly projecting protrusions/deflectors extend in a direction towards the motor exhaust ports, and/or are at least partially disposed in the motor exhaust ports to direct exhaust air out of the housing and prevent exhaust air from recirculating near the motor and electronic components of the tool.

A generator and a wind turbine are provided. The generator includes an active cooling circuit and a passive cooling circuit, the active cooling circuit is in communication with a closed space, and the passive cooling circuit is in communication with the external environment. The active cooling circuit includes mutually communicating chambers located at two axial ends of the generator, an air gap between a rotor and a stator of the generator, and radial channels distributed along an axial direction of the generator. The active cooling circuit is provided with a cooling device in communication with the closed space, and the stator is fixed on a fixed shaft through a stator bracket. The passive cooling circuit includes a first axial channel running through the stator, a second axial channel running through the stator bracket, and an outer surface of the generator. A heat exchanger is further arranged inside the generator.

Composite rotors provided herein include a rotor body extending along a longitudinal axis including a first component extending longitudinally along at least a portion of the rotor body and a second component extending longitudinally along at least a portion of the rotor body, at least a portion of the second component disposed concentrically around the first component, wherein the first component and the second component together define an internal region, wherein a radial thickness of the first component and a radial thickness of the second component vary along the longitudinal axis. The composite rotor also includes at least one magnet disposed on an inner surface of at least one of the first component or the second component within the internal region.

Composite rotors provided herein include a rotor body extending along a longitudinal axis including a first component extending longitudinally along at least a portion of the rotor body and a second component extending longitudinally along at least a portion of the rotor body, at least a portion of the second component disposed concentrically around the first component, wherein the first component and the second component together define an internal region, wherein a radial thickness of the first component and a radial thickness of the second component vary along the longitudinal axis. The composite rotor also includes at least one magnet disposed on an inner surface of at least one of the first component or the second component within the internal region.

A gas turbine engine includes a turbine rotor connected to a main compressor rotor. A tail cone is mounted inward of an exhaust core flow. A generator rotor is adjacent a generator stator. The generator rotor and stator are mounted within the tail cone. A passage connects a bypass flow path to the tail cone. A cooling air compressor is operable within the passage. The turbine rotor drives a shaft to drive the generator rotor and the cooling compressor. A method is also disclosed.

A gas turbine engine includes a turbine rotor connected to a main compressor rotor. A tail cone is mounted inward of an exhaust core flow. A generator rotor is adjacent a generator stator. The generator rotor and stator are mounted within the tail cone. A passage connects a bypass flow path to the tail cone. A cooling air compressor is operable within the passage. The turbine rotor drives a shaft to drive the generator rotor and the cooling compressor. A method is also disclosed.

A motor cooling fan unit comprises a tubular cover capable of surrounding a motor and a fan provided to blow air toward the interior of the cover. The motor cooling fan unit is configured to cause air blown from the fan to pass through a flow path between the motor and the cover. The cover comprises an exhaust part provided at a downstream area of the flow path. The exhaust part comprises: an open part for making the flow path communicate with the outside; and an exhaust adjusting member provided for the open part and movable between a shield position at which the exhaust adjusting member covers the open part and an open position at which the exhaust adjusting member opens the open part. The amount of movement of the exhaust adjusting member is adjusted to allow adjustment of the amount of the air in the flow path to be exhausted through the open part and a direction of the exhaust, or adjustment of the amount of the air to be exhausted or a direction of the exhaust.

A motor cooling fan unit comprises a tubular cover capable of surrounding a motor and a fan provided to blow air toward the interior of the cover. The motor cooling fan unit is configured to cause air blown from the fan to pass through a flow path between the motor and the cover. The cover comprises an exhaust part provided at a downstream area of the flow path. The exhaust part comprises: an open part for making the flow path communicate with the outside; and an exhaust adjusting member provided for the open part and movable between a shield position at which the exhaust adjusting member covers the open part and an open position at which the exhaust adjusting member opens the open part. The amount of movement of the exhaust adjusting member is adjusted to allow adjustment of the amount of the air in the flow path to be exhausted through the open part and a direction of the exhaust, or adjustment of the amount of the air to be exhausted or a direction of the exhaust.