Hitachi Industrial Equipment Systems Co., Ltd.

Shigeyuki Yorikane

Kenji Morita

Masahiko Takano

Kotaro Chiba

Yuta Kajie

Takeshi Tsuchiya

Yoshitaka Takeuchi

Hiroshi Ohta

Hideharu Tanaka

Toshiaki Yabe

Shuhei Nagata

Akira Iyozumi

Shota Tanimoto

Tomohiro Komatsu

Takashi Nakajima

Hiroyuki Matsuda

Masakazu Hase

Ryusuke Oshiro

Minako Kanada

Kazumasa Kanai

Toshiyuki Toyonaga

Yoshihiko Sagawa

An oil-feed-type air compressor includes a compressor main body driven by an electric motor, a separator that separates the oil from compressed air delivered from the compressor main body, an oil supply system that supplies the oil separated by the separator to working chambers of the compressor main body, an oil cooler that is disposed in the oil supply system and cools the oil by using cooling air generated by a cooling fan, and a controller. The controller stops the electric motor and the cooling fan when the continuation time of no-load operation has reached a predetermined value. Further, the controller predicts the return timing at which the electric motor is restarted, on the basis of a sensing history of the delivery-side pressure sensor, and predicts the delivery-side temperature of the compressor main body at the return timing.

Liquid-feed-type gas compressor

A gas compressor inhibits a supply delay of a compressed gas at a time of a return from no-load operation to load operation, and also reduces the consumed motive power. A controller switches between load operation and no-load operation by controlling a suction throttle valve according to a sensed delivery-side pressure, and also controls a rotation speed of an electric motor that drives the compressor. The controller is configured to compute a capacity C of an air supply system that supplies a compressed air generated by the air compressor to a use location of the compressed gas on a basis of load operation duration t1 and no-load operation duration t2, and set a target rotation speed of the electric motor at a time of no-load operation on a basis of the capacity C of the air supply system.

Gas compressor

A simpler notification is given about identifying causes of abnormalities and indicating dealing methods or countermeasures to deal with the causes of abnormalities. In a gas compressor including: a compressor body that compresses a gas; a drive source that drives the compressor body; at least one physical sensor that is disposed on at least one of a compressed-gas pipe or an electric system and detects a physical quantity in driving of the compressor body; a display unit; and a controller that processes the detected result from the physical sensor and causes the display unit to display information according to the processing, the controller stores in advance the associated relation between a preset range with respect to a rate of change of the physical quantity and information about at least one of a cause of a change in the physical quantity and a dealing method of dealing the cause, calculates a rate of change of the physical quantity on the basis of the detected result from the physical sensor, and causes the display unit to display information about at least one of the cause corresponding to the preset range and the dealing method of dealing with the cause when the calculated rate of change of the physical quantity is determined as falling in the preset range.

A screw compressor has first and second screw rotors that suck, compress, and deliver a working medium; a first bearing supporting one end of the first screw rotor coupled to a rotating shaft of a power source; a casing housing the first screw rotor and first bearing; a shaft-sealing member located on an opposite side of a tooth profiler for the first screw rotor relative to the first bearing and seals a through hole in the casing, through which a shaft of the first screw rotor coupled to the output shaft of the power source is inserted; a partition wall isolating the first bearing from the shaft-sealing member; and a liquid-supply route that is provided in the casing and has a first liquid supply opening for supplying a lubricating liquid to the shaft-sealing member and a second liquid supply opening for supplying the lubricating liquid to the first bearing.

Screw compressor

A screw compressor for compressing a working medium sucked through a suction opening and discharging the compressed working medium through a delivery opening, wherein the screw compressor includes: a male rotor and a female rotor that rotate while meshing with each other; a casing that houses the male rotor and the female rotor and is provided with a bore which forms a working chamber designed, together with the male rotor and the female rotor, to compress the working medium; a drive unit that rotationally drives at least one of the male rotor and the female rotor; a working chamber closing unit that forms a suction port for sucking the working medium into the working chamber and closes the working chamber when the working chamber reaches a specified capacity; and a suction space that connects the suction opening and the suction port to allow communication therebetween.

Screw compressor having working chamber closing member to regulate suction working medium flow to a working chamber

Provided is a liquid supply mechanism including: a plurality of liquid supply sections each including a plurality of branch paths whose central axes intersect with each other, and a supply path having a side surface to which the plurality of branch paths of the plurality of liquid supply sections are directly connected, respectively, and supplying liquid, which is supplied from an upstream, to the branch paths.

Screw compressor having a plurality of branch paths with intersects and central axes

A casing of a screw compressor has a delivery inner wall face facing delivery end faces of a male rotor and a female rotor. The delivery inner wall face of the casing has a shield area that shields at least a part of a track of an axial fluid communication path, which is a clearance that periodically occurs at the delivery end faces according to variation of intermeshing of the male and female rotors upon rotation thereof and is bounded by trailing flanks of the male and female rotors. The shield area of the casing is provided with a groove group made up of a plurality of grooves having longitudinal directions. The grooves of the groove group are juxtaposed in the circumferential direction of at least one rotor of the male and female rotors and are arranged such that their sides extending in the longitudinal directions are disposed adjacent to each other. Each groove of the groove group is configured such that its longitudinal direction oriented from the inner circumferential side of the one rotor toward the outer circumferential side is inclined with respect to the radial direction of the one rotor in the same direction as the rotational direction of the one rotor.

An oil feed type air compressor includes a compressor main body, a separator that separates the oil from the compressed air delivered from the compressor main body, and an oil feed system that supplies the oil to the working chambers and bearings of the compressor main body. The oil feed system includes an oil cooler that includes a cooling unit and a cooling unit connected on a downstream side of the cooling unit, an oil feed pipe that is connected to an outlet between the cooling unit and the cooling unit and that supplies the oil cooled by the cooling unit to the bearings of the compressor main body, and an oil feed pipe that is connected to an outlet on a downstream side of the cooling unit and that supplies the oil cooled by the cooling units to the working chambers of the compressor main body.

Liquid feed type gas compressor having a liquid supply system with first and second cooling units

A multi-stage screw compressor includes a plurality of stages of compressor bodies that compress a gas in sequence. Each of the stages of compressor bodies has both male and female rotors that are housed revolvably in a casing in a mutually meshing state. The male and female rotors each include a rotor lobe section having a suction-side end face and a discharge-side end face on one end and the other end thereof in the axial direction and having a twisted lobe extending from the suction-side end face to the discharge-side end face. The male and female rotors in a downstream-stage compressor body of at least one certain stage, excluding an upstream-stage compressor body as the first stage, among the plurality of stages of compressor bodies are each configured such that their lead increases from the suction side in the axial direction of the rotor lobe section toward the discharge side.

Multi-stage screw compressor

In a screw compressor, a lobe of a lobe profile of a female rotor includes: a first contour line defining a leading flank; a second contour line defining a trailing flank; and a third contour line defining a lobe tip having both endpoints at which the female has the maximum radius. In the lobe profile, when a first angle formed by two line segments linking a second rotation center as a vertex and both ends of the first contour line, a second angle formed by two line segments linking the second rotation center and both ends of the second contour line, and a third angle formed by two line segments linking the second rotation center and both ends of the third contour line, the third angle is greater on the delivery side in the axial direction, and the first angle is smaller on the delivery side in the axial direction.

Screw compressor and screw rotor

A liquid-supply-type screw compressor can suppress a rise in temperature of a liquid while reducing work for stirring the liquid. The compressor has male and female rotors, male- and female-rotor-side working chambers formed at grooves of the male and female rotors, respectively. The compressor also has a liquid supply nozzle arranged on one side in the rotor axial direction which is a low-pressure side of an intersection at which a high-pressure-side cusp intersects a ridge line of a trailing lobe tip of the female rotor that defines a female-rotor-side working chamber, the nozzle supplying liquid to the male-rotor-side working chamber; and a liquid-supply nozzle arranged on the other side in the rotor axial direction which is a high-pressure side of the intersection, and supplies the liquid to the male-rotor-side working chamber, and the liquid supply amount of the nozzle is made greater than the amount of the other liquid-supply nozzle.

Liquid supply type screw compressor

Provided is an oil feed type air compressor which can increase the determination accuracy regarding a deterioration state of oil. An oil feed type air compressorincludes a compressor main body, a separatorthat separates oil from compressed air discharged from the compressor main body, and an oil feeding systemthat feeds the oil separated by the separatorinto a compression chamber of the compressor main body. The oil feeding systemincludes a temperature control valvethat adjusts a diversion ratio for an oil coolerand a diversion ratio for a bypass pipeaccording to a temperature of the oil. The oil feed type air compressorincludes pressure sensorsA andB located in the oil feeding system, a discharge temperature sensorlocated on the discharge side of the compressor main body, and a controllerthat computes, when it is estimated that the diversion ratio for the oil cooleris 100% from the temperature sensed by the discharge temperature sensorexceeding a predetermined value Td, a difference ΔP between the pressure sensed by the pressure sensorA and the pressure sensed by the pressure sensorB and determines a deterioration state of the oil in reference to the difference ΔP.

Oil feed type air compressor

A position information antennareceives a position signal including position information about a sending source (satellite, base station, or the like) of a positioning radio wave. A communication antennatransmits position information about a compressor(air compressor) that compresses the air and receives meteorological information corresponding to the position of the compressorfrom a server on a cloud. A controllerspecifies the position of the compressorfrom the position signal received by the position information antennaand controls the compressoron the basis of the meteorological information corresponding to the position of the compressorreceived by the communication antenna

Air compressor

A compressor body includes a compression mechanism including a screw rotor that compresses gas, a casing that accommodates the compression mechanism and defines a compression working chambers therein, a suction side bearing that rotatably supports the screw rotor, a bearing chamber that accommodates the suction side bearing, and a liquid supply port that communicates with the compression working chambers and supplies liquid supplied from the outside of the casing into the compression working chambers. The casing has an internal liquid supply flow path that extends from a discharge side of the compression working chambers as an upstream side to a suction side of the compression working chambers as a downstream side and that supplies the liquid to the liquid supply port. The internal liquid supply flow path has a downstream portion reaching the bearing chamber and supplies the liquid to the suction side bearing.

Compressor body and compressor to supply liquid into working chambers and whose downstream portion reaches a suction bearing chamber

This screw compressor is provided with a screw rotor, a casing accommodating the screw rotor, and a liquid feed mechanism for feeding a liquid into an operating chamber enclosed by the casing, wherein the pitch of the screw rotor changes in the axial direction from a suction end surface toward a discharge end surface.

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Tokyo, Japan

Shigeyuki Yorikane