Abstract: A screw compressor slide valve with gas pulsation attenuation function includes valve walls and internal through holes. A screw compressor includes the screw compressor slide valve. A part of exhausted gas of the screw compressor is directly discharged from an exhaust port to an exhaust chamber to form a main exhaust flow channel; another part of the exhausted gas is discharged from the exhaust port into the exhaust chamber after being delayed by the internal through holes, which forms a branched exhaust flow channel. Since the branched exhaust flow channel is longer than the main exhaust flow channel, when the gas pulsation in the branched exhaust flow channel lags behind that in the main exhaust flow channel by 180-degree in phase, two gas pulsations in the two flow channels are offset due to opposite gas pulsation phases, which attenuates the gas pulsation, thereby suppressing induced vibration and noise.

Abstract: A lubrication system is provided for a turbine engine. A lubricant source includes a source outlet. Feed circuits are fluidly coupled with the source outlet in parallel. The feed circuits include a first feed circuit and a second feed circuit. The second feed circuit includes a pump with a pump inlet and a pump outlet. A bypass circuit is fluidly coupled with the pump inlet and the pump outlet. A bleed circuit is fluidly coupled with the first feed circuit. A flow regulator is configured to regulate flow through the bypass circuit during a first mode of operation and a second mode of operation. The flow regulator is configured to close the bleed circuit during the second mode of operation. A sensor system is configured to monitor fluid flow directed to the first feed circuit and/or the second feed circuit.

Abstract: A rotary vane pump including a housing, and a motor. The motor includes a shaft which is coupled to a rotor. The rotor defines a plurality of slots. A plurality of free moving vanes are disposed within the slots. In one example, the rotor is formed from a first material and the plurality of vanes are formed from the first material and impregnated with a second material. The first material can be a carbon material. The second material can be a resin material, an antimony material, a copper material, or a silver material.

Abstract: A method for controlling the liquid injection of a compressor device, where the compressor device includes at least one compressor element, the compressor element includes a housing that includes a compression space in which at least one rotor is rotatably affixed by bearings, and liquid is injected into the compressor element. The method includes providing two independent separated liquid supplies to the compressor element, where one liquid supply is injected into the compression space and the other liquid supply is injected at the location of the bearings.

Abstract: A compressor casing having an internal gas passage includes a first bearing housing arranged at a first end of the casing, a second bearing housing arranged at a second, opposite end of the casing, and a rotor case disposed between the first bearing housing and the second bearing housing. The rotor case includes an axially extending bore within which a plurality of rotors are receivable and a hollow internal cavity isolated from the bore. The internal cavity is fluidly coupled to the bore via at least one recess. At least one exit opening is formed in one of the first bearing housing and the second bearing housing. The at least one exit opening is operably coupled to the internal cavity of the rotor case.

Abstract: Some embodiments of the present disclosure provide a slide valve for a compressor and a screw compressor with the slide valve. The slide valve for the compressor includes a slide valve main body (10), the slide valve main body (10) is provided with a gas replenishing chamber (11) therein, a surface, facing to a compression chamber of the compressor, of the slide valve main body (10) is provided with a gas replenishing outlet hole (12), and the gas replenishing outlet hole (12) is in communication with the gas replenishing chamber (11).

Abstract: A pump with two independent motors is disclosed. The first motor is mechanically connected to a first rotor comprising a first plurality of teeth radiating from the center of the first rotor. The second motor is mechanically connected to a second rotor comprising a second plurality of teeth radiating from the center of the first rotor, wherein the first plurality of teeth meshes with the second plurality of teeth. A sealed case may house the first and second rotors, and the case may include a suction inlet and a pressure outlet. Rotating the rotors propels a liquid from the suction inlet to the pressure outlet. Because the motors are independent of each other, when one motor fails to rotate the other motor will rotate both rotors and maintain the propelling liquid from the suction inlet to the pressure outlet. The pump may be a gear pump or a rotary lobe pump.

Abstract: Control systems and methods for increasing efficiency of a compressor while the compressor capacity exceeds compressor load, by using a mechanical unloader such as a slide valve to reduce the internal volume ratio of the compressor and allow a more efficient speed to be maintained by a variable frequency drive (VFD) while reducing the compressor capacity based on the load. Control systems include the VFD, a controller for the VFD and the mechanical unloader, and temperature sensors. Compressor embodiments further include one or more compressors and mechanical unloaders operated by the control systems.

Abstract: A progressing cavity gas pump with a stator which has a stator interior with an elastomeric inner surface as well as a gas outlet and a gas inlet, between which a pump delivery direction is defined, and with a rotor which engages with the stator interior, wherein below the stator, a lubricant reservoir is arranged which is connected via lubricant conduit devices to the stator interior. A progressing cavity gas pumping method using a progressing cavity gas pump, gas coming from a gas inlet is delivered with a rotationally driven rotor within a stator and through a stator interior having an elastomeric inner surface to a gas outlet and is compressed, and wherein from a lubricant reservoir below the stator, a lubricant supply to the stator interior takes place via lubricant conduit devices, and lubricant from the stator interior is recycled via the lubricant conduit devices into the lubricant reservoir.

Abstract: In a water-supply line for performing water-supply to the rotors and the mechanical seal of a compressor, or in a condensed-water collection line for collecting condensed water of a dryer into the inlet port of the compressor, a water reservoir is provided at a position higher than the water-supply unit of the compressor. Moreover, there are provided a start-time water-supply line and a solenoid valve set up therein. Here, the start-time water-supply line establishes the connection between the lower portion of the water reservoir, and the inlet port of the compressor and the water-supply unit of the mechanical seal.

Abstract: An airtight compressor includes a compression mechanism disposed inside an airtight container in a position below a gas retention space. An oil supply passage supplies oil from an oil reservoir both to the gas retention space (14) and to a sliding portion of the compression mechanism in a compression space. The oil supply passage communicates the gas retention space with a second space located on an opposite side of the piston from the intake chamber. A second channel is a channel that is different from the oil supply passage. The second channel enables a gas medium to flow from the gas retention space to the second space. Preferably, passage resistance when the gas medium flows through the second channel is less than when the gas medium flows through the oil supply passage.

Abstract: A vacuum pump (10) suitable for mounting at a lower region of an engine such as in the oil sump of an engine. The vacuum pump (10) includes a casing (12) having a cavity (14) containing a movable member (18), wherein the cavity (14) is provided with an inlet (32) and an outlet (34) and the movable member (18) is movable to draw fluid into the cavity (14) through the inlet (32) and out of the cavity (14) through the outlet (34) so as to induce a reduction in pressure at the inlet. The vacuum pump (10) is further provided with an oil feed conduit (84) to supply oil to the cavity (14), the oil feed conduit (84) being provided with a valve (86) to prevent the flow of oil to the cavity (14) during periods when the pump is not operating.

Abstract: A rotary vacuum pump includes a suction chamber (12) in a housing (10). A rotor (14) is eccentrically mounted in the suction chamber (12). Sliding vanes (18) are connected to the rotor (14). Further, a discharge channel (30) is connected to the suction chamber (12) and to an oil chamber (32). A valve (38) is disposed between the discharge channel (30) and the oil chamber (32) in order to prevent the medium from flowing back from the oil chamber (32) into the suction chamber (12). At least one compensating channel (50) is connected to the discharge channel (30) and to the oil chamber (32).

Abstract: A compressor system includes a lubricant reservoir, a screw compressor, and a valve. The screw compressor includes a housing defining a compression chamber having a suction port, a discharge port, a first lubricant feed port located between the suction port and the discharge port, and a second lubricant feed port located between the discharge port and the first lubricant feed port. The valve is in fluid communication with the lubricant reservoir, the first lubricant feed port via a first lubricant feed passageway, and the second lubricant feed port via a second lubricant feed passageway. The valve is movable between a first position and a second position. In the first position, the valve fluidly connects the lubricant reservoir to the first lubricant feed passageway to direct lubricant to the first lubricant feed port. In the second position, the valve fluidly connects the lubricant reservoir to the second lubricant feed passageway to direct lubricant to the second lubricant feed port.

Abstract: The compressor includes a sealed housing defining a suction volume and a compression volume respectively provided on either side of a body contained in the housing, an oil injection circuit supplied with oil from an oil contained in a casing and adapted for injecting oil into the compression volume, the oil injection circuit comprising an electrovalve including a body attached to the wall of the sealed housing and a core movable under the action of a magnetic fluid between a closing position for injecting oil into the compression volume and an opening position preventing or limiting the injection of oil into the compression volume. The compressor includes a control system for moving the core of the electrovalve between the opening and closing positions based on the compressor speed and/or on the cooling gas discharge temperature.

Abstract: A two-stage screw compressor has a low-pressure stage screw compressor and a high-pressure stage screw compressor integrally constructed. Compression space is formed by a male rotor and a female rotor, and operation gas is fed for compression to the compression space. A method of supplying lubrication oil prevents degradation of volumetric efficiency caused by return of lubrication oil, coming from a bearing and a shaft sealing device, to the low-pressure stage screw compressor. As a result, refrigeration capacity is improved and the amount of the lubrication oil is reduced.

Abstract: Device to prevent the formation of condensate in compressed gas coming from an oil-injected compressor element which is connected to an oil separator which is connected to the compressor element by an injection pipe, and wherein a cooler is provided in the injection pipe which can be bridged by means of a bypass. A controlled mixing valve is connected to the injection pipe and to the bypass, and a control device controls the mixing valve to adjust the compressed air temperature by adjusting the flow distribution through the mixing valve.

Abstract: A capacity varying type rotary compressor and a refrigeration system having the same are provided. The capacity varying type rotary compressor includes a casing that contains a certain amount of oil and maintains a discharge pressure state; a motor installed in the casing that generates a driving force; one or more cylinder assembly fixed in the casing, having a compression space that compresses a refrigerant by a rolling piston that performs an orbit motion and a vane that performs a linear motion by contacting the rolling piston, and having a vane pressure chamber formed at a rear side of the vane that implements a normal driving as the vane contacts the rolling piston or a saving driving as the vane is separated from the rolling piston; and a mode switching device that selectively supplies a suction pressure or a discharge pressure to the vane pressure chamber of the cylinder assembly according to a driving mode.

Abstract: A positive displacement compressor designed for near isothermal compression. A rotor includes a curved sealing portion that coincides with a in an interior rotor casing wall. Liquid injectors provide cooling liquid. A gate moves within the compression chamber to either make contact with or be proximate to the rotor as it turns. Gate positioning systems position the gate in this manner, taking into account the shape of the rotor. Outlet valves allow for expulsion of liquids and compressed gas. The unique geometry and relationship between the parts provides for efficiencies and higher pressures not previously found in existing compressor designs.

Abstract: A water-lubricated compressor has a discharge on-off valve in a discharge channel located between a discharge port of a compressor body and a water separating/recovering unit. A water circulation on-off valve is disposed in a water circulation channel located between a water cooler and a water supply portion in the compressor body. A gas release channel provides communication between a gas phase portion of the water separating/recovering unit and the exterior of the water separating/recovering unit. A gas release on-off valve is disposed in the gas release channel. When the compressor body is not in operation, the discharge on-off valve and the water circulation on-off valve are closed and the gas release on-off valve is opened, allowing water to be recovered to the water separating/recovering unit. When there is no demand for compressed gas, it is possible to remove water from the water cooler, which otherwise may be damaged.

Abstract: A scroll compressor is provided which has favorable assembling property, does not require a thrust bearing, has a bearing structure for bearing a compression section at both sides thereof and has a simple structure of a scroll.

Abstract: A compressor (20) has an unloading slide valve (100). The valve has a valve element (102) having a range between a first condition and a second condition, the second condition being unloaded relative to the first condition. A piston (124) is in a cylinder (128) and mechanically coupled to the valve element. A control valve (40; 42) is coupled to a headspace (138) of the cylinder to selectively expose the headspace to a fluid source (144), pressure of fluid in the headspace producing a force on the piston and valve element in a direction from the second condition toward the first condition. The compressor includes means (190, 192; 210; 220) for relieving excess pressure in the headspace.

Abstract: An oil-bearing shaft (1) through which the lubrication for components of a transmission is provided, comprising at least one longitudinal bore hole (2) and at least one oil supply bore hole (2) with one longitudinal bore hole (2), each fluid-mechanically connected, whereby the oil supply bore hole (2) is oriented with a setting angle ? is proposed.

Abstract: A compressor apparatus (20) has a housing (22) having first (53) and second (58) ports along a flow path. One or more working elements (26; 28) cooperate with the housing (22) to define a compression path between suction (60) and discharge (62) locations along the flow path. An unloading valve (100) has a valve element (102) having a range between a first condition and a second condition, the second condition being unloaded relative to the first condition. Means (120, 160) bias the valve element toward a third condition intermediate the first and second conditions.

Abstract: A compressor may include a shell, a compression mechanism, a motor, and a vapor injection system. The compression mechanism may be contained within in the shell and include a non-orbiting scroll axially displaceably mounted to the shell. The non-orbiting scroll may have an exterior portion, an interior portion, and a vapor injection passage extending therethrough from the exterior portion to the interior portion. The motor may be contained within the shell and may be drivingly coupled to the compression mechanism. The vapor injection system may include a vapor injection device, a vapor injection fitting, and a vapor injection valve. The vapor injection fitting may be in communication with the vapor injection device and the vapor injection passage. The vapor injection valve may be disposed between the shell and the interior of the non-orbiting scroll.

Abstract: The compressor includes a sealed housing defining a suction volume and a compression volume respectively provided on either side of a body contained in the housing, an oil injection circuit supplied with oil from an oil contained in a casing and adapted for injecting oil into the compression volume, the oil injection circuit comprising an electrovalve including a body attached to the wall of the sealed housing and a core movable under the action of a magnetic fluid between a closing position for injecting oil into the compression volume and an opening position preventing or limiting the injection of oil into the compression volume. The compressor includes a control means for moving the core of the electrovalve between the opening and closing positions based on the compressor speed and/or on the cooling gas discharge temperature.

Abstract: A rotary pump includes a stator having a chamber delimited by a circumferential wall, a cylindrical rotor tangent to the circumferential wall of the chamber and suitable for being driven in rotation around an axis eccentric with respect to the chamber, and at least a vane diametrically traversing the rotor by delimiting in the rotor two half shells, mutually separated by the walls guiding the vane. The two half shells are hollow, and inside these hollow half shells are housed elastic leaf springs forming one-way valves with respect to four passageways formed in the half shells; the discharge of the air-oil mixture takes place, after a centrifugation and a partial recycling, through passageways, also in the case of a counter rotation of the pump. This configuration allows a bidirectional use of the same rotor.

Abstract: In order to improve a screw compressor for compressing refrigerant in a refrigerant circuit, comprising a compressor housing, in which a screw rotor receiving means and an inlet channel as well as an outlet channel for the refrigerant to be compressed are provided, at least one screw rotor arranged in the screw rotor receiving means, a drive for the at least one screw rotor and a lubricant supply which conveys lubricant from a lubricant reservoir acted upon by pressure via a line system at least to the at least one screw rotor during operation, in such a manner that the operation and the monitoring of the screw compressor are reliable it is suggested that a valve be provided in the line system of the lubricant supply, this valve being controllable by way of a difference in pressure between the pressure in the outlet channel and a reference pressure influenced by a pressure in the refrigerant circuit and opening when the screw rotor is compressing refrigerant as well as closing when the screw rotor is not comp

Abstract: A volumetric compressor comprising: a casing provided with a suction chamber and a delivery chamber, between which a pair of screw rotors is included; a pan containing oil, and a delivery adjustment unit equipped with a slide valve, cooperating with the rotors and with a fluid-operated actuator, in which it is possible to identify an active chamber with a sliding piston connected to the slide valve. The adjustment unit comprises a flow switching unit, that connects the active chamber of the actuator to the pan and to the suction chamber and comprises a static flow switch removably associated with a switching solenoid valve electrically connected to a control unit. The switching solenoid valve is suited to be associated, alternatively, with different static flow switches that make it possible to obtain deliveries of compressed fluid varying discretely or continuously, depending on the position of the slide valve with respect to the rotors.

Abstract: A screw-type vacuum pump (1) is tempered such that characteristics of the pump are not substantially altered when the pump is subjected to thermal stress. In order to achieve said aim, cooling is adjusted according to an operating state of the screw-type vacuum pump (1), preferably to maintain a substantially constant pump gap (4).

Abstract: Disclosed is a screw compactor comprising two screw rotors which are disposed in screw rotor bores inside a compressor housing and compress a coolant that enters at a coolant inlet and discharge said coolant at a coolant outlet, and a coolant inlet that is arranged within the compressor housing, said coolant being supplied by a coolant-injecting device via a conduit system in order to additionally cool the screw compressor. The inlet is disposed so as to extend into compression spaces that are enclosed by the screw rotors and the screw rotor bores. The aim of the invention is to create a screw compactor in which the compressive oscillations occurring at the inlet do not travel at all or only in an attenuated manner into the conduit system for the coolant-injecting device.

Abstract: A group is provided for a compressed air distribution unit of the type including an intake regulator, an oil bath-screw type compressor, an air/oil separating tank, a minimum pressure valve, an air cooling radiator, a pressurized air collection tank, a thermostatic valve, and an oil cooling radiator, wherein the group includes the air/oil separating tank, the thermostatic valve, the minimum pressure valve, the oil cooling radiator, the air cooling radiator all connected to a cover for the air/oil separating tank resulting in a single-block group.

Abstract: The invention relates to a water-injected screw compressor which comprises a compressor element (1) with an interior space (3), a suction conduit (7) which connects to an inlet part (6), situated at the top of this interior space (3), a pressure conduit (9) in which a vessel (10) is installed, and an injection conduit (22) between the vessel (10) and the interior space (3), which comprises a part (31) which is situated higher than the upper side of the inlet part (6). A connection conduit (36) is provide between the inlet part (6), on one hand, and a connection point, situated above the maximum water level (35) of the vessel (10), onto the part (32) of this injection conduit (22) extending downward towards its exit, on the other hand.

Abstract: An apparatus for preventing overheat of a scroll compressor comprising: an overload preventing device for connecting or cut off a power source by a temperature and a current; a valve housing formed as a predetermined shape and fixedly coupled to the fixed scroll; a volume type valve movably inserted into the valve housing for opening and closing the discharge hole of the fixed scroll; and a valve pressurizing means located in the valve housing for increasing an input current by pushing the volume type valve and thus by blocking the discharge hole when temperature of discharge gas discharged to the discharge hole of the fixed scroll is more than a predetermined temperature. Accordingly, when a temperature of discharge gas is drastically or gradually increased and thus becomes a preset high temperature by several conditions at the time of driving the compressor, a driving of the overheated state is stopped by an immediate reaction thus to prevent a component damage.

Abstract: An axial slide valve is provided with an axially extending fluid chamber at each end with one chamber receiving a spring and being acted on by suction pressure and the other chamber coacting with a fixed piston and being acted upon by discharge pressure or the like whereby the slide valve is positioned so as to balance the spring and fluid pressures and thereby the compressor capacity.

Abstract: The invention comprises an arrangement for controlling the flow of a coolant fluid in a compressor, in particular in a rotary compressor, in which a coolant-fluid inlet for coolant fluid discharged from the compressor and a coolant-fluid outlet for returning the coolant fluid into the compressor are provided. A fluid cooler is also provided through which, when necessary, part of the coolant fluid can be directed for cooling and a system-control actuator is used to control the magnitude of the proportion of the coolant fluid that is directed through the fluid cooler on the basis of system parameters, in particular on the basis of the temperature of the coolant fluid.

Abstract: An industrial robot including a manipulator having a control system. The manipulator includes a common gear housing having first and second inner compartments connected with a passage channel. First and second gears are arranged in the first and second inner compartments and are adapted to move the manipulator. A cooling and lubricant medium is disposed in the common gear housing and circulates between the first and second inner compartments through the passage channel.

Abstract: A scroll-type compressor has a piston valve mechanism for controlling the feeding of lubricating oil to slidable parts of the compressor. The piston valve mechanism includes a cylinder bore that connects a medium pressure chamber and a low pressure chamber, and a piston valve and a spring accommodated with the cylinder bore. The spring resiliently biases the piston valve toward the medium pressure chamber. The piston valve is driven by a pressure difference between the medium pressure chamber and the low pressure chamber, and by the spring. In one embodiment, an inwardly stepped, narrowed portion formed in the cylinder bore engages the piston valve to prevent further compression of the spring.

Abstract: A method and apparatus for compressing process fluids in a working chamber having a male and a female rotor, each supported by shafts in a first and a second bearing chamber maintained at low and high pressures at least equal to 90% of the low and high pressures in the working chamber, respectively. The compressor has a first pressurized lubrication reservoir connected to the first bearing chamber and a second pressurized lubrication reservoir connected to the second bearing chamber. The fluids in the working chamber, which may be corrosive, are kept out of the fluids in the bearing and gear chambers by labyrinth seals on the rotor shafts, the seals having grooves in communication with a pressurized buffer gas system. Leakage of buffer gas from the seals enters the bearing chambers and reservoirs, and is released from them at flow rates to control the bearing chamber pressures.

Abstract: The bearing cooling device causes cooling media to flow into the interior of a journal bearing 8 for supporting a shaft part 7 by lubrication of high viscous fluid and the interior of the shaft part 7 to cool the shaft part 7 and the bearing 8. At this time, cooling medium temperature of the bearing 8 is set to be higher than cooling medium temperature of the shaft part 7. It is constituted so that the cooling medium passes the cooling medium passage and thereafter passes the cooling medium passage internally of the bearing. A heated medium supply device for supplying a heated medium to each cooling medium passage may be provided. The bearing cooling device is used suitably for a gear pump.

Abstract: A scroll compressor comprising: a vessel; a compressing mechanism provided within said vessel, the compressing mechanism comprising an orbiting scroll and a non-orbiting scroll each having a spiral wrap formed in a base plate and an Oldham ring for preventing the orbiting scroll from rotating around its axis; an oil reservoir provided within a vessel; a crankshaft for transmitting a power for compressing a working fluid; and a frame on which a main bearing for supporting the crankshaft is provided, wherein the crankshaft is provided with oil supply passages for communicating a vicinity of an orbiting bearing and a vicinity of the main bearing, and openings of the oil supply passages in the vicinity of the orbiting bearing and in the vicinity of the main bearing are positioned so that a pressure of an oil film in the orbiting bearing opening generated during an operation of the compressor is higher than a pressure of an oil film in the-main bearing opening generated during an operation of the compressor.

Abstract: The invention relates to a method for controlling a compressor installation with at least one lubricated screw-type compressor element (1) connected to a pressure vessel (11) which is driven by an electric motor (10) which is regulated in function of the compression pressure, and which compresses the gas supplied through the gas inlet conduit (2). The return flow of lubricating agent through the return conduit (7) also is determined by a controlled valve (9) which is provided with a calibrated opening (29) and which is controlled by control means (43) which, as the number of revolutions of the screw-type compressor element (1) has dropped below a well-defined value, put the controlled valve (9) into the position in which it restricts the return flow of lubricating agent to a flow through the calibrated opening (29).

Abstract: A scroll-type compressor has a piston valve mechanism for controlling the feeding of lubricating oil to slidable parts of the compressor. The piston valve mechanism includes a cylinder bore that connects a medium pressure chamber and a low pressure chamber, and a piston valve and a spring accommodated with the cylinder bore. The spring resiliently biases the piston valve toward the medium pressure chamber. The piston valve is driven by a pressure difference between the medium pressure chamber and the low pressure chamber, and by the spring. In one embodiment, an inwardly stepped, narrowed portion formed in the cylinder bore engages the piston valve to prevent further compression of the spring.

Abstract: The invention concerns a compressor installation with a water-injected compressor element (1) having a water cycle (6) and a water supply device (15) for supplying water to the water cycle (6), containing a water supply line (16) with a controllable valve (18) and a reverse osmosis filter (17) therein. Onto the water cycle is connected a by-pass (21) in which are erected an ion exchanger (22) and a controllable valve (23). A valve (18) in the water supply line (16) is controlled by a device (20) for measuring the amount of water in the water cycle (6), and the valve (23) in the by-pass (21) is controlled by a device (24) for measuring the conductivity of the water.

Abstract: A feed pipe 26 for a sealing water is connected to a housing of the pump to communicate with an enclosed chamber which is defined between a position in which a helical seal line of screw rotors 17 isolates the enclosed chamber from a suction port 15 of the pump and another position in which the enclosed chamber begins to open to a discharge port 24. Alternatively, a feed pipe for the sealing water is connected to the suction port 15 of the vacuum pump, and the feed pipe 26 is provided with a valve V which opens when the suction pressure of the sealing water becomes lower than −380 mmHg.

Abstract: A scroll compressor includes a fluid injection system. The fluid injection system includes a fluid passage which extends from a position outside of the shell of the compressor to the fluid pockets created by the wraps of the scroll members. The fluid passage extends through the orbiting scroll member. The fluid injection system can be used to inject gaseous or liquid refrigerant, lubricant or the fluid injection system can be used to vent the moving pocket to the suction area of the compressor for capacity modulation.

Abstract: A discharge side housing 3 has a third cooling water chamber 19 communicating with a first cooling water chamber 7 of a main housing 1 through a cooling water passage 26. The third cooling water chamber 19 is connected to a cooling water outlet pipe 27 which is connected to an inlet port 28a of a three-way valve 28. The three-way valve 28 has a switching port 28b which can communicate with a pipe line 29 connected to the first cooling water chamber 7. The three-way valve 28 has an outlet 28c connected to a pipe line 30 which communicates with a second cooling water chamber 22 of a suction side housing 2. The second cooling water chamber 22 is connected to a cooling water discharge line 31 provided with a flow control valve 32 allowing a back pressure for a cooling water flowing thereinto.

Abstract: Upon starting instruction of a compressor before the compressor is started, a pressurized water jet line 20 is opened and pressurized water is jetted to the inside of the compressor. By this manner, a dry operation with rotors and a mechanical seal kept in a dry state is definitely prevented and the compressor can be started even after it is stopped for a long hour. Further, the compressed air is supplied to the inside of the water tank, and the water from the water tank is jetted to the inside of the compressor by its pressure. The compressed air ejected from the water tank is cooled below a saturation temperature of water content and the water content thereof is condensed and separated. The separated water content is supplied to the inside of the compressor, and an excess circulating water is discharged from the water tank. Thus, a long hour continuous operation can be performed without replenishing water.

Abstract: A CO.sub.2 compressor is disclosed for forcing and moving a lubricant under discharge pressure. If the oil path is reduced in size or a pressure reducing part is inserted to handle the large differential pressure caused between the discharge pressure and the intake pressure, the oil path would become liable to be easily clogged by foreign matter. In view of this, an intermittent oil supply mechanism is formed in the oil path using the sliding contact portion between a fixed member of the compressor body and a movable member. Thus, the substantial lubrication time period is shortened and the amount of oil supplied is limited.

Abstract: A scroll compressor includes a fluid injection system. The fluid injection system includes a fluid passage which extends from a position outside of the shell of the compressor to the fluid pockets created by the wraps of the scroll members. The fluid passage extends through the orbiting scroll member. The fluid injection system can be used to inject gaseous or liquid refrigerant, lubricant or the fluid injection system can be used to vent the moving pocket to the suction area of the compressor for capacity modulation.