An electric work machine with a product structure that effectively reduces noise caused by a brushless motor without changing the motor specifications. A hammer drill includes a brushless motor including a stator including an insulator, a cylindrical stator core, and a coil wound around the stator core via the insulator, and a rotor rotatable relative to the stator, a cylindrical member fixed along an entire outer circumference of the stator core and made of material with a Young's modulus higher than a Young's modulus of the insulator, and a housing accommodating the brushless motor and the cylindrical member.

A power tool including a housing, a controller within the housing, and a brushless motor within the housing and controlled by the controller. The brushless motor including a stator assembly including a stator core having stator laminations with an annular portion and inwardly extending stator teeth. The stator assembly defines a stator envelope in an axial direction extending between axial ends of stator end caps of the stator assembly. The brushless motor further includes a rotor assembly including a rotor core having rotor laminations and defining a central aperture that extends in the axial direction and that receives a shaft, and a position sensor board assembly including position sensors and configured to provide position information of the rotor core to the controller. The rotor assembly and the position sensor board assembly are provided at least partially within the stator envelope.

An electric work machine (1) includes: a motor (6) having a rotor (23), which rotates about a rotational axis relative to a stator (22A; 22B; 22C; 22D); an output part (8) driven by the rotor; and a temperature-detecting device (101; 111; 121; 131) disposed on or in the stator. The stator includes: a stator core (33; 330) having teeth (38; 380), which radially protrude from a yoke (37); an insulator (34; 340), which has tooth-covering parts (42; 420) that respectively cover at least a portion of surfaces of the respective teeth and is fixed to the stator core; and coils (35; 350) respectively wound on the teeth over the tooth-covering parts. The temperature-detecting device is disposed in a recess (56) provided on (in) the insulator.

A power tool includes a housing and an electric motor. The electric motor includes a rotor assembly including a rotor shaft and a stator assembly including a plurality of stator segments. Each stator segment includes a core, an insulator at least partially covering the core, and a coil winding. The insulator includes a mounting portion. The electric motor also includes a printed circuit board assembly configured to direct electric current to each coil winding, and a bus bar assembly attached to at least one of the mounting portions and configured to electrically connect the coil windings to the printed circuit board assembly. The bus bar assembly includes a molded body and a plurality of conductors. The bus bar assembly defines a bearing pocket. The electric motor further includes rotor bearing that is received into the bearing pocket and that supports the rotor shaft for rotation relative to the stator assembly.

A power tool includes a motor, a switch, a driver circuit, an operating element, and a controller. The motor includes a multi-phase winding. The driver circuit has multiple power elements and is configured to change a rotational state of the motor. The operating element has a first operating state and a second operating state, where a strength of an effective magnetic field of the multi-phase winding when the operating element is in the first operating state is less than a strength of an effective magnetic field of the multi-phase winding when the operating element is in the second operating state. The controller is configured to control conduction manners of the multiple power elements in the driver circuit according to an operating state of the operating element, so as to adjust the strength of the effective magnetic field of the multi-phase winding and change the rotational state of the motor.

An electric work machine (1) includes: an inner-rotor-type brushless motor (6) having a stator (20) disposed around a rotor (30); and an output part (10), which is directly or indirectly driven by the rotor. The rotor comprises a rotor core (32) and eight permanent magnets (33) fixed to the rotor core. The stator comprises a stator core (21), one or more insulators (22, 23) fixed to the stator core, and six coils (24), which are respectively wound on teeth (21T) of the stator core via the insulator(s).

A motor for electric power tools according to an embodiment includes: a rotor having a rotational shaft; a stator having a coil to rotate the rotor; a first substrate mounting a sensor element to detect a rotational position of the rotor; and a second substrate mounting a switching element to change, based on a result of detection by the sensor element, a conducting direction in which a current flows with respect to the coil. The first substrate and the second substrate are arranged side by side along, and intersect at right angles with, the rotational shaft.

A hand-held tool that includes a housing. The housing includes a handle. A tool also includes a motor assembly, a battery assembly and a circuit board. The motor assembly includes a motor, the motor including a rotatable motor output shaft, a motor positive terminal and a motor negative terminal. The motor assembly also includes a first rigid conductive electrical connector having a first end fixed to the motor positive terminal and a second end fixed to the circuit board. The battery assembly includes a battery cell with a battery cell positive terminal and a battery cell negative terminal. The battery assembly further includes a second rigid conductive electrical connector having a first end fixed to the battery cell positive terminal and a second end fixed to the circuit board.

A variable-speed control assembly for use in controlling speed of an electric motor of an electric device, the variable-speed control assembly including: a housing; a speed signaling circuit module located within the housing including a pair of spaced-apart electrically-conductive stationary contact members and a movable electrically-conductive contact member configured for movement relative to the pair of stationary contact members between at least one of an OFF position in which the movable contact member does not electrically connect the pair of stationary contact members, and, a plurality of ON positions in which the movable contact member electrically connects the pair of stationary contact members such that an electric current supplied to the speed signaling circuit module from a power supply of the electric device is able to flow between the pair of stationary contact members via the movable contact member; wherein the movable contact member includes an elastically-deformable material configured for deforming in to a plurality of different deformed configurations when arranged in each of the plurality of ON positions such that a contact area between the movable contact member and the pair of stationary contact members will vary in each of the plurality of ON positions resulting in an amount of electrical resistance across the movable contact member varying when arranged in each of the plurality of ON positions relative to the pair of stationary contact members; and whereby said speed signaling circuit module is configured for producing different output electrical signals configured for use in controlling speed of operation of the electric motor by reference to the variable electrical resistance across the movable contact member when arranged in each of the ON positions.

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.