Electric compressor with integrated vapor injection circuit

Abstract

To provide an electric scroll compressor configured to compress a refrigerant for use with a vapor injection system.SOLUTION: A compressor includes refrigerant inlet and outlet ports and a vapor injection port. A housing includes a vapor injection cavity and at least one vapor injection channel, which are integral with the housing. A compression device includes a fixed scroll and an orbiting scroll. The orbiting scroll and the fixed scroll form compression chambers for receiving the refrigerant from an intake volume and compressing the refrigerant as a drive shaft is rotated about the center axis. The fixed scroll includes at least one vapor outlet aperture in communication with the at least one vapor injection channel for allowing vapor to enter the compression chamber formed between the fixed scroll and the orbiting scroll.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 634,534, filed April 16, 2024 (Attorney Docket No. MAHLE-P0020P), the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates generally to electric compressors that compress refrigerants using scroll compression devices, and more particularly to electric scroll compressors having an integral vapor injection circuit.

[0003] Background technology Compressors have long been used in refrigeration systems. In particular, systems designed to provide cooling in a specific area use scroll-type compressors, in which an orbiting scroll rotates in a circular motion relative to a fixed scroll to compress a refrigerant. For example, such scroll-type compressors have long been used in HVAC systems in automobiles and other vehicles to provide air conditioning. Such compressors may also be used in reverse in applications requiring heat pumps. These compressors are typically driven using rotary motion obtained from the automobile's engine.

[0004] With the advent of battery-powered or electric vehicles and / or hybrid vehicles, where the vehicle may sometimes be powered solely by a battery, such compressors must be driven or powered by a battery rather than an engine. Such compressors may be referred to as electric compressors.

[0005] In addition to cooling the passenger compartment of a vehicle, the electric compressor may be used to provide heating or cooling to other areas or components of the vehicle. For example, it may be desirable to heat or cool the electronic systems and battery or battery compartment when the battery is charging, especially during fast charge modes, thereby generating heat that may damage or degrade the battery and / or other systems. It may also be used to cool the battery when it is not being charged or used, as heat may damage or degrade the battery. Because the electric compressor may operate at various times, such use may require electrical energy from the battery even when the vehicle is not running, thus reducing the battery's operating time.

[0006] Some scroll compressors use vapor injection to increase the compressor's capacity. In such systems, a portion of the compressed refrigerant from the compressor's output is controllably diverted through a vapor generator and sent back to the compressor at a higher temperature, pressure, and / or vapor content, where it may be inserted back into the compression cycle. Generally, vapor injection results in higher compressor efficiency and / or higher capacity. However, most prior art compressors with vapor injection utilize external assemblies and / or additional components, resulting in additional complexity and cost.

[0007] It is therefore desirable to provide an electrically driven compressor that has high efficiency, low noise, and maximum lifespan.The present invention is directed to one or more of the problems or advantages identified above.

[0008] Summary of the Invention In a first aspect of the present invention, a housing for an electric scroll compressor is provided. The housing includes a suction volume, a discharge volume, a vapor injection cavity, and at least one vapor injection channel coupled to the vapor injection cavity. The housing includes a central housing, a rear head coupled to the central housing, a refrigerant inlet port, a refrigerant outlet port, and a vapor inlet port. The refrigerant inlet port is coupled to the rear head and configured to introduce refrigerant into the suction volume. The refrigerant outlet port is coupled to the rear head and configured to allow compressed refrigerant to exit the discharge volume. The vapor inlet port is integral with the rear head and coupled to the vapor injection cavity. The vapor injection cavity and the at least one vapor injection channel are integral with the housing and at least partially defined by the rear head.

[0009] In a second aspect of the present invention, there is provided an electric scroll compressor configured to compress a refrigerant for use with a vapor injection system. The electric scroll compressor includes a housing, a refrigerant inlet port, a refrigerant outlet port, a vapor inlet port, a drive shaft, and a compression device. The housing has a central housing and a rear head and defines a suction volume, a discharge volume, a vapor injection cavity, and at least one vapor injection channel. The refrigerant inlet port is coupled to the housing and configured to introduce refrigerant into the suction volume. The refrigerant outlet port is coupled to the housing and configured to allow compressed refrigerant to exit the electric scroll compressor from the discharge volume. The vapor inlet port is integral with the rear head and coupled to the vapor injection cavity. The vapor injection cavity and the at least one vapor injection channel are integral with the housing and at least partially defined by the rear head. The drive shaft is rotatably coupled within the housing. The compression device is coupled to the drive shaft and configured to receive refrigerant from the suction volume and compress it as the drive shaft rotates. The compression device includes a fixed scroll and an orbiting scroll. The fixed scroll is positioned within and fixed relative to the housing. The orbiting scroll is coupled to the drive shaft. The orbiting scroll and the fixed scroll receive refrigerant from the suction volume and form a compression chamber for compressing the refrigerant as the drive shaft rotates. The fixed scroll includes at least one vapor injection port in communication with the at least one vapor injection channel to allow vapor to enter the compression chamber formed between the fixed scroll and the orbiting scroll.

[0010] In a third aspect of the present invention, there is provided an electric scroll compressor configured to compress a refrigerant for use with a vapor injection system. The electric scroll compressor includes a housing, a refrigerant inlet port, a refrigerant outlet port, a vapor inlet port, an inverter module, a motor, a drive shaft, and a compression device. The housing has a central housing and a rear head and defines a suction volume, a discharge volume, a vapor injection cavity, and at least one vapor injection channel. The refrigerant inlet port is coupled to the housing and configured to introduce refrigerant into the suction volume. The refrigerant outlet port is coupled to the housing and configured to allow compressed refrigerant to exit the electric scroll compressor from the discharge volume. The vapor injection port is integral with the rear head and coupled to the vapor injection cavity. The vapor injection cavity and the at least one vapor injection channel are integral with the housing and at least partially defined by the rear head. The inverter module is mounted within the housing and adapted to convert DC power to AC power. The motor is mounted within the housing and coupled to the inverter module. The drive shaft is coupled to the motor. The compressor is coupled to the drive shaft for receiving refrigerant from the suction volume and compressing the refrigerant as the drive shaft is rotated by the motor. The compressor includes a fixed scroll and an orbiting scroll. The fixed scroll is positioned within and fixed relative to the housing. The orbiting scroll is coupled to the drive shaft. The orbiting scroll and the fixed scroll form a compression chamber for receiving refrigerant from the suction volume and compressing the refrigerant as the drive shaft is rotated about the central axis. The fixed scroll includes at least one vapor outlet opening port in communication with the at least one vapor injection channel to allow vapor to enter the compression chamber formed between the fixed scroll and the orbiting scroll.

[0011] These and other features and advantages of the present invention will be more readily understood when considered in conjunction with the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0012] [Figure 1A] 1 is a cross-sectional view of an electric compressor according to an embodiment of the present invention. [Figure 1B] FIG. 1 is a functional block diagram of a system including an electrically driven compressor using vapor injection. [Figure 2A] FIG. 1 is a first perspective view of an electric compressor utilizing steam injection in accordance with an embodiment of the present invention. [Figure 2B] FIG. 2B is a second perspective view of the electric compressor of FIG. 2A. [Figure 3] FIG. 2B is a diagram of a portion of the electric compressor of FIG. 2A. [Figure 4A] FIG. 2B is a front view of a fixed scroll of the electric compressor of FIG. 2A. [Figure 4B] FIG. 2B is a first perspective view of the rear head of the electric compressor of FIG. 2A. [Figure 4C] FIG. 2B is a front view of a gasket of the electric compressor of FIG. 2A in accordance with one embodiment of the present invention. [Figure 4D] FIG. 4D is a rear view of the gasket of FIG. 4C. [Figure 4E] FIG. 4D is a perspective view of the gasket of FIG. 4C. [Figure 5] FIG. 4C is a second perspective view of the front cover of FIG. 4B. [Figure 6] FIG. 4C is a third perspective view of the rear head of FIG. 4B. [Figure 7A] FIG. 4C is a front view of the rear head of FIG. 4B. [Figure 7B] FIG. 4B is a front view of the fixed scroll of FIG. 4A. [Figure 8A] FIG. 2B is an internal view of a first portion of the electric compressor of FIG. 2A. [Figure 8B] FIG. 2B is an internal view of a second portion of the electric compressor of FIG. 2A. [Figure 9A] FIG. 2B is an internal view of a first portion of the electric compressor of FIG. 2A. [Figure 9B] FIG. 2B is an internal view of a second portion of the electric compressor of FIG. 2A. [Figure 10] FIG. 2B is a perspective view of a rear head of the electric compressor of FIG. 2A according to another embodiment of the present invention.

[0013] MODE FOR CARRYING OUT THE INVENTION 1A-1B, 2A-2B, 3, 4A-4B, 5-6, 7A-7B, 8A-8B, and 9A-9B, wherein like numerals indicate like or corresponding parts throughout the several views, a motor-driven compressor 10 having an outer housing 12 is provided. The motor-driven compressor 10 is particularly suited for an automobile, such as an automobile vehicle (not shown). The motor-driven compressor 10 may be used as a cooling device or heat pump for heating and / or cooling different aspects of the vehicle. For example, the motor-driven compressor 10 may be used as part of a heating, ventilation, and air conditioning (HVAC) system 76 of an electric vehicle (not shown) to cool or heat the passenger compartment. Additionally, the motor-driven compressor 10 may be used to heat or cool the passenger compartment, onboard electronics, and / or a battery used to power the vehicle while the vehicle is not operating, e.g., during a charging cycle. The electric compressor 10 may further be used while the vehicle is not operating and the battery is not being charged to preserve battery life or minimize degradation.

[0014] 1B, the HVAC system 76 may be configured to provide heat to an interior space, such as the cabin of a motor vehicle (not shown). As shown, the HVAC system 76 includes or defines a heating circuit 78.

[0015] In the illustrated embodiment, the electric compressor 10 is a scroll-type compressor that operates to quickly and efficiently compress refrigerant for use in various systems in motor vehicles, e.g., electric or hybrid vehicles. With particular reference to FIG. 1A , the electric compressor 10 includes an inverter section 14, a motor section 16, and a compression device (or compression assembly) 18 housed within an outer housing 12. The outer housing 12 includes an inverter back cover 20, an inverter housing 22 (which may be integral), a center housing 24, and a rear head 28 (which may be referred to as a discharge head). The center housing 24 houses the motor section 16 and the compression device 18.

[0016] In one embodiment, inverter back cover 20, inverter housing 22, center housing 24, and rear head 28 are constructed from machined aluminum. Motor-driven compressor 10 may be mounted within the body of a vehicle, for example, via multiple mounting points (not shown).

[0017] In one aspect of the electric compressor 10 of the present disclosure, the electric compressor 10 is provided with a steam system 100 (see below) to increase the efficiency of the compressor 10. Additionally, as described below, the steam system 100 can include a steam injection circuit 102.

[0018] Overall configuration and operation of electric compressor 10 The inverter back cover 20 and the inverter housing 22 form an inverter cavity 30. The inverter back cover 20 is attached to the inverter housing 22 by a plurality of bolts 32. An inverter gasket 42, positioned between the inverter back cover 20 and the inverter housing 22, prevents moisture, dust, and other contaminants from entering the inverter cavity 30.

[0019] An inverter module 72 is mounted within the inverter cavity 30 formed by the inverter back cover 20 and the inverter housing 22. The inverter module 72 may include an inverter circuit (not shown) mounted on a printed circuit board (not shown) mounted on the inverter housing 22. The inverter circuit converts direct current (DC) power received from outside the electric compressor 10 into three-phase alternating current (AC) power to supply / power the motor 54 (see below). The inverter circuit may also control the rotational speed of the electric compressor 10. A high-voltage DC current is supplied to the inverter circuit via the high-voltage connector 50. A low-voltage DC current for driving the inverter circuit, as well as control signals for controlling the operation of the inverter circuit and the motor section 16, may be supplied via the low-voltage connector 52.

[0020] The center housing 24 defines a motor cavity 56. The motor section 16 includes a motor 54 positioned within the motor cavity 56. With particular reference to FIG. 1A, in the illustrated embodiment, the motor 54 is a three-phase AC motor having a stator 58. The stator 58 has a generally hollow cylindrical shape with six individual coils (two per phase). The stator 58 is housed within and attached to the inverter housing 22 and remains stationary relative to the inverter housing 22.

[0021] The motor 54 includes a rotor 60 positioned within a stator 58 and centrally disposed relative to the stator. The rotor 60 has a generally hollow cylindrical shape and is positioned within the stator 58.

[0022] The drive shaft 70 is coupled to the rotor 60 and rotates therewith. In the illustrated embodiment, the drive shaft 70 is press-fit into a central opening 60A in the rotor 60. The drive shaft 70 has a first end 70A and a second end 70B. The inverter housing 22 includes a first drive shaft support member 22A positioned on the motor side of the inverter housing 22. A first ball bearing 62 positioned in the opening formed by the first drive shaft support member 22A supports and rotates the first end of the drive shaft 70. The central housing 24 includes a second drive shaft support member 24A. A second ball bearing 64 positioned in the opening formed by the second drive shaft support member 24A enables the second end 70B of the drive shaft 70 to rotate. In the illustrated embodiment, the first and second ball bearings 62, 64 are press-fit into openings formed by the first drive shaft support member 22A of the inverter housing 22 and the second drive shaft support member 24A of the central housing 24, respectively.

[0023] As described above, the electric compressor 10 is a scroll-type compressor. The compression device 18 includes a fixed scroll 26 and an orbiting scroll 66. The orbiting scroll 66 is fixed to a second end 70B of a drive shaft 70. The rotor 60 rotates together with the drive shaft 70 under the control of an inverter module 72 to drive the movement of the orbiting scroll 66.

[0024] Drive shaft 70 has a central axis 70C about which rotor 60 and drive shaft 70 rotate. Orbiting scroll 66 moves in an eccentric orbit, i.e., circular motion, about central axis 70C, but the orientation of orbiting scroll 66 remains constant relative to fixed scroll 26. The center of orbiting scroll 66 is located along an offset axis (not shown) of drive shaft 70.

[0025] Generally, mixed refrigerant and oil enters electric compressor 10 (at low pressure) through refrigerant inlet port 34 (see, e.g., FIG. 2A ), is compressed by compression device 18, and then exits electric compressor 10 (at high pressure) through refrigerant outlet port 36. Refrigerant follows a refrigerant path through electric compressor 10. Refrigerant enters the refrigerant inlet port and enters suction volume 74 formed between the motor side of inverter housing 22 adjacent the refrigerant inlet port and center housing 24. Refrigerant is then drawn through motor section 16 and enters the compression suction volume formed between the inner wall of fixed scroll 26 and orbiting scroll 66.

[0026] The fixed scroll 26 is mounted within the central housing 24. Refrigerant enters the compressor 18 from the compression suction volume. The fixed scroll 26 and the orbiting scroll 66 form the compression chamber 40 into which the low or unpressurized (saturation pressure) refrigerant enters from the compressor 18. As the orbiting scroll 66 moves and allows the compression chamber 40 to close, the volume of the compression chamber is reduced and the refrigerant is pressurized. At any point during the cycle, one or more compression chambers 40 are at various stages of the compression cycle. During the cycle of the compressor 10, refrigerant is transported toward the center of the compression chamber 40.

[0027] Returning to FIG. 1A, rear head 28 defines a discharge volume 44. Discharge volume 44 communicates with refrigerant output port 36. Pressurized refrigerant exits compression device 18 through one or more orifices 104 (see FIGS. 4A and 7B). The release of the pressurized refrigerant is controlled by reed mechanism 68.

[0028] 1A, the compressed refrigerant exits the electric compressor 10 and enters a heating circuit 78. The heating circuit 78 includes a main refrigerant loop 80 and a vapor system 100.

[0029] The main refrigerant loop 80 includes an indirect condenser 82, a receiver-drier (R / D) 86, and a steam generator 88. A first expansion valve 90 controls the amount of refrigerant entering the indirect condenser 82. The refrigerant enters the indirect condenser 82 where heat is exchanged with a refrigerant flowing to or from a heater 84 located within or associated with the cabin of the motor vehicle (as is well known).

[0030] The refrigerant may exit the indirect condenser 82 and enter a receiver / dryer (R / D) 86. The R / D 86 may act as a temporary storage vessel during periods of low system demand and may contain a desiccant to remove moisture from the moisture / water.

[0031] As part of the main refrigerant loop 80, the refrigerant may exit the R / D 82 and pass through a vapor generator 88. From the vapor generator 88, the refrigerant passes through an evaporator or chiller 98 before returning to the electric compressor 10 at a low temperature and pressure. A second expansion valve 92 controls the flow of fluid from the vapor generator 88 to the evaporator / chiller 98.

[0032] Steam System 1B and 2A-2B, 3, 4A-4B, 5-6, 7A-7B, 8A-8B, and 9A-9B, in one aspect of the invention, in the illustrated embodiment, heating circuit 78 includes a steam system 100. In the illustrated embodiment, steam system 100 includes a steam injection circuit 102.

[0033] 1B, the vapor injection circuit 102 is formed at least in part by the vapor generator 88. As shown in the illustrated embodiment, the refrigerant exiting the R / D 86 may be split. As mentioned above, a portion of the flow exiting the R / D 86 is part of the main refrigerant loop 80 and flows through the vapor generator 88 and the evaporator / chiller 98 and back to the electrically driven compressor 10.

[0034] A second portion of the flow exiting R / D 86 flows through (a different portion of) the steam generator and returns to electric compressor 10. The second portion of the flow exiting R / D 86 is controlled by third expansion valve 94. The refrigerant in the second portion of the flow exiting R / D 86 exits steam generator 88 at a higher temperature and pressure and / or vapor fraction as a result of heat transfer. This portion of the refrigerant is pumped back to electric compressor 10 at vapor injection port 38 of electric compressor 10 (see below).

[0035] In one aspect of the invention, compressor 10 can include several components configured to interface with vapor injection circuit 102 and housed within and / or integrally formed with other components of compressor 10. In one aspect of the invention, components of vapor injection system 100 are integrated within compressor 10, specifically, in the illustrated embodiment, with rear head 28. Exemplary compressors 10 including the integral components of vapor injection system 100 are shown in Figures 2A-2B, 3, 4A-4B, 5, 7, 7A-7B, 8A-8B, and 9A-9B.

[0036] As described above, the electric compressor 10 includes a housing or outer housing 12. In the illustrated embodiment, the outer housing 12 includes a center housing 24, an inverter back cover 20, and a rear head 28. With particular reference to FIG. 1A , the outer housing 12 at least partially defines an intake volume 74, a discharge volume 44, a steam injection cavity 108, and at least one steam injection channel 114.

[0037] 2A, 2B, and 3, the electric scroll compressor 10 further includes a refrigerant inlet port 34, a refrigerant outlet port 36, and a vapor injection port 38. The refrigerant inlet port 34 is coupled to the housing 12 and, in the illustrated embodiment, is connected to the center housing 24. The refrigerant inlet port 34 is configured to introduce refrigerant into the suction volume 74. The refrigerant outlet port 36 is coupled to the housing 12 and, in the illustrated embodiment, is connected to the rear head 28. The refrigerant outlet port 36 is configured to allow compressed refrigerant to exit the electric scroll compressor 10 through the discharge volume 44.

[0038] In the illustrated embodiment, the steam injection port 38 is integral with the rear head 28 and is coupled, i.e., in fluid communication, with the steam injection cavity 108. The steam injection cavity 108 and at least one steam injection channel 114 are integral with the housing 12 and are at least partially defined by the rear head 28.

[0039] As mentioned above, in the illustrated embodiment, the inverter module 72 is configured to convert DC power (provided externally) to AC power to drive the motor 54. In the illustrated embodiment, the inverter module 72 and the motor 54 are located within the housing 12. However, in other embodiments, the inverter module 72 or the inverter module 72 and the motor 54 may be located external to the housing 12 or the compressor 10.

[0040] Motor 54 controllably rotates drive shaft 70. Compressor 18 is coupled to and driven by drive shaft 70. Compressor 18 is configured to receive refrigerant from the suction volume and compress the refrigerant as drive shaft 70 is rotated by motor 54.

[0041] In the illustrated embodiment, the compression device 18 includes a fixed scroll 26 and an orbiting scroll 66. The fixed scroll 26 is positioned within and fixed to the housing 12. The orbiting scroll 66 is coupled to a drive shaft 70. The orbiting scroll 66 and the fixed scroll 26 receive refrigerant from a suction volume 74 and form compression chamber(s) 40 for compressing the refrigerant as the drive shaft 70 rotates about a central axis 70C.

[0042] With particular reference to Figures 3, 4B, 5, 6, and 9A, the fixed scroll 26 includes at least one steam outlet opening 110 in communication with at least one steam injection channel 114 to allow steam to enter the compression chamber 40 formed between the fixed scroll 26 and the orbiting scroll 66.

[0043] 5 and 6, in the illustrated embodiment, the rear head 28 includes a rear head (or interior) cavity 46 and a series of partition walls 48. The series of partition walls 48 divide the rear head cavity 46 into a discharge volume 44 and a steam injection cavity 108.

[0044] The discharge volume 44 may be further divided into sub-chambers 96 that form an oil separator integral with the rear head 28. Oil may be used to provide lubrication between the moving components of the electric compressor 10. During operation, the oil and refrigerant are mixed. The oil separator may be used to separate a portion of the oil from the oil-refrigerant mixture before the refrigerant exits the electric compressor 10.

[0045] 5 and 6, the subchambers 96 of the discharge volume 44 may include a central subchamber 96A. As shown, compressed refrigerant enters the central subchamber 96A from the compression chamber 40 through an orifice 104 in the fixed scroll 26 and the reed mechanism 68.

[0046] The steam injection channel 114 may be formed in or adjacent to the top surface of a series of partition walls 48. In the illustrated embodiment, the steam injection channel 114 has a first end 116 that is adjacent to and fluidly connected to the steam injection cavity 108. The steam injection channel 114 extends from the steam injection cavity 108 toward a second end 118 of the steam injection channel 114. As shown, in the illustrated embodiment, the steam injection channel 114 continues along opposing partition walls 48 that form the central subchamber 96A.

[0047] With particular reference to FIGS. 5, 6, 8B, 9B, and 10, the motorized scroll compressor 10 may further include a steam lead mechanism 106 positioned with the steam injection cavity 108 and fastened to the rear head 28. The steam lead mechanism 106 is positioned adjacent to the end of the steam inlet port 38 and is configured to control the flow of steam from the steam injection port 38 to the steam injection cavity 108. In the illustrated embodiment, the steam lead mechanism 106 includes a lead 106A, a fastener 106B, and a lead hold-down 106C. The fastener 106B connects or fastens the lead 106A to the rear head 28. The lead 106A is made from a flexible material, such as steel. The properties of the lead 106A, such as the material and strength, are selected to control the pressure at which steam can enter the steam injection cavity 108 from the steam injection port 38. The lead hold-down 106C may be made from a rigid, non-flexible material, such as stamped steel. The reed holddown 106C controls or limits the maximum displacement of the reed 106A. The vapor reed mechanism 106 forms a valve that allows vapor to controllably enter the compression chamber 40 and prevents backflow of vapor back into the vapor injection channel(s) 114.

[0048] When assembled, rear head 28 is adjacent to fixed scroll 26. A second end 118 of steam injection channel 114 is adjacent to and opens to a steam exit opening 110 in fixed scroll 26. Steam exit opening 110 allows steam from steam injection circuit 102, as it passes through steam reed feature 106, to travel from steam injection cavity 108, through steam injection channel 114, and through steam exit opening 110 in fixed scroll 26 into compression chamber 40.

[0049] 4C-4E, a gasket 112 may be positioned between the center housing 24 (and fixed scroll 26) and the rear head 28. The gasket 112 is positioned within the interface between the rear head 28 and the fixed scroll 26 and provides pressure separation between the high pressure in the discharge volume 44 and the steam injection cavity 108. The gasket 112 may be configured to provide a seal between the discharge volume 44 (and subchamber 96) and the steam injection cavity 108 and steam injection channel 114. As shown, the gasket 112 may provide several openings 120 positioned adjacent to the second end 118 of the steam injection channel 114 and the steam exit opening 110 in the fixed scroll 26 to allow steam to pass through.

[0050] In the illustrated embodiment, the compressor 10 includes a vapor reed mechanism 106, a vapor injection cavity 108, and one or more vapor injection channels 114. In the illustrated embodiment, the fixed scroll 26 is adjacent to the rear head 28. As shown, the rear head 28 defines a discharge volume 44 (which may include multiple chambers configured to separate oil from refrigerant prior to discharge from the compressor 10). In the illustrated embodiment, the vapor injection cavity 108 and the vapor injection channel 114 are defined by and are integral with the rear head 28. However, it should be noted that the vapor injection cavity 108 and / or the vapor injection channel 114 may be at least partially defined by the fixed scroll 26. The vapor injection cavity 108 is in fluid communication with the vapor injection port 38. A third expansion valve 94, external to the compressor 10, controls the flow of steam to the vapor injection port 38.

[0051] Under the control of the third expansion valve 94 , steam enters the compressor 10 through the steam injection port 38 and into the steam injection cavity 108 and steam injection channel 114 .

[0052] A rear head 28 according to a second embodiment of the invention, but with a different geometric layout, is shown in FIG.

[0053] The above invention has been described in accordance with the relevant legal standards, and therefore the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiments may become apparent to those skilled in the art and are within the scope of the invention.

Claims

1. A housing for an electric scroll compressor, the housing including: a suction volume; a discharge volume; a vapor injection cavity; and at least one vapor injection channel coupled to the vapor injection cavity; A central housing; a rear head coupled to the central housing; a refrigerant inlet port coupled to the rear head and configured to introduce refrigerant into the suction volume; a refrigerant outlet port coupled to the rear head and configured to allow compressed refrigerant to exit the discharge volume; a steam injection port integral with the rear head, the steam injection port being coupled to the steam injection cavity, the steam injection cavity and the at least one steam injection channel being integral with the housing and at least partially defined by the rear head; A housing comprising:

2. 2. The housing of claim 1, wherein the rear head includes a rear head cavity divided into the exhaust volume and the steam injection cavity by a series of partitions integral with the rear head.

3. The housing of claim 2 , wherein the series of partitions has an upper surface adjacent the central housing.

4. The housing of claim 3 , wherein the at least one steam injection channel is formed in the top surface of the series of partitions.

5. 5. The housing of claim 4, wherein the series of partitions divide the exhaust volume into a plurality of subchambers including a central subchamber, and the at least one steam injection channel includes a first steam injection channel and a second steam injection channel formed in the top surface of a partition on either side of the central subchamber.

6. The housing of claim 5 , further comprising a gasket positioned between the center housing and the rear head and configured to provide a seal between the exhaust volume and the steam injection cavity and the steam injection channel.

7. 1. An electric scroll compressor configured to compress a refrigerant for use with a vapor injection system, comprising: a housing having a central housing and a rear head, the housing defining an intake volume, a discharge volume, a steam injection cavity, and at least one steam injection channel; a refrigerant inlet port coupled to the housing and configured to introduce the refrigerant into the suction volume; a refrigerant outlet port coupled to the housing and configured to allow compressed refrigerant to exit the motorized scroll compressor from the discharge volume; a steam injection port integral with the rear head and coupled to the steam injection cavity, the steam injection cavity and the at least one steam injection channel being integral with the housing and at least partially defined by the rear head; a drive shaft rotatably coupled within the housing; a compression device coupled to the drive shaft configured to receive the refrigerant from the suction volume and compress it as the drive shaft rotates; a fixed scroll positioned within the housing and fixed relative to the housing; an orbiting scroll coupled to the drive shaft, the orbiting scroll and the fixed scroll forming a compression chamber for receiving the refrigerant from the suction volume and compressing the refrigerant as the drive shaft rotates, the fixed scroll including at least one vapor outlet opening in communication with the at least one vapor injection channel to allow vapor to enter the compression chamber formed between the fixed scroll and the orbiting scroll; a compression device including: An electric scroll compressor comprising:

8. The motorized scroll compressor of claim 7 , further comprising a reed mechanism positioned with the vapor injection cavity and configured to control the flow of vapor from the vapor injection port to the vapor injection cavity.

9. 8. The electric scroll compressor of claim 7, wherein the rear head includes a rear head cavity divided into the discharge volume and the vapor injection cavity by a series of partitions integral with the rear head.

10. 9. The motorized scroll compressor of claim 8, wherein the series of partition walls have an upper surface adjacent the central housing.

11. 10. The motorized scroll compressor of claim 9, wherein the at least one vapor injection channel is formed in the upper surface of the series of partition walls.

12. 11. The electric scroll compressor of claim 10, wherein the series of partitions divide the discharge volume into a plurality of subchambers including a central subchamber, and the at least one vapor injection channel includes a first vapor injection channel and a second vapor injection channel formed in the top surface of a partition on either side of the central subchamber.

13. 12. The electric scroll compressor of claim 11, further comprising a gasket positioned between the center housing and the rear head and configured to provide a seal between the discharge volume and the steam injection cavity and the steam injection channel.

14. 1. An electric scroll compressor configured to compress a refrigerant for use with a vapor injection system, comprising: a housing having a central housing and a rear head, the housing defining an intake volume, a discharge volume, a steam injection cavity, and at least one steam injection channel; a refrigerant inlet port coupled to the housing and configured to introduce the refrigerant into the suction volume; a refrigerant outlet port coupled to the housing and configured to allow compressed refrigerant to exit the motorized scroll compressor from the discharge volume; a steam injection port integral with the rear head and coupled to the steam injection cavity, the steam injection cavity and the at least one steam injection channel being integral with the housing and at least partially defined by the rear head; an inverter module mounted within the housing and adapted to convert DC power to AC power; a motor mounted within the housing and coupled to the inverter module; a drive shaft coupled to the motor; a compression device coupled to the drive shaft for receiving the refrigerant from the suction volume and compressing the refrigerant as the drive shaft is rotated by the motor, a fixed scroll positioned within the housing and fixed relative to the housing; an orbiting scroll coupled to the drive shaft, the orbiting scroll and the fixed scroll forming a compression chamber for receiving the refrigerant from the suction volume and compressing the refrigerant as the drive shaft rotates about a central axis, the fixed scroll including at least one vapor outlet opening in communication with the at least one vapor injection channel to allow vapor to enter the compression chamber formed between the fixed scroll and the orbiting scroll; a compression device including: An electric scroll compressor comprising:

15. 15. The motorized scroll compressor of claim 14, further comprising a reed mechanism positioned with the vapor injection cavity and configured to control the flow of vapor from the vapor injection port to the vapor injection cavity.

16. 15. The electric scroll compressor of claim 14, wherein the rear head includes a rear head cavity divided into the discharge volume and the vapor injection cavity by a series of partitions integral with the rear head.

17. 16. The motorized scroll compressor of claim 15, wherein the series of partition walls have an upper surface adjacent the central housing.

18. 17. The motorized scroll compressor of claim 16, wherein the at least one vapor injection channel is formed in the upper surface of the series of partition walls.

19. 18. The electric scroll compressor of claim 17, wherein the series of partitions divide the discharge volume into a plurality of subchambers including a central subchamber, and the at least one vapor injection channel includes a first vapor injection channel and a second vapor injection channel formed in the top surface of a partition on either side of the central discharge volume.

20. 20. The electric scroll compressor of claim 18, further comprising a gasket positioned between the center housing and the rear head and configured to provide a seal between the discharge volume and the steam injection cavity and the steam injection channel.

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