Electric compressor with scroll backpressure system

Abstract

To provide an electric compressor having high efficiency, low noise, and a maximum life.SOLUTION: The electric compressor includes a housing, refrigerant inlet port, a refrigerant outlet port, an inverter section, a motor section, a compression device and a front cover. The housing defines an intake volume and a discharge volume. The refrigerant inlet port is coupled to the housing and is configured to introduce the refrigerant to the intake volume. The compression device is a scroll-type compression device configured to compress the refrigerant. The refrigerant outlet port is coupled to the housing and is configured to allow compressed refrigerant to exit the scroll-type electric compressor from the discharge volume. The electric compressor including a scroll backpressure system, located at least partially, within a compression device body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to electric compressors, and more particularly to electric compressors that use a scroll compression device to compress a refrigerant.

[0002] Background technology Compressors have long been used in refrigeration systems. In particular, scroll-type compressors, in which an orbiting scroll rotates in a circular motion relative to a fixed scroll to compress a refrigerant, are used in systems designed to provide cooling in specific applications. For example, such scroll-type compressors have long been used in HVAC systems in automobiles and other vehicles to provide air conditioning. Furthermore, such compressors may be used in reverse in applications requiring heat pumps. Typically, these compressors are driven using rotary motion obtained from the automobile's engine.

[0003] With the advent of battery or electric vehicles and / or hybrid vehicles, where the vehicle may sometimes be powered solely by a battery, such compressors must be powered or operated by a battery rather than an engine. Such compressors may be referred to as electric compressors.

[0004] In addition to cooling the vehicle's passenger compartment, the electric compressor can 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 electronics system and the battery or battery compartment when charging the battery, especially in fast charge mode, because heat is generated that could damage or degrade the battery and / or other systems. It can also be used to cool the battery when it is not being charged or used, because heat could damage or degrade the battery. Because the electric compressor operates at various times, and may even operate when the vehicle is not running, such use obviously requires electrical energy from the battery, thus reducing the battery's operating time.

[0005] A scroll compressor typically includes a suction volume that receives refrigerant (from an external source) and a discharge volume located downstream of the fixed and orbiting scrolls that contains or collects the compressed refrigerant. In the compressor, back pressure can be used to press the orbiting scroll against the fixed scroll. Proper pressing of the orbiting scroll against the fixed scroll can ensure proper operation while allowing for thermal expansion, manufacturing tolerances, etc. Proper pressing can also help provide a proper seal between the scrolls.

[0006] The back pressure must be great enough to overcome the axial separation of the scrolls, however, too much back pressure can lead to loss of oil film between the scrolls, excessive friction, and reduced efficiency.

[0007] Additionally, electric compressors can operate at extremely high speeds, such as 2,000 RPM (or more), which can generate undesirable levels of noise.

[0008] It would therefore be desirable to provide an electric compressor that is highly efficient, quiet, and has a maximum lifespan.The present invention is directed to one or more of the above-identified problems or advantages.

[0009] Summary of the Invention In a first aspect of the present invention, an electric scroll compressor configured to compress a refrigerant is provided. The electric scroll compressor includes a housing, a refrigerant inlet port, a refrigerant outlet port, an inverter module, a motor, a drive shaft, a compression device, and a scroll backpressure system. The housing defines a suction volume and a discharge volume. 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 inverter module is mounted inside the housing and configured to convert DC power to AC power. The motor is mounted inside the housing. The drive shaft is coupled to the motor. The compression device receives refrigerant from the suction volume and is coupled to the drive shaft to compress the refrigerant when the drive shaft is rotated by the motor.

[0010] The compressor includes a compressor body, a fixed scroll, and an orbiting scroll. The fixed scroll is located within the housing and is fixed relative to the compressor body. 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 when the drive shaft is rotated about its central axis. The compressor forms a back pressure pocket.

[0011] The scroll backpressure system is located at least partially within the compressor body and includes a first pressure path and a second pressure path. The first pressure path is located between the discharge volume and the backpressure pocket and is configured to allow pressurized refrigerant in the discharge volume to be introduced into the backpressure pocket. The first pressure path is formed at least partially within the compressor body. The second pressure path is located between the backpressure pocket and the suction volume and includes a dump valve for controllably releasing the pressurized refrigerant in the backpressure pocket to the suction volume.

[0012] In a first embodiment of the present invention, an electric scroll compressor configured to compress a refrigerant is provided. The electric scroll compressor includes a housing, a refrigerant inlet port, a refrigerant outlet port, an inverter module, a motor, a drive shaft, a compression device, and a scroll backpressure system. The housing includes a center housing and a front cover and defines a suction volume and a discharge volume. The discharge volume is formed at least in part by the center housing and the front cover. 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 inverter module is mounted inside the housing and configured to convert DC power to AC power. The motor is mounted inside the housing, and the drive shaft is coupled to the motor.

[0013] The compressor receives refrigerant from the suction volume and is coupled to the drive shaft to compress the refrigerant when the drive shaft is rotated by the motor. The compressor includes a compressor body, a fixed scroll, and an orbiting scroll. The compressor body includes a thrust body. The back pressure pocket is at least partially defined by the thrust body. The fixed scroll is located within the housing and fixed relative to the compressor body. 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 when the drive shaft is rotated about the central axis. The compressor forms the back pressure pocket.

[0014] The scroll backpressure system is located at least partially within the compressor body and includes a first pressure path and a second pressure path.

[0015] The first pressure path is between the discharge volume and the back pressure pocket and is configured to allow pressurized refrigerant in the discharge volume to be introduced into the back pressure pocket. The first pressure path is formed at least partially within the compressor body.

[0016] The compressor body includes a thrust body. The back pressure pocket is at least partially defined by the thrust body. A first pressure path is formed through the front cover, the center housing, and the thrust body. The first pressure path includes a first pressure path end connected to the refrigerant outlet port and a second pressure path end connected to the back pressure pocket. The first pressure path includes a fixed orifice for restricting the flow of pressurized refrigerant from the discharge volume to the back pressure pocket.

[0017] The second pressure path is located between the backpressure pocket and the suction volume and includes a dump valve for controllably releasing pressurized refrigerant in the backpressure pocket to the suction volume, the dump valve being configured to maintain a constant pressure differential between the backpressure pocket and the suction volume and being located at least partially within the thrust body.

[0018] In a second embodiment of the present invention, an electric scroll compressor configured to compress a refrigerant is provided, the electric scroll compressor including a housing, a refrigerant inlet port, a refrigerant outlet port, an inverter unit, a motor unit, a compression device, and a scroll back pressure system.

[0019] The housing defines a suction volume and a discharge volume. A refrigerant inlet port is coupled to the housing and configured to introduce refrigerant into the suction volume. A refrigerant outlet port is coupled to the housing and configured to allow compressed refrigerant to exit the motorized scroll compressor from the discharge volume.

[0020] The inverter unit includes an inverter housing, an inverter back cover, and an inverter module. The inverter back cover is connected to the inverter housing to form an inverter cavity. The inverter module is mounted in the inverter cavity and configured to convert DC power into AC power.

[0021] The motor section includes a drive shaft and a motor. The drive shaft is disposed within the housing, has first and second ends, and defines a central axis. The motor is disposed within the housing for controllably rotating the drive shaft about the central axis. A compressor is coupled to the drive shaft to receive refrigerant from the suction volume and compress the refrigerant when the drive shaft is rotated by the motor.

[0022] The compressor includes a compressor body, a fixed scroll, and an orbiting scroll. The compressor body includes a thrust body. The back pressure pocket is at least partially defined by the thrust body. The fixed scroll is located within the housing and is fixed relative to the thrust body. 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 when the drive shaft is rotated about its central axis.

[0023] The scroll backpressure system is at least partially located within the compressor body and includes a first pressure path, a second pressure path, and a backpressure regulating valve. The first pressure path is located between the discharge volume and the backpressure pocket and is configured to allow pressurized refrigerant in the discharge volume to be introduced into the backpressure pocket. The first pressure path is at least partially formed within the thrust body. The second pressure path is located between the backpressure pocket and the suction volume and includes a dump valve for controllably releasing the pressurized refrigerant in the backpressure pocket to the suction volume.

[0024] A backpressure regulator valve is connected between the suction volume and the backpressure pocket and is located at least partially within the thrust body, and is configured to modify the flow of pressurized refrigerant through the first pressure path from the discharge volume to the backpressure pocket as a function of a pressure differential between the suction volume and the backpressure pocket.

[0025] The second pressure path includes a passageway and a dump valve. The passageway is located within the compressor body between the suction volume and the backpressure pocket. The dump valve is coupled between the discharge volume and the backpressure pocket and is configured to control refrigerant flow between the backpressure pocket and the suction volume as a function of a pressure differential between the discharge volume and the backpressure pocket.

[0026] 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]

[0027] [Figure 1] 1 is a cross-sectional view of an electric compressor according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of a portion of the electric compressor of FIG. 1 including a scroll backpressure system according to a first embodiment. [Figure 3A] 1 is an illustration of a portion of a motor-driven compressor including a scroll back pressure system according to a second embodiment. [Figure 3B] 1 is an illustration of a portion of a motor-driven compressor including a scroll back pressure system according to a second embodiment. [Figure 4A] 2 is a diagram of the back pressure regulating valve of the electric compressor of FIG. 1 in operation. [Figure 4B] FIG. 2 is a diagram of a back pressure regulating valve of the electric compressor of FIG. 1 in operation. [Figure 4C] 2 is a diagram of the back pressure regulating valve of the electric compressor of FIG. 1 in operation. [Figure 4D] 2 is a diagram of the back pressure regulating valve of the electric compressor of FIG. 1 in operation. [Figure 5A] FIG. 4 is a diagram of the dump valve of the electrically driven compressor of FIGS. 3A and 3B in operation. [Figure 5B] FIG. 4 is a diagram of the dump valve of the electrically driven compressor of FIGS. 3A and 3B in operation. [Figure 6] FIG. 5B is a perspective view of a thrust body of the electric compressor of FIGS. 5A to 5D. [Figure 7A]3C is a diagram of a portion of a motor-driven compressor including the scroll backpressure system of FIGS. 3A and 3B according to a second embodiment. [Figure 7B] 3C is a diagram of a portion of a motor-driven compressor including the scroll backpressure system of FIGS. 3A and 3B according to a second embodiment.

[0028] MODE FOR CARRYING OUT THE INVENTION Referring to Figures 1, 2, 3A, 3B, 4A-4D, 5A and 5B, 6, and 7A and 7B, where like numbers indicate like or corresponding parts throughout the several figures, a motor-driven compressor 10 having an outer housing 12 is presented. The motor-driven compressor 10 is particularly suited for an automobile, such as a motor vehicle (not shown). The motor-driven compressor 10 can be used as a cooling device or heat pump to heat and / or cool various aspects of the vehicle. For example, the motor-driven compressor 10 can be used as part of a heating, ventilation, and air conditioning (HVAC) system in an electric vehicle (not shown) to cool or heat the passenger compartment. Additionally, the motor-driven compressor 10 can be used to heat or cool the passenger compartment, onboard electronics, and / or a battery used to power the vehicle when the vehicle is not operating, such as during a charging cycle. Furthermore, the motor-driven compressor 10 can be used to preserve battery life or minimize degradation when the vehicle is not operating and the battery is not charging.

[0029] 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, such as electric or hybrid vehicles. 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 front cover 28 (sometimes referred to as a discharge head). The center housing 24 houses the motor section 16 and the compression device 28.

[0030] In one embodiment, the inverter back cover 20, inverter housing 22, center housing 24, and front cover 28 are constructed from machined aluminum. The electric compressor 10 can be mounted, for example, within the body of an automobile via multiple mounting points (not shown). In one aspect of the electric compressor 10 of the present disclosure, an electric compressor 10 having a scroll back pressure system 200 (see below) is provided.

[0031] 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 disposed between the inverter back cover 20 and the inverter housing 22 protects the inverter cavity 30 from moisture, dust, and other contaminants.

[0032] An inverter module (not shown) is mounted within the inverter cavity 30 formed by the inverter back cover 20 and the inverter housing 22. The inverter module 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 to / operate the motor 54 (see below). Furthermore, the inverter circuit may control the rotational speed of the electric compressor 10. A high-voltage DC current is supplied to the inverter circuit via a high-voltage connector (not shown). 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 a low-voltage connector (not shown).

[0033] Center housing 24 defines a motor cavity 56. Motor section 16 includes a motor 54 disposed within motor cavity 56. With particular reference to FIG. 1, in the illustrated embodiment, motor 54 is a three-phase AC motor having a stator 58. Stator 58 has a generally hollow cylindrical shape with six individual coils (two for each phase). Stator 58 is housed within, attached to, and remains stationary relative to motor housing 22.

[0034] The motor 54 is disposed within a stator 58 and includes a rotor 60 that is centrally located relative to the stator 58. The rotor 60 has a generally hollow cylindrical shape and is disposed within the stator 58.

[0035] A drive shaft 90 is connected to the rotor 60 and rotates therewith. In the illustrated embodiment, the drive shaft 90 is press-fit into a central opening 60C of the rotor 60. The drive shaft 90 has a first end 90A and a second end 90B. The inverter housing 22 includes a first drive shaft support member 22B disposed on the motor side of the inverter housing 22. A first ball bearing 62 disposed within the opening formed by the first drive shaft support member 22 supports and allows rotation of the first end of the drive shaft 90. The center housing 24 includes a second drive shaft support member 24A. A second ball bearing 64 disposed within the opening formed by the second drive shaft support member 24A allows rotation of the second end 90B of the drive shaft 90. 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 center housing 24, respectively.

[0036] 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 of the rotor 60B. The rotor 60, which includes a drive shaft 90, rotates under the control of the inverter module 44, driving the orbiting scroll 66 to move.

[0037] Drive shaft 90 has a central axis 90C about which rotor 60 and drive shaft 90 rotate. Orbiting scroll 66 moves about central axis 90C in an eccentric orbit, i.e., a circular motion in which 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 90.

[0038] Generally, a mixed refrigerant and oil (at low pressure) enters the electric compressor 10 through the refrigerant inlet port 68, is compressed by the compression device 18, and then exits the electric compressor 10 (at higher pressure) through the refrigerant outlet port 70. The refrigerant follows a refrigerant path through the electric compressor 10. The refrigerant enters the refrigerant inlet port 68 and enters a suction volume 74 formed between the motor side of the inverter housing 22 adjacent the refrigerant inlet port 68 and the center housing 24. The refrigerant is then drawn through the motor section 16 and enters a compression suction volume formed between the inner wall of the fixed scroll 26 and the orbiting scroll 66.

[0039] The fixed scroll 26 is mounted within the center housing 24. Refrigerant enters the compressor 18 from the compression suction volume. The fixed scroll 26 and the orbiting scroll 66 form a compression chamber 80 into which low-pressure or unpressurized (saturation pressure) refrigerant enters from the compressor 18. As the orbiting scroll 66 moves to allow the compression chamber 80 to close, the volume of the compression chamber decreases and the refrigerant becomes pressurized. At any one time during the cycle, one or more compression chambers 80 are in different stages of the compression cycle. During the cycle of the compressor 10, refrigerant is transported toward the center of the compression chamber 80.

[0040] Returning to Figure 1, the front cover 28 defines a discharge volume 82. The discharge volume 82 communicates with a refrigerant output port. Pressurized refrigerant exits the compressor 18 through one or more orifices (not shown). The release of the pressurized refrigerant is controlled by a reed mechanism 86.

[0041] Scroll Back Pressure System In one aspect of the present invention, the electric compressor 10 can include a scroll back pressure system 200. The scroll back pressure system 200 can be provided in a compressor 10 configured to utilize a refrigerant such as refrigerant grade CO2 (R744). However, the present invention is not limited to a compressor using a particular refrigerant.

[0042] In the disclosed embodiment, the housing or outer housing 12 includes a center housing 24, and the compressor 18 includes a thrust body 130. In the illustrated embodiment, the center housing 24 and thrust body 130 form part of a compressor body 202. A scroll backpressure system 200 may be disposed, at least partially, within the compressor body 202. As described in further detail below, the scroll backpressure system 200 controllably manages or regulates backpressure, i.e., the pressure of refrigerant in a backpressure pocket 204 (see below) relative to the intake pressure in the suction volume 74, to overcome the axial separation of the fixed scroll 26 and the orbiting scroll 66, while avoiding applying excessive pressure that would result in excessive friction between the scrolls 26, 66. The backpressure pocket 204 is located within the compressor 18 adjacent to one side of the orbiting scroll 66, such that the pressurized refrigerant in the backpressure pocket 204 exerts a force on the orbiting scroll 66 in the direction of the fixed scroll 26.

[0043] The pressure of the refrigerant in the suction volume 74 may be referred to as the suction pressure. The pressure of the refrigerant in the discharge volume 82 may be referred to as the discharge pressure. The pressure of the refrigerant in the back pressure pocket 204 may be referred to as the back pressure.

[0044] As described in further detail below, in one embodiment of the invention, backpressure system 200 includes a first pressure path 206 and a second pressure path 208. First pressure path 206 is located between discharge volume 82 and backpressure pocket 204 and is configured to allow pressurized refrigerant in discharge volume 82 to be introduced into backpressure pocket 204. First pressure path 206 is formed at least in part within compressor body 202. Second pressure path 208 is located between backpressure pocket 204 and suction volume 74. Second pressure path 208 may include a dump valve 210 (see below) for controllably venting pressurized refrigerant in backpressure pocket 204 to suction volume 74.

[0045] 2, an exemplary scroll backpressure system 200 according to a first embodiment is shown. As noted above, in the illustrated embodiment, the housing 12 includes the center housing 24 and the front cover 28. As shown, the discharge volume 82 may be defined, at least in part, by the center housing 24, the front cover 28, and the refrigerant outlet port 70.

[0046] In the first embodiment, the first pressure path 206 includes a first pressure path end 212 connected to the refrigerant outlet port 70 and a second pressure path end 214 connected to the backpressure pocket 204. As shown, the first pressure path 206 is disposed within and may be partially integral with the center housing 24. Additionally, the first pressure path 206 may include a fixed orifice 216 to restrict the flow of pressurized refrigerant from the discharge volume to the backpressure pocket.

[0047] As described above, the compressor body 202 may be formed in part by the center housing 24 and the thrust body 130. As shown, the thrust body 130 may include a threaded opening 218 between the suction volume 74 and the backpressure pocket 204. In the first embodiment shown in FIG. 2, a dump valve 210 may be threaded into the threaded opening 218. The dump valve 210 is configured to maintain a constant pressure differential between the backpressure pocket 204 and the suction volume 74.

[0048] The back pressure pocket 204 may be defined, at least in part, by the compressor body 202 and, more specifically, by the thrust body 130 .

[0049] 2, dump valve 210 is spring biased to a closed position. When the pressure of the refrigerant in backpressure pocket 204, i.e., the backpressure, exceeds a threshold value, dump valve 210 opens, allowing excess refrigerant to escape into suction volume 74. When the backpressure falls below the threshold value, dump valve 210 closes, preventing the passage of refrigerant.

[0050] In the illustrated embodiment, the first pressure path 206 may be formed through the front cover 28 , the center housing 24 , and the thrust body 130 .

[0051] 3A, 3B, 4A-4D, 5A, 5B, and 6, an exemplary scroll backpressure system 200 according to a second embodiment is shown. In the second embodiment, first and second pressure paths 206, 208 are within the compressor body 202, and more specifically, within the thrust body 130.

[0052] 3A and 3B, a diagram of the thrust body 130 and first pressure path 206 in a second embodiment is shown. In the second embodiment, the first pressure path 206 includes a first pressure passage 220 and a backpressure regulator valve 222. The first pressure passage 220 is located within the thrust body 130. The first pressure passage 220 has a first end 220A that opens to the discharge volume 82 and a second end 220B that opens to the backpressure pocket 204. The flow of refrigerant between the discharge volume 82 and the backpressure pocket 204 is controlled by the backpressure regulator valve 222 as a function of the pressure difference between the intake pressure in the suction volume 74 and the pressure in the backpressure pocket 204 (see below).

[0053] As described above, the backpressure regulator valve 222 is connected between the suction volume 74 and the backpressure pocket 204. The backpressure regulator valve 222 is configured to modify the flow of pressurized refrigerant from the discharge volume 82 to the backpressure pocket 204 through the first passage 220 of the first pressure path 206 as a function of the pressure differential between the suction volume 74 and the backpressure pocket 204. With particular reference to FIGS. 4A-4D, 5, and 7A, in one embodiment, the backpressure regulator valve 222 may be a slide regulator valve 226 integrated into the compressor body 202, and more specifically, the thrust body 130. As shown, the slide regulator valve 226 may include a valve body 226A (formed by the thrust body 130), a valve pin 226B, and a valve spring 226C.

[0054] The operation of the sliding regulator valve 226 is illustrated in Figures 4A-4D. At start-up of the compressor 10, the sliding regulator valve 226 may be in a fully open position (shown in Figure 4A) providing a direct path between the discharge volume 82 and the back pressure pocket 204. Thus, the suction pressure, back pressure, and discharge pressure are equal.

[0055] As the back pressure increases but has not yet reached the target pressure, the back pressure acts on one end of the valve stem 226B, compressing the spring 226C and moving the pin 226B, which begins to close the discharge path between the discharge volume 82 and the back pressure pocket 204 (see FIG. 4B).

[0056] As shown in FIG. 4C, when the back pressure reaches the target pressure, spring 226C is further compressed and pin 226B blocks the discharge path between discharge volume 82 and back pressure pocket 204.

[0057] If the back pressure leaks or drops below the target pressure, the valve spring 226C moves the valve pin 226B, opening the discharge path (see Figure 4D) until the target pressure is again achieved.

[0058] 3B, a diagram of the thrust body 130 and second pressure path 208 in the second embodiment is shown. In the second embodiment, the second pressure path 208 includes a second pressure passage 224. The second pressure passage 224 is located within the thrust body 130. The second pressure passage 224 has a first end 224A that opens to the backpressure pocket 204 and a second end 224B that opens to the suction volume 74. The flow of refrigerant between the backpressure pocket 204 and the suction volume 74 is controlled by a dump valve 210 as a function of the pressure difference between the discharge pressure in the discharge volume 82 and the pressure in the backpressure pocket 204 (see below).

[0059] As mentioned above, in the illustrated embodiment, the second pressure path 208 includes the second pressure passage 224 and the dump valve 210. The second pressure passage 224 may be disposed within the compressor body 202, and more specifically, within the thrust body 130 between the suction volume 74 and the back pressure pocket 204.

[0060] As shown in Figures 3B, 6, and 7B, the dump valve 210 is connected between the discharge volume 82 and the backpressure pocket 204 and controls the flow of refrigerant between the backpressure pocket 204 and the suction volume 74 as a function of the pressure differential between the discharge volume 82 and the backpressure pocket 204.

[0061] 5A, 5B, 6, and 7B, in one embodiment, dump valve 210 may be a second sliding adjustment valve 228 integrated into compressor body 202, and more specifically, thrust body 130. As shown, second sliding adjustment valve 228 may include a valve body 228A (formed by thrust body 130), a valve pin 228B, and a valve spring 224C.

[0062] The operation of the second slide regulator valve 228 is shown in Figures 5A and 5B. During normal operation of the compressor 10, the discharge pressure is greater than the back pressure. The valve pin 228B is pushed against the back pressure, blocking the passage of refrigerant from the back pressure pocket 204 to the suction volume 74 (see Figure 5A).

[0063] When the compressor 10 is shut down, the shutdown pressure and discharge pressure equalize at a pressure less than the back pressure. The valve pin 228B is pushed toward the discharge side, opening the second slide regulator valve 228. This allows refrigerant to escape from the back pressure pocket 204 into the suction volume 74, equalizing the pressure and preventing axial overload between the scrolls 26, 66 (see FIG. 5B).

[0064] The above invention has been described in accordance with relevant legal standards, i.e., the description is illustrative rather than limiting in nature. Variations and modifications to the disclosed embodiments may become apparent to those skilled in the art and may be included within the scope of the invention.

Claims

1. An electric scroll compressor configured to compress a refrigerant, a housing defining an intake volume and a discharge volume; 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; an inverter module mounted within the housing and configured to convert DC power to AC power; a motor mounted within the housing; a drive shaft coupled to the motor; a compression device coupled to the drive shaft, receiving the refrigerant from the suction volume and compressing the refrigerant when the drive shaft is rotated by the motor, A compression device body; a fixed scroll located within the housing and fixed relative to the compressor body; an orbiting scroll coupled to the drive shaft; It contains a compression device, the orbiting scroll and the fixed scroll defining a compression chamber that receives the refrigerant from the suction volume and compresses the refrigerant as the drive shaft is rotated about its central axis, the compression device defining a back pressure pocket; a scroll backpressure system located at least partially within the compressor body, comprising: a first pressure path between the discharge volume and the back pressure pocket, the first pressure path being at least partially defined within the compressor body and configured to allow pressurized refrigerant in the discharge volume to be introduced into the back pressure pocket; a second pressure path between the backpressure pocket and the suction volume including a dump valve for controllably releasing pressurized refrigerant in the backpressure pocket to the suction volume; a scroll back pressure system including An electric scroll compressor comprising:

2. 2. The electric scroll compressor according to claim 1, wherein the housing includes a center housing and a front cover, and the discharge volume is defined at least in part by the center housing, the front cover, and the refrigerant outlet port.

3. 3. The motor-driven scroll compressor according to claim 2, wherein the first pressure path has a first compression path end connected to the refrigerant outlet port.

4. 4. The motor-driven scroll compressor according to claim 3, wherein the first pressure path has a second compression path end connected to the back pressure pocket.

5. 5. The motor-driven scroll compressor according to claim 4, wherein the first pressure path is located within the center housing and is partially integrated with the center housing.

6. 6. The motorized scroll compressor of claim 5, wherein the first pressure path includes a fixed orifice that restricts the flow of the pressurized refrigerant from the discharge volume to the back pressure pocket.

7. The motorized scroll compressor of claim 6 , wherein the dump valve is configured to maintain a constant pressure differential between the back pressure pocket and the suction volume.

8. 3. The electric scroll compressor according to claim 2, wherein the compressor body includes a thrust body, the back pressure pocket is at least partially defined by the thrust body, and the first pressure path is formed through the front cover, the center housing, and the thrust body.

9. 9. The motor-driven scroll compressor according to claim 8, wherein the first pressure path has a first pressure path end connected to the refrigerant outlet port.

10. 10. The motorized scroll compressor of claim 9, wherein the first pressure path has a second pressure path end connected to the back pressure pocket.

11. 11. The motorized scroll compressor of claim 10, wherein the first pressure path includes a fixed orifice that restricts the flow of the pressurized refrigerant from the discharge volume to the back pressure pocket.

12. 12. The motorized scroll compressor of claim 11, wherein the dump valve is configured to maintain a constant pressure differential between the backpressure pocket and the suction volume.

13. The motorized scroll compressor of claim 12 , wherein the back pressure valve is located at least partially within the thrust body.

14. 2. The electric scroll compressor of claim 1, further comprising a backpressure regulating valve connected between the suction volume and the backpressure pocket, the backpressure regulating valve configured to modify the flow of pressurized refrigerant through the first pressure path from the discharge volume to the backpressure pocket as a function of a pressure differential between the suction volume and the backpressure pocket.

15. 15. The motorized scroll compressor of claim 14, wherein the second pressure path includes a passage and the dump valve, the passage being located within the compressor body between the suction volume and the back pressure pocket.

16. 16. The motorized scroll compressor of claim 15, wherein the dump valve is coupled between the discharge volume and the backpressure pocket and controls refrigerant flow between the backpressure pocket and the suction volume as a function of a pressure differential between the discharge volume and the backpressure pocket.

17. 2. The electric scroll compressor of claim 1, wherein the compressor body includes a thrust body, and the back pressure pocket is at least partially defined by the thrust body.

18. 18. The electric scroll compressor of claim 17, further comprising a backpressure regulating valve connected between the suction volume and the backpressure pocket and located at least partially within the thrust body, the backpressure regulating valve configured to modify the flow of pressure refrigerant through the first pressure path from the discharge volume to the backpressure pocket as a function of a pressure differential between the suction volume and the backpressure pocket.

19. 19. The motorized scroll compressor of claim 18, wherein the second pressure path includes a passage and the dump valve, the passage being located within the thrust body between the suction volume and the back pressure pocket.

20. 20. The motorized scroll compressor of claim 19, wherein the dump valve is coupled between the discharge volume and the backpressure pocket and controls refrigerant flow between the backpressure pocket and the suction volume as a function of a pressure differential between the discharge volume and the backpressure pocket.

21. An electric scroll compressor configured to compress a refrigerant, a housing including a center housing and a front cover, the housing defining an intake volume and a discharge volume, the discharge volume being at least partially defined by the center housing and the front cover; 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; an inverter module mounted within the housing and configured to convert DC power to AC power; a motor mounted within the housing; a drive shaft coupled to the motor; a compression device coupled to the drive shaft, receiving the refrigerant from the suction volume and compressing the refrigerant when the drive shaft is rotated by the motor, a compressor body including a thrust body, the back pressure pocket being at least partially defined by the thrust body; a fixed scroll located within the housing and fixed relative to the compressor body; an orbiting scroll coupled to the drive shaft; It contains a compression device, the orbiting scroll and the fixed scroll defining a compression chamber that receives the refrigerant from the suction volume and compresses the refrigerant as the drive shaft is rotated about its central axis, the compression device defining a back pressure pocket; a scroll backpressure system located at least partially within the compressor body, comprising: a first pressure path between the discharge volume and the back pressure pocket, the first pressure path being formed at least partially within the compressor body and configured to allow pressurized refrigerant in the discharge volume to be introduced into the back pressure pocket, the compressor body including a thrust body, the back pressure pocket being at least partially formed by the thrust body, the first pressure path being formed through the front cover, the center housing, and the thrust body, the first pressure path having a first pressure path end connected to the refrigerant outlet port, a second pressure path end connected to the back pressure pocket, and a fixed orifice that restricts the flow of the pressurized refrigerant from the discharge volume to the back pressure pocket; a second pressure path between the backpressure pocket and the suction volume including a dump valve for controllably releasing pressurized refrigerant in the backpressure pocket to the suction volume, the dump valve configured to maintain a constant pressure differential between the backpressure pocket and the suction volume, the second pressure path being located at least partially within the thrust body; and a scroll back pressure system including An electric scroll compressor comprising:

22. An electric scroll compressor configured to compress a refrigerant, a housing defining an intake volume and a discharge volume; 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; Inverter housing, an inverter back cover connected to the inverter housing and forming an inverter cavity; and an inverter module mounted within the inverter cavity and configured to convert DC power to AC power; an inverter unit including a drive shaft located within the housing, the drive shaft having first and second ends and defining a central axis; and a motor located within the housing for controllably rotating the drive shaft about the central axis; a motor section including: a compression device coupled to the drive shaft, receiving the refrigerant from the suction volume and compressing the refrigerant when the drive shaft is rotated by the motor, a compressor body including a thrust body, the back pressure pocket being at least partially defined by the thrust body; a fixed scroll located within the housing and fixed relative to the thrust body; an orbiting scroll coupled to the drive shaft; It contains a compression device, the orbiting scroll and the fixed scroll defining a compression chamber that receives the refrigerant from the suction volume and compresses the refrigerant as the drive shaft is rotated about the central axis; a scroll backpressure system located at least partially within the compressor body, comprising: a first pressure path between the discharge volume and the back pressure pocket, the first pressure path being at least partially formed within the thrust body and configured to allow pressurized refrigerant in the discharge volume to be introduced into the back pressure pocket; a second pressure path between the back pressure pocket and the suction volume including a valve for controllably venting pressurized refrigerant in the back pressure pocket to the suction volume; a backpressure regulating valve connected between the suction volume and the backpressure pocket and located at least partially within the thrust body, the backpressure regulating valve configured to modify the flow of pressure refrigerant through the first pressure path from the discharge volume to the backpressure pocket as a function of the pressure difference between the suction volume and the backpressure pocket; It contains a scroll backpressure system, wherein the second pressure path includes a passageway and the dump valve, the passageway being located within the compressor body between the suction volume and the backpressure pocket, and the dump valve being coupled between the discharge volume and the backpressure pocket and configured to control refrigerant flow between the backpressure pocket and the suction volume as a function of a pressure differential between the discharge volume and the backpressure pocket; An electric scroll compressor comprising:

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