Hitachi, Ltd.

Masayuki Yamada

Kunio Takada

Sumio Sudo

Kenji Otani

Saburo Maru

Sadashi Tanaka

Ryoji Okada

Toshihiro Yamada

Mitsuaki Haneda

Kooji Aizawa

Seiji Miura

Katsutoshi Nii

Hiromichi Anan

Akira Manabe

Kazunobu Ohashi

Yutaka Shimada

Kooju Aizawa

An underground water channel is provided in an underground of a large depth, and rain water and the like flow into this underground channel from flood control channels, conduits and rivers through vertical shafts. A pump well of a pump station is connected to a downstream end of the underground channel, and water flowing into the pump well is discharged by a pump to a discharge tank. The pump is disposed generally at a medium water level of the underground channel, and a lowest water level L.W.L enabling draining is the medium water level of the underground channel. In an open channel flow operation of an open channel-closed channel mixed flow operation, water level of the underground channel is maintained at the lowest water level L.W.L, so that the underground channel is in an open channel condition. In the closed channel flow operation, the underground channel is fully filled with water, and further water level rises into the vertical shafts, so that the underground channel is in a closed channel condition. By changing an outflow factor in accordance with rainfall patterns, the rate of flow into the vertical shafts can be accurately estimated, so that the large-depth underground drainage facility can be run in a stable manner.

Large-depth underground drainage facility and method of running same

An electronic file system and electronic filing method for achieving a high speed input operation under hardware and software environments employing a general-purpose architecture. An image control board having a predetermined capacity of memory and a CPU is connected to a computer system (personal computer), and a plurality of serial devices are connected to the image control board so as to permit these serial devices to be operated in parallel.

Electronic file system and method adapted for use with a general-purpose

Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit. The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC-12% sintered article is attained.

Bearing unit, drainage pump and hydraulic turbine each incorporating the

In a drainage pump station, a driving machine has a capacity greater than a shaft power necessary for no-discharge operation of a pump, and during severe flooding the pump is operated at an overload exceeding its design capacity. During maintenance operation water is fed from a river on the delivery side of the pump station into the station. When an inflow of rainwater into the pump station is great the pump is operated at the necessary capacity, when it becomes small the water level is kept above a rated value, and when the inflow rate is zero the pump discharge is increased to a capacity at which sediment can be discharged. A suction blower is disposed at the top of a suction sump and interstage valves are disposed in entrances of vertical shafts to effect efficient ventilation of the underground waterway. A feed channel is operated as a pressure channel and the pump is of variable capacity and the water level in the underground waterway is controlled to be constant.

Drainage pump station and drainage operation method for drainage pump

A vertical-shaft multi-stage pump has adjustable vanes on its lower stage. A vane angle operating mechanism has an operating shaft extending through a hollow portion of the drive shaft of the upper stage and a link mechanism connected to the operating shaft and the adjustable vane impeller for converting axial motion of the operating shaft into vane angle rotational motion. The pump is particularly suited for use in an underground drainage system.

Underground drainage facility, vertical-shaft multi-stage adjustable

Drainage pump and a hydraulic turbine incorporating a bearing member,

An underground drainage facility including a drainage pump adapted to be operated if an inflow water channel is constructed as a closed channel. Overflow weirs in water channels such as rivers or the like on an inflow side are less than a maximum water level. A vertical-shaft multi-stage adjustable-vane impeller is used as a drainage pump. Consequently, even a drainage pump of a high pressure head and large capacity can perform a waiting running and accommodate a variation in a quantity of inflowing water to the drainage facility.

Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit. The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC - 12% sintered article is attained.

A vertical shaft type pump including a bearing device in which water in the pump is utilized as lubricating water without supplying water to the bearing from the outside of the pump, thereby repeatedly conducting no-load operation in the air (in such a state that water is not pumped) stably for a long period of time. In the pump, a water storage tank upwardly opened is fixed to a rotary shaft, and the lubricating water (the water in the pump) is retained within the water storage tank so that the bearing is operated while being always soaked in the lubricating water. Also, foreign substances in the water storage tank are mixed with the water without deposition, and the water containing the foreign substances is replaced by the newly pumped water.

Vertical shaft type pump

A movable blade pump including an actuating mechanism for imparting rotational movement to blades which mechanism is contained in an impeller boss sealed against the outside and filled with hydraulic fluid and is driven by a hydraulic cylinder device secured to a suction casing below the impeller boss. Feed and discharge of hydraulic fluid into and from the hydraulic piston device are effected through fluid passages formed in the suction casing and a fixed mounting for the hydraulic fluid device, and the blades are set at any angular positions within the range of the stroke of the piston.

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Tsuchiura, Japan

Masayuki Yamada