Abstract: A laminated core includes a plurality of electrical steel sheets stacked in a thickness direction, each of the electrical steel sheets includes an annular core back part; a plurality of fastening parts are provided in the core back part at intervals in a circumferential direction; an adhesion region is formed on an outer circumferential side from the fastening parts in the core back part; and a non-adhesion region is formed on an inner circumferential side from the fastening parts in the core back part.

Abstract: A motor can be driven so that the total loss of a loss of a motor and a loss of an inverter decreases. In a relationship between an optimum carrier frequency at which the total loss is minimized and a torque of a motor M, a lowest value of the optimum carrier frequency is derived, and a relationship between the torque of the motor M and the carrier frequency is determined to have a portion in which the carrier frequency is substantially constant or decreases as the torque of the motor M increases in a range equal to or less than the torque of the motor M corresponding to the lowest optimum carrier frequency and a portion in which the carrier frequency is substantially constant or increases as the torque of the motor M increases in a range equal to or more than the torque of the motor M corresponding to the lowest optimum carrier frequency.

Abstract: A laminated core includes a plurality of electrical steel sheets stacked in a thickness direction, the electrical steel sheet includes an annular core back part and a plurality of tooth parts that protrude from the core back part in a radial direction and are disposed at intervals in a circumferential direction of the core back part, a fastening part is provided in a portion of the core back part corresponding to the tooth part, and an adhesion part is provided in the tooth part.

Abstract: The iron loss of an iron core excited by an inverter power supply is reduced. A modulation operation-setting device 1430 for the inverter power supply controls a maximum value Hmax and a minimum value Hmin of a field intensity H in at least one minor loop such that the loss (iron loss, copper loss, and switching loss) of the entire system is less than the loss of the entire system when an electric device is operated with a target waveform (excluding harmonics).

Abstract: The present invention is a stator core having a plurality of laminated electrical steel sheets, in which, among a plurality of teeth (121a to 121p) of the stator core, a width of teeth along a direction in which magnetic characteristics are excellent may be narrower than a width of teeth along a direction in which the magnetic characteristics are poor.

Abstract: A laminated core includes a plurality of electrical steel sheets stacked in a thickness direction, each of the electrical steel sheets includes an annular core back part; a plurality of fastening parts are provided in the core back part at intervals in a circumferential direction; an adhesion region is formed on an outer circumferential side from the fastening parts in the core back part; and a non-adhesion region is formed on an inner circumferential side from the fastening parts in the core back part.

Abstract: A laminated core includes a plurality of electrical steel sheets stacked in a thickness direction, the electrical steel sheet includes an annular core back part and a plurality of tooth parts that protrude from the core back part in a radial direction and are disposed at intervals in a circumferential direction of the core back part, a fastening part is provided in a portion of the core back part corresponding to the tooth part, and an adhesion part is provided in the tooth part.

Abstract: The iron loss of an iron core excited by an inverter power supply is reduced. A modulation operation-setting device 1430 for the inverter power supply controls a maximum value Hmax and a minimum value Hmin of a field intensity H in at least one minor loop such that the loss (iron loss, copper loss, and switching loss) of the entire system is less than the loss of the entire system when an electric device is operated with a target waveform (excluding harmonics).

Abstract: A motor can be driven so that the total loss of a loss of a motor and a loss of an inverter decreases. In a relationship between an optimum carrier frequency at which the total loss is minimized and a torque of a motor M, a lowest value of the optimum carrier frequency is derived, and a relationship between the torque of the motor M and the carrier frequency is determined to have a portion in which the carrier frequency is substantially constant or decreases as the torque of the motor M increases in a range equal to or less than the torque of the motor M corresponding to the lowest optimum carrier frequency and a portion in which the carrier frequency is substantially constant or increases as the torque of the motor M increases in a range equal to or more than the torque of the motor M corresponding to the lowest optimum carrier frequency.

Abstract: A method of annealing a metal member includes: disposing a first heater in an inner space of a hollow cylindrical metal member having an inner peripheral surface provided with plural teeth protruding toward a central direction, the first heater radiating infrared light and being disposed so as to extend parallel to a direction of a central axis of the metal member; heating the metal member from the inner space with the first heater; and gradually cooling the metal member after heating.

Abstract: Provided is a method of annealing a metal member, including: disposing a first heater in an inner space of a hollow cylindrical metal member having an inner peripheral surface provided with plural teeth protruding toward a central direction, the first heater radiating infrared light and being disposed so as to extend parallel to a direction of a central axis of the metal member; heating the metal member from the inner space with the first heater; and gradually cooling the metal member after heating.