Abstract: A motor and a method for manufacturing thereof use a rotor having permanent magnets and stators. The highest revolving speed of a motor is adjusted by using end plates of different thickness. The end plates are made of a magnetic material and disposed at the end faces of the rotor. The end plates made of a magnetic material provide part of the magnetic flux generated from the permanent magnets with short circuits within the inside of the rotor. The magnetic flux that links with the coil can be adjusted by using end plates of different thickness. Therefore, the highest revolving speed of a motor can be finely adjusted with ease.

Abstract: A motor has a stator having a plurality of teeth for receiving windings, a yoke connected to each tooth, and a rotor having permanent magnets facing the stator. An inner wall surface of each tooth faces the rotor with an air-gap therebetween. Each tooth is separated from an adjacent tooth by a slot-open-section extending between a tailing end of the tooth and a leading end of the adjacent tooth. The inner wall surface of each tooth has an arc extending from a center of the slot-open-section toward the tailing end. The air-gap at the tailing end of each tooth is greater than the air-gap at the leading end of each tooth. The inner wall surface of each tooth includes a straight-line tailing section extending from the center of the slot-open-section toward the leading end. The straight-line tailing section extends tangentially from the arc.

Abstract: A compressor and an electric motor in which their weights are successfully reduced by employing a light-metal conductor wire for a winding, by reducing constituent components of a stator and a rotor of the electric motor, by providing a notch or a hole, and by eliminating the need for components necessary to mount the stator in a housing or a casing.

Abstract: An electric motor accommodated fixedly in position within its own casing or a housing of a compressor is provided with a non-conductive member between its stator and the casing or the housing, for preventing the stator and the casing or housing from making contact with each other. The non-conductive member is made of a material having a thermal expansion coefficient greater than that of the stator, such as resin.

Abstract: In a method of magnetizing a material of a permanent magnet portion provided in a rotor for a permanent-magnet motor, the material of the permanent magnet portion is embedded inside the rotor body, while the permanent magnet material has anisotropy in a direction penetrating the permanent magnet portion in section, and then the rotor is incorporated in a magnetizing unit and held in a rotatable manner, and the permanent magnet material is magnetized by flowing a magnetizing current through windings under the condition that the rotor is rotatably held in the magnetizing unit. Thus, the permanent magnet material is completely magnetized in a normalized direction, and even if the rotor is shifted from the normalized position, the rotor is retained back to the normalized position by a magnetic torque.

Abstract: In a method of magnetizing a material of a permanent magnet portion provided in a rotor for a permanent-magnet motor, the material of the permanent magnet portion is embedded inside the rotor body, while the permanent magnet material has anisotropy in a direction penetrating the permanent magnet portion in section, and then the rotor is incorporated in a magnetizing unit and held in a rotatable manner, and the permanent magnet material is magnetized by flowing a magnetizing current through windings under the condition that the rotor is rotatably held in the magnetizing unit. Thus, the permanent magnet material is completely magnetized in a normalized direction, and even if the rotor is shifted from the normalized position, the rotor is retained back to the normalized position by a magnet torque.

Abstract: An electric motor accommodated fixedly in position within its own casing or a housing of a compressor is provided with a non-conductive member between its stator and the casing or the housing, for preventing the stator and the casing or housing from making contact with each other. The non-conductive member is made of a material having a thermal expansion coefficient greater than that of the stator, such as resin.

Abstract: A compressor and an electric motor in which their weights are successfully reduced by employing a light-metal conductor wire for a winding, by reducing constituent components of a stator and a rotor of the electric motor, by providing a notch or a hole, and by eliminating the need for components necessary to mount the stator in a housing or a casing.

Abstract: In a method of magnetizing a material of a permanent magnet portion provided in a rotor for a permanent-magnet motor, the material of the permanent magnet portion is embedded inside the rotor body, while the permanent magnet material has anisotropy in a direction penetrating the permanent magnet portion in section, and then the rotor is incorporated in a magnetizing unit and held in a rotatable manner, and the permanent magnet material is magnetized by flowing a magnetizing current through windings under the condition that the rotor is rotatably held in the magnetizing unit. Thus, the permanent magnet material is completely magnetized in a normalized direction, and even if the rotor is shifted from the normalized position, the rotor is retained back to the normalized position by a magnetic torque.

Abstract: The motor includes the following elements: a stator-core having plural teeth, and a yoke that links the teeth, coils wound on the teeth in a concentrated winding form, and a rotor with interior permanent magnets. The rotor with interior permanent magnets includes the following elements: a rotor core having plural slits of which ends extend closely to the rotor circumference, permanent magnets positioned in the slits, non-magnetic-sections provided between the circumference of the rotor-core and respective ends of permanent magnets. This construction allows the motor to withstand persistently demagnetization, to be a smaller size with high efficiency, and to be manufactured in a highly efficient manner. The motor can be integrated as a driver into an apparatus driving unit.

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.

Abstract: A brushless motor having at least one current influence detector (10a, 10b, 10c) for detecting influence of an induced voltage caused by variations of current flowing in an armature winding (3). Furthermore, a positional signal detecting circuit means (11) detects a positional signal corresponding to rotational position of the rotor (2) in accordance with the voltage signal appearing at the armature winding (3) and the output signal issued from the at least one current influence detector (10a, 10b, 10c).

Abstract: A rotor of a motor includes a plurality of sets of permanent magnets 8a, 8b embedded in the rotor. Each includes a permanent magnet at an inner side and another permanent magnet at an outer side with a distance between them. Each permanent magnet 8a, 8b is formed like an arch projecting towards the center of the rotor. Magnetic flux flows easily through an interval between the permanent magnets at inner and outer sides, and the inductance in a q-axis is enlarged. Then, the reluctance torque is generated in addition to the magnet torque, and the motor has a high torque and a high output power.

Abstract: In the direct current motor having Ns pieces of stator teeth and Nr pieces of magnetic poles, each of the plural magnetic poles is disposed shifted with the predetermined shift angles .DELTA..theta.i around a rotor from the angular reference position defined by even angles around the axis of the rotor, respectively, and the shift angles .DELTA..theta.i are defined by the below-mentioned expression concerning the least common multiple Nc between the Ns and the Nr;-180/Nc.ltoreq.shift angle.DELTA..theta.i.ltoreq.+180/Nc,wherein, signs "-" and "+" in the expression show a shift direction from the angular reference position in the circumferential direction.