Matsushita Electric Industrial Co., Ltd.

Hiroshi Itoh

Masayuki Shinto

Yoshinari Asano

Hiroshi Murakami

Yukio Honda

Kazushige Narazaki

Haruhiko Kado

Hideharu Hiwaki

Naoyuki Kadoya

Toshiyuki Tamamura

Yoshinori Asano

Hirokazu Yamauchi

A motor is provided that reduces vibration and noise by suppressing the vibration transmitted from a stator to a housing. Also an apparatus loaded with this motor is provided, that is highly efficient with less vibration and low noise. Notches formed at an outer circumference of a yoke are located on outer peripheral sides of slots, the notches are not in contact with the housing, the yoke located on outer circumferential sides of teeth is provided with axially penetrating through-holes, and an outer circumference of the stator core located on outer circumferential sides of the through-holes is in close contact with the housing, thus making it possible to obtain the motor with high efficiency, less vibration and low noise.

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

An inverter-driven motor which is driven by an inverter power source and includes an insulating member for insulating a winding wire and an iron core of the inverter-driven motor from each other at a groove. The insulating member is formed by not less than two insulating films and at least one of the insulating films is formed with a plurality of bores.

Inverter-driven motor

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

An inexpensive enclosed type rotary compressor capable of diminishing vibration. A balance weight is split into two parts. A first balance weight is formed by die casting, forging, sintering or the like to be in such a form that its end portions each having a hole for accommodating by a fixing protrusion are thinner than the remaining portion, and a second balance weight is formed as a single plate or laminated plates in plural layers and securedly sandwiched between the end ring of a rotator and the first balance weight. As a result, the balance weight can be standardized, realizing cost efficiency.

Enclosed type rotary compressor

A permanent magnet rotor includes a rotor shaft, a yoke mounted on the rotor shaft to form a magnetic path, a plurality of permanent magnets secured to the outer surface of the yoke, and a non-magnetic metallic cylindrical cover mounted on the permanent magnets. The cylindrical cover has a plurality of axially equidistantly spaced grooves defined in the outer surface thereof so as to extend circumferentially thereof. The cylindrical cover may have a continuous spiral groove in place of the plurality of axially equidistantly spaced grooves.

Growing community of inventors

Takefu, Japan

Hiroshi Itoh