CN117345594A - Compressor and system comprising a compressor - Google Patents

Abstract

The application discloses compressor and system including it, the compressor includes: a housing, a drive motor and a rotating shaft, and an impeller device and a rotor device. The rotation shaft is capable of driving the impeller device and the rotor device to rotate synchronously, so that the driving motor, the impeller device and the rotor device rotate synchronously at the same rotation speed. In the compressor of the application, the impeller device and the rotor device are arranged in the shell, gas is subjected to first-stage compression through the impeller device before entering the rotor device so as to improve the pressure and density of the gas, and then enters the rotor device to be subjected to second-stage compression so as to further reduce the volume of the gas and improve the pressure. Therefore, the compressor can have a larger compression ratio, intake amount, and compressor efficiency than a screw compressor having the same rotor arrangement.

Description

Compressor and system comprising a compressor

Technical Field

The present application relates to the field of heating, ventilation, air conditioning (and/or heat pump) and refrigeration (HVACR) systems, and in particular to a compressor and a system comprising a compressor.

Background

Existing temperature control systems (e.g., air conditioning and/or heat pump and/or refrigeration systems) include a compressor, a condenser, a throttling device, and an evaporator connected by piping and are filled with a refrigerant. The refrigerant circulates among the compressor, the condenser, the throttling device and the evaporator, and can perform air conditioning, refrigeration or heating. Specifically, the refrigerant is first compressed into a high-temperature and high-pressure refrigerant gas in the compressor, then releases heat and is liquefied/condensed into a high-pressure refrigerant liquid when flowing through the condenser, then throttled into a low-pressure refrigerant in the throttle device, then absorbs heat and is vaporized/evaporated into a low-pressure refrigerant gas when flowing through the evaporator, and finally the low-pressure refrigerant gas is returned to the compressor, thus completing the circulation of the refrigerant in the HVACR system.

The compressor is the most important and critical component in HVACR systems, affecting the energy consumption and refrigeration capacity of the above-mentioned systems. Generally, the higher the working efficiency of the compressor, the lower the energy consumption of the system, the larger the air intake of the compressor, the larger the refrigerating capacity/heating capacity of the system, and the higher the compression ratio of the compressor, the higher the heating water outlet temperature of the system.

Disclosure of Invention

The present application provides in a first aspect a compressor comprising: a housing, a drive motor and a rotating shaft, and an impeller device and a rotor device. The housing includes a compressor inlet and a compressor outlet. The drive motor and the rotating shaft are disposed within the housing, the drive motor being connected to the rotating shaft and configured to drive the rotating shaft to rotate. The impeller device and the rotor device are arranged in the shell, connected to the rotating shaft and positioned on two opposite sides of the driving motor, so that the rotating shaft can drive the impeller device and the rotor device to synchronously rotate, and the driving motor, the impeller device and the rotor device can synchronously rotate at the same rotating speed. The driving motor, the impeller device and the rotor device are arranged to rotate along with the rotating shaft, gas entering the compressor from the inlet of the compressor firstly flows through the impeller device to be compressed for a first stage to increase the pressure of the gas, then flows through the driving motor to cool the driving motor, then flows through the rotor device to be compressed for a second stage to further increase the pressure of the gas, and finally the gas is discharged from the outlet of the compressor.

According to the first aspect, at least one fluid passage is provided between the drive motor and the housing, the fluid passage extending in the axial direction of the rotary shaft. Wherein the gas after the first stage of compression by the impeller means is capable of flowing through the drive motor along the at least one fluid passage to cool the drive motor.

According to the first aspect, the compressor further comprises a diffuser. The diffuser is disposed downstream of the impeller device and upstream of the drive motor, the diffuser configured to further increase the pressure of the gas after the first stage of compression is completed.

According to the first aspect, the diffuser is a vaneless diffuser or a vaned/vaneless hybrid diffuser.

According to the first aspect described above, the impeller device comprises an impeller cover and an impeller. The impeller is disposed within the impeller cover, the impeller configured to increase airflow kinetic energy and pressure by movement of the airflow.

According to the first aspect, the impeller is a mixed flow impeller configured to increase the kinetic energy and pressure of the air flow by radial and axial movement of the air flow.

According to the first aspect described above, the diffuser is configured to guide the gas flowing through the impeller device to be discharged toward the drive motor in the axial direction of the rotation shaft.

According to the first aspect, the diffuser includes an annular flow passage. Wherein an upstream portion of the annular flow passage is aligned with an outlet end of the impeller device in a direction of gas flow, and a downstream portion of the annular flow passage has a gradually increasing cross-sectional area so that a flow rate of gas discharged from the annular flow passage is gradually reduced.

According to the first aspect described above, the rotor means comprises a male rotor and a female rotor which are intermeshed. Wherein the male rotor is coupled to the rotation shaft to be driven to rotate by the rotation shaft, and the female rotor is driven to rotate by the male rotor.

According to the first aspect, the driving motor is a variable frequency motor configured to drive the rotation shaft to rotate at a rotation speed of 1000-20000 rotations per minute.

According to the first aspect, the driving motor is configured to drive the rotation shaft to rotate at a rotation speed of 2000-12000 rpm.

According to the first aspect, the driving motor is a constant speed motor.

The present application provides in a second aspect a system comprising a compressor according to any one of the first aspects, the system being an air conditioning system and/or a heat pump system and/or a refrigeration system and/or an industrial refrigeration system.

Other features, advantages, and embodiments of the application may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Furthermore, it is to be understood that both the foregoing summary and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the application as claimed. It should also be understood that while particular arrangements of components are disclosed and illustrated in the exemplary embodiments, other arrangements are also within the scope of the present application. However, the detailed description and specific examples merely indicate preferred embodiments of the present application. Various changes and modifications within the spirit and scope of the present application will become apparent to those skilled in the art from this detailed description.

Drawings

FIG. 1A is a perspective view of a compressor according to one embodiment of the present application;

FIG. 1B is a left side view of the compressor of FIG. 1A;

FIG. 2A is a cross-sectional view of the compressor of FIG. 1B taken along line A-A;

FIG. 2B is a cross-sectional view of the compressor of FIG. 1B taken along line B-B;

FIG. 3A is a perspective view of the impeller assembly of FIG. 2A at an angle;

FIG. 3B is a perspective view of the impeller assembly of FIG. 2A at another angle;

FIG. 4A is a perspective view of the diffuser of FIG. 2A at an angle;

FIG. 4B is a perspective view of the diffuser of FIG. 2A at another angle;

fig. 5 is a perspective view of the rotary shaft of fig. 2A.

Detailed Description

Various embodiments of the present application are described below with reference to the accompanying drawings, which form a part of the specification of the present application. It is to be understood that, although directional terms, such as "front", "rear", "upper", "lower", "left", "right", "top", "bottom", etc., may be used in this application to describe various example structural portions and elements of the present application, these terms are used herein for convenience of description only and are determined based on the example orientations shown in the drawings. Because the embodiments disclosed herein may be arranged in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting.

Fig. 1A and 1B illustrate a structure of a compressor 100 according to an embodiment of the present application, for explaining an external structure of the compressor 100. Wherein fig. 1A is a perspective view of a structure of a compressor 100, and fig. 1B is a left side view of fig. 1A. As shown in fig. 1A and 1B, the compressor 100 includes a housing 101, the housing 101 including a compressor inlet 102 and a compressor outlet 103. The housing 101 has a substantially long cylindrical shape, and the compressor inlet 102 and the compressor outlet 103 are located at both ends of the housing 101, respectively. After entering the compressor 100 from the compressor inlet 102, the refrigerant gas flows substantially along the longitudinal direction of the casing, is compressed, and then exits the compressor 100 from the compressor outlet 103. In the present embodiment, the compressor inlet 102 is located at the left end portion of the housing 101, and the compressor outlet 103 is located at the side portion of the right end of the housing 101.

Fig. 2A and 2B illustrate an internal structure of the compressor 100 as shown in fig. 1A. Wherein fig. 2A shows a cross-sectional view of the compressor 100 along line A-A, fig. 2B shows a cross-sectional view of the compressor 100 along line B-B, and the dashed box shows a partial enlarged view. As shown in fig. 2A and 2B, the compressor 100 further includes a rotation shaft 208, an impeller device 220, a driving motor 210, and a rotor device 211, which are disposed within the housing 101. The rotation shaft 208 extends in a common length direction with the housing 101, and the rotation shaft 208 rotates about its axis x. The impeller means 220, the driving motor 210 and the rotor means 211 are all connected directly to the rotation shaft 208 and are rotated synchronously with the rotation of the rotation shaft 208 at the same rotation speed. In this embodiment, the impeller device 220 is connected to the left end of the rotating shaft 208, i.e., the end near the compressor inlet 102. The rotor device 211 is connected to the right side of the rotation shaft 208, i.e. the side close to the compressor outlet 103. The drive motor 210 is connected between the impeller means 220 and the rotor means 211, i.e. substantially in the middle of the rotation shaft 208. Thus, the gas entering the interior of the compressor 100 from the compressor inlet 102 can flow through the impeller device 220, the drive motor 210, and the rotor device 211 in this order, and then be discharged from the compressor outlet 103 to the compressor 100. In the present embodiment, the driving motor 210 is used to drive the rotation shaft 208 to rotate, and the rotation of the rotation shaft 208 can drive the impeller device 220 and the rotor device 211 to rotate synchronously, so that the impeller device 220, the driving motor 210 and the rotor device 211 can rotate synchronously at the same rotation speed.

The impeller assembly 220 includes an impeller cover 221 and an impeller, the impeller and the impeller cover 221 rotating together about an axis x. In this embodiment, the impeller and impeller cover 221 are integrally cast or machined (i.e., a shrouded impeller with a rotating impeller housing). The impeller includes a plurality of blades and/or a flow splitter that span between the impeller hub and the impeller cover. The impeller is connected to the left end of the rotation shaft 208 such that rotation of the rotation shaft 208 can drive rotation of the impeller and the impeller cover 221, thereby guiding the gas flowing into the impeller from the compressor inlet 102 to undergo the first stage compression through the impeller. In other embodiments, the impeller device may include a separate impeller cover (i.e., an open impeller with the impeller cover stationary). During the first stage of compression, the volume of gas is compressed such that the gas pressure increases and the gas can be guided by the impeller to move in a predetermined direction and be discharged to the subsequent part. In the present embodiment, the impeller includes a mixed flow impeller 222, and the mixed flow impeller 222 is fastened to the left end of the rotary shaft 208 by bolts 225 or other means. The mixed flow impeller 222 increases the flow kinetic energy and pressure through radial and axial movement of the flow. In some particular embodiments, gas enters the mixed flow impeller 222 axially from the compressor inlet 102, and the mixed flow impeller 222 directs the gas to exit diagonally to the axial direction. The mixed flow impeller 222 is capable of elevating the gas pressure more while guiding the gas flow in a more compact space than the centrifugal/radial flow impeller and the axial flow impeller. In some other embodiments, the impeller may also comprise a full centrifugal/radial flow impeller or an axial flow impeller. A more specific structure of the impeller device 220 will be described in detail with reference to fig. 3A and 3B.

The compressor 100 also includes a diffuser 241 disposed within the housing 101. The diffuser 241 is disposed immediately adjacent to the impeller device 220 and downstream of the impeller device 220. And the diffuser 241 is disposed upstream of the drive motor 210. That is, the gas in the compressor 100 flows through the impeller device 220, then through the diffuser 241, and then through the driving motor 210. The diffuser 241 is capable of converting a portion of the kinetic energy of the gas flowing from the impeller device 220 into pressure energy to further raise the pressure of the gas. In the present embodiment, the diffuser 241 is configured to guide the gas discharged obliquely from the impeller device 220 to be discharged toward the driving motor 210 in the axial direction. And in this embodiment, the diffuser 241 is a vaneless diffuser. In other embodiments, the diffuser 241 may also be a vaned diffuser or a combination of vaneless and vaned diffusers. The diffuser 241 includes an annular flow passage 242 therein. In the direction of gas flow, the upstream portion (i.e., the left portion) of the annular flow passage 242 is aligned with the outlet end 326 (see fig. 3B) of the impeller device 220 so that the gas discharged from the impeller device 220 can directly enter the diffuser 241. The cross-sectional area of the downstream portion of the annular flow passage 242 becomes gradually larger so that the flow rate of the gas discharged from the annular flow passage 242 is gradually reduced, thereby increasing the pressure of the gas discharged from the downstream portion (i.e., right side portion) of the annular flow passage 242 toward the driving motor while avoiding flow separation.

In the present embodiment, the diffuser 241 is fixedly connected to the housing 101 such that rotation of the rotation shaft 208 does not affect the diffuser 241, and the diffuser 241 does not rotate following rotation of the rotation shaft 208. The compressor 100 further includes a bearing 251, the bearing 251 being mounted between the rotation shaft 208 and the diffuser 241 to support rotation of the rotation shaft 208 along the axis x by the diffuser 241, and a more specific structure of the diffuser 241 will be described in detail with reference to fig. 4A and 4B.

The drive motor 210 includes a relatively rotatable motor rotor portion 256 and a motor stator portion 254. The motor stator portion 254 is fixedly connected to the housing 101, such as by screws 255 or otherwise secured to the housing 101. The motor rotor portion 256 is fixedly coupled to the rotation shaft 208 such that rotation of the motor rotor portion 256 drives rotation of the rotation shaft 208. In the present embodiment, the rotation shaft 208 is provided with a groove 258, and the motor rotor portion 256 is mounted with a driving key 257, and the groove 258 and the driving key 257 cooperate with each other so that the motor rotor portion 256 is fixedly coupled to the rotation shaft 208. Upon energization of the drive motor 210, the motor stator portion 254 and the motor rotor portion 256 rotate the motor rotor portion 256 relative to the motor stator portion 254 by electromagnetic interaction with each other. At least one fluid passage 253 is provided between the motor stator portion 254 of the driving motor 210 and the inner wall of the housing 101, and the at least one fluid passage 253 extends in the axial direction of the rotation shaft 208 and fluidly communicates the air outlet of the diffuser 241 with the rotor inlet of the rotor device 211, so that the air flow discharged from the diffuser 241 in the axial direction can flow through the driving motor 210 to cool the driving motor 210 and then enter the rotor device 211 for the second stage of compression. Since the impeller device 220 is of a speed type compression, the compression ratio thereof is relatively low, and thus the temperature of the gas discharged from the impeller device 220 and the diffuser 241 is low, so that the gas discharged from the impeller device 220 and the diffuser 241 can flow through the driving motor 210 to serve to cool the motor stator portion 254 of the driving motor 210. In the present embodiment, there is at least one fluid passage 253 defined by a groove attached to the inner wall of the housing 101, and the at least one fluid passage 253 includes five fluid passages 253 (not specifically shown in the drawings) uniformly arranged around the axis x. In other embodiments, the fluid channels 253 may be provided in any other known manner, or in other numbers, such as a greater or lesser number. In some embodiments, the fluid channel 253 may be provided as an annular fluid channel disposed about the axis x. Also in this embodiment, the drive motor 210 further includes a plurality of through holes 259 extending axially through the motor rotor portion 256, the through holes 259 also communicating with the gas outlet of the diffuser 241 and the rotor inlet of the rotor assembly 211 such that a portion of the gas axially discharged from the diffuser 241 may flow through the through holes 259 to cool the motor rotor portion 256 of the drive motor 210 before the gas enters the rotor assembly 211 for a second stage of compression. In some other embodiments, the through holes 259 may not be included, but only the fluid passages 253. A more specific structure of the driving motor 210 will be described in detail with reference to fig. 5.

In the present embodiment, the rotor device 211 includes a pair of rotors arranged in parallel side by side, the pair of rotors including a male rotor 212 and a female rotor 213. The male rotor 212 is connected to the rotation shaft 208 such that the male rotor 212 can be driven to rotate by the rotation shaft 208. The female rotor 213 intermeshes with the male rotor 212 such that rotational energy of the male rotor 212 drives the female rotor 213 to rotate therewith. In the present embodiment, the male rotor 212 is integrally formed with the rotation shaft 208 such that the male rotor 212 rotates together with the rotation shaft 208. More specifically, the male rotor 212 and the female rotor 213 are each provided with a plurality of helical teeth, and a pair of rotors are engaged with each other by the respective teeth. The rotor device 211 has a rotor inlet 216 and a rotor outlet 217, the rotor inlet 216 being located at the left end of the rotor device 211 and being in fluid communication with the fluid channel 253. The rotor outlet 217 is located at the right end of the rotor device 211 and is in fluid communication with the compressor outlet 103. And a pair of rotors cooperate with the housing 101 to form a plurality of spaced compression pockets 218. As the pair of rotors rotate, each compression pocket 218 moves rightward from the rotor inlet 216 to the rotor outlet 217 along the axial direction of the rotary shaft 208, and the volume of the compression pocket 218 is gradually reduced, so that the gas in the compression pocket 218 is gradually compressed, thereby enabling the gas flowing through the rotor apparatus 211 to complete the second stage of compression.

Thus, gas entering the compressor 100 from the compressor inlet 102, after being first compressed by the impeller means 220, can flow through the drive motor 210 to cool the drive motor 210, then through the rotor means 211 to complete the second compression of the gas, and finally out of the compressor 100 from the compressor outlet 103. After the gas is pressurized from the compressor inlet 102 through the impeller device 220, the density of the gas entering the rotor device 211 is increased compared to a compressor that does not include the impeller device 220 and uses only the rotor device 211 to compress the gas. Thus, with the compressor 100 achieving the same discharge volumetric flow and discharge pressure, the gas compressed in two stages through the impeller device 220 and the rotor device 211 can have a greater suction volumetric flow and compression ratio. The heat pump system using the compressor 100 of the present application can have a larger cooling/heating amount and a higher heating outlet temperature. And an air conditioning/refrigeration system using the compressor 100 of the present application can have a larger refrigerating capacity.

In some embodiments, compressor 100 may further include a slide valve (not shown) disposed about rotor assembly 211 to further control and regulate the compression ratio of compressor 100. And in some embodiments the rotor arrangement may also comprise only one screw rotor.

In the present embodiment, the driving motor 210 is a variable frequency motor. The variable frequency motor can enable the rotating shaft 208 to have a larger rotating speed range, and the rotating speed requirements of the impeller device 220 and the rotor device 211 are met. In the present embodiment, the driving motor 210 is configured to drive the rotation shaft 208 to rotate at a rotation speed of 1000-20000 rotations per minute. That is, the rotational speeds of the impeller means 220 and the rotor means 211 are each 1000-20000 revolutions per minute. In some embodiments, the drive motor 210 is configured to drive the rotation shaft 208 to rotate at a rotational speed of 2000-12000 revolutions per minute. And in some embodiments the drive motor may also be a fixed speed motor and may be used in conjunction with other additional components such as a rotor slide valve unloading mechanism or pre-rotation vanes.

The impeller device 220 compresses gas in a speed-type compression manner, and thus the rotation speed of the impeller device 220 is required to be high. Generally, the lower the rotational speed of the impeller device 220, the larger the impeller size, with the same compression ratio achieved. Thus, in some embodiments, in order to maintain the impeller size within the range of the housing 101, the impeller device 220 is set to a rotational speed of 1000 revolutions per minute or more. In other embodiments, the impeller device 220 is set to a rotational speed of 2000 revolutions per minute or more.

The rotor device 211 compresses gas in a positive displacement compression mode, the gas in the compression cavity is compressed through the volume change of the compression cavity formed by meshing the male rotor and the female rotor, and the rotating speed requirement of the rotor device 211 is not high. The rotational speed of the rotor arrangement 211 cannot be too high, which is limited by the highest rotational speed of use of the screw compressor rolling bearing, and if too high, wear of the rotor engagement is accelerated, which affects the reliability of the rotor arrangement 211. In some embodiments, rotor apparatus 211 is set to a rotational speed within 20000 revolutions per minute. In other embodiments, rotor apparatus 211 is set to a rotational speed within 12000 revolutions per minute.

Therefore, setting the rotation shaft 208 to a rotation speed within 1000-20000 rpm can satisfy the needs of the impeller device 220 and the rotor device 211, so that the impeller device 220 and the rotor device 211 are connected to the same rotation shaft 208 to perform coaxial, synchronous, and same-rotation-speed operation.

In the heat pump systems commonly used at present, the compression ratio of the system is generally in the range of 2-15 times. The second stage compression of rotor assembly 211 typically requires a compression ratio of less than 8 to ensure smooth system operation and avoid under-compression conditions. In a unit comprising the same compressor, a refrigerating working condition with a low compression ratio is generally operated in summer, and a heating working condition with a high compression ratio is generally operated in winter. The applicant has found that the dual-condition operation requirements of the heat pump system for both cooling and heating can be better compromised when the compression ratio of the first stage compression of the impeller device 220 is between 1.2 and 1.8. Mixed flow impeller 222 having a medium to low compression ratio is therefore particularly suitable for impeller apparatus 220 of the present application. It will be appreciated by those skilled in the art that the impeller means 220 may also comprise a centrifugal impeller for heat pump systems where the compression ratio is particularly high.

Fig. 3A and 3B show a specific structure of the impeller device 220, wherein fig. 3A is a perspective view of the impeller device 220 from left to right, and fig. 3B is a perspective view of the impeller device 220 from right to left. As shown in fig. 3A and 3B, the mixed flow impeller 222 includes a plurality of blades 361 and an impeller hub 327, and the impeller hub 327 is disposed inside the impeller cover 221 and spaced apart from the impeller cover 221. The vane 361 is located between the impeller cover 221 and the impeller hub 327. The right side between the impeller cover 221 and the impeller hub 327 forms an annular outlet end 326 from which the gas exits the impeller device 220.

The impeller assembly 220 further includes an annular outer ring 323 and an annular inner ring 324, with the compressor inlet 102 defined between the outer ring 323 and the inner ring 324. Specifically, the left side of the impeller cover 221 has a circular opening 328, and the outer ring 323 is formed by projecting the edge of the circular opening 328 axially outward. The impeller apparatus 220 further includes a support base 329, the support base 329 being located to the left of the center of the impeller hub 327 such that the bolts 225 can pass through the support base 329 to connect the mixed flow impeller 222 to the rotating shaft 208. The inner race 324 is formed by an edge of the support pedestal 329 protruding axially outwardly. Thereby, the compressor inlet 102 can be formed in the circular opening 328 between the outer ring 323 and the inner ring 324. Gas enters the left side of the mixed flow impeller 222 from the compressor inlet 102, is compressed by the rotating blades 361, and is discharged from the right side outlet end 326.

Fig. 4A and 4B show a specific structure of the diffuser 241, wherein fig. 4A is a perspective view of the diffuser 241 from left to right, and fig. 4B is a perspective view of the diffuser 241 from right to left. As shown in fig. 4A and 4B in combination with fig. 2A, the diffuser 241 includes an outer wall 443 and an inner wall 445, the outer wall 443 being disposed outside the inner wall 445 around the inner wall 445 and spaced apart from the inner wall 445 to form the annular flow passage 242. In the present embodiment, the inner surface of the outer wall 443 is first extended in the axial direction from left to right and then gradually diverges outward. And the outer surface of the inner wall 445 extends axially and then gradually tapers inwardly. Thus, the annular flow passage 242 between the inner surface of the outer wall 443 and the outer surface of the inner wall 445 extends generally axially in the left-to-right axial direction and then gradually expands outwardly to form a streamlined (e.g., bell-mouthed) shape having a gradually changing cross-sectional area.

The diffuser 241 further includes a center sleeve 448, the center sleeve 448 being connected at the center of the inner wall 445. The center sleeve 448 extends in the axial direction, and the center sleeve 448 has a hollow shape, an inside of which is used to accommodate the bearing 251 so that the diffuser 241 can be mounted to the rotation shaft 208.

The diffuser 241 further includes at least one support rib 446, the support rib 446 extending radially and being connected between the inner wall 445 and the outer wall 443 to connect the inner wall 445 and the outer wall 443 without affecting the annular flow passage 242. In the present embodiment, the at least one support rib 446 includes three support ribs 446 which are uniformly arranged in the circumferential direction. In other embodiments, the support ribs 446 may be provided in other numbers.

The diffuser 241 further includes at least one stiffener 447, the stiffener 447 extending radially and being connected between the left side of the inner wall 445 and the central sleeve 448. The reinforcing ribs 447 can strengthen the inner wall 445 forming the annular flow passage 242 to avoid the gas having a higher pressure, which is subjected to the first stage of compression, from pressing the inner wall 445 radially inward while flowing through the annular flow passage 242. In the present embodiment, the at least one reinforcing bead 447 includes three reinforcing beads 447 which are uniformly arranged in the circumferential direction. In other embodiments, the stiffener 447 may be provided in other numbers. The diffuser in this embodiment is a vaneless diffuser. In other embodiments, the diffuser may be a vaned diffuser or a combination of both vaned and vaneless.

Fig. 5 shows a perspective structural view of the driving motor 210, the rotation shaft 208, and the male rotor 212. As shown in fig. 5, a threaded hole 552 is provided in the left end surface of the rotary shaft 208, and the threaded hole 552 is adapted to cooperate with the bolt 225 to securely connect the impeller device 220 to the left end of the rotary shaft 208. The rotation shaft 208 further includes, in order from left to right, a stepped portion 562 and a stepped portion 563, each of which is formed to protrude radially from an outer surface of the rotation shaft 208. The stepped portion 562 serves to limit the impeller device 220, for example, a central portion of the impeller hub 327 of the impeller device 220 can be abutted against a radial surface of the stepped portion 562. The step 563 serves to limit the diffuser 241, for example, a center portion of the bearing 251 of the diffuser 241 can be abutted against a radial surface of the step 563. Thus, the impeller device 220 and the diffuser 241 can be connected to the leftmost end of the rotation shaft 208.

The male rotor 212 of the rotor arrangement 211 is arranged on the opposite side of the rotation shaft 208 from the impeller arrangement 220, i.e. on the right side of the rotation shaft 208.

The drive motor 210 is connected to the right of the impeller means 220 and the diffuser 241 and to the left of the male rotor 212. And the first stage compressed gas discharged from the impeller device 220 and the diffuser 241 may enter the rotor device 211 through the fluid passage 253 outside the motor stator portion 254, or may enter the rotor device 211 through the through holes 259 in the motor rotor portion 256. And the drive motor 210 is connected to the rotation shaft 208 through a drive key 257 on the motor rotor portion 256 and a groove 258 on the rotation shaft 208. When the motor stator portion 254 is fixed to the housing 101, rotation of the motor rotor portion 256 relative to the motor stator portion 254 can drive the rotation shaft 208 to rotate relative to the housing 101.

Thus, the impeller means 220, the drive motor 210 and the rotor means 211 can be in fluid communication and rotate synchronously with the rotation shaft 208.

In some embodiments, the impeller device may comprise a mixed flow or centrifugal/radial flow or axial flow impeller, including single stage or multiple stage, including shrouded (closed) or partially shrouded (semi-open) or shrouded (open) impeller structures, including full-blade or full-blade and splitter/partial-blade or any other blade structure.

In some embodiments, the impeller device may comprise a centrifugal/radial flow impeller, or a mixed flow impeller, or an axial flow impeller, including a plurality of blades between an impeller hub and an impeller shroud or housing, and configured to increase airflow kinetic energy and pressure by airflow motion. The impeller means may comprise a shrouded impeller (i.e. shrouded, impeller cover rotating) or a shrouded impeller (i.e. open, impeller cover stationary). The impeller device may be without a splitter (i.e., full blades) or may be with a splitter (i.e., partial blades). The outlet of the impeller means may be fully radial (centrifugal/radial flow impeller) or angled (mixed flow impeller) or fully axial (axial flow impeller). The impeller device may be manufactured by casting, machining, additive manufacturing, or any other manufacturing method. The surface treatment of the impeller may be polished or non-polished or ground or non-ground or any other surface treatment. Each blade includes a leading edge and a trailing edge opposite the leading edge. The pressure side surface extends between a leading edge and a trailing edge. The suction side surface is opposite the pressure side surface and extends between a leading edge and a trailing edge. The impeller blade surface may have any, some or all of the following features or characteristics: sweep, twist, tilt, bow, ripple, groove, S-shape, or any other alternative feature to improve the efficiency and performance of the impeller.

In some embodiments, the diffuser may also be a vaned diffuser, or a combination of vaneless and vaned diffusers, or any other diffuser configuration. The diffuser is configured to increase the static pressure of the refrigerant gas by decreasing the velocity thereof while guiding the gas to flow toward the driving motor in the axial direction of the rotating shaft. The diffuser includes an annular flow passage. The upstream portion of the annular flow passage is aligned with the outlet of the impeller assembly and the downstream portion of the annular flow passage is aligned with the drive motor. The diffuser cross-sectional area between the upstream and downstream portions is gradually varied to reduce flow velocity and increase flow pressure while avoiding flow separation.

In some embodiments, the drive motor may be of the variable frequency (variable speed) motor type, or may be of the fixed frequency (constant speed) motor type or any other motor configuration.

In some embodiments, the rotor arrangement may comprise a single rotor or a dual rotor helical rotor, or any other rotor configuration or combination of rotor configurations.

In some embodiments, a slide valve or any other mechanical device arrangement may be installed around the rotor device to further control and adjust the compression ratio of the compressor.

Existing screw compressors generally include only a drive motor and a rotor assembly that are coupled to a common rotational shaft for synchronous rotation. The screw compressor is a positive displacement compressor, and after the screw compressor sucks air, the air compresses the air volume through a rotor device to increase the air pressure. In some screw compressors, the internal volume ratio of the screw compressor may be adjusted by providing a slide valve, but is limited by the structural design, and is up to 5.0. For some heat pump systems requiring higher compression ratios, single stage screw compressors generally fail to achieve the compression ratio required by the system, such that the screw compressor is under-compressed for a long period of time, resulting in large vibration of the screw compressor and high discharge temperature. If two or more stages of compressors are arranged in the pipeline of the heat pump system, the system is complex in structure and high in cost.

And for air conditioning/heat pump systems using certain new types of environmentally friendly refrigerants (e.g., R1234 ze), it is difficult to meet the refrigeration capacity requirements of the heat pump system under the same air conditioning operating water temperature conditions, since these refrigerants typically have a lower refrigeration capacity per unit volume. It is not possible to directly use these environmentally friendly refrigerants in existing heat pump system units. It is also generally necessary to increase the volume and displacement of the heat pump system unit to meet the refrigeration capacity requirement, resulting in increased modification costs.

In the compressor of the application, the impeller device and the rotor device are integrally arranged in the shell, the refrigerant gas is subjected to first-stage compression through the impeller device to improve the pressure and density of the gas before entering the rotor device, and then enters the rotor device to be subjected to second-stage compression to further reduce the volume of the gas and improve the pressure. Therefore, the compressor can have a larger compression ratio, intake amount, and compressor efficiency than a screw compressor having the same rotor arrangement.

The compressor of this application sets up driving motor between impeller device and rotor device, utilizes impeller device exhaust gas to cool off driving motor, has solved driving motor radiating problem. The variable frequency motor is particularly suitable for solving the problem that the variable frequency motor generates too much heat when the variable frequency motor is used for driving the rotating shaft to rotate.

The rotational speed of the rotation axis of the compressor of this application is set up in suitable scope, can make impeller device, driving motor and rotor device synchronous revolution, does not need additionally to use gear change, simple structure. And the impeller means is of small size and can be accommodated in the housing together with the drive motor and the rotor means. And by designing the impeller device with proper size, the exhaust gas quantity of the impeller device is matched with the suction gas quantity of the rotor device, so that the compressor has higher efficiency.

The impeller device of the present application includes a mixed flow impeller that is capable of greater compression efficiency than an axial flow impeller. Compared to centrifugal impellers, mixed flow impellers can have lower pressure losses after being discharged from the impeller means. And still include axial diffuser in this application among the compressor, axial diffuser is except realizing increasing the effect of gas pressure, can also guide the axial flow of gas along the rotation axis, cooperates with mixed flow impeller and has further reduced the pressure loss of gas.

And the compressor of this application on the structure basis of current screw compressor, only need be close to the tip that inhales the air side set up impeller device can, change less, consequently reduced the transformation cost.

Further, since the compressor of the present application increases the suction amount compared to the conventional screw compressor, the air conditioning/heat pump system including the compressor of the present application can achieve a larger cooling amount when using a conventional refrigerant (e.g., R134 a) and has a better environmental protection effect when using a refrigerant having a lower unit cooling amount (e.g., R1234 ze).

While the present disclosure has been described in conjunction with the examples of embodiments outlined above, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that are or may be presently or later be envisioned, may be apparent to those of ordinary skill in the art. Accordingly, the examples of embodiments of the disclosure as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit or scope of the disclosure. Accordingly, the present disclosure is intended to embrace all known or earlier developed alternatives, modifications, variations, improvements and/or substantial equivalents. The technical effects and problems of the present specification are illustrative and not restrictive. It should be noted that the embodiments described in the present specification may have other technical effects and may solve other technical problems.

Claims (13)

1. A compressor, characterized by comprising:

a housing including a compressor inlet and a compressor outlet;

a driving motor and a rotation shaft provided within the housing, the driving motor being connected to the rotation shaft and configured to drive the rotation shaft to rotate; and

the impeller device and the rotor device are arranged in the shell, connected to the rotating shaft and positioned on two opposite sides of the driving motor, so that the rotating shaft can drive the impeller device and the rotor device to synchronously rotate, and the driving motor, the impeller device and the rotor device can synchronously rotate at the same rotating speed;

the driving motor, the impeller device and the rotor device are arranged to rotate along with the rotating shaft, gas entering the compressor from the inlet of the compressor firstly flows through the impeller device to be compressed for a first stage to increase the pressure of the gas, then flows through the driving motor to cool the driving motor, then flows through the rotor device to be compressed for a second stage to further increase the pressure of the gas, and finally the gas is discharged from the outlet of the compressor.

2. The compressor as set forth in claim 1, wherein:

at least one fluid channel is arranged between the driving motor and the shell, and the fluid channel extends along the axial direction of the rotating shaft;

wherein the gas after the first stage of compression by the impeller means is capable of flowing through the drive motor along the at least one fluid passage to cool the drive motor.

3. The compressor as set forth in claim 2, further comprising:

a diffuser disposed downstream of the impeller means and upstream of the drive motor, the diffuser configured to further increase the pressure of the gas after the first stage of compression is completed.

4. A compressor as claimed in claim 3, wherein:

the diffuser is a vaneless diffuser or a vaned/vaneless hybrid diffuser.

5. A compressor as claimed in claim 3, wherein:

the impeller assembly includes an impeller cover and an impeller disposed within the impeller cover, the impeller configured to increase airflow kinetic energy and pressure through movement of the airflow.

6. The compressor as set forth in claim 5, wherein:

the impeller is a mixed flow impeller configured to increase the kinetic energy and pressure of the air flow by radial and axial movement of the air flow.

7. The compressor as set forth in claim 6, wherein:

the diffuser is configured to direct gas flowing through the impeller device toward the drive motor in an axial direction of the rotation shaft.

8. The compressor of claim 7, wherein:

the diffuser includes an annular flow passage, wherein an upstream portion of the annular flow passage is aligned with an outlet end of the impeller device in a direction of gas flow, and a downstream portion of the annular flow passage has a gradually increasing cross-sectional area such that a flow rate of gas discharged from the annular flow passage is gradually reduced.

9. The compressor as set forth in claim 1, wherein:

the rotor device includes a male rotor and a female rotor engaged with each other, wherein the male rotor is coupled to the rotation shaft to be driven to rotate by the rotation shaft, and the female rotor is driven to rotate by the male rotor.

10. The compressor as set forth in claim 1, wherein:

the driving motor is a variable frequency motor and is configured to drive the rotating shaft to rotate at a rotating speed of 1000-20000 revolutions per minute.

11. The compressor as set forth in claim 10, wherein:

the drive motor is configured to drive the rotation shaft to rotate at a rotation speed of 2000-12000 rpm.

12. The compressor as set forth in claim 10, wherein:

the driving motor is a constant-speed motor.

13. A system comprising a compressor according to any one of claims 1-12, said system being an air conditioning system and/or a heat pump system and/or a refrigeration system and/or an industrial refrigeration system.