A screw compressor includes an outlet housing. The outlet housing includes a passage that is configured to communicate compressed fluid from a screw rotor to a discharge. A removable cover plate is configured to cover a portion of the passage. A method of varying a volume index for a screw compressor is also disclosed.

A screw compressor includes an outlet housing. The outlet housing includes a passage that is configured to communicate compressed fluid from a screw rotor to a discharge. A removable cover plate is configured to cover a portion of the passage. A method of varying a volume index for a screw compressor is also disclosed.

A screw compressor includes a compressor housing defining a working chamber, the housing including a plurality of bores; a first rotor having helical threads, the first rotor being housed in a first of the plurality of bores; a second rotor having helical threads intermeshing with the helical threads of the first rotor, the second rotor being housed in a second of the plurality of bores; an inlet port that receives a fluid to be compressed; an outlet port that receives a compressed fluid; and an intermediate discharge port disposed between the compression chamber and the outlet port, the intermediate discharge port including a sealing member and a biasing mechanism, fluid flow being prevented between the compression chamber and the intermediate discharge port when in a flow-blocked state, and fluid flow being enabled from the compression chamber through the intermediate discharge port when in a flow-permitted state.

Compression of water vapour as R718 is disclosed with and without addition of additives as an aqueous solution in rotational displacement machines, i.e. refrigeration, air-conditioning and heat pump technology. To largely avoid over or under-compression, it is proposed for the easiest possible adaptation of the currently effective internal volume ratio as so-called iV value in the displacer that the compressor housing starting from the outlet side with rotor profile length L.sub.R over a length L.sub.iV comprises planar, i.e. flat iV disks (3.sub.j) with the index j for 1≤j≤n; n is the number of disks; n≥1 with a width b.sub.j per iV disk having planar surfaces P.sub.F preferably perpendicular to the neutral axis A.sub.N. The iV disks are displaced in a targeted manner individually by movement control devices (5.sub.j) per iV disk in each case by a distance s.sub.i where 0<s.sub.i≤s.sub.j.

Compression of water vapour as R718 is disclosed with and without addition of additives as an aqueous solution in rotational displacement machines, i.e. refrigeration, air-conditioning and heat pump technology. To largely avoid over or under-compression, it is proposed for the easiest possible adaptation of the currently effective internal volume ratio as so-called iV value in the displacer that the compressor housing starting from the outlet side with rotor profile length L.sub.R over a length L.sub.iV comprises planar, i.e. flat iV disks (3.sub.j) with the index j for 1≤j≤n; n is the number of disks; n≥1 with a width b.sub.j per iV disk having planar surfaces P.sub.F preferably perpendicular to the neutral axis A.sub.N. The iV disks are displaced in a targeted manner individually by movement control devices (5.sub.j) per iV disk in each case by a distance s.sub.i where 0<s.sub.i≤s.sub.j.

A scroll compressor according to the present invention includes a casing having a hermetic inner space divided into a low pressure portion and a high pressure portion, an orbiting scroll disposed within the inner space of the casing and performing an orbiting motion, a non-orbiting scroll forming a compression chamber together with the orbiting scroll, the compression chamber having a suction chamber, an intermediate pressure chamber and a discharge chamber, a back pressure chamber assembly coupled to the non-orbiting scroll to form a back pressure chamber, a valve accommodation groove formed on at least one of the non-orbiting scroll or the back pressure chamber assembly, a bypass hole formed from the intermediate pressure chamber into the valve accommodation groove in a penetrating manner, a check valve accommodated in the valve accommodation groove and opening and closing the bypass hole according to pressure of the intermediate pressure chamber, a communication passage communicating the valve accommodation groove and the low pressure portion with each other, and a control valve selectively opening and closing the communication passage, whereby a facilitated fabrication, improved responsiveness and relaxed restriction for a specification of a valve can be achieved.

Provided is a compressor including a valve unit including: at least two guide pins passing through a discharge valve; and through holes allowing the guide pins to pass therethrough to control oblique motion of the discharge valve with respect to a horizontal direction during up and down movement of the discharge valve. When the discharge valve obliquely moves up and down with respect to the horizontal direction, the guide pin comes into contact with at least two points of an inner circumferential surface of the through hole so that the oblique movement of the discharge valve is restricted, thereby improving the durability of the discharge valve and reducing noise during operation of the compression.

A compressor may include first and second scrolls, and an axial biasing chamber. Spiral wraps of the scrolls mesh with each other and form compression pockets including a suction-pressure compression pocket, a discharge-pressure compression pocket, and intermediate-pressure compression pockets. The axial biasing chamber may be disposed axially between the second end plate and a component. Working fluid disposed within the axial biasing chamber may axially bias the second scroll toward the first scroll. The second end plate includes outer and inner ports. The outer port is disposed radially outward relative to the inner port. The outer port may be open to a first one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber. The inner port may be open to a second one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber.

A compressor may include first and second scrolls, and an axial biasing chamber. Spiral wraps of the scrolls mesh with each other and form compression pockets including a suction-pressure compression pocket, a discharge-pressure compression pocket, and intermediate-pressure compression pockets. The axial biasing chamber may be disposed axially between the second end plate and a component. Working fluid disposed within the axial biasing chamber may axially bias the second scroll toward the first scroll. The second end plate includes outer and inner ports. The outer port is disposed radially outward relative to the inner port. The outer port may be open to a first one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber. The inner port may be open to a second one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber.

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. The controller carries out switching to load operation when the discharge pressure drops to the lower-limit pressure L. In the gas compressor, the controller outputs a command of a lower rotation speed than the full-load rotation speed to the rotation speed converting means when the discharge pressure rises and reaches the upper-limit pressure H. The controller outputs a command of the full-load rotation speed to the rotation speed converting means when the discharge pressure drops and reaches the lower-limit pressure L.