Abstract: A screw compressor includes a screw rotor including: a rotor lobe part and a discharge-side shaft part; and a casing having a housing chamber that houses the rotor lobe part, a shaft hole through which the discharge-side shaft part passes, and a liquid feed path that introduces a liquid to the shaft hole. A second shaft section of the discharge-side shaft part disposed in the shaft hole and the shaft hole of the casing have a first opposed surface and a second opposed surface opposed to each other with a gap. The discharge-side shaft part has an annular groove on the first opposed surface, and the liquid feed path opens at a position opposed to the annular groove on the second opposed surface of the shaft hole. The second shaft section of the discharge-side shaft part and the shaft hole of the casing have, in an area remoter from the rotor lobe part than the annular groove, a tapered structure as a structure with a diameter smaller toward such a direction as to get further away from the rotor lobe part.

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.

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 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: 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 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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: 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: 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: 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.