Hitachi, Ltd.

Seiko Seiki Co., Ltd.

Seiji Sakagami

Takashi Nagaoka

Masahiro Mase

Shinjiro Ueda

Akira Nishiuchi

Hirofumi Sakurai

Tsutomu Okazaki

Nobukatsu Arai

Katsuaki Kikuchi

Shinjiroo Ueda

Takeshi Okawada

Tetsuo Udagawa

Yoshihisa Awada

Noboru Matsumura

Shinji Koyano

Chiaki Urano

Takashi Nagaoka, Deceased

Yuichi Kinoshita

There is disclosed a supercharger for an engine in which intake air is increased in pressure by the use of exhaust gas flowed into the supercharger from the engine, and is fed to the engine. An impeller 2, having a plurality of blades formed on an outer peripheral portion thereof, is received within a casing 1, and a ring-like fluid passage is formed around the plurality of blades, and a first partition 3 and a second partition 4 are provided in the fluid passage to divide this fluid passage into two fluid passages, that is, an exhaust gas passage 6 and an intake air passage 9. There is provided a fluid machine construction for causing the exhaust gas of the engine to flow into and out of the exhaust gas passage, and for causing the intake air to flow into and out of the intake air passage. With this construction, the pressure of the intake air can be satisfactorily increased over a wide range of the engine speed from a low speed to a relatively high speed, and therefore the supercharging of the engine can be effected with the inexpensive machine construction.

Supercharger for engine

A turbo vacuum pump has a rotor and magnetic bearings. The magnetic bearings are held in a housing having a suction port and an exhaust port, and support the rotor rotatably. A peripheral flow pump stage and screw pump stage are formed in the rotor, so that the pressure at the exhaust port can be at or near atmospheric pressure level. Before starting the turbo vacuum pump, the magnetic bearings are operated to displace a rotor position and to scrape off the reaction products which have deposited inside the pump. In addition, before starting the turbo vacuum pump, a stator of the pump is heated up to decrease a binding force of the reaction products. Therefore, the pump can be restarted, even if the rotor has locked by the solidification of deposited reaction products formed during stopping of the pump.

Turbo vacuum pump with a magnetically levitated rotor and a control unit

A turbo vacuum pump for compressing a low-pressure gas to discharge the compressed gas into atmosphere comprises pump stator having a gas flow passage comprising a plurality of annular flow passages on an inner surface thereof arranged stepwise diameters of which become smaller toward downstream and passages intercommunicating with adjacent annular flow passages and a gas discharge port communicated with one of the plurality of annular flow passages disposed at the most downstream. The pump stator includes a cylindrical spiral grooved pump impeller and a plurality of peripheral flow pump impellers facing the annular flow passages provided downstream of the cylindrical spiral grooved pump impeller and having stepwise diameters which become smaller toward downstream to form a peripheral flow pump stage. The suction casing has a spiral groove on a cylindrical inner surface thereof arranged with a predetermined clearance in relation to the spiral grooved pump impeller of the pump rotor so as to form a spiral grooved pump stage and a gas suction port communicated with the spiral grooved pump stage.

Turbo vacuum pump

A turbo vacuum pump has a housing provided with a suction port and a discharge port, an evacuation pump disposed in the housing for compressing a gas suctioned through the suction port and discharging the compressed gas through the discharge port, and a motor for driving the evacuation pump, the motor and the evacuation pump having a common rotor. The rotor is supported at its both axial ends by bearings. A spiral grooved dynamic seal is disposed in the vicinity of the suction port and at the opposite side of the suction port to the evacuation pump. The diameter of the spiral grooved dynamic seal, at the smallest, is greater than the outside diameter of the final stage impeller of the evacuation pumps.

A compact, easy-to-handle turbo vacuum pump includes a housing having an inlet port and an outlet port; a cylindrical rotor disposed in the housing and having a stepped peripheral surface and a plurality of blades secured to protruding corners of the steps; and a pumping mechanism portion in which a pumping stage is formed by a stator which faces the blades of the rotor across a narrow gap, and in which peripheral pump flow paths are provided in step-like recessions inside the stator. The turbo vacuum pump further includes a rotating shaft which is connected to the rotor and is rotatably supported by a radial gas bearing and a thrust gas bearing; and a motor portion for operating the rotor. Gas sucked in through the inlet port can be discharged into the atmosphere through the outlet port.

A turbo vacuum pump has a housing provided with a suction port and a discharge port, an evacuation pump disposed in the housing for compressing a gas sucked through the suction port and discharging the compressed gas through the discharge port, and a motor for driving the evacuation pump, the motor and the evacuation pump having a common rotor. The rotor is supported at its both axial ends by bearings. A spiral grooved dynamic seal is disposed in the vicinity of the suction port and at the opposite side of the suction port to the evacuation pump. The diameter of the spiral grooved dynamic seal, at the smallest, is greater than the outside diameter of the final stage impeller of the evacuation pump.

Since a peripheral-flow pump according to the present invention has a peripheral-flow impeller having a cylindrical staircase shape whose outer diameter increases in one direction only like a staircase, a stator, which conventionally has been of a complicated configuration composed of two pieces, can be formed into an integral molding without any deterioration in pump performance. Accordingly, the production of pumps is facilitated.

Growing community of inventors

Ibaraki, Japan

Seiji Sakagami