Abstract: A multi-stage screw compressor includes a plurality of stages of compressor bodies that compress a gas in sequence, and each stage of the plurality of 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 as 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.

Abstract: 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.

Abstract: 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.

Abstract: 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, wherein an open space that connects the suction opening and the suction port to allow communication therebetween is provided between a shaft

Abstract: 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.

Abstract: 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.

Abstract: In a screw compressor, a lobe profile of cross-sections perpendicular to the axial direction in a female rotor that rotates about a second rotation center changes in the axial direction. One lobe of the lobe profile of the female rotor includes: a first contour line defining a leading flank on a rotation direction side of the female rotor with a lobe bottom as a boundary point; a second contour line defining a trailing flank on an opposite side of the rotation direction; and a third contour line defining a lobe tip having both endpoints at which the female has the maximum radius.

Abstract: 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.

Abstract: 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 compressor 1 includes a compressor main body 3, a separator 6 that separates oil from compressed air discharged from the compressor main body 3, and an oil feeding system 8 that feeds the oil separated by the separator 6 into a compression chamber of the compressor main body 3. The oil feeding system 8 includes a temperature control valve 20 that adjusts a diversion ratio for an oil cooler 18 and a diversion ratio for a bypass pipe 19 according to a temperature of the oil.

Abstract: The liquid level of a liquid supply compressor including a gas-liquid separator is dynamically monitored. A liquid supply gas compressor includes a compressor body; a gas-liquid separator separates liquid from compressed gas, to store the liquid; a liquid piping system supplies liquid stored to the compressor body; an internal pipe extends in an internal space of the gas-liquid separator, and includes at least two hole portions, with different disposition positions in a height direction, on an internal side to communicate with the piping system; and a sensor detecting pressure or temperature of fluid flowing through the piping system.

Abstract: 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.

Abstract: 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.

Abstract: A liquid supply type screw compressor that can suppress a rise in temperature of a liquid while reducing work for stirring the liquid is provided. The liquid supply type screw compressor has a male rotor 11A and a female rotor 11B, male-rotor-side working chambers formed at grooves of the male rotor 11A, and female-rotor-side working chambers formed at grooves of the female rotor 11B.

Abstract: 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 opening and the second opening. The profile of the first opening includes: a first profile line that forms one of a pair of lateral edges of a lingulate protrusion configured to close off the second working chamber and extends toward a reference point; 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 profile line with the second profile line. The second opening is a first groove that opens into the first opening at the second connection line and extends toward a reference line.

Abstract: 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.

Abstract: 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.

Abstract: A technique is provided that can further reduce power at the time of “unload operation control” in a gas compressor that generates a compressed gas at a set pressure by constant-speed control. The gas compressor includes a compressor main unit, a drive source, an intake throttle valve, a gas release valve, rotation speed converting means, a pressure detecting device that detects a discharge pressure, and a controller that, the relationship between an upper-limit pressure H and a lower-limit pressure L being H>L, carries out opening the intake throttle valve and closing the gas release valve and operating the drive source at a full-load rotation speed until the discharge pressure reaches the upper-limit pressure H. The controller carries out at least one of closing the intake throttle valve and opening the gas release valve to reduce the discharge pressure to within a predetermined range when the discharge pressure reaches the upper-limit pressure H.

Abstract: 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.

Abstract: A position information antenna 22b receives a position signal including position information about a sending source (satellite, base station, or the like) of a positioning radio wave. A communication antenna 22a transmits position information about a compressor 100 (air compressor) that compresses the air and receives meteorological information corresponding to the position of the compressor 100 from a server on a cloud. A controller 13 specifies the position of the compressor 100 from the position signal received by the position information antenna 22b and controls the compressor 100 on the basis of the meteorological information corresponding to the position of the compressor 100 received by the communication antenna 22a.

Abstract: 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.