Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi, Ltd.

Hitachi-johnson Controls Air Conditioning, Inc.

Kotaro Chiba

Shigeyuki Yorikane

Takeshi Tsuchiya

Kenji Morita

Masahiko Takano

Yoshitaka Takeuchi

Yuta Kajie

Minako Kanada

Kentaro Yamamoto

Toshikazu Harashima

Nae Hisano

Shuhei Nagata

Toshiaki Yabe

Kosuke Sadakata

Masanao Kotani

Ryota Iijima

Shota Tanimoto

Ryoji Kawai

Tomohiro Komatsu

Hitoshi Nishimura

Sachio Sekiya

Yasuaki Iizuka

Ryuichiro Yonemoto

Eisuke Kato

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 gas compressor includes a compression mechanism, a separator tank that introduces lubricating oil to be supplied to the compression mechanism and a mixed fluid of a working fluid and lubricating oil discharged from the compression mechanism and separates the lubricating oil. An oil cooler cools the lubricating oil from the separator tank. An oil circulation path supplies cooled lubricating oil to the compression mechanism. The gas compressor includes a suction temperature sensor that detects suction temperature of the working fluid, a discharge pressure sensor that detects discharge pressure of the compressed working fluid, a rotation speed sensor that detects rotation speed of the motor. A lubricating oil state estimation unit estimates the temperature of the lubricating oil based on the detected suction temperature, discharge pressure, and rotation speed of the motor. The lubricating oil state estimation unit uses this result to estimate the deterioration state of the lubricating oil.

Gas 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

A liquid-cooled rotary compressor includes a compressor main body having a compression chamber formed by a fixed wall and a rotating wall and compressing gas, and a liquid injection path for injecting a coolant into the compression chamber, and adjusts a discharge flow rate by changing a rotational speed of the rotating wall. The compressor includes a liquid amount adjusting unit that adjusts an amount of the coolant supplied from the liquid injection path to the compressor main body according to a change in the rotational speed of the rotating wall, and a compressed gas supply path that supplies compressed gas to a downstream side of the liquid amount adjusting unit in the liquid injection path. The compressed gas is supplied from the compressed gas supply path to the liquid injection path according to the amount of the coolant supplied to the compressor main body.

Liquid-cooled rotary compressor and coolant supply method therefor

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.

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

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.

Screw compressor having a screw rotor whose pitch changes in an axial direction from a suction end surface toward a discharge end surface

A delivery port of a rotary-screw compressor includes a first opening having a profile configured to interrupt communication with a second working chamber of a suction process that opens only in the axial direction; a second opening connected to the first opening; and a third opening connected to the first and second openings. The profile of the first opening includes a first profile line that forms one of a pair of lateral edges of a lingulate protrusion; a second profile line that forms another one of the pair of the lateral edges of the protrusion; a third profile line that extends toward the reference point along the root circle of the female rotor; and a second connection line that connects the first and second profile lines. The second opening opens into the first opening at the second connection line. The third opening opens into the first groove.

Liquid-feeding rotary-screw compressor

A screw compressor includes plural screw rotors, plural suction-side bearings that each rotatably support the suction side of the plural screw rotors and plural discharge-side bearings that each rotatably support the discharge side of the plural screw rotors, and a casing that houses the plural screw rotors, the plural suction-side bearings, and the plural discharge-side bearings. Each screw rotor includes a lobe section with plural lobes and a suction-side shaft section and a discharge-side shaft section each disposed at both ends of the lobe section. The casing has a housing chamber that houses the lobe sections of the plural screw rotors and a lubrication path in which liquid that lubricates the plural suction-side bearings circulates. In the lubrication path, respective passages to lubricate each of the plural suction-side bearings are connected in series and a most downstream part is connected to the housing chamber.

Screw compressor having a lubrication path for a plurality of suction side bearings

A screw compressor includes a screw rotor, a casing, and a delivery side shaft sealing unit. The delivery side shaft sealing unit includes an annular groove, a seal ring, and a shaft sealing fluid supply passage. Pressure of the fluid that is supplied to the one side, in the axial direction, of the seal ring via the shaft sealing fluid supply passage is set higher than pressure that acts on a first side surface, in an axial direction with respect to a first side wall surface of the annular groove, of the seal ring.

Screw compressor having a different pressure of the fluid applied to the seal ring on the delivery side shaft sealing unit

A screw compressor includes a screw rotor, a casing, and a fluid supply portion to supply fluid in a membrane form into a compression chamber in the casing. The screw rotor has a male and female rotors. A male bore covering the male rotor and a female bore covering the female rotor are formed on the inner surface of the casing. An intersection line, on a higher pressure side, of the male and female bores is defined as a compression cusp. In a bore development view, a trajectory made by the first intersection of an extension line of a female lobe ridge and a male lobe ridge being moved, along with the rotation of the male and female rotors, is defined as a trajectory line. An opening of the fluid supply section to the compression chamber is positioned between the compression cusp and the trajectory line.

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Tokyo, Japan

Kotaro Chiba