Ebara Corporation

Kenichi Kajiwara

Kikuichi Mori

Hideo Ikeda

Hiroshi Uchida

Yoshiaki Miyazaki

Shinichiro Arakawa

Sou Kuroiwa

Shoji Ito

Masahito Kawai

Masahiko Kishi

Yukio Murai

Nobuhiro Higaki

Kaoru Nakajima

Tetsutaro Fujiwara

Akihiro Ohsaki

Aki Ishikawa

Koichi Kunimasa

Chitoshi Morita

Jun-ichi Sunaga

A multistage pump according to the present invention has a plurality of intermediate casings () formed by press-forming a steel plate. The intermediate casing has a cylindrical side portion (), a stage flat portion () with which an axial end face of an adjacent intermediate casing is held in contact, a stage side portion () extending axially from the stage flat portion, and a bottom portion () extending radially inward from the stage side portion. A relief plate () having an outer circumferential end face which is held in contact with an inner surface of a cylindrical side portion of the adjacent intermediate casing is attached to the bottom portion of the intermediate casing. The relief plate, the stage side portion, the stage flat portion, and the inner surface of the cylindrical side portion of the adjacent intermediate casing form a space in which an O-ring () is fitted.

Multistage pump

An impeller () according to the present invention has a disk-like main plate (), a blade () joined to the main plate, and a side plate () having a suction port. A boss hole () is formed in a central portion of the main plate for attaching a boss which engages with a pump shaft to the boss hole. A step portion () is formed around the boss hole, which is formed in the main plate, by drawing.

Impeller

According to the present invention, in a water supply apparatus which converts output power of a solar cell with an inverter to drive a motor pump for pumping up water, a DC brushless motor having no sensor for detecting a position of a rotatable shaft is used as a motor for driving the pump. Further, the water supply apparatus, having a pump and a frequency converter for supplying electric power to the pump and controlling a rotational speed of the pump, includes a standard current value table in which rotational frequencies of the pump and standard current values as criteria for shutoff operation at the rotational frequencies are associated with each other, a rotational frequency detecting device for detecting a rotational frequency of the pump, a standard current value acquiring device for acquiring a standard current value corresponding to the rotational frequency detected by the rotational frequency detecting device with reference to the standard current value table, a current detecting device for detecting a current value supplied to the pump, and a comparing device for comparing the current value detected by the current detecting device with the standard current value acquired by the standard current value acquiring device.

Water supply

The present invention relates to a fastener and a fastening method for joining together two or more members including at least one complicate-shaped plate. A fastener comprises a cap nut () having a main body and a thin-walled portion () projecting from the main body, and a bolt () screwed into the cap nut (). The cap nut () is fixed to a plate-like member () by inserting the thin-walled portion () into a through-hole () of the plate-like member () and caulking the thin-walled portion ().

Fastener and fastening method

A casing cover is used in separating a motor assembly and a pump assembly from each other in a pump device. The casing cover has a cylindrical wall portion having a motor-side positioning portion disposed on one of an inner and outer circumferential surface of the cylindrical wall portion for being fitted to a member of the motor assembly, and a pump-side positioning portion disposed on the other of an inner and outer circumferential surface of the cylindrical wall portion for being fitted to a member of the pump assembly.

Casing cover and pump device

An annular flange member is provided which is adapted to be provided around a fluid passage opening of a housing of a hydraulic machine to connect a fluid conduit means to the fluid passage opening. The annular flange member comprises an inside surface facing the housing, an outside surface opposite the inside surface, and a through hole extending from the inside surface to the outside surface and fluidly communicated with the fluid passage opening. The outside surface is provided with an O-ring receiving groove surrounding the through hole which is formed by a half die cutting press operation. A hydraulic machine is provided which includes a flange member as noted above.

Fluid machinery, a flange for fluid machinery, and a method for manufacturing them

Pipe joint for pump

A sheet-metal centrifugal pump casing comprising a casing shell having a suction port and being formed of a steel plate by means of deep drawing using a press, and having a suction flange firmly attached to the suction port of the casing shell is disclosed. The centrifugal pump casing further comprises a partition body firmly attached to the inner surface of the casing shell for partitioning a space within the casing shell into a suction chamber and a pressure chamber, and a diffuser which is integrally extended from the suction side end portion of the partition body and which tapers off toward peripheral edge of said suction port so that an axial gap is formed between the end edge of the diffuser and the peripheral edge of said suction port. Since the axial gap is formed between the end edge of the diffuser and the peripheral edge of the suction port, even in the case of the suction flange is acted upon by an external force such as by piping, a deformation does not affect the partition body, thus, problems such as contact between the partition body and the impeller may be completely avoided.

Sheet-metal centrifugal pump casing

A pump casing manufactured by press forming of steel plate and including a volute casing encircling a pump impeller so as to form a fluid path around the pump impeller is disclosed. The cross-sectional area of the fluid path is gradually increased towards a discharge port of the pump casing. The pump casing includes a casing body which is formed at first by press forming a metal plate into a cylindrical cup shape having an opening portion at one side thereof and a closed bottom portion at the other side of the same, and then by press forming the cylindrical cup shaped casing body so as to have a volute portion radially outwardly expanded from a cylindrical surface of the casing body at an axially intermediate portion thereof which radially opposite to the pump impeller, a casing flange outwardly extending from the opening portion and an aperture serving as a suction port at the bottom portion. Since no separate volute member is provided within the pump casing to form the volute portion, the outer diameter of the pump casing can be made small and also the shape of the fluid path in the volute casing can be made smooth.

Pump casing

A pump impeller manufactured by press forming of steel plate and comprising a boss formed with a central bore for connecting the boss to a main shaft of the pump through key and key way engagement, and a main shroud fixed to the boss is disclosed. The impeller is characterized in that the boss is formed with a polygonal portion on the periphery of the boss and the main shroud is formed at central portion thereof with a polygonal recess fitting to the polygonal portion of the boss. A retainer plate is mounted on the boss at an end portion thereof opposite to an end portion from which the main shroud is fitted to the boss and is connected by welding to the main shroud. Thereby, since the power is transmitted from the boss to the main shroud through polygonal surfaces, no substantial stress concentration occurs at the power transmitting area.

Growing community of inventors

Tokyo, Japan

Kenichi Kajiwara