A miniature handheld electric traction device including a shell, a power supply part, a power motor, a reduction gear set, a braking part and a winding drum, wherein the power motor, the reduction gear set and the winding drum are arranged in the shell; the power motor is linked with the winding drum through the reduction gear set; a surface of the winding drum is wound with a traction rope; the reduction gear set includes a planetary gear; the sun gear of the planetary gear is coaxial with the winding drum; the power motor or the motor shaft of the power motor is inserted into the inner ring of the winding drum; the motor shaft is linked with the planetary gear.

An electric power tool includes: a motor unit including a motor; a driving block for transmitting a rotational output of the motor to a front-end tool; and a rotation detector that detects an angle of rotation of the motor. The rotation detector includes a rotating body attached to a motor shaft and a position detector that outputs a rotational position signal corresponding to a rotational position of the rotating body. The rotating body includes an opening, and the motor shaft is press fitted and fixed to the opening of the rotating body.

A method for ascertaining, without an encoder, a rotational angle position of the rotor of a brushless DC motor, includes the steps of: detecting a voltage induced in a stator of the brushless DC motor; checking whether the voltage induced in the stator is lower than a threshold value; and if the induced voltage is lower than the threshold value, then ascertaining an initial rotational angle position of the rotor based on an Indirect Flux detection by Online Reactance Measurement, and subsequently updating the rotational angle position proceeding from the calculated initial rotational angle position using at least one continuous test signal.

Provided are a motor for an electric toothbrush and an electric toothbrush having the same. The motor includes a housing and at least one pair of rotor iron core groups fixed within the housing, wherein each rotor iron core group is formed by stacking a plurality of rotor iron cores, each of the plurality of rotor iron cores includes an iron core main body portion and an iron core convex portion protruding outwards from the periphery of the iron core main body portion; and at least one pair of rotor iron core groups are inserted into two axially extending iron core brackets, and the two iron core brackets are each provided with a clamping groove, with the clamping grooves having openings opposite to each other.

A reciprocating tool includes a motor, a reciprocating member, and a crank mechanism. The motor is disposed in a housing. The reciprocating member projects from the housing. The crank mechanism converts rotation of a rotation shaft of the motor into reciprocation of the reciprocating member. The crank mechanism rotates around an axis in a lateral direction by rotation transmission from the rotation shaft, and the crank mechanism includes a crank member having an eccentric pin, a connecting rod coupling the eccentric pin to the reciprocating member, and a balancer coupled to the eccentric pin, and the balancer is supported by the eccentric pin alone in the housing.

An electric work machine (1) includes: a brushless motor having a stator disposed around a rotor (30); and an output part driven by the rotor. The rotor has a rotor core (31) and first and second magnetic-pole parts (34S, 34N) disposed around a circumferential direction of the rotor core. When the induced voltage of the brushless motor is given as Va, the power-supply voltage of the brushless motor is given as Vb, the rotational speed of the brushless motor is given as ω, a first induced voltage constant, which is expressed by Va/ω, is given as Ea [V/krpm], a pole-pairs count, which is the number of the first magnetic-pole parts or the second magnetic-pole parts, is given as Pi, and a second induced voltage constant, which is expressed as Ea/Pi, is given as Eb [V/krpm pole-pairs count], the motor satisfies the condition: Eb≤0.025×Vb.

A blower in one aspect of the present disclosure includes: a housing including a suction port and a discharge port; a motor in the housing; a fan in the housing; a motor drive circuit; and a control circuit. The control circuit detects an insufficient airflow from the suction port to the discharge port based on an operation parameter. The operation parameter is associated with an operation of the motor.

An oscillating power tool with an electric motor is provided, including an armature shaft with an armature and a fan wheel, including an eccentric arranged on the armature shaft at one end thereof, a first balancing mass for balancing an unbalance of the eccentric and possibly an eccentric bearing, being arranged in the proximity of the eccentric or the eccentric bearing, respectively, however, at an axial distance, further including a second balancing mass for balancing a couple unbalance caused by the axial distance between the eccentric and the eccentric bearing, respectively, and the first balancing weight, wherein the second balancing mass is arranged on the armature shaft at the side facing away from the eccentric or the eccentric bearing. Also a method for balancing such an electric motor is provided.

A power tool is provided including a motor case and a handle portion. An electric motor having a drive shaft is mounted within the motor case. A circuit board is disposed in the handle portion to accommodate a motor drive circuit. The motor drive circuit includes a rectifier configured to receive an alternating current from an alternating current (AC) power source and convert it to a direct current supplied to a DC power bus, and a bridge circuit having motor switches connected between the rectifier and the electric motor. A bus capacitor is mounted on the circuit board and coupled across the DC power bus. An auxiliary capacitor having higher capacitance than the bus capacitor is switchably coupled across the DC power bus. The handle portion includes a support member protruding radially outwardly to accommodate the auxiliary capacitor.

An electronic module is provided including power switches mounted on a circuit board and configured as an inverter circuit for an electric motor. A sliding member is coupled to an actuator. A power contact switch is provided including a first conductive body, a second conductive body, and a contact switch. The first and second conductive bodies are mounted on a first surface of the circuit board and include pins received through through-holes of the circuit board to make electrical contact with two conductive tracks on a second surface of the circuit board. The contact switch pivotably is secured to the first conductive body and pivotably moveable by the sliding member to make contact with the second conductive body with movement of the actuator. A flyback diode is electrically connected between the first and second conductive track on the second surface of the circuit board parallel to the power contact switch.