Abstract: A scroll compressor and a refrigerating machine including the scroll compressor are provided. An oil supply channel may be formed in a fixed scroll of the compressor so as to provide for communication between a back pressure chamber and compression chambers formed between the fixed scroll and an orbiting scroll. The oil supply channel enables oil to be smoothly introduced from the back pressure chamber into each compression chamber, so that frictional losses and refrigerant leakage in the compression chambers may be effectively prevented, and efficiency of the compressor and the refrigerating machine including the compressor may be enhanced.

Abstract: A scroll compressor (CP) in which the cylinder oil circulation rate of lubricant is optimized during the operation to improve the compression efficiency is provided. In the scroll compressor (CP) having a stepped shape, the cylinder oil circulation rate of lubricant taken into the scroll compressor (CP) and circulated together with refrigerant is set to fall within the range from 1% or more to 10% or less.

Abstract: An oil lubricated compressor which includes a bypass oil line connecting respective oil paths upstream and downstream of the motor. The bypass oil path permits oil to be detoured around the motor in a tube that is external to the compressor shell and flows back into the shell near the scroll inlet. The oil bypass line returns “excess” oil directly to sump 28, rather than having it flow from sump 27 to sump 28 through an air-gap, thereby reducing both the drag on the motor and the input power.

Abstract: A scroll-type refrigerant compressor includes a drive shaft with an off-axis lubrication conduit which is supplied with oil from an oil pan located in the lower part of the compressor by an oil pump that is disposed at a first end of the shaft. The lubrication conduit has lubrication holes at the different shaft guide bearings. The second end of the shaft is equipped with a device that enables the orbital movement of the moving scroll of the compressor. The aforementioned shaft also includes a return conduit which is inclined in relation to the axis of the shaft and which extends over at least part of the length thereof. One of the ends of the return conduit opens at the wall of the shaft in the area located beyond the rotor on the side of the oil pan. In addition, fluid communication is provided between the lubrication conduit and the return conduit.

Abstract: A compressor with a built-in centrifugal oil separator is characterized in that the oil separator is formed between a first member and a second member constituting a compressor by the coupled structure of the first member and the second member. In the compressor, by simplifying the structure of the oil separation part, the productivity can be improved, the cost can be reduced, and the freedom of the design of the discharge port position can be ensured.

Abstract: A scroll compressor for compressible fluids includes a fixed housing having a spiral-shaped feed chamber which contains a working fluid. A displacement member interacts with the feed chamber and includes a driveshaft which is supported in the housing and has an eccentric disk, a carrier disk which is mounted on the driveshaft, and spiral blades which extend out from both sides of the carrier disk. The displacement member is supported by a bearing on the eccentric disk. A lubricant supply system feeds lubricant to the bearing via the driveshaft and the eccentric disk, with a seal assembly sealing a lubricant chamber against the feed chamber.

Abstract: A scroll compressor and an air conditioner in which improvement of performance is achieved by a gas injection cycle and increase in manufacturing cost is prevented are provided.

Abstract: A baffle member for use in scroll compressors. In one exemplary embodiment, the baffle member is attached to a portion of the crankcase and, in use, deflects lubricant that may be thrown from the thrust surface of the crankcase during operation of the compressor away from the flow of working fluid, and also aids in directing the flow of working fluid away from the thrust surface of the crankcase and toward a suction inlet in the compression mechanism.

Abstract: An oil pump for a compressor includes a driving shaft having an oil passage, a gear driving unit coupled to the drive shaft, a pump body having a driving shaft insertion groove, a friction reducing member assembled on the driving shaft insertion groove to reduce friction between the driving shaft and pump body, and a a gear unit coupled to the pump body and rotating with rotation of the driving shaft. The pump may further include a pump cover coupled to the pump body and having an intake for inhaling oil.

Abstract: A scroll compressor is provided. The scroll compressor includes a casing, an oil pump, an oil retrieving port, and an oil retrieving unit. The casing has a fluid storage area in a lower portion thereof. The oil pump is provided in the lower portion of the casing, and has a suction unit which suctions fluid from the fluid storage area. The oil retrieving port is in the casing to allow oil retrieved from an external oil separator to flow into the casing. The oil retrieving unit is connected to the oil retrieving port and provides a path which directs the retrieved oil to the suction unit.

Abstract: A motor-driven scroll type compressor has a motor that includes a rotary shaft and rotates the rotary shaft, a bearing for rotatably supporting front end of the rotary shaft, a fixed scroll member, a movable scroll member driven by rear end of the rotary shaft, compression chambers defined by the movable scroll member and the fixed scroll member and a housing. The rotation of the rotary shaft makes an orbital motion of the movable scroll member around the axis of the rotary shaft and accordingly the compression chambers are moved radially and inwardly thereby to compress the refrigerant gas. The compressor further has a suction chamber communicating with the compression chambers, a discharge chamber, an oil separation chamber separating lubricating oil from the refrigerant gas and communicating with the discharge chamber and a back pressure chamber provided in front of the movable scroll member in the housing and facing to the rear end of the rotary shaft.

Abstract: A horizontal type scroll compressor is provided with a support plate separating an inside of the sealed container into a first space in which the compressor mechanism portion and the electric motor portion are stored, and a second space in which the discharge pipe is provided, and a communication path communicating a bottom portion of the first space and a space above the drive shaft within the second space in a lower side of the support plate, and regulates an oil level by the communication path in the case that the oil level difference becomes large at a time of a high-speed operation. In order to stabilize the oil supply to the bearing or the like, the oil is supplied by an oil pump provided in a shaft end portion of the drive shaft close to an oil reserving chamber.

Abstract: A scroll type compressor has a fixed scroll member, a movable scroll member, an oil reservoir, a back-pressure chamber, an oil extraction passage, a flow passage, and a partition wall. The back-pressure chamber disposed behind the movable scroll member is in communication with a discharge chamber. The oil extraction passage having a regulating valve or a throttle connects the back-pressure chamber to the oil reservoir. The oil return passage and the flow passage connect the oil reservoir to a suction chamber, respectively. The flow passage introduces excess lubricating oil into the suction chamber when the level of lubricating oil in the oil reservoir becomes higher than a predetermined level. The partition wall disposed between the openings of the oil extraction passage for restricting lubricating oil from the oil extraction passage other than the excess lubricating oil collected in the oil reservoir from flowing to the flow passage.

Abstract: A compressor includes a tubular vertical shaft, which rotates about its vertical axis, a cylinder block for supporting the tubular vertical shaft, a rotor for driving the rotation of the tubular vertical shaft, and a stator affixed to the cylinder block. A lubricant is channelled from the lower end of the tubular vertical shaft through an inlet of its interior path to the outlet. A magnet is disposed within the interior path to trap ferrous contaminants in he lubricant before the lubricant is distributed to other parts of the compressor.

Abstract: An orbit control device for a scroll compressor is disclosed including at least one pin disposed in an orbit scroll, a support plate having at least one support hole formed therein, and a guide plate having at least one guide hole formed therein. Contact of an outer surface of the pin with an inner surface of the guide hole militates against a deviation by the orbit scroll from a desired trajectory.

Abstract: Disclosed herein is an oil supply structure of a scroll compressor. The oil supply structure is provided to prevent a slender hole of an oil supply screw from being clogged with sludge, the oil supply screw being provided between a backpressure space, which is defined between an orbiting scroll and a main frame, and a space which is defined between a fixed scroll and the main frame, and adapted to supply oil from the backpressure space into the space. The oil supply screw includes an orifice having a center hole longitudinally perforated through the center of an upper portion of a screw body of the oil supply screw and a slender hole continuously perforated below the center hole to have the same axis as that of the center hole, and a sludge discharger having a non-flat-plane configuration and formed at a lower entrance end of the screw body.

Abstract: Provided is a scroll compressor having an improved function of oil circulation and back pressure control. The scroll compressor includes: a housing; a drive part for generating a rotational force; a drive shaft driven by the drive part; and a scroll compression part including a stationary scroll fixed regardless of rotation of the drive shaft and having a scroll wrap for compressing sucked fluid and a discharge port for supplying coolant into a discharge chamber, and an orbiting scroll orbited depending on rotation of the drive shaft and having a scroll wrap, characterized in that the coolant compressed by the scroll compression part is conveyed to the discharge chamber, the coolant of the discharge chamber is separated into oil and gas in an oil separator, the gas being discharged through a discharge hole and the oil being supplied into a back pressure chamber through a return path formed in the stationary scroll, and the oil is returned into a suction chamber through a back pressure adjustment valve.

Abstract: A horizontal scroll-type compressor utilizes the pressure differential between the discharge pressure and the suction pressure to route lubricant from the discharge chamber to the components within the intake chamber. The compressor may utilize a lubricant separator within the discharge chamber to separate the working fluid from the lubricant prior to the working fluid exiting the compressor. The compressor may use an internal passageway that extends from the discharge chamber to a position adjacent the crankshaft to provide lubricant to the internal lubricant passage within the crankshaft.

Abstract: A scroll compressor includes a baffle member in a high pressure region of the housing where compressed fluid is stored. The baffle serves to carry and transfer pressure loads away from the central region to an outer periphery region where such loads can be transferred to the outer housing. Deflection, stress and wear on the scroll compressor bodies may be reduced.

Abstract: Lubrication of bearing surfaces in a scroll compressor is enhanced by a vent arrangement which makes use of increased centrifugal force, achieved by locating the outlet of the vent arrangement radially outside of the nominal circumference of the compressor's drive shaft, to both remove refrigerant gas from compressor locations where such gas can inhibit the flow and delivery of lubricant to such surfaces and to increase the lift of lubricant out of the compressor's lubricant sump. Oil retained in the upper surface of the compressor drive shaft is made immediately available for bearing lubrication upon compressor start-up to further enhance compressor lubrication.

Abstract: A compressor housing defines a motor accommodating chamber. The pressure in the motor accommodating chamber is equal to the pressure in a suction chamber. A first reservoir chamber is located in a discharge chamber. A second reservoir chamber is defined about the discharge chamber. A communicating passage connects the first reservoir chamber with the second reservoir chamber. A restrictor is located in the communicating passage. An oil return passage connects the second reservoir chamber with the suction chamber. A connecting passage connects the motor accommodating chamber with the suction chamber. Therefore, leakage of electricity is prevented.

Abstract: A scroll compressor, wherein a guide passage facing the supply passage of a fixed side substrate part is formed at the outer peripheral portion of a fixed scroll engaged with a movable scroll along the axial direction of the fixed scroll. A lubricating oil is stored in an oil storage tank surrounded by a set of weir walls formed along the guide passage and the movable side substrate part of the movable scroll facing a fixed side spiral wall. The movable side substrate part is radially displaced by the turning action of the movable scroll to supply the lubricating oil stored in the oil storage tank to the movable scroll side.

Abstract: A lubricant backflow structure of a compressor includes a casing, a scrolling set, and a transmission mechanism. An oil tank is arranged under the casing, an internally longitudinal wall of which is formed as an oil backflow passage, an inlet of which is corresponded to one side of the scrolling set for receiving a lubricant, and an outlet of which is formed above the oil tank. Thereby, when a working fluid (e.g. refrigerant) enters into the casing, it won't mix with the lubricant therein, capable of reducing oil consumption and enhancing thermally exchanging efficiency of the system.

Abstract: A compressor may include a compressor housing, an oil sump, an intake chamber, a compression mechanism, a drive shaft, and a first oil passage. The oil sump may be in communication with the compression mechanism. The intake chamber may be defined within the housing. The drive shaft may include first and second ends with an oil inlet passage located therebetween. The first end may be disposed within the intake chamber and may be drivingly engaged with the compression mechanism. The second end may extend outside of the housing for driven engagement external to the housing. The oil inlet passage may be located within the intake chamber. The first oil passage may be disposed within the housing and in communication with the oil sump and the oil inlet passage.

Abstract: Disclosed herein is a muffler of a scroll compressor. The muffler includes a first muffler having a pair of chambers defined above an outlet of a fixed scroll to communicate with the outlet and a gas passage hole formed at the center of an upper end thereof, and a second muffler located around the first muffler to be spaced apart from the gas passage hole of the first muffler and having a chamber including one or more guidance paths of the fixed scroll. The muffler can achieve reduction of operational noise, sufficient separation of oil contained in discharge gas, and efficient isolation between a discharge pressure inside the muffler and outside suction pressure.

Abstract: An oil pump of a scroll compressor is provided. The oil pump includes a pump body to which a drive shaft is inserted; a gear unit inserted to a lower side of the pump body and rotating by the rotation of the drive shaft; and a pump cover coupled to a lower side of the pump body and including an inlet through which oil is introduced, an outlet through which the introduced oil is discharged to the drive shalt, and one or more noise reducing portions reducing noise generated during a pumping process.

Abstract: An oil pump for a compressor is provided. The oil pump includes a pump body coupled to a driving shaft, and a pumping member coupled to the pump body so as to define a pumping part and a pump cover is coupled to a lower side of the pump body therebetween. A lower suction unit provided at a lower side of the pump body draws fluid into the pump from a lower portion of a supply area, and an upper suction unit draws fluid into the pump from an upper portion of the oil supply area.

Abstract: This refrigerating compressor comprises a sealed chamber delimiting a suction volume and a compression volume arranged respectively either side of a body contained in the chamber, and an oil injection circuit arranged to inject oil into the compression volume. The oil injection circuit comprises a moving blocking piece, operated by a centrifugal force, between a first position enabling oil injection into the compression volume and a second position preventing or limiting oil injection into the compression volume, the blocking piece being arranged to be displaced into its second position when the speed of the compressor exceeds a predetermined value.

Abstract: The invention relates to a scroll-type refrigerant compressor The inventive compressor comprises: a sealed chamber which is defined by a ferrule (2) and which contains a suction volume and a compression volume; and an electric motor which is disposed on the suction side and which comprises a stator (7) and a rotor (8), the latter being solidly connected to a drive shaft (26). The stator (7) is surrounded by an intermediate casing (6) which defines (i) an annular volume (13) with the moving ferrule (2) of the compressor and (ii) a chamber (11) containing the coil end of the motor and facing the compression volume side. The end of the intermediate casing that faces the side opposite the compression volume is disposed at the end of the stator facing the side opposite the compression volume or set back from same. In addition, means (14) are provided in order to convey at least part of the gas arriving at the gas inlet in the ferrule into the chamber (11) containing the coil end.

Abstract: A scroll compressor is provided with an orifice plug inserted into an oil passage. The plug has an opening which is positioned to restrict the flow of oil through the passage, and in particular at higher speeds. The opening is formed at an outer periphery of the plug, and may be positioned at a location spaced furthest from the center of rotation of the shaft.

Abstract: A scroll compressor including an oil separator is provided. The oil separator may be provided with a rotor or a shaft of a driving motor of the compressor so that refrigerant gas and oil discharged from a compression chamber may be separated by a centrifugal force. The oil separator may include a plurality of oil separation holes formed in an eccentric mass and a rotor. Rotation of the shaft/rotor and subsequent rotation of the eccentric mass generates a centrifugal force, causing separation of oil from refrigerant gas contained in the oil separation holes. Accordingly, oil is maintained in the casing, and is prevented from being discharged out of the compressor, thus preventing abrasion due to oil deficiency and a degradation in reliability of the compressor. Furthermore, oil is prevented from being discharged to a refrigerating system externally coupled to the compressor, thereby enhancing performance of the refrigerating system.

Abstract: A scroll fluid machine is configured by engaging a fixed scroll and an orbiting scroll having spiral bodies formed on base plates. A seal member is provided between a rear surface of the orbiting scroll and a frame member arranged opposite thereto to divide a rear side chamber into an inner space and an outer space. The inner space inside the seal member is subjected to a pressure substantially corresponding to a discharge pressure, and the outer space is subjected to a pressure lower than that of an inner back pressure chamber to press the orbiting scroll against the fixed scroll. The scroll members are formed such that the width of a groove and the thickness of a tooth of the spiral body formed inside the seal member are larger than those of the spiral body formed outside the seal member.

Abstract: According to the present invention, an oil supply passage is formed in a suction space of a fixed scroll part, and an oil collision part is provided in the suction space. The oil collision part is provided in the suction space, an amount of oil to be supplied is controlled, refrigerant and lubricant oil are sufficiently mixed with each other. Tangents of ends of the oil collision part are made acute angle to smoothen the flow of the refrigerant.

Abstract: A compressor comprises, in a container body, an electric element, and a compressive element driven by the electric element. An oil storage is provided in the bottom, and an oil pump is provided to suck up oil from the oil storage. The oil pump includes a cylinder fixed to a lower support frame, a rotator axially installed on the lower end of a driveshaft and operative to rotate within an inner space of the cylinder, and a suction pipe having an upper end connected to a communication notch formed in the cylinder and a lower end inserted and arranged in the oil storage. In this compressor, the upper end of the suction pipe is protruded into the communication notch of the cylinder to configure an oil residue pool.

Abstract: The present invention provides a compressor capable of supplying a lubricating oil stably to the refrigerant suction side of a compression section even if a lubricating oil is discharged into an oil storage chamber with great force. In this compressor, the oil storage chamber is provided so that two chambers of a first oil storage chamber and a second oil storage chamber communicate with each other, the lubricating oil discharged from a separation chamber is received by the first oil storage chamber, and the lubricating oil is supplied from the second oil storage chamber to the refrigerant suction side of the compression section. Therefore, even if the oil surface of the first oil storage chamber is disturbed by the force of the lubricating oil discharged from the separation chamber, the lubricating oil can always be supplied stably without hindrance to the supply of lubricating oil to the refrigerant suction side of the compression section.

Abstract: A hermetic type scroll compressor according to the invention includes a scroll compressor element in which an end plate of a orbiting scroll and an end plate of a fixed scroll are assembled such that they slide against each other, an electric motor element which drives the scroll compressor element, a hermetic casing housing the scroll compressor element and the electric motor element and holding lubricating oil collected at a bottom thereof, and an oil separator disposed on a discharge side of the scroll compressor element. An interior of the hermetic casing is kept at an intermediate pressure between a suction pressure and a discharge pressure. An oil return mechanism is provided, which intermittently returns lubricating oil from the oil separator to sliding parts of the orbiting scroll end plate and the fixed scroll end plate. The hermetic type scroll compressor 31 can be improved in performance and reliability while promoting cost reduction.

Abstract: A scroll compressor may include a shell, a bearing housing, first and second scroll members, and a ring member. The bearing housing may be supported within the shell and may include at least three axially extending arms. The first scroll member may be supported on the bearing housing and may include a circumferential outer surface. The second scroll member may be supported on the bearing housing and may be meshingly engaged with the first scroll member. The second scroll member may be disposed between the first scroll member and the bearing housing. The ring member may include an open center portion surrounding the circumferential outer surface of the first scroll member therein. A portion of the ring member may be disposed between the arms of the bearing housing and the circumferential outer surface of the first scroll member.

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 and oil separation device therefore are provided. The oil separation device is integrated with a compressor and includes a first case having a refrigerant inlet into which a refrigerant mixed with oil is sucked and an oil recollecting member through which oil separated from the refrigerant flows, and a second case positioned outside of the first case and having a refrigerant outlet through which refrigerant separated from an oil is discharged. With this constructions, a pipe connecting the compressor and a separate oil separation device is not required, thereby reducing fabrication costs and facilitating installation.

Abstract: A scroll compressor is provided with a housing having a discharge chamber to which a high-pressure refrigerant is discharged from a scroll unit, a discharge path connecting the discharge chamber and an outlet port 78 of the housing, a separating device arranged in the discharge path and separating a part of the lubricating oil from the refrigerant, and a relief valve arranged in a downstream side of the separating device in the discharge path. When a pressure within the discharge path exceeds a relief pressure, the relief valve is opened so as to eject the refrigerant to an outer side of the compressor from the discharging path.

Abstract: A cup-shaped shield surrounds a counter weight on the lower end of a rotor of the refrigeration compressor. The shield advantageously restricts lubricant flow to the rotating lower end of the rotor whereby power consumption of the motor is reduced. The shield may be axially and/or rotationally limited by engagement with a lower bearing assembly. The shield may be used on a scroll compressor. The shield may also be used on a rotor without having a counter weight on the lower end thereof.

Abstract: A compressor and oil blocking device therefor are provided which are capable of preventing oil from spreading onto, for example, a balance weight, which are capable of preventing oil from being excessively sucked into a compression device by a separating device disposed between a driving motor and the compression device, and which are capable of constantly maintaining a predetermined amount of oil in compression chambers regardless of a rotational speed of the driving motor by directly supplying oil to a bearing surface and the compression chambers and by easily discharging gas from an oil drain passage. A trochoid gear pump may be used to smoothly supply oil to the compression device. Further, a synchronous reluctance motor may be used to enhance a performance of the compressor and to expand a driving region of the compressor.

Abstract: Lubrication of bearing surfaces in a scroll compressor is enhanced by a vent arrangement which makes use of increased centrifugal force, achieved by locating the outlet of the vent arrangement radially outside of the nominal circumference of the compressor's drive shaft, to both remove refrigerant gas from compressor locations where such gas can inhibit the flow and delivery of lubricant to such surfaces and to increase the lift of lubricant out of the compressor's lubricant sump. Oil retained in the upper surface of the compressor drive shaft is made immediately available for bearing lubrication upon compressor start-up to further enhance compressor lubrication.

Abstract: A hermetic compressor uses an oil pump that includes a trochoid gear. Therefore, regardless of the rotation speed of a driving motor of the compressor, a sufficient amount of oil can always be pumped. The oil pump unit may include a plurality of suction holes with openings at different heights. If the refrigerant and oil separate, at least one of the openings will admit oil into the oil pump unit, to ensure lubricating oil is supplied to the moving parts of the compressor.

Abstract: In a scroll-type fluid machine (4), a refrigerant in a discharge chamber (80) is adjusted at prescribed discharge pressure by using a discharge valve (84), discharged from a scroll unit (52), and supplied to a refrigeration circuit (2), and the machine has a circulation path (7) for introducing the refrigerant in the discharge chamber from the refrigeration circuit toward a drive casing (22) while maintaining the refrigerant pressure, and an inlet path (93) formed in a compression casing (24) and leads the refrigerant in the circulation path to the rear side of a movable scroll (54) to make the led refrigerant counteract the refrigerant discharge pressure acting on the front side of the movable scroll.

Abstract: An oil discharge preventing apparatus of a scroll compressor comprises: a balance weight coupled to a rotor of a driving motor so as to offset an unbalance generated when an orbiting scroll performs an orbiting motion by receiving a rotation force of the driving motor; and a lower fixed oil guide fixedly coupled between the balance weight and the rotor, for preventing oil from being spread in a casing and guiding the oil downwardly to a bottom of the casing, whereby an oil leakage to the outside of the casing can be minimized, the number of construction components can be reduced, and assembling processes can be simplified.

Abstract: A scroll compressor utilizes scroll wrap profiles which are designed with a rapid compression scroll wrap profile. This profile utilizes a shorter wrap and lower vane aspect ratios during the compression process. The non-orbiting scroll member is integrated with the main bearing housing. The drive shaft extends through the main bearing housing, through the non-orbiting scroll member and through the orbiting scroll member. In one embodiment, a counterweight is disposed adjacent the orbiting scroll member. In another embodiment, and upper bearing housing is disposed adjacent the orbiting scroll member. In yet another embodiment, an upper bearing housing is disposed adjacent the orbiting scroll member with a counterweight disposed adjacent the upper bearing housing.

Abstract: An oil feeding propeller of a scroll compressor for preventing deterioration of oil feeding generated when a rotation shaft is rotated in reverse is disclosed. The propeller is tightly fitted into the lower side of the oil passage of the rotation shaft, sucks oil into the shell due to rotation shaft of shaft to raise oil to a compression part of the scroll compressor. The propeller includes a plate without operative direction for feeding oil in a predetermined direction so as to raise a predetermined quantity of oil regardless of the rotation direction shaft.

Abstract: A rotary compressor for preventing, to the maximum extent possible, oil within the compressor from being discharged to a gas discharge port. The rotary compressor includes a drive device and a compression device which are mounted in a hermetic container. The hermetic container includes an upper cover formed with a gas discharge port. The rotary compressor includes a scroll chamber defined in an inner surface of the upper cover around the discharge port, to separate oil from gas to be discharged, and a discharge guiding member installed inside the upper cover, to guide the gas, discharged from the hermetic container, into the scroll chamber and to guide the gas, having passed through the scroll chamber, to the discharge port.

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.