The invention provides a power tool, a motor and a rotor thereof. The rotor includes a housing, a rotating shaft fixed on the housing, a yoke accommodated in the housing, and permanent magnets mounted on the yoke. The housing includes a bottom wall and a sidewall extending from an outer periphery of the bottom wall in an axial direction of the rotor. The rotor further includes a cooling fan, the cooling fan is located at an axial distal end of the sidewall away from the bottom wall. The rotating shaft, the yoke, the permanent magnets, the cooling fan and the housing are formed into a non-detachable whole by overmolding.

An electric motor assembly includes an outer rotor motor, a sensor, and a brake assembly. The outer rotor motor includes a stator and a rotor. The rotor at least partly circumscribes the stator and is rotatable relative to the stator about an axis. The rotor includes a rotor core extending radially outwardly to present axially opposite first and second sides, and a plurality of magnets supported relative to the rotor core. The sensor is operable to sense a condition associated with the electric motor assembly. The brake assembly is operably coupled to the rotor core to selectively reduce the rotational speed of the rotor. The brake assembly is positioned at least partly axially outward from the first side of the rotor core, and the sensor is positioned at least partly axially outward from the second side of the rotor core.

A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

A rotating electrical machine includes a rotor and a magnet unit. The rotating electrical machine also includes a cylindrical stator and a housing. The stator is equipped with a stator winding made up of a plurality of phase windings. The stator is arranged coaxially with the rotor and faces the rotor. The housing has the rotor and the stator disposed therein. The rotor includes a cylindrical magnet retainer to which the magnet unit is secured and an intermediate portion which connects between a rotating shaft of the rotor and the magnet retainer and extends in a radial direction of the rotating shaft. A first region located radially inside an inner peripheral surface of a magnetic circuit component made up of the stator and the rotor is greater in volume than a second region between the inner peripheral surface of the magnetic circuit component and the housing in the radial direction.

A rotating electrical machine includes a rotor and a magnet unit. The rotating electrical machine also includes a cylindrical stator and a housing. The stator is equipped with a stator winding made up of a plurality of phase windings. The stator is arranged coaxially with the rotor and faces the rotor. The housing has the rotor and the stator disposed therein. The rotor includes a cylindrical magnet retainer to which the magnet unit is secured and an intermediate portion which connects between a rotating shaft of the rotor and the magnet retainer and extends in a radial direction of the rotating shaft. A first region located radially inside an inner peripheral surface of a magnetic circuit component made up of the stator and the rotor is greater in volume than a second region between the inner peripheral surface of the magnetic circuit component and the housing in the radial direction.

In a rotating electrical machine, a magnet unit and an armature core member are configured to satisfy the following relation Br×Ma≤Bsc×Wsc. In the relation, Br represents a remanent flux density of the magnet unit, Ma represents a distance of a farther circumferential surface of each of first magnets in the circumferential direction, Bsc represents a saturation magnetic flux density of the armature core member, and Wsc represents a thickness of the armature core member in a radial direction thereof.

In a rotating electrical machine, a magnet unit and an armature core member are configured to satisfy the following relation Br×Ma≤Bsc×Wsc. In the relation, Br represents a remanent flux density of the magnet unit, Ma represents a distance of a farther circumferential surface of each of first magnets in the circumferential direction, Bsc represents a saturation magnetic flux density of the armature core member, and Wsc represents a thickness of the armature core member in a radial direction thereof.

Systems and methods relate to a vertical takeoff and landing (VTOL) platform that can include a stator and a rotor magnetically levitated by the stator. The rotor and stator can be annular, such that the rotor rotates about a rotational axis. The stator can include magnets that provide guidance, levitation, and drive forces to drive the rotor, as well as to control operation of rotor blades of the rotor that can be independently rotated to specific pitch angles to control at least one of lift, pitch, roll, or yaw of the VTOL platform. Various controllers can be used to enable independent and redundant control of components of the VTOL platform.

Systems and methods relate to a vertical takeoff and landing (VTOL) platform that can include a stator and a rotor magnetically levitated by the stator. The rotor and stator can be annular, such that the rotor rotates about a rotational axis. The stator can include magnets that provide guidance, levitation, and drive forces to drive the rotor, as well as to control operation of rotor blades of the rotor that can be independently rotated to specific pitch angles to control at least one of lift, pitch, roll, or yaw of the VTOL platform. Various controllers can be used to enable independent and redundant control of components of the VTOL platform.

An outer-rotor brushless direct-current motor is provided. The motor includes a motor can that supports the motor components and a fan mounted on a rotor shaft inside the motor can to generate an airflow through the motor can. The motor can includes exhaust openings formed around the fan to allow the airflow to be expelled radially away from the fan, and intake openings formed at a distance from the exhaust openings to allow an airstream to be received radially into the motor can.