A compressor is provided and may include a first scroll member having an end plate and a spiral wrap extending from the end plate. The end plate may include a first modulation port and a second modulation port each in fluid communication with a compression pocket formed by the spiral wrap. A first modulation valve ring may be movable relative to the end plate between a first position blocking the first modulation port and a second position spaced apart from the first modulation port. A second modulation valve ring may movable relative to the end plate between a first position blocking the second modulation port and a second position spaced apart from the second modulation port. The second modulation ring may be located radially inward from the first modulation valve ring.

FIELD

The present disclosure relates to compressor capacity modulation assemblies.

BACKGROUND

This section provides background information related to the present disclosure and which is not necessarily prior art.

Compressors may be designed for a variety of operating conditions. The operating conditions may require different output from the compressor. In order to provide for more efficient compressor operation, capacity modulation assemblies may be included in a compressor to vary compressor output depending on the operating condition.

SUMMARY

This section provides a general summary of the disclosure, and is not comprehensive of its full scope or all of its features.

A compressor is provided and may include a first scroll member having an end plate and a spiral wrap extending from the end plate. The end plate may include a first modulation port and a second modulation port each in fluid communication with a compression pocket formed by the spiral wrap. A first modulation valve ring may be movable relative to the end plate between a first position blocking the first modulation port and a second position spaced apart from the first modulation port. A second modulation valve ring may movable relative to the end plate between a first position blocking the second modulation port and a second position spaced apart from the second modulation port. The second modulation ring may be located radially inward from the first modulation valve ring.

In another configuration, a compressor is provided and may include a first scroll member having an end plate and a spiral wrap extending from the end plate. The end plate may include a first modulation port and a second modulation port each in fluid communication with a compression pocket formed by the spiral wrap. A first modulation valve ring may be movable relative to the end plate between a first position blocking the first modulation port and a second position spaced apart from the first modulation port. A second modulation valve ring may be movable relative to the end plate between a first position blocking the second modulation port and a second position spaced apart from the second modulation port. A first modulation control chamber may be formed between the first modulation valve ring and the second modulation valve ring, whereby the first modulation control chamber receives pressurized fluid to move the second modulation valve ring between the first position and the second position.

DETAILED DESCRIPTION

The present disclosure is suitable for incorporation in many different types of scroll and rotary compressors, including hermetic machines, open drive machines and non-hermetic machines. For exemplary purposes, a compressor10is shown as a hermetic scroll refrigerant-compressor of the low-side type, i.e., where the motor and compressor are cooled by suction gas in the hermetic shell, as illustrated in the vertical section shown inFIG. 1.

With reference toFIG. 1, compressor10is provided and may include a hermetic shell assembly12, a bearing housing assembly14, a motor assembly16, a compression mechanism18, a seal assembly20, a refrigerant discharge fitting22, a discharge valve assembly24, a suction gas inlet fitting26, and a capacity modulation assembly28. As shown inFIG. 1, shell assembly12houses bearing housing assembly14, motor assembly16, compression mechanism18, and capacity modulation assembly28.

Shell assembly12may generally form a compressor housing and may include a cylindrical shell29, an end cap32at the upper end thereof, a transversely extending partition34, and a base36at a lower end thereof. End cap32and partition34may generally define a discharge chamber38. Discharge chamber38may generally form a discharge muffler for compressor10. While illustrated as including discharge chamber38, it is understood that the present disclosure applies equally to direct-discharge configurations. Refrigerant discharge fitting22may be attached to shell assembly12at an opening40in end cap32. Discharge valve assembly24may be located within discharge fitting22and may generally prevent a reverse-flow condition. Suction gas inlet fitting26may be attached to shell assembly12. Partition34may include a discharge passage44therethrough providing communication between compression mechanism18and discharge chamber38.

Bearing housing assembly14may be affixed to shell29at a plurality of points in any desirable manner, such as staking. Bearing housing assembly14may include a main bearing housing46, a bearing48disposed therein, bushings50, and fasteners52. Main bearing housing46may house bearing48therein and may define an annular flat thrust bearing surface54on an axial end surface thereof. Main bearing housing46may include apertures (not shown) extending therethrough and receiving fasteners52.

Motor assembly16may generally include a motor stator58, a rotor60, and a drive shaft62. Motor stator58may be press fit into shell29. Drive shaft62may be rotatably driven by rotor60and may be rotatably supported within first bearing48. Rotor60may be press fit on drive shaft62. Drive shaft62may include an eccentric crank pin64having a flat66thereon.

Compression mechanism18may generally include an orbiting scroll68and a non-orbiting scroll70. Orbiting scroll68may include an end plate72having a spiral vane or wrap74on the upper surface thereof and an annular flat thrust surface76on the lower surface. Thrust surface76may interface with annular flat thrust bearing surface54on main bearing housing46. A cylindrical hub78may project downwardly from thrust surface76and may have a drive bushing80rotatably disposed therein. Drive bushing80may include an inner bore in which crank pin64is drivingly disposed. Crank pin flat66may drivingly engage a flat surface in a portion of the inner bore of drive bushing80to provide a radially compliant driving arrangement. An Oldham coupling82may be engaged with the orbiting and non-orbiting scrolls68,70to prevent relative rotation therebetween.

Non-orbiting scroll70may include an end plate84defining a discharge passage92and having a spiral wrap86extending from a first side87thereof, an annular hub88extending from a second side89thereof opposite the first side, and a series of radially outwardly extending flanged portions90(FIG. 1) engaged with fasteners52. Fasteners52may rotationally fix non-orbiting scroll70relative to main bearing housing46while allowing axial displacement of non-orbiting scroll70relative to main bearing housing46. Spiral wraps74,86may be meshingly engaged with one another defining pockets94,96,98,100,102,104(FIG. 1). It is understood that pockets94,96,98,100,102,104change throughout compressor operation.

A first pocket94inFIG. 1, may define a suction pocket in communication with a suction pressure region106of compressor10operating at a suction pressure (Ps) and a second pocket104inFIG. 1, may define a discharge pocket in communication with a discharge pressure region108of compressor10operating at a discharge pressure (Pd) via discharge passage92. Pockets96,98,100,102intermediate the first and second pockets94,104inFIG. 1, may form intermediate compression pockets operating at intermediate pressures between the suction pressure (Ps) and the discharge pressure (Pd).

Referring toFIGS. 2athrough 4b, end plate84may additionally include a biasing passage110, first and second modulation ports112a,112band third and fourth modulation ports114a,114b. Biasing passage110, first and second modulation ports112a,112b(FIG. 2A), and third and fourth modulation ports114a,114b(FIG. 2B) may each be in fluid communication with one of the intermediate compression pockets96,98,100,102. Biasing passage110may be in fluid communication with one of the intermediate compression pockets operating at a higher pressure than ones of intermediate compression pockets in fluid communication with first, second, third and fourth modulation ports112a,112b,114a,114b. Third and fourth modulation ports114a,114bmay be in fluid communication with ones of the intermediate compression pockets operating at a higher pressure than ones of the intermediate compression pockets in fluid communication with first and second modulation ports112a,112b.

Annular hub88may include first and second portions116,118axially spaced from one another forming a stepped region120therebetween. First portion116may be located axially between second portion118and end plate84and may have an outer radial surface122defining a first diameter (D1) greater than or equal to a second diameter (D2) defined by an outer radial surface124of second portion118.

Capacity modulation assembly28may include a first modulation valve ring126a, a second modulation valve ring126b, a modulation lift ring128, a retaining ring130, a first modulation control valve assembly132a, and a second modulation control valve assembly132b.

First modulation valve ring126amay include an inner radial surface134, an outer radial surface136, a first axial end surface138defining an annular recess140and a valve portion142, first and second passages144a,144b, and third and fourth passages146a,146b. Inner radial surface134may include first, second, and third portions148a,148b,148c. The first and second portions148a,148bmay define a second axial end surface152therebetween while the second and third portions148b,148cmay define a third axial end surface153. First portion148amay define a third diameter (D3) greater than a fourth diameter (D4) defined by the second portion148b. Third portion148cmay define a fifth diameter (D5) greater than the fourth diameter (D4) and greater than the third diameter (D3). The first and fourth diameters (D1, D4) may be approximately equal to one another and the first portion116of hub88may be sealingly engaged with the second portion148bof first modulation valve ring126avia a seal154located radially therebetween. More specifically, seal154may include an o-ring seal and may be located within an annular recess156in second portion148bof first modulation valve ring126a. Alternatively, ring seal154could be located in an annular recess (not shown) in annular hub88.

Second modulation valve ring126bmay be located radially between outer radial surface122and the first portion148aof inner radial surface134, and located axially between the second axial end surface152and the second side89of end plate84. Accordingly, the second modulation valve ring126bmay be an annular body defining inner and outer radial surfaces155a,155b, and first and second axial end surfaces157a,157b. Inner and outer radial surfaces155a,155bmay be sealingly engaged with outer radial surface122of annular hub88and with first portion148aof inner radial surface134, respectively, via first and second seals163a,163b. More specifically, first and second seals163a,163bmay include o-ring seals and may be located within respective annular recesses165a,165bformed in inner radial surface155aof second modulation valve ring126band formed in first portion148aof inner radial surface134, respectively. First modulation valve ring126aand second modulation valve ring126bmay cooperate to define a first modulation control chamber174abetween the second axial end surface152of the first modulation valve ring126aand the first axial end surface157aof the second modulation valve ring126b. Third passage146amay be in fluid communication with first modulation control chamber174a.

With reference toFIG. 5, the second axial end surface157bof second modulation valve ring126bmay include a series of bores167and a series of biasing members169respectively disposed in the series of bores167. The biasing members169may be helical springs that bias the second modulation valve ring126bin an axial direction away from the end plate84. More specifically, the biasing members169may provide a first axial force (F1) between the non-orbiting scroll70and the second modulation valve ring126b, urging the second modulation valve ring126baxially away from non-orbiting scroll70. In one configuration, second axial end surface157bincludes four bores167and four biasing members169. While the second axial end surface157bis described as including four bores167and four biasing members169, the second axial end surface157bmay include any number of bores167and any number of biasing members169.

With additional reference toFIGS. 2A through 4B, modulation lift ring128may be located within annular recess140and may include an annular body defining inner and outer radial surfaces158,160, and first and second axial end surfaces159,161. Inner and outer radial surfaces158,160may be sealingly engaged with inner and outer sidewalls162,164of annular recess140via first and second seals166,168, respectively. More specifically, first and second seals166,168may include o-ring seals and may be located within annular recesses170,172in inner and outer radial surfaces158,160of modulation lift ring128. First modulation valve ring126aand modulation lift ring128may cooperate to define a second modulation control chamber174bbetween annular recess140and first axial end surface159of modulation lift ring128. First passage144amay be in fluid communication with second modulation control chamber174b. With reference toFIG. 6, second axial end surface161of modulation lift ring128may face end plate84and may include a series of protrusions177defining radial flow passages178therebetween.

Seal assembly20may form a floating seal assembly and may be sealingly engaged with non-orbiting scroll70and first modulation valve ring126ato define an axial biasing chamber180. More specifically, seal assembly20may be sealingly engaged with outer radial surface124of annular hub88and third portion148cof first modulation valve ring126a. Axial biasing chamber180may be defined axially between an axial end surface182of seal assembly20and third axial end surface153of first modulation valve ring126a. Second passage144band fourth passage146bmay be in fluid communication with axial biasing chamber180.

Retaining ring130may be axially fixed relative to non-orbiting scroll70and may be located within axial biasing chamber180. More specifically, retaining ring130may be located within a recess117in first portion116of annular hub88axially between seal assembly20and first modulation valve ring126a. Retaining ring130may form an axial stop for first modulation valve ring126a.

First modulation control valve assembly132amay include a solenoid-operated valve and may be in fluid communication with first and second passages144a,144bin first modulation valve ring126aand with suction pressure region106. Second modulation control valve assembly132bmay include a solenoid-operated valve and may be in fluid communication with third and fourth passages146a,146bin first modulation valve ring126aand with suction pressure region106.

With additional reference toFIGS. 7 through 9, during compressor operation, first and second modulation control valve assemblies132a,132bmay each be operated in first and second modes. Accordingly, the compressor10may be operated in at least three modes of operation.FIGS. 7 through 9schematically illustrate operation of first modulation control valve assembly132aand second modulation control valve assembly132ain three modes of operation.

In the first mode, shown inFIGS. 2A, 2B and 7, first modulation control valve assembly132amay provide fluid communication between second modulation control chamber174band suction pressure region106, and second modulation control valve assembly132bmay provide fluid communication between first modulation control chamber174aand axial biasing chamber180. More specifically, during operation in the first mode, first modulation control valve assembly132amay provide fluid communication between first passage144aand suction pressure region106, and second modulation control valve assembly132bmay provide fluid communication between third passage146a, fourth passage146b, and axial biasing chamber180.

In the second mode, shown inFIGS. 3A, 3B and 8, first modulation control valve assembly132amay provide fluid communication between second modulation control chamber174band axial biasing chamber180, and second modulation control valve assembly132bmay provide fluid communication between first modulation control chamber174aand axial biasing chamber180. More specifically, first modulation control valve assembly132amay provide fluid communication between first and second passages144a,144bduring operation in the second mode.

In the third mode, shown inFIGS. 4A, 4B and 9, first modulation control valve assembly132amay provide fluid communication between second modulation control chamber174band axial biasing chamber180, and second modulation control valve assembly132bmay provide fluid communication between first modulation control chamber174aand suction pressure region106. More specifically, during operation in the third mode, second modulation control valve assembly132amay provide fluid communication between third passage146aand suction pressure region106.

First modulation valve ring126amay define a first radial surface area (A1) facing away from non-orbiting scroll70radially between second and third portions148b,148cof inner radial surface134of first modulation valve ring126awhere A1=(π)(D52−D42)/4. Inner sidewall162may define a diameter (D6) less than a diameter (D7) defined by outer sidewall164. First modulation valve ring126amay define a second radial surface area (A2) opposite first radial surface area (A1) and facing non-orbiting scroll70radially between sidewalls162,164of inner radial surface134of first modulation valve ring126awhere A2=(π)(D72−D62)/4. First radial surface area (A1) may be less than second radial surface area (A2). First modulation valve ring126amay be displaced between first and second positions based on the pressure provided to second modulation control chamber174bby first modulation control valve assembly132a. First modulation valve ring126amay be displaced by fluid pressure acting directly thereon, as discussed below.

Second axial end surface152of first modulation valve ring126amay further define a third radial surface area (A3) formed on an opposite side of first modulation valve ring126athan the first radial surface area (A1) and facing non-orbiting scroll70radially between the first and second portions148a,148bof first modulation valve ring126awhere A3=(π)(D32−D42)/4. Third radial surface area (A3) may be less than second radial surface area (A2).

When first and second modulation control valve assemblies132a,132bare operated in the first mode, first and second modulation valve rings126a,126bmay each be in respective first positions (FIGS. 2A and 2B). A first intermediate pressure (Pi1) within axial biasing chamber180applied to first radial surface area (A1) may provide a second axial force (F2) operating in a direction opposite the first axial force (F1), urging first modulation valve ring126aaxially toward non-orbiting scroll70. The first intermediate pressure (Pi1) is supplied to the axial biasing chamber180via biasing passage110. Suction pressure (Ps) within second modulation control chamber174bmay provide a third axial force (F3) opposite the second axial force (F2), and first intermediate pressure (Pi1) within first modulation control chamber174amay provide a fourth axial force (F4) opposite the second axial force (F2). Suction pressure (Ps) is supplied to second modulation control chamber174bvia control valve assembly132aand first passage144awhile first intermediate pressure (Pi1) is supplied via control valve assembly132b, third passage146a, and fourth passage146bto first modulation control chamber174a.

The third and fourth axial forces (F3, F4) may urge first modulation valve ring126aaxially away from non-orbiting scroll70. However, second axial force (F2) may be greater than the combined third and fourth axial forces (F3, F4) even though biasing chamber180and control chamber174aare both at intermediate pressure (Pi1) because second radial surface (A2) is greater than third radial surface area (A3) and control chamber174bis at suction pressure (Ps), which is less than intermediate pressure (Pi1). Fourth axial force (F4) may be greater than the first axial force (F1). Therefore, first and second modulation valve rings126a,126bmay each be in the respective first position (FIGS. 2A and 2B) during operation of first and second modulation control valve assemblies132a,132bin the first mode. The first position may include valve portion142of first modulation valve ring126aabutting end plate84and closing first and second modulation ports112a,112b, and second modulation valve ring126babutting end plate84and closing third and fourth modulation ports114a,114b. This position places the compressor10in a full-capacity state, as each port112a,112b,114a,114bis closed, thereby allowing each pocket94-104to fully compress fluid disposed therein.

When first and second modulation control valve assemblies132a,132bare operated in the second mode, first modulation valve ring126amay be in a second position, and second modulation valve ring126bmay be in the first position (FIGS. 3A, 3B). In the second mode, first intermediate pressure (Pi1) within second modulation control chamber174bmay provide a fifth axial force (F5) acting on first modulation valve ring126aand opposite second axial force (F2) urging first modulation valve ring126aaxially away from non-orbiting scroll70. Because second modulation control chamber174band axial biasing chamber180are in fluid communication with one another during operation of the first modulation control valve assembly132ain the second mode (FIG. 3A) via passages144a,144b, both may operate at approximately the same first intermediate pressure (Pi1). Fifth axial force (F5) may be greater than second axial force (F2), however, because second radial surface area (A2) is greater than first radial surface area (A1). Therefore, first modulation valve ring126amay be in the second position (FIG. 3A) during operation of first modulation control valve assembly132ain the second mode. The second position may include valve portion142of first modulation valve ring126abeing displaced from end plate84and opening first and second modulation ports112a,112b. First modulation valve ring126amay abut retaining ring130when in the second position, as control chamber174ais at first intermediate pressure (Pi1) via passages146a,146bof control valve assembly132a(FIG. 3B).

First modulation valve ring126aand modulation lift ring128may be forced in axial directions opposite one another during operation of first and second modulation control valve assemblies132a,132bin the second mode (FIGS. 3A and 3B). More specifically, first modulation valve ring126amay be displaced axially away from end plate84and modulation lift ring128may be urged axially toward end plate84. Protrusions177of modulation lift ring128may abut end plate84and first and second modulation ports112a,112bmay be in fluid communication with suction pressure region106via radial flow passages178when first modulation valve ring126ais in the second position.

When the valve assemblies132a,132bare operated in the second mode (FIGS. 3A and 3B), the compressor10is in a reduced-capacity state, as ports112a,112bare opened, thereby preventing the pockets associated with ports112a,112bfrom fully compressing a fluid disposed therein. Operation of the compressor10in this state results in operation of the compressor10at approximately seventy percent (70%) of total compressor capacity.

When first and second modulation control valve assemblies132a,132bare operated in the third mode, first and second modulation valve rings126a,126bmay each be in their respective second positions (FIGS. 4A, 4B). In the third mode, suction pressure (Ps) within first modulation control chamber174amay provide a sixth axial force (F6) acting on second modulation valve ring126band opposite first axial force (F1) of the biasing members169. Suction pressure (Ps) is supplied to chamber174avia third passage146aof valve assembly132a. First axial force (F1) may be greater than sixth axial force (F6), therefore urging second modulation valve ring126baxially away from non-orbiting scroll70under the force of biasing members169.

In addition, second modulation control chamber174bmay be at first intermediate pressure (Pi1), providing the fifth axial force (F5) acting on first modulation valve ring126a, as described above with respect to the second mode of operation. Therefore, first and second modulation valve rings126a,126bmay each be in their respective second positions during operation of first and second modulation control valve assemblies132a,132bin the third mode. The second position of first modulation valve ring126amay include valve portion142being displaced from end plate84and opening first and second modulation ports112a,112b. The second position of second modulation valve ring126bmay include the first axial end surface157bbeing displaced from end plate84and opening third and fourth modulation ports114a,114b. Third and fourth modulation ports114a,114bmay be in fluid communication with suction pressure region106via radial flow passages178when first and second modulation valve rings126a,126bare each in their respective second positions.

When the valve assemblies132a,132bare in the third mode, the compressor10is in a reduced-capacity mode, as each modulation port112a,112b,114a,114bis opened, thereby preventing the associated pocket from fully compressing a fluid disposed therein. A capacity of the compressor10is less than the capacity of the compressor10when the valve assemblies132a,132bare in the second mode. For example, compressor capacity may be at approximately fifty percent (50%) of total compressor capacity.