Hitachi, Ltd.

Nippon Pillar Packing Co., Ltd.

Hitachi Plant Technologies, Ltd.

Hitachi Industrial Products, Ltd.

Hitchi Industries Co., Ltd.

Nippon Plant Packing Co. Ltd.

Taiji Hashimoto

Tetsuya Kuwano

Tomohiro Naruse

Tao Hu

Haruo Miura

Akira Suzuki

Takeshi Tsukamoto

Mitsuru Fujiwara

Hirotsugu Kawanaka

Takeshi Kazama

Eiji Okumachi

Tomoyoshi Okamura

Kouichi Irie

Masanobu Ninomiya

Yoshihisa Maeda

Hitoharu Kimura

Mitsuhiro Narita

Ryuhei Tsukahara

Kazuo Amano

Takaki Fukuchi

Shinji Imaoka

Youhei Tanno

Sadamitsu Yamauchi

A bolt fastening structure has an upper flange and a lower flange of a casing to which inner pressure is applied, the upper flange and the lower flange defining an abutting interface therebetween; a bolt hole formed through the abutting interface; and a counterbored portion formed asymmetric about a bolt hole center. The abutting interface includes a first region extending from a bolt hole inner side edge to an upper and lower flanges inner edge and being a region where the upper flange and the lower flange are in surface-to-surface contact with each other; and a partial contact region extending from a bolt hole outer side edge to an upper and lower flanges outer edge and being a region where the upper flange and the lower flange are partially in surface-to-surface contact with each other. In the partial contact region, the upper flange and the lower flange are in surface-to-surface contact with each other in a second region, and the first region is larger than the second region.

Bolt fastening structure and turbo-machine using same

In a centrifugal steam compressor having sealing water discharge at pressure higher than atmospheric pressure, a simple structure in which a high-pressure piping system is omitted as much as possible from a sealing water circulation system is realized. A shaft seal systemis capable of supplying high-pressure sealing water and low-pressure sealing water. The shaft seal system has a circulating water reservoirto store circulating water, a positive displacement pumpto suck the circulating water from the reservoir, and is capable of supplying the sealing water to a first pressure regulating valveprovided in a high-pressure side sealing water lineof a centrifugal compressorand a second pressure regulating valveprovided in a low-pressure side sealing water lineof the centrifugal compressor, an accumulatorprovided between the positive displacement pump and the first and second pressure regulating valves, return pipingsandto return the sealing water, which water-seals seal means of the centrifugal compressor, to the circulating water reservoir, and depressurization meansandinterpositioned in the middle of the return pipings.

Centrifugal steam compressor and shaft seal system used with same

A shaft-seal device for high-temperature fluid including a seal case () formed as a metallic cylindrical structure of a single unit and comprised of a main body portion (), first and second holding portions (), first and second partition portions (), a channel formation portion () forming a minute annular channel () with the outer circumference surface of a rotary shaft (), and an o-ring holding portion (). The seal case is installed in an apparatus housing () with first and second o-rings () in between. The intra-seal case region (A), in which sealing rings () of mechanical seals () are provided, and the high-temperature fluid region, which is an intra-apparatus housing region (A), are partitioned by a cooling chamber () into and from which coolant () is supplied and discharged via feed/discharge coolant paths ().

Shaft-seal device for high-temperature fluid

Size reduction of a barrel-type casing using a shear key is aimed for while ensuring a necessary area of a head cover end surface. A shoulder is formed on the axially outer side of the outer circumferential surface of a head cover. The inner surface of a casing is provided with a circumferentially extending groove. Shear key structure includes a first shear key member disposed in the shoulder and the groove, such that at least a portion of its outer circumferential surface is in contact with the inner circumferential surface of the groove, and a second shear key member disposed adjacent to the first shear key member in the groove, the second shear key member having an axially projecting shoulder, its outer circumferential surface being in contact with an inner circumferential surface of the casing. The first and second shear key members are circumferentially segmented respectively into three or more members, and each member is radially fixed to the casing but not axially fastened to each other, to allow slight displacement between the first and second shear key members by a shear force.

End wall closure apparatus

A welding apparatus and a welding method are employed for laser narrow groove welding which performs welding scanning a laser beam in the welding direction while feeding a solid filler metal into a narrow groove. The welding apparatus includes a laser beam irradiation head having a mechanism periodically oscillating an irradiation point of the laser beam with a predetermined amplitude in the bottom of the groove, and a filler metal control device having a solid filler metal feeder feeding the solid filler metal to the molten pool formed in the bottom of the groove by the laser beam and adjusting the feeding position independent of a motion of the laser beam irradiation head so that the tip position of the solid filler metal detected is constantly positioned in the center of the groove.

Laser narrow groove welding apparatus and welding method

A pump device for pressurizing a fluid to be fed, comprises: a rotary shaft, a bearing including a bearing surface adapted to face to the rotary shaft so that the rotary shaft is supported on the bearing surface in a rotatable manner, and an impeller fixed to the rotary shaft to be rotatable with the rotary shaft so that the fluid is pressurized by a rotation of the impeller.

Pump device

A pump, comprising: an impeller having blades; and a casing for storing the impeller therein, on an inner surface of which, confronting to the impeller, are formed plural numbers of shallow grooves in a direction of pressure gradient of fluid, around a periphery thereof, wherein the fluid being increased up in pressure by the blades flows within the grooves in a reverse direction, directing to an upstream side, so as to spout out at a place where re-circulations occur when the flow rate is low in amount. Also, an outlet angle of the blade is set to be within a region from 30 degree to 90 degree. Further, preferably, front guide vanes are provided, so that a direction of absolute flow at an outlet of the impeller is directed into an axial direction of the pump at an amount of designed flow rate.

Pump

A screw compressor including a scavenging port, which is separate from a discharge port, located on or in a vicinity of a discharge-side end face of the working space of the casing, for scavenging gas therethrough from a compression chamber near to a completion of a suction stroke. Gas of high temperature leaking from a compression chamber on high-pressure side into a compression chamber on a low-pressure side (in the suction stroke) can be scavenged from the compressor to outside, thereby avoiding a reduction in suction volume efficiency, an increase in consumption of power, and a rise in temperature of gas to be compressed which might otherwise be caused by the gas of high temperature leaking into the compression chambers during a suction stroke.

Screw compressor with scavenging port

Growing community of inventors

Tsuchiura, Japan

Taiji Hashimoto