Seiko Instruments Inc

Chisso Corporation

Boc Edwards Technologies Limited

Other

Kawasaki Steel Corporation

Boc Edwards Japan Limited

Akira Yamauchi

Jun Saito

Shingo Kikukawa

Hirotaka Namiki

Hiroyuki Maehara

Hitoshi Sato

Manabu Nonaka

Yoshinobu Ohtachi

Hideo Nobuhara

Takaharu Ishikawa

Takanori Nakashima

Kenichi Sorimachi

Tsutomu Ushioda

Masahiko Taniguchi

Kazuhiro Kimura

Shuji Takeuchi

Yoshitaka Morimoto

Shunji Kawazoe

Mototake Tsutsui

Tadashi Tanaka

Seiji Itoyama

Yasuhiro Shiraishi

Chikashi Okayama

Michitaka Sasaki

Hirokazu Tozawa

Yoshitaka Kobayashi

Hirohisa Ishii

Junichiro Yokota

Toshiki Yamamoto

Tooru Fukazawa

Masayuki Yamamoto

Masataka Sugimoto

Yasuhiko Nakagawa

Yuuichi Yamanaka

Shouji Kawano

Okikazu Kuwahara

Hideki Enosawa

Mitsuhiro Touhara

Tadamitu Hamasaki

Yoichi Kugimiya

Yuichi Yamanaka

Jun Shinozaki

Hiroaki Ito

Provided is a connecting structure for a vacuum pump, which can block propagation of electrical noise, generated by a main body of the vacuum pump. Between both ends of a connection piping for connecting the vacuum pump to a vacuum chamber of an apparatus to be connected with and evacuated by the vacuum pump, there is interposedly provided an electrical insulating portion formed of an insulating material so as to provide electrical insulation therebetween. The electrical insulation portion may be provided to a connection piping member such as a damper (or a valve depending on the connection arrangement) for absorbing mechanical vibrations.

Connecting structure for vacuum pump

Vibrations generated by a vacuum pump are prevented from propagating to external equipment such as an electron microscope. A casing (a separate casing portion and a casing main body) that houses a stator, stator blades, a rotor portion, and rotor blades as an exhaust function portion is connected to an inlet port portion in which an inlet port for sucking in a gas from the outside is formed, through an elastic member. An suction space between the casing and the inlet port portion is sealed by a bellows cylinder sealing means, and motion regulating members and motion regulating members and which regulate the amount of separation between the inlet port portion and the casing, and change shape due to relative motion between the two, are formed between the inlet port portion and the casing. The elastic member can maintain an appropriate amount of elastic force by means of the motion regulating members, good vibration reducing characteristics can be obtained at all times, and the propagation of vibrations to external equipment and the like, causing loss of function and endurance of the equipment, can be prevented. Further, plastic deformation and breakage of the elastic member and the sealing member can be prevented, and in addition, the vacuum pump can be prevented from running wild due to a sudden accident.

Vacuum pump

To reduce vibration caused by an unbalance of magnetic force generated in a motor portion due to run-out of a rotor in a magnetic bearing apparatus having the motor portion. The vibration of the rotor is detected by means of a radial direction sensor mounted for controlling a magnetic bearing. Then, the vibration in the motor portion is inferred from the run-out of the rotor detected by the radial direction sensor by using the geometric positional relationship between the rotor and the radial direction sensor. The relationship between the unbalance amount of the magnetic force and the amount of run-out of the rotor in the motor portion is formed into the database through experiments or simulation in advance, and the unbalance amount of magnetic force is obtained from this database. Then, the magnetic force resisting the unbalance amount of this magnetic force is generated to offset this unbalance amount.

Magnetic bearing apparatus

A protective device is provided for protecting a turbo molecular pump having a rotor mounted for undergoing rotation, an intake port for sucking gas by rotation of the rotor, and an exhaust port for exhausting the gas sucked from the intake port. The protective device has a detecting device for detecting the occurrence of an abnormal phenomenon in the turbo molecular pump. An abnormal phenomenon inference device infers a type of the abnormal phenomenon detected by the detecting device. A value obtaining device infers a magnitude of damage given to the turbo molecular pump by the abnormal phenomenon inferred by the abnormal phenomenon inference device and obtains a value weighted based on the inferred magnitude of the damage. A value accumulation device accumulates the value obtained by the value obtaining device. A sum obtaining device obtains a sum of the values accumulated in the value accumulation device. A protecting device protects the turbo molecular pump in a case where the sum obtained by the sum obtaining device exceeds a predetermined value.

Protective device for a turbo molecular pump and method of protecting a turbo molecular pump

Propylene polymer composition and its foam moldings

A vacuum pump has a casing having an inlet port and an outlet port, a flange integral with the casing and having a peripheral inner surface defining the inlet port and an end surface for connection to a container to be evacuated, and exhaust means for drawing in a gas through the inlet port and discharging the gas through the outlet port. A coating of material having low heat conductivity is disposed on the end surface of the flange.

To provide a vacuum pump that may heat a flow path of gas effectively with small electric power. A vacuum pump provided with an outer sleeve, a stator received in a hollow portion of the outer sleeve, a rotor received rotatably within the hollow portion of the outer sleeve for forming a flow path of gas in cooperation with the stator, a base to which the outer sleeve and the stator are to be fixed and supported, a heating electromagnet for generating heat by current supply and forming a magnetic field, a magnetic member forming a magnetic path of magnetic force by the heating electromagnet, and a heat radiation plate made of aluminum and fixed to the magnetic member.

Magnetic bearing apparatus and vacuum pump having magnetic bearing apparatus

There is provided a vacuum pump which suppresses the propagation of vibrations to an external container without the use of a damper. The vacuum pump has an outer cylindrical portion, a rotor portion and a stator portion accommodated within the outer cylindrical portion to define a transferring portion for a gas sucked from an inlet port, a magnetic bearing for supporting the rotor portion with respect to the stator portion, a motor for rotating the rotor portion with respect to the stator portion, and a base for supporting the outer cylindrical portion and the stator portion. A vibration absorbing member is interposed between the stator portion and the base, which has a natural frequency F&equals;(f1&plus;f3)/2&plusmn;(f1&minus;f3)/4, provided that f1, f2 and f3 respectively denote a natural frequency of nutation in conical mode, a natural frequency in parallel mode and a natural frequency of procession in the conical mode, when the rotor portion is rotated at a rated speed.

Vaccum pump

A composite-type electromagnet for a radial magnetic bearing has four composite-type electromagnet parts. Each part has four electromagnet cores formed of a magnetic material. The cores each have two protruding poles. A control coil is wound around each of the protruding poles and a biasing permanent magnet is disposed between each of the cores. The electromagnet cores and the biasing permanent magnets are in direct contact such that only a minute gap exists at a junction therebetween. A viscous material, adhesive material, or a magnetic fluid such as grease, having therein a material having high permeability and high saturation magnetic flux density is disposed in the minute gap so as to minimize magnetic flux leakage at the junction.

Composite-type electromagnet and radial magnetic bearing

A turbo molecular pump has a rotor having rotor blades arranged in multiple stages. Each of the rotor blades has a proximal end fixed to the rotor and a distal end. Stator blades are arranged in multiple stages. Each stator blade has a proximal end and a distal end. The rotor blades and the stator blades are alternately arranged in spaced-apart relation in an axial direction so that a spatial clearance between the proximal end of each of the rotor blades and the distal end of an adjacent stator blade is smaller than a spatial clearance between the distal end of each of the rotor blades and the proximal end of the adjacent stator blade. Each of the rotor blades comprises a cantilever member having upper and lower surfaces. At least one of the upper and lower surfaces of the cantilever member is contoured to define a flexure curve line represented by the formula &Dgr;&equals;(WL /8EI)(1&minus;(4X/3L)&plus;(X /3L )), where E (kgf/mm ) represents the Young's modulus of the material of the cantilever member, I (mm ) represents the geometrical moment of inertia of the cantilever member, L (mm) represents the length of the cantilever member, W (kgf/mm) represents a load distributed on the cantilever member, and &Dgr; represents a flexure amount of the cantilever member at a distance x (mm) from the distal end of the cantilever member.

Turbo molecular pump

The invention is a flame-retardant polyolefin composition that comprises 100 parts by weight of a propylene homopolymer or a propylene-ethylene copolymer containing at least 50% by weight of propylene polymer units, and from 0.01 to 5 parts by weight of a polyethylene having an intrinsic viscosity &lsqb;&eegr;&rsqb; of from 15 dl/g to 100 dl/g, and contains a non-halogen flame retardant.

Flame retardant polyolefin composition

A plastic molded product of olefin (co)polymer composition comprises 0.01-5.0 weight parts high molecular weight polyethylene with an intrinsic viscosity &eegr; in the range of 15-100 dl/g measured in 135&deg; C. tetralin and preferably 100 weight parts polypropylene. The high molecular weight polyethylene has an average particle size in the range of 1-5000 nm and is finely dispersed as fine granules in the polypropylene, so that high melt strength and high crystallization temperature are attained, enabling various molding methods to be performed with high speed productivity. Using the polymer composition, plastics such as a resin foam, a film, a sheet, a layered plastic article with a coated substrate surface, a hollow plastic article, an injection molded plastic article, a fiber, a nonwoven web or a continuous tube-shaped plastic are provided. The olefin (co)polymer composition is obtained by preparing high molecular weight polyethylene granules using e.g. a titanium transition metal compound catalyst, and adding these, e.g. as a polymerization catalyst of propylene, singly or together with a polyolefin preparing catalyst.

Molded resin articles

A vacuum pump comprises an inlet port into which a gas is introduced, an outlet port from which the gas is discharged, a stator, a motor, and a rotor opposing the stator and driven by the motor to undergo rotation to cooperate with the stator to force the gas from the inlet port to the outlet port. The rotor has a body, a spiral thread disposed on the body, and a thread groove disposed between adjacent lines of the spiral thread. An axial length of the spiral thread is shorter than an axial length of the rotor so that a terminal end portion of the spiral thread terminates short of an axial end of the rotor. The terminal end portion of the spiral thread slopes inward toward a surface portion of one of the thread grooves. A junction surface between a terminal end portion of the slope of the spiral thread and the surface portion of the thread groove forms a recessed portion.

Growing community of inventors

Chiba, Japan

Akira Yamauchi