Abstract: 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.

Abstract: A dry turbo vacuum pump has a multistage circumferential impeller supported on a shaft, and a stator which cooperates with it to form a multistage peripheral flow pump. A centrifugal pump arranged at an inlet side of the peripheral flow pump is also mounted on the same shaft, so that gas sucked from the inlet is discharged to the atmosphere from the peripheral flow pump. The multistage peripheral flow pump and at least one stage of the centrifugal pump are integrated.

Abstract: 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.

Abstract: 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.

Abstract: A vacuum pump of the present invention comprises a housing including a suction port and an exhaust port, a stator fixed in the housing, a rotor rotatably supported in the housing, and a cooling jacket provided adjacent to the stator. Gas suctioned from the suction port and having a pressure substantially equal to or close to the atmospheric pressure is exhausted from the exhaust port. A cooling fluid having a thermal conductivity less than that of water, for example, of 0.08 to 0.25 Kcal/m.h..degree.C. flows through the cooling jacket. When the gas contains aluminum chloride, the cooling fluid flows into the cooling jacket in such a manner that the temperature inside a gas conduit is maintained to be higher than the sublimation temperature of aluminum chloride. Lubrication oil may be supplied as the cooling fluid to the cooling jacket from the same supply line as lubrication oil supplied to oil lubricating bearings provided below a pump mechanism unit.

Abstract: This invention concerns a production method and a processing apparatus for semiconductor devices, as well as an evacuating apparatus used for the processing apparatus. According to this invention, since the evacuation system of pressure-reduction processing apparatus for conducting various wafer processings during production steps of semiconductor devices is constituted only with oil-free vacuum pump, deleterious oil contaminations or carbonation products of oils produced from oils upon heating are not present in the pressure-reducing processing chamber as compared with conventional pressure-reducing processing apparatus using a vacuum oil pump as an evacuation pump and the production method of semiconductor devices using such apparatus.

Abstract: 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.

Abstract: A vacuum pump with a heating portion for preventing adhesion of reaction products on a discharge side thereof.

Abstract: This invention concerns a production method and a processing apparatus for semiconductor devices, as well as an evacuating apparatus used for the processing apparatus. According to this invention, since the evacuation system of pressure-reduction processing apparatus for conducting various wafer processings during production steps of semi-conductor devices is constituted only with oil-free vacuum pump, deleterious oil contaminations or carbonation products of oils produced from oils upon heating are not present in the pressure-reducing processing chamber as compared with conventional pressure-reducing processing apparatus using a vacuum oil pump as an evacuation pump and the production method of semiconductor devices using such apparatus.

Abstract: According to the turbo molecular pump of the present invention, a regenerative pump is constructed by arcuate eddy current grooves having a predetermined angle with respect to the surface of the outer periphery of a rotor and which are circumferentially engraved in array in the rotor and an arcuate ventilating channel engraved in the circumferential direction in a stator, and a partition is defined in the stator circumferentially partitioning the ventilating channel, so that the working range on the low vacuum side may be extended.

Abstract: A vacuum pump with a seal structure for a pump unit of the vacuum pump and a driving mechanism for rotating a rotor in the pump stages of the pump is disclosed. The seal structure is provided with a narrow gap sealing arrangement formed by a stationary member which is opposed to the portion of a shaft of the driving mechanism which is between the pump unit and an upper bearing supporting the same shaft, which narrow gap sealing arrangement comprises first, second and third seal portions; a mechanism for supplying a discharge gas to the first seal portion; and a mechanism for supplying a purge gas to the second and third seal portions. Owing to these parts, the feed rate of the purge gas can be minimized, and the entry of the oil mist, which occurs during the lubrication of the bearing, into the interior of the pump unit can be prevented. This enables the interior of the pump unit to be kept clean.

Abstract: A vacuum pump including a centrifugal compressor stage on the side of a suction opening and a circumferential flow compressor on the side of an exhaust opening. The centrifugal compressor pump works as a Siegbahn pump at a steady state, and works as a centrifugal compressor under a transient condition at the initial stage of the pump operation, thus obtaining a high pumping speed under the transient condition.

Abstract: A cryogenic liquefied pump system which includes a pump having a drive motor, bearings, a drive shaft, and an impeller adapted to be disposed in a vessel storing a cryogenic liquid. An outer insulating tank is mounted in the vessel and an inner insulating tank is mounted inside the outer insulating tank, with a vacuum layer being interposed between the inner and outer insulating tanks. An inner side of the inner insulated tank, in which the motor and bearings are arranged, is maintained at a room temperature, with a tip portion of the inner insulating tank being formed into an outer case extending into a cryogenic region outside of the outer insulated tank.