Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Kenzo Kajiwara

Ryoso Masaki

Hirohisa Yamamura

Hiroyuki Yamada

Shigeki Morinaga

Kazuo Tahara

Kenji Takahashi

Kazuhiko Kawaike

Heikichi Kuwahara

Hiroshi Hamano

Toshio Suzuki

Masaaki Nakano

Eiichi Okuyama

Nobuo Inoue

Kouki Nagai

An interior cooling air flow is moved by an interior fan through an inside ventilation passage provided on an inside surface of a stator frame of a totally-enclosed type motor. An exterior cooling air produced by an exterior fan is passed through an outside surface of ventilation passage provided on an outside the stator frame. An inner heat radiation rib is provided in the axial direction on an inner face the inside ventilation passage so that the temperature rise of the motor can be reduced by an improvement in the cooling characteristic. In this way, a compact size totally-enclosed type motor having an improved cooling characteristic is obtained.

Totally-enclosed type motor

Controller for electric vehicle

A control apparatus for an induction motor and an electric car propelling motor includes an inverter for supplying a driving current to the induction motor on the basis of a predetermined control signal, a rotational speed sensor for detecting a rotational speed of the induction motor, a V/f control circuit responsive to an input speed command signal for producing a control signal for the inverter, a vector control circuit for producing an inverter control signal on the basis of the speed command signal and the rotational speed signal of the rotational speed sensor, an abnormality detecting circuit for detecting abnormality of the rotational speed sensor. A change-over circuit having inputs supplied with outputs of the V/f control circuit and the vector control circuit, respectively, selects the inverter control signal from the V/f control circuit in response to detection of abnormality of the rotational speed sensor while selecting the inverter control signal supplied from the vector control circuit so long as no abnormality is detected in the rotational speed sensor.

Control apparatus for induction motor

A bearing device for a horizontal shaft type rotating machine includes an oil tank formed at the lower portion of the bearing box for storing lubricant oil for the bearing, the oil tank being divided by a bearing support plate between an oil feeding chamber and an oil collecting chamber; an oil feeding apparatus which pumps up the lubricant oil in the oil feeding chamber and feeds the lubricant oil onto the bearing; and a pair of diffusion flow passages; each of the pair of diffusion flow passages being formed along the inner wall of the oil tank and connects the oil collecting chamber with the oil feeding chamber; each of the diffusion flow passages permitting diffusion and movement of the lubricant oil from the oil collecting chamber to the oil feeding chamber. Each of the diffusion flow passages including a baffle chamber and a narrow gap flow passage downstream of the baffle chamber and having a smaller cross section flow passage area than the baffle chamber and the upper portion of the baffle chamber being open to the air, whereby air bubbles contained in the collected high temperature lubricant oil are removed at an early stage of their return travel from the oil collecting chamber to the oil feeding chamber.

Bearing device for horizontal shaft type rotating machine

Growing community of inventors

Hitachi, Japan

Kenzo Kajiwara