A rotary electric machine includes a bearing that holds a rotation shaft and is capable of rotating the rotation shaft, a housing accommodating the bearing, a rotor that is fixed to the rotation shaft and rotates, and a stator that is fixed to the housing. The stator includes a stator core including a tooth portion protruding toward the rotor and extending along the rotation shaft, a winding wound around the stator core, and magnetic detectors attached to an end portion of the stator core in a direction in which the rotation shaft extends while being separated from each other in a rotation direction of the rotation shaft.

A method for determining a state of an electric motor having a stator (2) and a rotor (3) rotatably mounted relative to the stator (2) is disclosed. Due to a rotary motion of the rotor (3), a pressure difference (p) relative to an environment (15) of the electric motor (1, 1′, 1″, 1′″) is caused in an air space (16) inside the electric motor (1, 1′, 1″, 1′″). Here, in a normal state of the electric motor (1, 1′, 1″, 1′″), the pressure difference depends on an actual rotational speed (n) of the rotor (3). A corresponding electric motor suitable for carrying out this method is disclosed, wherein the electric motor may be part of a fan.

A method for determining a state of an electric motor having a stator (2) and a rotor (3) rotatably mounted relative to the stator (2) is disclosed. Due to a rotary motion of the rotor (3), a pressure difference (p) relative to an environment (15) of the electric motor (1, 1′, 1″, 1′″) is caused in an air space (16) inside the electric motor (1, 1′, 1″, 1′″). Here, in a normal state of the electric motor (1, 1′, 1″, 1′″), the pressure difference depends on an actual rotational speed (n) of the rotor (3). A corresponding electric motor suitable for carrying out this method is disclosed, wherein the electric motor may be part of a fan.

A system is described in which a magnetic mover includes at least one mover identification device. The system also includes a stator defining a work surface and including an actuation coil assembly and at least one stator identification device operable to interact with the at least one mover identification device. One or more sensors are used to sense a position of the first magnetic mover. One or more stator driving circuits are used to drive the actuation coil assembly to thereby move the first magnetic mover over the work surface. The first magnetic mover includes one or more magnetic components positioned such that interaction of one or more magnetic fields emitted by the one or more magnetic components with one or more magnetic fields generated by the actuation coil assembly when driven by the one or more stator driving circuits enables movement of the first magnetic mover in at least two degrees of freedom.

An object is to improve estimation accuracy of the internal distribution state of a rotating electric machine. The rotating electric machine includes a stator; a rotor rotatably provided on a radially inner side of the stator; a shaft provided as a rotary shaft of the rotor; a bracket supporting the shaft rotatably relative to the stator via a bearing; and a sensor provided to the shaft between the rotor and the bearing.

A diagnosis system diagnoses the integrity of an opening/closing device capable of opening and closing by driving a motor. A driving current acquisition unit acquires a driving current of the motor. A diagnosis unit defines a current waveform from a temporal change of the driving current acquired by the driving current acquisition unit and diagnoses the integrity of the opening/closing device based on the current waveform.

A diagnosis system diagnoses the integrity of an opening/closing device capable of opening and closing by driving a motor. A driving current acquisition unit acquires a driving current of the motor. A diagnosis unit defines a current waveform from a temporal change of the driving current acquired by the driving current acquisition unit and diagnoses the integrity of the opening/closing device based on the current waveform.

Provided is an electrically powered tool having an improved sensor substrate mounting structure, the electrically powered tool being configured so that a brushless type motor is axially contained in a cylindrical housing. The electrically powered tool has: a cylindrical housing for axially containing a motor; a control unit for controlling the motor; and a sensor substrate having mounted thereon a plurality of position detecting elements for detecting the rotational position of a rotor. The sensor substrate is gripped between the insulator of the motor and the housing and held on the housing side when axially mounting the motor. The sensor substrate is annularly shaped and has formed at the center thereof a through-hole through which a bearing for the motor is passed. The portion of the sensor substrate, on which a Hall IC is mounted, is provided with a synthetic resin cover member for protecting the Hall IC against dust.

Provided is an electrically powered tool having an improved sensor substrate mounting structure, the electrically powered tool being configured so that a brushless type motor is axially contained in a cylindrical housing. The electrically powered tool has: a cylindrical housing for axially containing a motor; a control unit for controlling the motor; and a sensor substrate having mounted thereon a plurality of position detecting elements for detecting the rotational position of a rotor. The sensor substrate is gripped between the insulator of the motor and the housing and held on the housing side when axially mounting the motor. The sensor substrate is annularly shaped and has formed at the center thereof a through-hole through which a bearing for the motor is passed. The portion of the sensor substrate, on which a Hall IC is mounted, is provided with a synthetic resin cover member for protecting the Hall IC against dust.

A bearing device includes: a magnetic ring fixed to an inner ring; and a stator fixed to an outer ring so as to face magnetic ring. Magnetic ring and stator constitute a claw pole type generator. Stator includes a coil and a magnetic yoke surrounding coil. The magnetic yoke is configured by combining a first member and a second member that are magnetic bodies. First member and second member have an identical shape. Each of first member and second member has a plurality of second claws arranged in a comb shape. A plurality of first claws of first member and the plurality of second claws of second member are alternately arranged on a surface facing magnetic ring.