Matsushita Electric Industrial Co., Ltd.

Masayuki Shinto

Yoshinari Asano

Hiroshi Murakami

Yukio Honda

Naoyuki Kadoya

Hiroshi Itoh

Hiroshi Ito

Kazushige Narazaki

Shizuka Yokote

Noriyoshi Nishiyama

Taro Kishibe

Haruhiko Kado

Hisakazu Kataoka

Toshiyuki Tamamura

Hiroshi Dohi

Osaaki Morino

Toshio Yamamoto

Takeshi Morishige

Yoshinori Asano

A structure of a rotor used in a synchronous motor employing both of permanent magnets and a stator using concentrated windings is disclosed. Slits () provided in a section of a rotor laminated in a direction of a rotary shaft are shaped like an arc or a bow, and the shape protrudes toward an outside rim of rotor (). Permanent magnets () are inserted into slits (). This structure produces less magnetic salient poles than a conventional rotor, so that a magnetic flux density can be lowered, and an efficient motor with less loss is obtainable.

Permanent magnet synchronous motor

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.

Magnetizing method for a permanent-magnet motor

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.

Motor using rotor including interior permanent magnet, and apparatus-driving-unit employing the same motor

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.

Magnetizing method for rotor magnet of reluctance magnet motor

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.

Motor using a rotor including an interior permanent magnet

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).

Brushless motor with rotor position detection compensation caused by

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.

Motor with built-in permanent magnets

In a brushless motor having a stator with windings mounted in plural slots and a rotor with a permanent magnet consisting of plural poles, the poles have two kinds of occupation angles on the whole in the rotating direction of the rotor, and a difference between the two occupation angles is equal to one slot-pitch.

Brushless motor

A rotor for a rotary machine with permanent magnets includes an iron core member, permanent magnets, each having an arcuate cross section and arranged on an outer periphery of the iron core member, and a non-magnetic metallic pipe applied, under pressure, over outer peripheries of arcuate magnets. Each of the arcuate magnets is formed with chamfering on one end portion on its outer circumferential face in an axial direction, and the chamfering is small at its central portion, and becomes larger towards opposite sides in a widthwise direction of the arcuate magnet.

Growing community of inventors

Sabae, Japan

Masayuki Shinto