Abstract: A scroll compressor is provided in which a boss of an orbiting scroll is inserted into and coupled to a boss coupling recess of a crank shaft, so that friction loss of a bearing portion of the crank shaft may be reduced, compression efficiency and reliability of the compressor may be enhanced, and noise and material costs may be reduced. A bush bearing may be formed as a coating on the boss of the orbiting scroll, so that a thickness of the bearing portion of the crank shaft may be reduced. Since an outer circumferential surface of the bearing portion is in contact with an inner circumferential surface of the boss coupling recess, damage to the bearing portion may be prevented.

Abstract: A compressor is provided and may include a driveshaft and an orbiting scroll member driven by the driveshaft. The orbiting scroll member may include an end plate, a spiral wrap extending from the end plate, and a chamber formed by the orbiting scroll member and disposed on an opposite side of the end plate than the spiral wrap. A counterweight may be fixed for rotation with the driveshaft and may be received within the chamber of the orbiting scroll member.

Abstract: A compressor includes a housing, a first scroll member, a second scroll member and a valve assembly. The first scroll member is positioned within the housing and includes a first end plate portion and a second end plate portion coupled to the first end plate portion and having a first spiral wrap extending therefrom. The first end plate portion and the second end plate portion define a discharge passage. The second scroll member is positioned within the housing and includes a second spiral wrap meshingly engaged with the first spiral wrap. The valve assembly is supported by at least one of the first end plate portion and the second end plate portion at a location radially outward from the discharge passage.

Abstract: In order to suppress the damage and the degradation in durability of a bearing of an expander, simplify the configuration of the expander, and reduce the manufacturing cost thereof, an expander of the present invention includes an expander rotor that is rotationally driven by an expanding force transmitted from vapor of a working medium introduced into an expansion chamber and a first bearing that supports a first rotation shaft of the expander rotor to a vapor inlet, a casing includes therein first bearing chambers that have a pressure lower than that of the vapor inlet and accommodate the first bearing, and a passage that leads lubricant to a low-pressure portion having a pressure lower than that of the first bearing chamber is connected to a position above the lowermost portion of the first bearing in the first bearing chamber.

Abstract: A scroll-type compressor for a CO2 vehicle air conditioning system, having a movable displacement spiral which is rotatably connected to an eccentric bearing and which engages into a counterpart spiral such that, between the windings of the displacement spiral and of the counterpart spiral, there are formed chambers which travel radially inward in order to compress the refrigerant and discharge the refrigerant into a pressure chamber, wherein the displacement spiral is arranged on the suction side and the counterpart spiral is arranged on the high-pressure side. The scroll-type compressor is wherein the eccentric bearing is arranged in the displacement chamber between the displacement spiral and the counterpart spiral and has a bearing bushing which is formed integrally with the displacement spiral and the base of which is in alignment with the face side of the windings of the displacement spiral.

Abstract: A scroll-type compressor for a CO2 vehicle air conditioning system, having a mechanical drive which is connected by a drive shaft to an eccentric bearing. A movable displacement spiral is rotatably connected to the eccentric bearing and engages into a counterpart spiral such that, between the displacement spiral and the counterpart spiral, radially inwardly traveling chambers are formed in order to compress the refrigerant and discharge it into a pressure chamber. Wherein the counterpart spiral is movable in alternating fashion relative to the displacement spiral in an axial direction, wherein, between the counterpart spiral and the displacement spiral, there is arranged at least one spring for exerting an axial release force on the counterpart spiral, and at least one piston engages on the counterpart spiral, in order to exert an axial closing force on the latter, adjacent to the pressure chamber in an off-center position.

Abstract: A scroll compressor is provided in which the amount of lubricant oil supply is appropriately controlled over a low to high rotational frequency range of the scroll compressor. The scroll compressor has an oil supply unit and an oil supply passage. The oil supply unit includes a small hole with a diameter not exceeding a seal ring width of the sealing part and a groove which are formed on the end plate of the boss portion on the back side of the orbiting scroll. As the orbiting scroll orbitally moves, oil in the high pressure hydraulic chamber pools in the small hole to be discharged, across the seal ring, into the back pressure chamber. The oil supply passage communicates between the high pressure hydraulic chamber and the back pressure chamber.

Abstract: A refrigerant compressor includes a compressor mechanism part 2, and a motor and a crank shaft 101 for driving the compressor mechanism part, in a sealed case 100, and includes sliding bearings 103, 104, and 105 at least either in an engagement part between the compressor mechanism part and the crank shaft or in a rotation support part of the crank shaft. Further, an unleaded resin impregnation material is used for at least one of the sliding bearings, the crank shaft is made of a ferrous material, and a hard carbon film including hydrogen is formed on a part of the crank shaft sliding with the sliding bearing using the unleaded resin impregnation material.

Abstract: At least one bypass opening is formed in a base of a scroll member, and communicates with at least one compression chamber. The bypass opening communicates with a passage leading to a suction pressure chamber within a compressor shell. A valve includes an element electrically powered to move between a first position at which it blocks flow of refrigerant from the bypass port to the passage leading to the suction pressure chamber, and a second position at which it allows flow of refrigerant between the bypass port and the passage leading to the suction pressure chamber. A portion of the valve, which is electrically powered, is mounted outside of the compressor shell.

Abstract: A scroll compressor having a scroll supporter and/or movement limiter is provided. The scroll compressor may include a casing, a main frame fixedly installed within the casing, a first scroll rotatably supported by the main frame, a second scroll supported by the main frame, such that the second scroll is movable in a vertical direction with respect to the first scroll, a guide that guides movement of the second scroll in the vertical direction, while preventing the second scroll from being rotated in an axial direction; and a movement limiter disposed on an inner wall of the casing and separated from the second scroll, the movement limiter being configured to limit a movement distance of the second scroll in an upward direction.

Abstract: A scroll compressor including a casing, a scroll compression mechanism that compresses refrigerant, a driving motor that has a driving shaft and is connected to the scroll compression mechanism through the driving shaft to drive the scroll compression mechanism, a main frame that supports the scroll compression mechanism in the casing, a bearing plate that supports the driving shaft of the driving motor in the casing and has an opening portion through which upper and lower spaces above and below the bearing plate intercommunicate with each other, and a first cover that covers the surrounding of the driving shaft between the driving motor and the bearing plate, wherein the cover is configured so as to be passable through the opening portion.

Abstract: A compressor is provided that may include a drive shaft, a compression mechanism, a bearing and an unloader. The drive shaft may include a main body and a crank pin extending from the main body. The compression mechanism may include first and second members. The crank pin may drivingly engage the second member and cause motion of the second member relative to the first member. The bearing may rotatably supporting the main body of the drive shaft. The unloader may rotatably engage the bearing and slidably engage the main body.

Abstract: This compressor comprises first and second volutes describing an orbital relative movement and each comprising a plate from which a spiral extends, the two spirals being engaged one inside the other and defining pairs of compression chambers of variable volume. The compressor has a housing formed in that surface of the plate of the first volute which is turned towards the spirals, which housing opens into one of the compression chambers, refrigerant delivery means leading into the housing, and a nonreturn device being mounted in the housing, the nonreturn device preventing communication between the delivery means and the compression chamber into which housing opens in a first or closed position, and allowing communication between the delivery means and said compression chamber in a second or open position.

Abstract: A compressor includes a housing, a first scroll member, a second scroll member and a valve assembly. The first scroll member is positioned within the housing and includes a first end plate portion and a second end plate portion coupled to the first end plate portion and having a first spiral wrap extending therefrom. The first end plate portion and the second end plate portion define a discharge passage. The second scroll member is positioned within the housing and includes a second spiral wrap meshingly engaged with the first spiral wrap. The valve assembly is supported by at least one of the first end plate portion and the second end plate portion at a location radially outward from the discharge passage.

Abstract: A compressor may include a compression mechanism, a driveshaft, and a lever. The compression mechanism may include orbiting and non-orbiting scroll members meshingly engaging each other. The driveshaft may include an eccentric crank pin engaging the orbiting scroll member such that rotation of the driveshaft about a first axis causes orbital motion of the orbiting scroll relative to the non-orbiting scroll. The lever may be mounted for rotation with the driveshaft about the first axis and may be rotatable relative to the driveshaft about a second axis.

Abstract: A compressor may include a shell assembly, a first scroll member located within the shell assembly and including a first end plate and a first spiral wrap extending from the first end plate, and a second scroll member located within the shell assembly, supported for orbital movement relative to the first scroll member and including a second end plate and a second spiral wrap extending from the second end plate and meshingly engaged with the first spiral wrap to form compression pockets. The first scroll member may define a fluid injection port and the second scroll member may define a passage in communication with the fluid injection port and at least one of the compression pockets to provide pressurized vapor from the fluid injection port to the at least one of the compression pockets.

Abstract: A scroll compressor is constructed by combining a stationary scroll and an orbiting scroll formed by erecting a scroll-shape wrap upright on a base plate meshing with each other. A scroll member constructing the stationary scroll or the orbiting scroll is constructed of an inner layer member 601 forming a core metal and an outer layer member 600 arranged so as to surround the inner layer member and forming an outer layer part, the inner layer member is constructed of a material with higher modulus of elasticity than that of the outer layer member, and separation prevention parts (uneven parts 603, depressions 604, or holes 605) preventing the inner layer member and the outer layer member from separating with each other due to difference in coefficient of thermal expansion thereof are arranged in the inner layer member.

Abstract: A compressor may include a first scroll member, a second scroll member and a drive shaft. The first scroll member may include a first end plate defining a first discharge port and a first spiral wrap extending from the first end plate. The second scroll member may include a second end plate defining a first variable volume ratio port and a second spiral wrap extending from the second end plate and meshingly engaged with the first spiral wrap and forming compression pockets. The variable volume ratio port may be located radially outward relative to the first discharge port and in communication with a first compression pocket. The drive shaft may be engaged with the second scroll member and driving orbital displacement of the second scroll member relative to the first scroll member.

Abstract: A scroll compressor includes a fixed scroll, an orbiting scroll, a crankshaft rotationally supported on a frame to drive the orbiting scroll, a seal member between an orbiting scroll back surface and the frame, a back pressure chamber of discharge pressure at an inner peripheral side of the seal member, another back pressure chamber of low pressure at an outer peripheral side so that the orbiting scroll is pressed against the fixed scroll with the pressures of these back pressure chambers, and a guide ring supporting an end surface of the seal member at a side opposite to the orbiting scroll and including a guide portion guiding an inner peripheral surface of the seal member so that the seal member is brought into close contact with the orbiting scroll back surface by a wave spring through the guide ring.

Abstract: Disclosed is a scroll compressor. As two side surfaces of a rotation preventing member are formed to be flat with keys, the rotation preventing member, a main frame, and an orbiting scroll may be easily processed and partial frictions and noise due to the keys may be prevented. Furthermore, since the orbiting scroll is entirely and stably supported by a ring portion of the rotation preventing member, the occurrence of a tilting moment of the orbiting scroll may be reduced. This may enhance the stability and the performance of the scroll compressor.

Abstract: A suction chamber and the oil injection port are linked, under a certain range of revolution angle, via a suction working chamber formed in the radially outer side by a orbiting scroll outer curve and a fixed scroll inner curve under a certain range of revolution angle. An opening of the oil injection port is provided on a bottom surface between teeth of the fixed scroll so that the suction working chamber formed, in a radially inner side, by a orbiting scroll inner curve and a fixed scroll outer curve and the suction chamber are positioned not to be linked with the oil injection port.

Abstract: A compressor assembly method may include locating a first scroll member on a bearing housing of a compressor having a second scroll member located axially between the first scroll member and the bearing housing. A first outer radial surface on the bearing housing and a second outer radial surface on the first scroll member with an alignment assembly may be engaged to concentrically align the bearing housing and the first scroll member. The first scroll member may be coupled relative to the bearing housing.

Abstract: A synthetic resin bearing and a scroll compressor using the same are provided. In the synthetic resin bearing as a journal bearing fixed to an orbiting scroll or a main frame and relatively rotated with respect to a rotational shaft in a scroll compressor, the journal bearing is made of a PEEK material, and a thickness t of the journal bearing is smaller than a thickness t1 with which a temperature in a contact surface thereof with the rotational shaft during an operation of the scroll compressor corresponds to a glass transition temperature.

Abstract: A scroll compressor may be provided with a check valve interposed between a balance chamber and a discharge chamber. The check valve may allow balance chamber pressure to remain low during start-up of the compressor. Low balance chamber pressure may allow an orbiting scroll to remain unclamped to a fixed scroll thereby reducing torque required to initiate rotation of the orbiting scroll. After steady-state operational speed is reached the check valve may close and the scrolls may be clamped together to produce a desired steady-state operating condition for the compressor.

Abstract: A stationary base plate includes a sub-bypass hole, which communicates between a suction chamber and a first compression chamber, and a main bypass hole, which communicates between the suction chamber and a second compression chamber. A rotational center of the orbiting scroll and the sub-bypass hole are located along a first imaginary line. The rotational center of the orbiting scroll is also located along a second imaginary line, which is perpendicular to the first imaginary line. The main bypass hole opens at a location of the stationary base plate, which is on a side of the second imaginary line where the sub-bypass hole is located, so that timing of communicating between the suction chamber and the first compression chamber with each other is deviated from timing of communicating between the suction chamber and the second compression chamber with each other.

Abstract: In a scroll compressor, a pass hole is formed at a position overlapping with a discharge sector of a discharge hole, where a sector for passing a refrigerant through the pass hole is overlapped with a sector for discharging the refrigerant through a discharge hole. This may prevent over-compression of a refrigerant when the scroll compressor is driven at a low speed. This may enhance efficiency of the scroll compressor in a low speed driving mode and under a low load condition.

Abstract: A compressor may include a shell, a compression mechanism, a crankshaft, a bearing support, and a lubricant sump. The compression mechanism may be disposed in the shell and may compress a working fluid. The crankshaft may be disposed at least partially in the shell and may drivingly engage the compression mechanism. The bearing support may rotatably support the crankshaft. The lubricant sump may retain a volume of lubricant and may be disposed between the bearing support and the compression mechanism.

Abstract: A scroll compressor includes a discharge valve assembly having a valve member, a valve stop supported within the compressor shell and including an aperture there through and a communication member. The communication member defines a fluid passage extending into the discharge chamber from the valve stop toward the first discharge outlet in the discharge chamber and provides fluid communication between the aperture in the valve stop and a location downstream of the valve stop. A first side of the valve member abuts the valve stop when in an open position and the valve stop provides communication between the first side of the valve member and the communication member via the aperture.

Abstract: A scroll compressor includes a high-pressure space capable of communicating with a discharge port and a back pressure space capable of communicating with an intermediate port. A fluid passage includes a seal ring that closes the fluid passage when the pressure of the back pressure space is lower than that of the high-pressure space, and opens the fluid passage when the pressure of the back pressure space is higher than that of the high-pressure space.

Abstract: A scroll compressor 40 comprises: housing 12, orbiting scroll 26 and fixed scroll 41. The drive shaft 14 has an eccentric shaft portion 18 so that rotation of the eccentric shaft portion imparts an orbiting motion to the orbiting scroll relative to the fixed scroll. Axial spacers 42 are located between the fixed scroll and the housing for spacing the fixed scroll relative to the orbiting scroll. When the scroll compressor 40 is assembled and tested and it is desired to perform shimming, the fixed scroll can be removed and a selected spacer placed in position prior to re-assembling the fixed scroll.

Abstract: A scroll compressor includes scroll compressor bodies with axial tip seals projecting from the respective scroll ribs of fixed and movable scroll compressor bodies. An extended thrust region is provided in surrounding relation to an inner axial tip sealing region to provide for carrying thrust loads in the event that the scroll compressor bodies are forced axially together. Part of the thrust region may carry a tip seal, while another part may be free of a tip seal. This provides for at least a nominal reverse operation capability.

Abstract: A compressor may include first and second scroll members and a compensation member. The first scroll member may include a first end plate and a first spiral wrap extending therefrom. The second scroll member may include a second end plate and a second spiral wrap. The second end plate may be positioned proximate to a distal end of the first spiral wrap. The first end plate may be positioned proximate to a distal end of the second spiral wrap. The compensation member may engage the first scroll member and having a first reaction to a temperature change causing the first scroll member to maintain a sealed relationship between the first end plate and the distal end of the second spiral wrap.

Abstract: A scroll compressor includes a housing; a fixed scroll fixed in the housing; an orbiting scroll that has an orbiting end plate on which a spiral orbiting wall is provided upright and that is supported in the housing so as to be able to orbit while being prevented from rotating, in a state where the orbiting wall is engaged with the fixed wall; a suction section that makes refrigerant containing lubricant flow into a suction chamber provided in the housing; and a plurality of supply flow paths that are provided on a sliding surface between the housing and the orbiting end plate and that are connected to the suction chamber.

Abstract: A compressor includes a housing, a first scroll member, a second scroll member and a modulation assembly. The first scroll member includes a first end plate having a discharge passage, a first spiral wrap, and a first aperture extending through the first end plate. The second scroll member includes a second end plate having a second spiral wrap extending therefrom and meshingly engaged with the first spiral wrap to form a series of pockets. The first aperture is in communication with a first of the pockets. The modulation assembly is in communication with the first aperture and is operable in a full capacity mode where the first aperture is isolated from a suction pressure region providing full capacity operation and in a reduced capacity mode where the first aperture is in communication with the suction pressure region providing approximately zero capacity operation.

Abstract: A compressor may include a shell, a housing fixed within the shell, first and second scroll members disposed within the shell, a sleeve guide, a fastener, and a washer. The first scroll member may have a first spiral wrap extending from a first end plate and a radially outward extending scroll flange defining an opening. The second scroll member may have a second spiral wrap intermeshed with the first spiral wrap. The sleeve guide may be disposed within the opening in the scroll flange and may define an axial bore. The fastener may be disposed within the axial bore and engaged with the housing. The washer may be located between a head of the fastener and the scroll flange. A first portion of the washer may extend radially outward from the fastener head and may define a rotational stop inhibiting washer rotation through engagement with a rotationally fixed structure.

Abstract: Scroll pumping apparatus includes a first scroll element and a second scroll element; a drive mechanism operatively coupled to the second scroll element for producing orbiting motion of the second scroll element relative to the first scroll element, the drive mechanism having an axis of rotation; and an isolation element to isolate a first volume and a second volume in the scroll pumping apparatus. The isolation element includes a first resilient annular member coupled, directly or indirectly, to the first scroll element, a second resilient annular member coupled, directly or indirectly, to the second scroll element, and a tubular member coupled between the first and second annular members.

Abstract: A scroll compressor includes first and second scroll members housed in a casing. The first scroll member has a fluid inlet and a first through hole spaced from the fluid inlet. A fluid introducing pipe is configured to connect to the first through hole. A piston, having an annular groove and a second through hole, is disposed in the first through hole and is biased toward the fluid introducing pipe. The piston is configured to shut an end of the first through hole when fluid pressure larger than the biasing force is introduced into the fluid introducing pipe and to open the end of the first through hole when fluid pressure smaller than the biasing force is introduced into the fluid introducing pipe. A piston ring is fitted into the annular groove of the piston and has a stepped fitting end.

Abstract: Provided is a scroll type compressor which reduces variations in the pressing load of a rotating scroll on a fixed scroll, reduces the impact at the start of the compressor and suppresses noises, and can provide excellent durability. A peripheral elastic body 51 and a bottom-portion elastic body 52, which is brought into a compressed condition in the axis line direction of the main shaft 31, are interposed between a stopper pin 41 on the rotating scroll side and a concave portion 42 on the main shaft 31 side, whereby working errors of each part are compensated and the rotating scroll is constantly brought into close contact with the fixed scroll to maintain the sealing of the compression chamber.

Abstract: A scroll type compressor including a fixed scroll, a movable scroll engaged with the fixed scroll and a hermetically sealed container, one of the fixed scroll and the movable scroll including an intercommunication path having a lower hole opened to the outside of the one scroll and an insertion hole formed by subjecting the lower hole to reaming processing from the one end to a position of a predetermined depth of the lower hole, a pin member that is slightly smaller in diameter than the intercommunication path and movably inserted in the intercommunication path, and a screw member that is provided at one end of the intercommunication path to close the one end of the intercommunication path so as to press the pin member against the end of the back side of the intercommunication path.

Abstract: A scroll compressor 40 comprises: housing 12, orbiting scroll 26 and fixed scroll 41. The drive shaft 14 has an eccentric shaft portion 18 so that rotation of the eccentric shaft portion imparts an orbiting motion to the orbiting scroll relative to the fixed scroll. Axial spacers 42 are located between the fixed scroll and the housing for spacing the fixed scroll relative to the orbiting scroll. When the scroll compressor 40 is assembled and tested and it is desired to perform shimming, the fixed scroll can be removed and a selected spacer placed in position prior to re-assembling the fixed scroll.

Abstract: A scroll type compressor including a fixed scroll, a movable scroll engaged with the fixed scroll, and a hermetically sealed container in which the fixed scroll and the movable scroll are mounted. The fixed scroll or the movable scroll has an intercommunication path for lubricating oil that is opened to the outside of the one scroll at one end thereof, extends radially inside the scroll and has a high-pressure opening intercommunicating with a high-pressure portion of the container and a low-pressure opening intercommunicating with a low-pressure portion in the scroll, a pin member disposed in the intercommunication path so as to be movable radially in the scroll, a screw member closing one end of the intercommunication path, and a stopper provided at a predetermined position in the intercommunication path to regulate radial movement of the pin member.

Abstract: A compressor includes a shell assembly, first and second scroll members and a capacity modulation assembly. The first and second scroll members form a series of pockets. A first modulation port defined in the first scroll member is in communication with a first pocket. The capacity modulation assembly is in communication with the first modulation port and is operable in full, partial and first and second pulse width modulation (PWM) capacity modes. The full capacity mode includes the first modulation port isolated from a suction pressure region of the compressor, the partial capacity mode includes the first modulation port in communication with the suction pressure region, the first PWM capacity mode includes a capacity between full and partial capacity via PWM between the full and partial capacity modes and the second PWM capacity mode includes a capacity between full and zero capacity by providing PWM of the capacity modulation assembly.

Abstract: A scroll compressor has a housing enclosing a compressor pump unit which includes an orbiting scroll member and a non-orbiting scroll member. Each of the orbiting and non-orbiting scroll members include a base and a generally spiral wrap extending from the base. The wraps interfit to define compression chambers, with a central-most discharge pressure chamber, and circumferentially spaced intermediate pressure chambers being defined. The base of the non-orbiting scroll includes ports associated with the intermediate pressure chambers. At least one port is associated with the discharge pressure chamber. Valves are associated with each of the ports. A discharge plenum is defined downstream of the ports and valves within the housing. A back pressure chamber is defined behind the base of one of the orbiting and non-orbiting scroll members, and taps a refrigerant from the discharge pressure chamber.

Abstract: A compressor includes orbiting and non-orbiting scrolls forming first and second fluid pockets therebetween. First and second ports are disposed in the non-orbiting scroll and radially spaced apart from each other. The first port communicates with the first pocket at a first radial position and the second port communicates with the second pocket at a second radial position. A blocking device is movable between a first position preventing communication between the ports and a fluid source and a second position allowing communication between the ports and the fluid source. The first and second pockets have first and second pressures, respectively. One of the pressures may have a disproportionate pressure change compared to the other of the pressures after at least one of the pockets communicates with the fluid source through at least one of the ports. The disproportionate pressure change biases the orbiting scroll relative to the non-orbiting scroll.

Abstract: A scroll compressor that includes: a housing, a drive unit configured to generate a rotating force; and a scroll compression unit having a fixed scroll having a spiral scroll wrap for compressing a suctioned fluid and fixed irrespective of a rotation of a drive shaft of the drive unit and a swivel scroll swiveled according to rotation of the drive shaft and having a spiral scroll wrap, comprises: a main frame disposed within the housing to support a rear surface of the swivel scroll and having a back pressure chamber in an interior thereof; a thrust plate disposed between the swivel scroll and the main frame; and a sealing member inserted between the swivel scroll and the main frame. The sealing member includes a first sealing member inserted between the swivel scroll and the thrust plate, and a second sealing member inserted between the thrust plate and the main frame.

Abstract: A scroll compressor that includes a housing and scroll compressor bodies disposed in the housing. The scroll bodies include a first scroll body and a second scroll body. The first and second scroll bodies have respective bases and respective scroll ribs that project from the respective bases. Further, the scroll ribs mutually engage such that the second scroll body is movable relative to the first scroll body to compress fluid. A drive shaft has an eccentric drive pin configured to engage a drive hub on the second scroll body. The scroll compress also includes a slider block that fits over the drive pin. The slider block has a first drive surface configured to engage a second drive surface of the drive pin. In particular embodiments, the slider block can tilt about one or more edges of the second drive surface when the drive shaft is deflected under load.

Abstract: A scroll compressor includes first and second scroll bodies having respective bases and respective scroll ribs that project from the respective bases such that the scroll ribs mutually engage. The second scroll body is movable relative to the first scroll body for compressing fluid. A drive shaft has a longitudinal axis and an eccentric drive pin configured to engage a drive hub on the second scroll body. A counterweight has a hub portion, and a perimeter portion positioned radially outward from the hub portion. A radial axis divides the counterweight into a first and second regions. The mass of the hub portion in the first region being roughly equal to the mass of the hub portion in the second region, and the mass in the perimeter portion being distributed between the first and second regions such that the center of mass of the counterweight is located along the radial axis.

Abstract: A scroll type compressor has a rotary shaft, a fixed scroll member, a movable scroll member and a rib. The fixed scroll member has a fixed end plate and a fixed scroll wall. The fixed end plate has first and second sides. The fixed scroll wall is formed on the first side. The movable scroll member has a movable end plate and a movable scroll wall. The movable scroll wall is formed on the movable end plate. The movable scroll member is adapted to make an orbital motion in accordance with the rotation of the rotary shaft whereby a compression chamber to decrease the volume of the compression chamber with the orbital motion of the movable scroll member is formed between the fixed scroll member and the movable scroll member. The rib is provided on the second side so as to extend behind the inner end of the fixed scroll wall.

Abstract: A compressor includes first and second scroll members, a structure supporting the second scroll member, and a first piston. The first scroll member includes a first end plate and a first spiral wrap. The second scroll member includes a second end plate and a second spiral wrap engaged with the first spiral wrap to form compression pockets. The second end plate includes a first aperture in communication with a first compression pocket. The structure includes a first recess and first and second passages. The first piston is axially displaceable between first and second positions within the first recess. The first piston isolates the first passage from communication with the second passage when in the first and second positions, prevents communication between the first aperture and the first passage when in the first position, and provides communication between the first aperture and the first passage when in the second position.

Abstract: A compressor includes first and second scroll members, a piston and a control valve. The first scroll member includes an end plate defining a capacity modulation passage. The first and second scroll members form a suction pocket, an intermediate compression pocket and a discharge pocket. The capacity modulation passage is in communication with the first intermediate compression pocket. The piston is supported on the first scroll member and partially defines a modulation control chamber. The control valve is in communication with the control chamber and selectively provides communication between the control chamber and one of the first and second pressure sources to displace the piston between a closed position and an open position. The piston isolates the capacity modulation passage from communication with the suction pressure region when in the closed position and provides communication between the capacity modulation passage and the suction pressure region when in the open position.