Compressor and system comprising same

Abstract

A compressor and a system comprising same. The compressor (100) comprises: a housing (101), a driving motor (210), a rotating shaft (208), an impeller device (220), and a rotor device (211). A gas first passes through the impeller device (220) for first-stage compression to increase the pressure and density of the gas, and then enters the rotor device (211) for second-stage compression to further reduce the volume of the gas and increase the pressure. The compressor has higher compression ratio, air intake capacity and compressor efficiency.

Description

Compressor and system including compressor Technical Field

[0001] 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 including the compressor. Background Art

[0002] Existing temperature control systems (such as air conditioning and / or heat pumps and / or refrigeration systems) include a compressor, a condenser, a throttling device and an evaporator connected by pipes and filled with refrigerant. The refrigerant circulates between the compressor, condenser, throttling device and evaporator, and can perform air conditioning, cooling or heating to the outside. 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, and then is throttled into a low-pressure refrigerant in the throttling device, and then absorbs heat and is vaporized / evaporated into a low-pressure refrigerant gas when flowing through the evaporator. Finally, the low-pressure refrigerant gas returns to the compressor, completing the cycle of the refrigerant in the HVACR system.

[0003] The compressor is the most important and critical component in an HVACR system, affecting the system's energy consumption and cooling capacity. Generally speaking, the higher the compressor's efficiency, the lower the system's energy consumption. A greater intake volume increases the system's cooling and heating capacity. Furthermore, a higher compression ratio results in a higher heating water temperature.

[0004] Summary of the Invention

[0005] In a first aspect, the present application provides a compressor comprising: a housing, a drive motor, a rotating shaft, an impeller assembly, and a rotor assembly. The housing comprises 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 assembly and the rotor assembly are disposed within the housing, connected to the rotating shaft, and located on opposite sides of the drive motor, such that the rotating shaft can drive the impeller assembly and the rotor assembly to rotate synchronously, thereby causing the drive motor, the impeller assembly, and the rotor assembly to rotate synchronously at the same speed. The drive motor, the impeller assembly, and the rotor assembly are configured to rotate with the rotating shaft. Gas entering the compressor from the compressor inlet first flows through the impeller assembly for a first stage of compression to increase the gas pressure, then flows through the drive motor to cool the drive motor, then flows through the rotor assembly for a second stage of compression to further increase the gas pressure, and finally exits the compressor from the compressor outlet.

[0006] According to the first aspect, at least one fluid channel is provided between the drive motor and the housing, the fluid channel extending axially along the rotating shaft. Gas compressed in the first stage by the impeller assembly can flow through the drive motor along the at least one fluid channel to cool the drive motor.

[0007] According to the first aspect, the compressor further comprises a diffuser disposed downstream of the impeller assembly and upstream of the drive motor, the diffuser being configured to further increase the pressure of the gas after completing the first stage of compression.

[0008] According to the first aspect above, the diffuser is a vaneless diffuser, a vaned diffuser, or a vaned / vaneless hybrid diffuser.

[0009] According to the first aspect, the impeller device includes an impeller cover and an impeller. The impeller is disposed in the impeller cover and is configured to increase the kinetic energy and pressure of the airflow through the movement of the airflow.

[0010] According to the first aspect above, the impeller is a mixed flow impeller configured to increase the kinetic energy and pressure of the airflow through radial and axial motion of the airflow.

[0011] 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.

[0012] According to the first aspect, the diffuser includes an annular flow channel. In the direction of gas flow, an upstream portion of the annular flow channel is aligned with an outlet end of the impeller assembly, and a downstream portion of the annular flow channel has a gradually increasing cross-sectional area, such that a flow velocity of gas discharged from the annular flow channel is gradually reduced.

[0013] According to the first aspect, the rotor device includes a male rotor and a female rotor meshing with each other, wherein the male rotor is connected to the rotating shaft to be driven to rotate by the rotating shaft, and the female rotor is driven to rotate by the male rotor.

[0014] According to the first aspect above, the drive motor is a variable frequency motor, and the drive motor is configured to drive the rotating shaft to rotate at a speed of 1000-20000 rpm.

[0015] According to the first aspect above, the drive motor is configured to drive the rotating shaft to rotate at a speed of 2000-12000 rpm.

[0016] According to the first aspect above, the drive motor is a constant speed motor.

[0017] In a second aspect, the present application provides a system comprising the compressor described in any one of the first aspects, wherein the system is an air-conditioning system and / or a heat pump system and / or a refrigeration system and / or an industrial refrigeration system.

[0018] By considering the following detailed description, drawings and claims, other features, advantages and embodiments of the present application can be set forth or become apparent. In addition, it should be understood that the above-mentioned summary of the invention and the following detailed description are exemplary and are intended to provide further explanation without limiting the scope of the claimed application. It should also be understood that, although specific component arrangements are disclosed and shown in these exemplary embodiments, other arrangements may also be within the scope of the present application. However, the detailed description and specific examples only indicate preferred embodiments of the present application. For those skilled in the art, various changes and modifications within the spirit and scope of the present application will become apparent through this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1A is a perspective structural diagram of a compressor according to one embodiment of the present application;

[0020] FIG1B is a left side view of the compressor shown in FIG1A;

[0021] FIG2A is a cross-sectional view of the compressor shown in FIG1B along line AA;

[0022] FIG2B is a cross-sectional view of the compressor shown in FIG1B along line BB;

[0023] FIG3A is a three-dimensional structural diagram of the impeller device in FIG2A at an angle;

[0024] FIG3B is a three-dimensional structural diagram of the impeller device in FIG2A at another angle;

[0025] FIG4A is a three-dimensional structural diagram of the diffuser in FIG2A at an angle;

[0026] FIG4B is a three-dimensional structural diagram of the diffuser in FIG2A at another angle;

[0027] FIG. 5 is a perspective structural diagram of the rotating shaft in FIG. 2A . DETAILED DESCRIPTION

[0028] Various specific embodiments of the present application will be described below with reference to the accompanying drawings that form a part of the specification of this application. It should be understood that although directional terms such as "front," "back," "upper," "lower," "left," "right," "top," and "bottom" are used in this application to describe various example structural parts 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 accompanying drawings. Because the embodiments disclosed in this application can be arranged in different orientations, these directional terms are intended to be illustrative only and should not be considered as limiting.

[0029] Figures 1A and 1B show the structure of a compressor 100 according to an embodiment of the present application, which are used to illustrate the external structure of the compressor 100. Figure 1A is a three-dimensional structural diagram of the compressor 100, and Figure 1B is a left view of Figure 1A. As shown in Figures 1A and 1B, the compressor 100 includes a shell 101, and the shell 101 includes a compressor inlet 102 and a compressor outlet 103. The shell 101 is roughly cylindrical in shape, and the compressor inlet 102 and the compressor outlet 103 are respectively located at both ends of the shell 101. After the refrigerant gas enters the compressor 100 from the compressor inlet 102, it flows roughly along the length direction of the shell, and is discharged from the compressor outlet 103 after being compressed. In this embodiment, the compressor inlet 102 is located at the left end of the shell 101, and the compressor outlet 103 is located on the side of the right end of the shell 101.

[0030] Figures 2A and 2B illustrate the internal structure of the compressor 100 shown in Figure 1A. Figure 2A shows a cross-sectional view of the compressor 100 along line AA, and Figure 2B shows a cross-sectional view of the compressor 100 along line BB. The dashed box shows an enlarged view of a portion. As shown in Figures 2A and 2B, the compressor 100 also includes a rotating shaft 208, an impeller assembly 220, a drive motor 210, and a rotor assembly 211 disposed within the housing 101. The rotating shaft 208 extends along a common longitudinal direction with the housing 101 and rotates about its axis x. The impeller assembly 220, the drive motor 210, and the rotor assembly 211 are all directly connected to the rotating shaft 208 and rotate synchronously with the rotation of the rotating shaft 208 at the same speed. In this embodiment, the impeller assembly 220 is connected to the left end of the rotating shaft 208, i.e., the end near the compressor inlet 102. The rotor assembly 211 is connected to the right end of the rotating shaft 208, i.e., the side near the compressor outlet 103. The drive motor 210 is connected between the impeller assembly 220 and the rotor assembly 211, that is, is located approximately in the middle of the rotating shaft 208. Thus, gas entering the compressor 100 through the compressor inlet 102 can flow through the impeller assembly 220, the drive motor 210, and the rotor assembly 211 in sequence, and then exit the compressor 100 through the compressor outlet 103. In this embodiment, the drive motor 210 is used to drive the rotating shaft 208 to rotate. The rotation of the rotating shaft 208 can drive the impeller assembly 220 and the rotor assembly 211 to rotate synchronously, so that the impeller assembly 220, the drive motor 210, and the rotor assembly 211 can rotate synchronously at the same speed.

[0031] The impeller assembly 220 includes an impeller cover 221 and an impeller, and the impeller and the impeller cover 221 rotate together around the axis x. In this embodiment, the impeller and the impeller cover 221 are cast or machined as one piece (i.e., a closed impeller with a rotating impeller shell). The impeller includes a plurality of blades and / or diverters spanning between the impeller hub and the impeller cover. The impeller is connected to the left end of the rotating shaft 208 so that the rotation of the rotating shaft 208 can drive the impeller and the impeller cover 221 to rotate, thereby guiding the gas flowing into the impeller from the compressor inlet 102 to pass through the impeller for the first stage of compression. In other embodiments, the impeller assembly may include a separate impeller cover (i.e., an open impeller with a stationary impeller cover). During the first stage of compression, the volume of the gas is compressed, causing the gas pressure to increase, and the gas can be guided by the impeller to move in a predetermined direction and be discharged to subsequent components. In this embodiment, the impeller includes a mixed flow impeller 222, which is fastened to the left end of the rotating shaft 208 by bolts 225 or other means. The mixed flow impeller 222 increases the kinetic energy and pressure of the airflow through radial and axial movement of the airflow. In some specific embodiments, the gas enters the mixed flow impeller 222 axially from the compressor inlet 102, and then the mixed flow impeller 222 guides the gas to be discharged in an oblique direction inclined to the axial direction. Compared with centrifugal / radial flow impellers and axial flow impellers, the mixed flow impeller 222 can significantly increase the gas pressure while guiding the gas flow in a more compact space. In some other embodiments, the impeller may also include a full centrifugal / radial flow impeller or an axial flow impeller. The more specific structure of the impeller device 220 will be described in detail in conjunction with Figures 3A and 3B.

[0032] The compressor 100 also includes a diffuser 241 disposed in the casing 101. The diffuser 241 is adjacent to the impeller device 220 and is disposed downstream of the impeller device 220. The diffuser 241 is also disposed upstream of the drive motor 210. That is, the gas in the compressor 100 first flows through the impeller device 220, then flows through the diffuser 241, and then flows through the drive motor 210. The diffuser 241 can convert part of the kinetic energy of the gas flowing out of the impeller device 220 into pressure energy to further increase the pressure of the gas. In this embodiment, the diffuser 241 is configured to guide the gas discharged obliquely from the impeller device 220 to be discharged axially toward the drive motor 210. 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 a vaneless diffuser and a vaned diffuser. The diffuser 241 includes an annular flow channel 242. In the direction of gas flow, the upstream portion (i.e., the left portion) of the annular flow channel 242 is aligned with the outlet end 326 (see FIG. 3B ) of the impeller assembly 220, so that the gas discharged from the impeller assembly 220 can directly enter the diffuser 241. The cross-sectional area of ​​the downstream portion of the annular flow channel 242 gradually increases, so that the flow velocity of the gas discharged from the annular flow channel 242 is gradually reduced, thereby increasing the pressure of the gas discharged from the downstream portion (i.e., the right portion) of the annular flow channel 242 to the drive motor, while avoiding flow separation.

[0033] In this embodiment, the diffuser 241 is fixedly connected to the casing 101 such that the rotation of the rotating shaft 208 does not affect the diffuser 241, and the diffuser 241 does not rotate in conjunction with the rotation of the rotating shaft 208. The compressor 100 further includes a bearing 251 installed between the rotating shaft 208 and the diffuser 241 to support the rotation of the rotating shaft 208 along the axis x via the diffuser 241. The more specific structure of the diffuser 241 will be described in detail with reference to Figures 4A and 4B.

[0034] The drive motor 210 includes a motor rotor portion 256 and a motor stator portion 254 that can rotate relative to each other. The motor stator portion 254 is fixedly connected to the housing 101, for example, by screws 255 or other means. The motor rotor portion 256 is fixedly connected to the rotating shaft 208 so that the rotation of the motor rotor portion 256 can drive the rotating shaft 208 to rotate. In this embodiment, a groove 258 is provided on the rotating shaft 208, and a drive key 257 is installed on the motor rotor portion 256. The groove 258 and the drive key 257 cooperate with each other to ensure that the motor rotor portion 256 is fixedly connected to the rotating shaft 208. After the drive motor 210 is energized, the motor stator portion 254 and the motor rotor portion 256 rotate relative to the motor stator portion 254 through the electromagnetic interaction between them. At least one fluid channel 253 is defined between the motor stator portion 254 of the drive motor 210 and the inner wall of the housing 101. The at least one fluid channel 253 extends axially along the rotating shaft 208 and fluidically connects the air outlet of the diffuser 241 and the rotor inlet of the rotor assembly 211. This allows the airflow axially discharged from the diffuser 241 to flow through the drive motor 210 to cool the drive motor 210 before entering the rotor assembly 211 for the second stage of compression. Because the impeller assembly 220 employs velocity compression and has a relatively low compression ratio, the temperature of the gas discharged from the impeller assembly 220 and diffuser 241 is relatively low. Consequently, the gas discharged from the impeller assembly 220 and diffuser 241 flowing through the drive motor 210 can cool the motor stator portion 254 of the drive motor 210. In this embodiment, at least one fluid channel 253 is defined by a groove connected to the inner wall of the housing 101. The at least one fluid channel 253 includes five fluid channels 253 (not specifically shown) evenly arranged around the axis x. In other embodiments, the fluid channels 253 may be arranged in any other known manner or in a different number, such as a greater or lesser number. In some embodiments, the fluid channels 253 may be arranged as an annular fluid channel around the axis x. In this embodiment, the drive motor 210 also includes several through-holes 259 axially extending through the motor rotor portion 256. The through-holes 259 also connect the gas outlet of the diffuser 241 and the rotor inlet of the rotor assembly 211. This allows a portion of the gas axially discharged from the diffuser 241 to flow through the through-holes 259, thereby cooling the motor rotor portion 256 of the drive motor 210 before the gas enters the rotor assembly 211 for the second stage of compression. In other embodiments, the through-holes 259 may be omitted, and only the fluid channels 253 may be included. A more specific structure of the driving motor 210 will be described in detail with reference to FIG. 5 .

[0035] In this embodiment, the rotor assembly 211 includes a pair of rotors arranged in parallel and side by side. The pair of rotors includes a male rotor 212 and a female rotor 213. The male rotor 212 is connected to the rotating shaft 208 so that it can be driven to rotate by the rotating shaft 208. The female rotor 213 meshes with the male rotor 212 so that the rotation of the male rotor 212 drives the female rotor 213 to rotate together. In this embodiment, the male rotor 212 is integrally formed with the rotating shaft 208 so that the male rotor 212 and the rotating shaft 208 rotate together. More specifically, the male rotor 212 and the female rotor 213 are each provided with a plurality of helical teeth, and the pair of rotors form a meshing structure through their respective teeth. The rotor assembly 211 has a rotor inlet 216 and a rotor outlet 217. The rotor inlet 216 is located at the left end of the rotor assembly 211 and is in fluid communication with the fluid passage 253. The rotor outlet 217 is located at the right end of the rotor assembly 211 and is in fluid communication with the compressor outlet 103. A plurality of compression chambers 218 are formed between the pair of rotors and the housing 101. As the pair of rotors rotate, each compression chamber 218 moves rightward from the rotor inlet 216 to the rotor outlet 217 along the axial direction of the rotation shaft 208. Simultaneously, the volume of the compression chamber 218 gradually decreases, so that the gas in the compression chamber 218 is gradually compressed, thereby enabling the gas flowing through the rotor assembly 211 to complete the second stage of compression.

[0036] Thus, the gas entering the compressor 100 from the compressor inlet 102, after undergoing the first stage of compression by the impeller assembly 220, can flow through the drive motor 210 to cool the drive motor 210, and then pass through the rotor assembly 211 to complete the second stage of compression of the gas, and finally exit the compressor 100 from the compressor outlet 103. After the gas passes through the impeller assembly 220 from the compressor inlet 102 to increase its pressure, the density of the gas entering the rotor assembly 211 is increased compared to a compressor that does not include the impeller assembly 220 and only uses the rotor assembly 211 to compress the gas. Therefore, when the compressor 100 achieves the same exhaust volume flow rate and exhaust pressure, the gas after being compressed by the impeller assembly 220 and the rotor assembly 211 can have a larger intake volume flow rate and compression ratio. Therefore, a heat pump system using the compressor 100 of the present application can have a greater cooling capacity / heating capacity and a higher heating water outlet temperature. In addition, an air conditioning / refrigeration system using the compressor 100 of the present application can have a greater cooling capacity.

[0037] In some embodiments, the compressor 100 may further include a slide valve (not shown) disposed around the rotor assembly 211 to further control and adjust the compression ratio of the compressor 100. In some embodiments, the rotor assembly may also include only one screw rotor.

[0038] In this embodiment, the drive motor 210 is a variable frequency motor. A variable frequency motor can provide the rotating shaft 208 with a wider speed range, meeting the speed requirements of the impeller assembly 220 and the rotor assembly 211. In this embodiment, the drive motor 210 is configured to drive the rotating shaft 208 to rotate at a speed of 1000-20,000 rpm. In other words, the speeds of the impeller assembly 220 and the rotor assembly 211 are both 1000-20,000 rpm. In some embodiments, the drive motor 210 is configured to drive the rotating shaft 208 to rotate at a speed of 2000-12,000 rpm. In some embodiments, the drive motor can also be a fixed speed motor and can be used in conjunction with other additional components, such as a rotor slide valve unloading mechanism or pre-rotation vanes.

[0039] Impeller assembly 220 compresses gas using a velocity compression method, thus requiring a relatively high rotational speed for impeller assembly 220. Generally speaking, to achieve the same compression ratio, the lower the speed of impeller assembly 220, the larger the impeller size. Therefore, in some embodiments, to keep the impeller size within the confines of housing 101, impeller assembly 220 is set to a rotational speed of 1000 rpm or greater. In other embodiments, impeller assembly 220 is set to a rotational speed of 2000 rpm or greater.

[0040] The rotor assembly 211 compresses gas using a positive displacement compression method. The gas in the compression chamber is compressed by the volume change of the compression chamber formed by the meshing of the male and female rotors. The rotational speed of the rotor assembly 211 is not required to be high. Due to the maximum operating speed limit of the screw compressor's rolling bearings, the rotational speed of the rotor assembly 211 cannot be too high. If the rotational speed is too high, it will accelerate the wear of the rotor meshing and affect the reliability of the rotor assembly 211. In some embodiments, the rotor assembly 211 is set to a rotational speed of no more than 20,000 rpm. In other embodiments, the rotor assembly 211 is set to a rotational speed of no more than 12,000 rpm.

[0041] Therefore, setting the rotation speed of the rotating shaft 208 to within 1000-20000 rpm can meet 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 rotating shaft 208 to perform coaxial, synchronous, and same speed operation.

[0042] In the commonly used heat pump systems currently, the compression ratio of the system is generally in the range of 2-15 times. The compression ratio of the second stage compression of the rotor device 211 usually needs to be less than 8 to ensure the smooth operation of the system and avoid the under-compression state. And in the unit including the same compressor, the cooling condition with a low compression ratio is generally operated in the summer, and the heating condition with a high compression ratio is generally operated in the winter. The applicant found that when the compression ratio of the first stage compression of the impeller device 220 is between 1.2-1.8, it can better take into account the dual-condition application requirements of the heat pump system for cooling and heating. Therefore, the mixed flow impeller 222 with a medium and low compression ratio is particularly suitable for the impeller device 220 of the present application. It can be understood by those skilled in the art that for heat pump systems with particularly high compression ratio requirements, the impeller device 220 may also include a centrifugal impeller.

[0043] Figures 3A and 3B illustrate the specific structure of impeller assembly 220. Figure 3A is a perspective view of impeller assembly 220 viewed from left to right, while Figure 3B is a perspective view of impeller assembly 220 viewed from right to left. As shown in Figures 3A and 3B, mixed flow impeller 222 includes several blades 361 and an impeller hub 327. Impeller hub 327 is located within impeller cover 221 and spaced a certain distance from impeller cover 221. Blades 361 are located between impeller cover 221 and impeller hub 327. An annular outlet 326 is formed on the right side between impeller cover 221 and impeller hub 327, through which gas exits impeller assembly 220.

[0044] The impeller assembly 220 also includes a circular outer ring 323 and a circular 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, with the outer ring 323 formed by the axially outward projection of the edge of the circular opening 328. The impeller assembly 220 also includes a support seat 329 located to the left of the center of the impeller hub 327. Bolts 225 can pass through the support seat 329 to connect the mixed flow impeller 222 to the rotating shaft 208. The inner ring 324 is formed by the axially outward projection of the edge of the support seat 329. Thus, the compressor inlet 102 is 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 326.

[0045] Figures 4A and 4B illustrate the specific structure of diffuser 241, with Figure 4A being a three-dimensional structural view of diffuser 241 viewed from left to right, and Figure 4B being a three-dimensional structural view of diffuser 241 viewed from right to left. As shown in Figures 4A and 4B in conjunction with Figure 2A, diffuser 241 includes an outer wall 443 and an inner wall 445. Outer wall 443 surrounds inner wall 445 and is positioned outside of inner wall 445 at a predetermined distance to form an annular flow channel 242. In this embodiment, in the axial direction from left to right, the inner surface of outer wall 443 first extends axially and then gradually expands outward. Similarly, the outer surface of inner wall 445 first extends axially and then gradually expands inward. Thus, the annular flow channel 242 between the inner surface of the outer wall 443 and the outer surface of the inner wall 445 first extends axially in the axial direction from left to right, and then gradually expands outward to form a streamlined shape (such as a bell-mouth shape) with a gradually changing cross-sectional area.

[0046] The diffuser 241 further includes a central sleeve 448 connected to the center of the inner wall 445. The central sleeve 448 extends axially and is hollow, and its interior is used to accommodate a bearing 251 so that the diffuser 241 can be mounted to the rotating shaft 208.

[0047] The diffuser 241 further includes at least one support rib 446 extending radially and connecting the inner wall 445 and the outer wall 443, thereby connecting the inner wall 445 and the outer wall 443 without affecting the annular flow channel 242. In this embodiment, the at least one support rib 446 includes three support ribs 446, which are evenly arranged along the circumference. In other embodiments, the support ribs 446 may be provided in other numbers.

[0048] The diffuser 241 also includes at least one reinforcing rib 447, which extends radially and is connected between the left side of the inner wall 445 and the center sleeve 448. The reinforcing rib 447 can strengthen the strength of the inner wall 445 used to form the annular flow channel 242 to prevent the gas with a higher pressure after the first stage of compression from radially squeezing the inner wall 445 inward when flowing through the annular flow channel 242. In this embodiment, the at least one reinforcing rib 447 includes three reinforcing ribs 447, which are evenly arranged along the circumference. In other embodiments, the reinforcing ribs 447 can also be set to other numbers. In this embodiment, the diffuser is a vaneless diffuser. In other embodiments, the diffuser can be a vaned diffuser or a combination of vaned and vaneless diffusers.

[0049] Figure 5 shows a three-dimensional structural diagram of the drive motor 210, the rotating shaft 208, and the male rotor 212. As shown in Figure 5, the left end surface of the rotating shaft 208 is provided with a threaded hole 552. The threaded hole 552 is configured to engage with the bolt 225 to securely connect the impeller assembly 220 to the left end of the rotating shaft 208. The rotating shaft 208 also includes, in order from left to right, a step portion 562 and a step portion 563. Each step portion protrudes radially from the outer surface of the rotating shaft 208. The step portion 562 is used to position the impeller assembly 220. For example, the center portion of the impeller hub 327 of the impeller assembly 220 can abut against the radial surface of the step portion 562. The step portion 563 is used to position the diffuser 241. For example, the center portion of the bearing 251 of the diffuser 241 can abut against the radial surface of the step portion 563. Thus, the impeller assembly 220 and the diffuser 241 can be connected to the leftmost end of the rotating shaft 208.

[0050] The male rotor 212 in the rotor device 211 is disposed on a side of the rotating shaft 208 opposite to the impeller device 220 , that is, on the right side of the rotating shaft 208 .

[0051] The drive motor 210 is connected to the right side of the impeller assembly 220 and the diffuser 241, and to the left side of the male rotor 212. The first-stage compressed gas discharged from the impeller assembly 220 and the diffuser 241 can enter the rotor assembly 211 through the fluid channel 253 outside the motor stator portion 254, or through the through hole 259 within the motor rotor portion 256. The drive motor 210 is connected to the rotating shaft 208 via a drive key 257 on the motor rotor portion 256 and a groove 258 on the rotating shaft 208. When the motor stator portion 254 is fixed relative to the housing 101, the rotation of the motor rotor portion 256 relative to the motor stator portion 254 can drive the rotating shaft 208 to rotate relative to the housing 101.

[0052] As such, impeller arrangement 220 , drive motor 210 , and rotor arrangement 211 can be in fluid communication and rotate synchronously with rotating shaft 208 .

[0053] In some embodiments, the impeller device may include a mixed flow or centrifugal / radial or axial flow impeller, including single stage or multi-stage, including shrouded (closed) or partially shrouded (semi-open) or unshrouded (open) impeller structure, including full blades or full blades and splitter / partial blades or any other blade structure.

[0054] In some embodiments, the impeller assembly may include a centrifugal / radial 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 the kinetic energy and pressure of the airflow through the movement of the airflow. The impeller assembly may include an impeller with a shroud (i.e., closed, with a rotating impeller cover) or an impeller without a shroud (i.e., open, with a fixed impeller cover). The impeller assembly may be without a splitter (i.e., full blades) or with a splitter (i.e., partial blades). The outlet of the impeller assembly may be fully radial (centrifugal / radial impeller) or angled (mixed flow impeller) or fully axial (axial flow impeller). The impeller assembly 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 the leading edge and the trailing edge. The suction side surface is opposite the pressure side surface and extends between the leading edge and the trailing edge. The impeller blade surface may have any, some or all of the following features or characteristics: swept, twisted, tilted, bowed, corrugated, grooved, S-shaped or any other alternative features to improve the efficiency and performance of the impeller.

[0055] In some embodiments, the diffuser may also be a vaned diffuser, or a combination of a vaneless diffuser and a vaned diffuser, or any other diffuser structure. The diffuser is configured to increase the static pressure of the refrigerant gas by reducing its velocity while directing the gas to flow axially along the rotating shaft toward the drive motor. The diffuser includes an annular flow channel. The upstream portion of the annular flow channel is aligned with the outlet of the impeller assembly, while the downstream portion of the annular flow channel is aligned with the drive motor. The cross-sectional area of ​​the diffuser gradually changes between the upstream and downstream portions to reduce the flow velocity and increase the flow pressure while avoiding flow separation.

[0056] In some embodiments, the drive motor may be a variable frequency (variable speed) motor type, a fixed frequency (fixed speed) motor type, or any other motor configuration.

[0057] In some embodiments, the rotor arrangement may include a single rotor or a dual rotor helical rotor, or any other rotor structure or combination of rotor structures.

[0058] In some embodiments, a sliding valve or any other mechanical device configuration may be installed around the rotor assembly to further control and adjust the compression ratio of the compressor.

[0059] Existing screw compressors generally only include a drive motor and a rotor device, which are connected to a common rotating shaft for synchronous rotation. The screw compressor is a volumetric compressor. After the screw compressor inhales air, the gas passes through the rotor device to compress the gas volume to increase the gas pressure. In some screw compressors, although the internal volume ratio of the screw compressor can be adjusted by setting a sliding valve, due to the limitations of the structural design, the maximum internal volume ratio of the screw compressor is 5.0. For some heat pump systems that require a higher compression ratio, single-stage screw compressors generally cannot achieve the compression ratio required by the system, causing the screw compressor to be in an under-compression state for a long time, resulting in large vibration of the screw compressor and high exhaust temperature. If two or more stages of compressors are set in the pipeline of the heat pump system, it will lead to a complex system structure and high cost.

[0060] Furthermore, for air conditioning / heat pump systems using certain new environmentally friendly refrigerants (such as R1234ze), these refrigerants typically have low cooling capacity per unit volume, making it difficult to meet the cooling capacity requirements of heat pump systems under the same air conditioning operating water temperature conditions. Therefore, these environmentally friendly refrigerants cannot be directly used in existing heat pump systems. Often, the size and displacement of the heat pump system must be increased to meet the cooling capacity requirements, resulting in increased modification costs.

[0061] In the compressor of this application, an impeller assembly and a rotor assembly are integrated into the casing. Before entering the rotor assembly, the refrigerant gas undergoes a first-stage compression by the impeller assembly to increase the gas's pressure and density. It then enters the rotor assembly for a second-stage compression to further reduce the gas's volume and increase its pressure. Consequently, compared to screw compressors with the same rotor assembly configuration, the compressor can achieve a greater compression ratio, suction volume, and compressor efficiency.

[0062] The compressor of the present application disposes the drive motor between the impeller assembly and the rotor assembly, utilizing the exhaust gas from the impeller assembly to cool the drive motor, thereby resolving the heat dissipation problem of the drive motor. This is particularly suitable for resolving the problem of excessive heat generation by a variable frequency motor when the variable frequency motor is used to drive the rotating shaft.

[0063] The rotational speed of the rotary shaft of the compressor of the present application is set within a suitable range, enabling the impeller assembly, drive motor, and rotor assembly to rotate synchronously, eliminating the need for additional speed change gears and resulting in a simple structure. Furthermore, the impeller assembly is relatively small, allowing it to be housed within the housing along with the drive motor and rotor assembly. Furthermore, by designing an impeller assembly of appropriate size, the impeller assembly's exhaust volume is matched to the rotor assembly's intake volume, resulting in higher compressor efficiency.

[0064] The impeller assembly of the present application includes a mixed-flow impeller, which can achieve greater compression efficiency compared to axial-flow impellers. Compared to centrifugal impellers, mixed-flow impellers can also experience lower pressure loss after discharge from the impeller assembly. Furthermore, the compressor of the present application also includes an axial diffuser. In addition to increasing gas pressure, the axial diffuser can also guide gas flow along the axial direction of the rotating shaft, further reducing gas pressure loss in conjunction with the mixed-flow impeller.

[0065] Furthermore, the compressor of the present application only needs to be equipped with an impeller device at the end close to the suction side based on the structure of the existing screw compressor, which requires relatively minor changes, thus reducing the cost of transformation.

[0066] In addition, since the compressor of the present application has an increased intake capacity compared to conventional screw compressors, the air conditioning / heat pump system including the compressor of the present application can achieve a larger cooling capacity when using conventional refrigerants (such as R134a), and has better environmental protection effects when using refrigerants with lower unit cooling capacity (such as R1234ze).

[0067] Although the present disclosure has been described in conjunction with the examples of the embodiments outlined above, it is likely that various alternatives, modifications, variations, improvements, and / or substantial equivalents will be apparent to those skilled in the art, at least with ordinary skill in the art, whether known or currently or soon to be foreseen. Therefore, the examples of the embodiments of the present disclosure set out above are intended to be illustrative rather than restrictive. Various changes may be made without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is intended to include all known or earlier developed alternatives, modifications, variations, improvements, and / or substantial equivalents. The technical effects and technical problems in this specification are exemplary rather than restrictive. It should be noted that the embodiments described in this specification may have other technical effects and may solve other technical problems.

Claims

1. A compressor, characterized in that include: a housing including a compressor inlet and a compressor outlet; a driving motor and a rotating shaft, the driving motor and the rotating shaft being disposed in the housing, the driving motor being connected to the rotating shaft and being configured to drive the rotating shaft to rotate; as well as an impeller device and a rotor device, wherein the impeller device and the rotor device are arranged in the housing, connected to the rotating shaft, and located on opposite sides of the driving motor, so that the rotating shaft can drive the impeller device and the rotor device to rotate synchronously, thereby making the driving motor, the impeller device and the rotor device rotate synchronously at the same speed; In which, the drive motor, the impeller device and the rotor device are configured to rotate with the rotating shaft, and the gas entering the compressor from the compressor inlet first flows through the impeller device for a first-stage compression to increase the pressure of the gas, then flows through the drive motor to cool the drive motor, and then flows through the rotor device for a second-stage compression to further increase the pressure of the gas, and finally discharges the compressor from the compressor outlet.

2. The compressor according to claim 1, characterized in that: At least one fluid channel is provided between the driving motor and the housing, and the fluid channel extends along the axial direction of the rotating shaft; The gas compressed in the first stage by the impeller device can flow through the drive motor along the at least one fluid channel to cool the drive motor.

3. The compressor according to claim 2, characterized in that Also includes: A diffuser is disposed downstream of the impeller device and upstream of the drive motor, and is configured to further increase the pressure of the gas after completing the first stage of compression.

4. The compressor according to claim 3, characterized in that: The diffuser is a bladeless diffuser, a bladed diffuser, or a bladed / bladeless mixed diffuser.

5. The compressor according to claim 3, characterized in that: The impeller device includes an impeller cover and an impeller. The impeller is disposed in the impeller cover and is configured to increase the kinetic energy and pressure of the airflow through the movement of the airflow.

6. The compressor according to claim 5, characterized in that: The impeller is a mixed flow impeller configured to increase the kinetic energy and pressure of the airflow through radial and axial motion of the airflow.

7. The compressor according to claim 6, characterized in that: 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 rotating shaft.

8. The compressor according to claim 7, characterized in that: The diffuser includes an annular flow channel, wherein, in the direction of gas flow, the upstream portion of the annular flow channel is aligned with the outlet end of the impeller device, and the cross-sectional area of ​​the downstream portion of the annular flow channel gradually increases so that the flow velocity of the gas discharged from the annular flow channel is gradually reduced.

9. The compressor according to claim 1, characterized in that: The rotor device includes a male rotor and a female rotor meshing with each other, wherein the male rotor is connected to the rotating shaft to be driven to rotate by the rotating shaft, and the female rotor is driven to rotate by the male rotor.

10. The compressor according to claim 1, characterized in that: The driving motor is a variable frequency motor, and the driving motor is configured to drive the rotating shaft to rotate at a speed of 1000-20000 rpm.

11. The compressor according to claim 10, characterized in that: The driving motor is configured to drive the rotating shaft to rotate at a speed of 2000-12000 rpm.

12. The compressor according to claim 10, characterized in that: The driving motor is a constant speed motor.

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

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