Abstract: The identification method according to an embodiment is used for an identification device for identifying the type of a brushless DC motor. A brushless DC motor includes an output terminal for outputting a signal. The output terminal is able to output a signal obtained by superimposing signal types. The signal resulting from the superimposition is different depending on the types of brushless DC motors. In the identification method, power is supplied to a brushless DC motor, and the signal resulting from the superimposition that is output from the output terminal of the brushless DC motor is input to an identification device. The signal resulting from the superimposition is separated into signal types, and the separated signals are used to identify the type of the brushless DC motor.

Abstract: A motor includes a stator that includes an annular core back, teeth extending radially outside from the core back and being arranged in a circumferential direction, an insulator covering at least a portion of the teeth, and a coil defined by a conductive wire wound around each of the teeth via the insulator. A radially inside surface of the core back includes core back protrusions extending radially inside and provided with a space therebetween in the circumferential direction. The insulator includes an annular upper lid portion extending radially inside farther than a radially inside surface of the core back at an axially upper side of the core back and a side wall portion extending to an axially lower side from a lower surface of the upper lid portion. At least a portion of the side wall portion is disposed within the space between the adjacent core back protrusions.

Abstract: The identification method according to an embodiment is used for an identification device for identifying the type of a brushless DC motor. A brushless DC motor includes an output terminal for outputting a signal. The output terminal is able to output a signal obtained by superimposing signal types. The signal resulting from the superimposition is different depending on the types of brushless DC motors. In the identification method, power is supplied to a brushless DC motor, and the signal resulting from the superimposition that is output from the output terminal of the brushless DC motor is input to an identification device. The signal resulting from the superimposition is separated into signal types, and the separated signals are used to identify the type of the brushless DC motor.

Abstract: A motor includes a stator that includes an annular core back, teeth extending radially outside from the core back and being arranged in a circumferential direction, an insulator covering at least a portion of the teeth, and a coil defined by a conductive wire wound around each of the teeth via the insulator. A radially inside surface of the core back includes core back protrusions extending radially inside and provided with a space therebetween in the circumferential direction. The insulator includes an annular upper lid portion extending radially inside farther than a radially inside surface of the core back at an axially upper side of the core back and a side wall portion extending to an axially lower side from a lower surface of the upper lid portion. At least a portion of the side wall portion is disposed within the space between the adjacent core back protrusions.

Abstract: A first part formed of a first material is positioned to a second part formed of a second material, which is different from the first material in degree of modification due to environmental variation, by contacting surfaces of the first and second parts. At least three projections are formed on the contact surface of the first part along a circle whose center is coincident with a reference point. Grooves are formed on the contact surface of the second part so that the respective projections are fitted therein and that have wall surfaces to which the projections can contact at the inner and outer sides of the projections. The width of the grooves is determined so that the projections contact the inner or outer wall surface of the grooves even when the first and second parts deform in different degrees due to environmental variation.

Abstract: A stepping motor includes: a stator having main magnetic poles each having small stator teeth on its tip, a core-back portion that connects outer portions of the poles, and windings wound around the poles; and two sets of rotor units that are arranged in an axial direction and face the stator with an air gap therebetween. Each rotor unit consists of two rotor cores that are separated in the axial direction and a magnet sandwiched thereby and magnetized in the axial direction. Each rotor core has small rotor teeth around its outer surface. The rotor cores of each rotor unit are deviated by ½ pitch of the small rotor teeth, and the two rotor units are arranged to make the magnetic polarities of the small rotor teeth of the adjacent two rotor cores identical. A magnet thickness Tm and a rotor core thickness Tc satisfy 0.25?Tm/Tc?0.45.

Abstract: A stepping motor includes: a stator having main magnetic poles each having small stator teeth on its tip, a core-back portion that connects outer portions of the poles, and windings wound around the poles; and two sets of rotor units that are arranged in an axial direction and face the stator with an air gap therebetween. Each rotor unit consists of two rotor cores that are separated in the axial direction and a magnet sandwiched thereby and magnetized in the axial direction. Each rotor core has small rotor teeth around its outer surface. The rotor cores of each rotor unit are deviated by ½ pitch of the small rotor teeth, and the two rotor units are arranged to make the magnetic polarities of the small rotor teeth of the adjacent two rotor cores identical. A magnet thickness Tm and a rotor core thickness Tc satisfy 0.25?Tm/Tc?0.45.

Abstract: A first part formed of a first material is positioned to a second part formed of a second material, which is different from the first material in degree of modification due to environmental variation, by contacting surfaces of the first and second parts. At least three projections are formed on the contact surface of the first part along a circle whose center is coincident with a reference point. Grooves are formed on the contact surface of the second part so that the respective projections are fitted therein and that have wall surfaces to which the projections can contact at the inner and outer sides of the projections. The width of the grooves is determined so that the projections contact the inner or outer wall surface of the grooves even when the first and second parts deform in different degrees due to environmental variation.