Matsushita Electric Industrial Co., Ltd.

Hiroshi Ito

Hiroshi Murakami

Yoshinari Asano

Yukio Honda

Masayuki Shinto

Naoyuki Kadoya

Shizuka Yokote

Masakazu Tanahashi

Emiko Igaki

Kazushige Narazaki

Takeshi Kimura

Osamu Yamashita

Takeshi Morishige

A ceramic electronic device is protected at the surface from retention of water, thus having improved operation reliability, and a method of manufacturing the device is provided. A protective layer is formed on the ceramic element and external electrodes by dehydrating condensation of organic silicon compound.

Ceramic electronic device and method of manufacturing the device

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

Growing community of inventors

Takefu, Japan

Hiroshi Ito