Abstract: A screw compressor includes a rotatable screw rotor and a plurality of gate rotors. The screw rotor has helical grooves formed in an outer circumferential surface of the screw rotor. The gate rotors have a plurality of radially disposed teeth meshing with the grooves of the screw rotor. The helical grooves include a first screw groove and a second screw groove. The first screw groove compresses a fluid from one end side of the screw rotor to an other end side of the screw rotor. The second screw groove compresses the fluid from the other end side of the screw rotor to the one end side of the screw rotor.

Abstract: A single-screw compressor includes a screw rotor including a spiral groove, a casing, and a gate rotor. The gate rotor includes a plurality of radial gates configured to mesh with the spiral groove. A clearance between one of the gates disposed in the spiral groove and a wall surface of a discharge side portion of the spiral groove is larger than a clearance between the gate disposed in the spiral groove and a wall surface of a suction side portion of the spiral groove. The wall surface of the discharge side portion of the spiral groove is a portion extending from a predetermined position of the spiral groove at a certain point in a compression phase to the terminal end of the spiral groove. The wall surface of the suction side portion of the spiral groove being a portion other than the discharge side portion.

Abstract: A single screw compressor structure includes a screw rotor and a casing, which houses the screw rotor. A tapered outer circumferential surface of the screw rotor has a plurality of helical grooves, with an outer diameter that increases from an inlet side toward a discharge side. The casing includes an outer tube member having a circular inner hole to form an interior, and an inner tube member is fixed to the interior of the outer tube member. The inner tube member has a tapered inner surface that opposes the tapered outer circumferential surface of the screw rotor. A single screw compressor further including a gate rotor is assembled by adjusting mesh between the screw rotor and the gate rotor, aligning the tapered outer and inner circumferential surfaces relative to one another, and integrally coupling the outer and inner tube members to each other.

Abstract: In a screw rotor (40), a first suction-side area (45) is formed in a first side wall surface (42) of a spiral groove (41). In the first side wall surface (42), a portion extending from a start point to a point until immediately before a compression chamber (23) is in a completely-closed state defines the first suction-side area (45). The first suction-side area (45) is thinner than a portion of the first side wall surface (42) other than the first suction-side area (45), and does not contact a gate (51) of a gate rotor (50).

Abstract: In a single screw compressor, gates (51) of gate rotors (50) are to be engaged with spiral grooves (41) of a screw rotor (40). In each spiral groove (41) of the screw rotor (40), an area extending from a start point of the spiral groove (41) to a position in a compression stroke is a suction-side portion (45), and the remaining portion (portion up to a terminal point of the spiral groove (41)) is a discharge-side portion (46). In the discharge-side portion (46), a clearance between a wall surface (42, 43, 44) therein and the gate (51) is substantially “0 (zero).” A clearance between the wall surface (42, 43, 44) in the suction-side portion (45) and the gate (51) is wider than that between the wall surface (42, 43, 44) in the discharge-side portion (46) and the gate (51), and is gradually narrowed from the start point toward the terminal point in the spiral groove (41).

Abstract: A single screw compressor structure includes a screw rotor and a casing. The screw rotor has a plurality of helical grooves formed in an outer peripheral surface thereof. The casing houses the screw rotor. The screw rotor includes a main tapered portion having a tapered outer diameter that becomes larger from an intake side toward a discharge side of the screw rotor, and a reversely tapered portion that is located on a downstream side of a maximum outer diameter portion of the outer surface and on the discharge side of the main tapered portion. The reversely tapered portion has a reversely tapered outer diameter that becomes smaller as the reversely tapered portion extends away from the maximum outer diameter portion.

Abstract: A compressor includes a screw rotor and a gate rotor. The screw rotor has a plurality of spirally extending groove portions disposed radially outwardly from the center axis of the screw rotor. The gate rotor has a plurality of tooth portions circumferentially arranged on an outer circumference to engage the groove portions. Preferably, an inclination angle of a groove portion side face contacting the tooth portions is inclined relative to a circumferential direction of the gate rotor varies. Alternatively a first plane contains the screw rotor center axis, a second plane orthogonally intersects the screw rotor center axis, a third plane orthogonally intersects the first and second planes, the gate rotor center axis is on the third plane, and the tooth portions do not overlap the first plane as viewed orthogonally relative to the third plane.

Abstract: A compressor includes a screw rotor and a gate rotor arranged to form a compression chamber. The screw rotor has an outer circumferential surface with at least one groove portion. The gate rotor has a plurality of tooth portions. Preferably, a first plane contains the screw rotor center axis, a second plane orthogonally intersects the screw rotor center axis, and a third plane orthogonally intersects the first plane and the second plane. The gate rotor center axis passes through an intersection point of the first, second and third planes. The gate rotor center axis is inclined relative to the second plane toward the same side as the groove portions of the screw rotor, as viewed in a direction perpendicular to the third plane.

Abstract: In a screw rotor (40), a first suction-side area (45) is formed in a first side wall surface (42) of a spiral groove (41). In the first side wall surface (42), a portion extending from a start point to a point until immediately before a compression chamber (23) is in a completely-closed state defines the first suction-side area (45). The first suction-side area (45) is thinner than a portion of the first side wall surface (42) other than the first suction-side area (45), and does not contact a gate (51) of a gate rotor (50).

Abstract: In a single screw compressor, gates (51) of gate rotors (50) are to be engaged with spiral grooves (41) of a screw rotor (40). In each spiral groove (41) of the screw rotor (40), an area extending from a start point of the spiral groove (41) to a position in a compression stroke is a suction-side portion (45), and the remaining portion (portion up to a terminal point of the spiral groove (41)) is a discharge-side portion (46). In the discharge-side portion (46), a clearance between a wall surface (42, 43, 44) therein and the gate (51) is substantially “0 (zero).” A clearance between the wall surface (42, 43, 44) in the suction-side portion (45) and the gate (51) is wider than that between the wall surface (42, 43, 44) in the discharge-side portion (46) and the gate (51), and is gradually narrowed from the start point toward the terminal point in the spiral groove (41).

Abstract: A screw compressor includes a rotatable screw rotor and a plurality of gate rotors. The screw rotor has helical grooves formed in an outer circumferential surface of the screw rotor. The gate rotors have a plurality of radially disposed teeth meshing with the grooves of the screw rotor. The helical grooves include a first screw groove and a second screw groove. The first screw groove compresses a fluid from one end side of the screw rotor to an other end side of the screw rotor. The second screw groove compresses the fluid from the other end side of the screw rotor to the one end side of the screw rotor.

Abstract: A single-screw compressor includes a screw rotor including a spiral groove, a casing, and a gate rotor. The gate rotor includes a plurality of radial gates configured to mesh with the spiral groove. A clearance between one of the gates disposed in the spiral groove and a wall surface of a discharge side portion of the spiral groove is larger than a clearance between the gate disposed in the spiral groove and a wall surface of a suction side portion of the spiral groove. The wall surface of the discharge side portion of the spiral groove is a portion extending from a predetermined position of the spiral groove at a certain point in a compression phase to the terminal end of the spiral groove. The wall surface of the suction side portion of the spiral groove being a portion other than the discharge side portion.

Abstract: A single screw compressor structure includes a screw rotor and a casing. The screw rotor has a plurality of helical grooves formed in an outer peripheral surface thereof. The a casing houses the screw rotor. The screw rotor includes a main tapered portion having a tapered outer diameter that becomes larger from an intake side toward a discharge side of the screw rotor, and a reversely tapered portion that is located on a downstream side of a maximum outer diameter portion of the outer surface and on the discharge side of the main tapered portion. The reversely tapered portion has a reversely tapered outer diameter that becomes smaller as the reversely tapered portion extends away from the maximum outer diameter portion.

Abstract: A single screw compressor structure includes a screw rotor and a casing, which houses the screw rotor. A tapered outer circumferential surface of the screw rotor has a plurality of helical grooves, with an outer diameter that increases from an inlet side toward a discharge side. The casing includes an outer tube member having a circular inner hole to form an interior, and an inner tube member is fixed to the interior of the outer tube member. The inner tube member has a tapered inner surface that opposes the tapered outer circumferential surface of the screw rotor. A single screw compressor further including a gate rotor is assembled mesh between the screw rotor and the gate rotor, aligning the tapered outer and inner circumferential surfaces relative to one another, and integrally coupling the outer and inner tube members to each other.

Abstract: A compressor includes a screw rotor and a gate rotor arranged to form a compression chamber. The screw rotor has an outer circumferential surface with at least one groove portion. The gate rotor has a plurality of tooth portions. Preferably, a first plane contains the screw rotor center axis, a second plane orthogonally intersects the screw rotor center axis, and a third plane orthogonally intersects the first plane and the second plane. The gate rotor center axis passes through an intersection point of the first, second and third planes. The gate rotor center axis is inclined relative to the second plane toward the same side as the groove portions of the screw rotor, as viewed in a direction perpendicular to the third plane.

Abstract: A compressor includes a screw rotor and a gate rotor. The screw rotor has a plurality of spirally extending groove portions disposed radially outwardly from the center axis of the screw rotor. The gate rotor has a plurality of tooth portions circumferentially arranged on an outer circumference to engage the groove portions. Preferably, an inclination angle of a groove portion side face contacting the tooth portions is inclined relative to a circumferential direction of the gate rotor varies. Alternatively a first plane contains the screw rotor center axis, a second plane orthogonally intersects the screw rotor center axis, a third plane orthogonally intersects the first and second planes, the gate rotor center axis is on the third plane, and the tooth portions do not overlap the first plane as viewed orthogonally relative to the third plane.

Abstract: Regulating compression capability to a load is performed by an inverter (15) that regulates revolution number of an electric motor (11). This makes unload control in capability regulation unnecessary, preventing operational efficiency from lowering. Further, a capacity control valve for capacity control is eliminated for a simplified valve control mechanism. Regulating a variable inner volume ratio achieves the highest compressor efficiency corresponding to operating condition (capability). When a low inner volume ratio command is issued, a slide valve (19) is moved by a compression section controller (27) in an axial direction toward the electric motor (11). This advances completion time of a compression step to advance discharge of a compressed gas. When a high inner volume ratio command is issued, the slide valve (19) is moved in an axial direction toward a piston (25), which delays time of completion of compression step to delay discharge of a compressed gas.

Abstract: Present invention provides a single screw compressor from which only a small amount of gas to be compressed leaks and which can be manufactured at low costs. There are provided a screw rotor 1 having six grooves 2, 2, . . . and a gate rotor 4 having 12 teeth 5, 5, . . . which are installed in a casing. Since six, which is the number of the grooves of the screw rotor 2, and twelve, which is the number of the teeth 5 of the gate rotor, have a common divisor, only predetermined teeth 6 are engaged with a groove 2. Therefore, engagement combinations of the grooves 2 and the teeth 5 are divided into six groups. In each of these groups, dimension accuracy is controlled so that the grooves 2 and the teeth 5 engaged each other have appropriate clearances. Since manufacture is easier when dimension accuracy is controlled within each group than when dimension accuracy of all grooves 2 and teeth 5 is controlled at one time as in a conventional case, this single screw compressor becomes inexpensive.

Abstract: Present invention provides a single screw compressor from which only a small amount of gas to be compressed leaks and which can be manufactured at low costs. There are provided a screw rotor 1 having six grooves 2, 2, . . . and a gate rotor 4 having 12 teeth 5, 5, . . . which are installed in a casing. Since six, which is the number of the grooves of the screw rotor 2, and twelve, which is the number of the teeth 5 of the gate rotor, have a common divisor, only predetermined teeth 6 are engaged with a groove 2. Therefore, engagement combinations of the grooves 2 and the teeth 5 are divided into six groups. In each of these groups, dimension accuracy is controlled so that the grooves 2 and the teeth 5 engaged each other have appropriate clearances. Since manufacture is easier when dimension accuracy is controlled within each group than when dimension accuracy of all grooves 2 and teeth 5 is controlled at one time as in a conventional case, this single screw compressor becomes inexpensive.