Abstract: The present invention provides a permanent-magnet-synchronous-motor having a stator with concentrated windings with the following structure so that permanent magnet (6) is hard to subjected to demagnetization magnetic field: 0.3 Lg<La?2.0 Lg, where La is a clearance between teeth of stator (1), and Lg is an air-gap between stator (1) and rotor (2). Outer walls of both ends of the permanent magnet (6) disposed within rotor (2) in a rim direction may be tapered toward inside from a rotor rim in a radial direction and to form a recessed section on the outer walls of the magnets. As a result, withstanding force against demagnetization is expected to increase.

Abstract: The present invention provides a permanent-magnet-synchronous-motor having a stator with concentrated windings with the following structure so that permanent magnet (6) is hard to subjected to demagnetization magnetic field: 0.3 Lg<La?2.0 Lg, where La is a clearance between teeth of stator (1), and Lg is an air-gap between stator (1) and rotor (2). Outer walls of both ends of the permanent magnet (6) disposed within rotor (2) in a rim direction may be tapered toward inside from a rotor rim in a radial direction and to form a recessed section on the outer walls of the magnets. As a result, withstanding force against demagnetization is expected to increase.

Abstract: The present invention provides a permanent-magnet-synchronous-motor having a stator with concentrating windings with the following structure so that permanent magnet (6) is hard to subjected to demagnetization magnetic field: 0.3 Lg<La?2.0 Lg, where La is a clearance between teeth of stator (1), and Lg is an air-gap between stator (1) and rotor (2), and yet outer walls of both ends of the permanent magnet (6) disposed within rotor (2) in a rim direction are tapered toward inside from a rotor rim in a radial direction and thus form recessed section on the outer walls of the magnets. As a result, withstanding force against demagnetization is expected to increase.

Abstract: In a conventional blowing apparatus, vibration is increased depending upon a combination of rotor magnetic poles, the number of stator salient poles and blades of a fan. In a blowing apparatus comprising a stator having a core including a M-number of salient poles, and a rotor having permanent magnets having a P-number of magnetic poles rotatably disposed such as to be opposed to magnetic pole surfaces of the stator, the stator and the rotor, in combination, forming a motor for rotating a fan having a N-number of blades, mN≠nM or mN≠nP is satisfied. With this feature, a synergism between vibration generated by cogging torque of the motor and vibration generated by rotation of the fan is moderated, and vibration and noise are reduced.

Abstract: In a conventional blowing apparatus, vibration is increased depending upon a combination of rotor magnetic poles, the number of stator salient poles and blades of a fan. In a blowing apparatus comprising a stator having a core including a M-number of salient poles, and a rotor having permanent magnets having a P-number of magnetic poles rotatably disposed such as to be opposed to magnetic pole surfaces of the stator, the stator and the rotor, in combination, forming a motor for rotating a fan having a N-number of blades, mN≠nM or mN≠nP is satisfied. With this feature, a synergism between vibration generated by cogging torque of the motor and vibration generated by rotation of the fan is moderated, and vibration and noise are reduced.

Abstract: A rotor magnet of a three-phase reluctance magnet motor is magnetized by coupling two of the three outer terminals (RS), and feeding a positioning current between the outer terminals RS and a third terminal (T) for positioning the rotor at a magnetizing position with reluctance torque. Then, rotor is kept from moving by holding the shaft of the rotor with the rotor positioned at the magnetized position. Next, the outer terminals RS are separated and magnetizing current is fed between the outer terminals R and S to magnetize the rotor magnet.

Abstract: In a motor having a permanent magnet built in a rotor, a hole for preventing a short-circuit of magnetic flux is disposed so that the hole is adjacent to the outer rim of rotor core, and adjoins to a slit for receiving a permanent magnet as well as the permanent magnet per se. This structure prevents a short-circuit of magnetic flux generated by both ends of the permanent magnet, and the magnetic flux at both ends of the magnet can flow to a stator, thereby contributing to generate torque effectively. As a result, the highly efficient motor with less cogging torque, less vibration and lower noise can be provided.