Centrifugal Compressor and Air Conditioning Equipment

Abstract

The present invention relates to a centrifugal compressor and an air conditioning device. The centrifugal compressor includes: a main shaft (1); a diffuser (3), with a first thrust bearing (10) provided at one end of the diffuser (3) away from the diffusing surface; a support assembly (5), with a second thrust bearing (10') provided at one end of the support assembly (5) facing the diffuser (3); and a thrust disk (4), configured to rotate together with the main shaft (1) and axially located between the diffuser (3) and the support assembly (5). The thrust disk (4) has a thrust portion (41), and the gaps between both sides of the thrust portion (41) and the first thrust bearing (10) and the second thrust bearing (10') are defined by mutual abutment between the diffuser (3) and the support assembly (5). Such a centrifugal compressor can accurately ensure the gaps of the thrust bearings, ensure the performance of the thrust bearings, and improve the operation stability of the compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of air compression equipment, and particularly to a centrifugal compressor and an air conditioning device. Background Art

[0002] Hydrodynamic gas bearings have the advantages of high precision, low friction loss, long service life, small vibration, no pollution, and no need to provide lubricating medium. At the same time, they are suitable for high-speed and high-precision occasions and have broad application prospects in centrifugal compressors, especially miniaturized centrifugal compressors. However, the clearance of gas bearings is very small, only on the order of several micrometers or even dozens of micrometers, and the machining accuracy of parts is required to be sub-micron level. Therefore, it is very important to ensure the clearance of the thrust surface of the thrust bearing. If the clearance control is inaccurate, the performance of the thrust bearing will be reduced, and in severe cases, the bearing will fail. Summary of the Invention

[0003] The object of the present invention is to provide a centrifugal compressor and an air conditioning device, which can improve the assembly accuracy of the thrust bearing in the compressor.

[0004] According to a first aspect of the present invention, a centrifugal compressor is provided, including:

[0005] A main shaft;

[0006] A diffuser, one end of the diffuser away from the diffusing surface is provided with a first thrust bearing;

[0007] A support assembly, one end of the support assembly facing the diffuser is provided with a second thrust bearing; and a thrust disc, configured to be rotatable together with the main shaft and axially located between the diffuser and the support assembly. The thrust disc has a thrust portion, and the clearances between both sides of the thrust portion and the first thrust bearing and the second thrust bearing are defined by mutual abutment of the diffuser and the support assembly.

[0008] Further, one end of the diffuser away from the diffusing surface is provided with a first groove, the first thrust bearing is arranged at the bottom of the first groove along the axial direction, and the thrust portion is located in the first groove.

[0009] Further, the centrifugal compressor further includes a housing and a radial bearing, wherein the support assembly includes:

[0010] A fixing plate, the second thrust bearing is arranged on one side of the fixing plate facing the diffuser; and

[0011] A bearing support, arranged on one side of the fixing plate away from the diffuser, the first end of the bearing support is connected to the fixing plate, and the second end is connected to the housing, and is used to support the main shaft through the radial bearing.

[0012] Further, the fixing plate and the bearing support form an integral structure.

[0013] Furthermore, the fixing plate is also used to limit the displacement of the radial bearing along the axial direction towards the diffuser side.

[0014] Furthermore, a positioning ring is provided at one end of the fixing plate facing the bearing support, a ring-shaped second groove is provided on the bearing support, the positioning ring is embedded in the second groove, and the inner wall of the positioning ring cooperates with the outer wall of a partial length section of the radial bearing.

[0015] Furthermore, the centrifugal compressor further includes a housing and a radial bearing. Among them, the support assembly includes:

[0016] A bearing support, which is connected to the housing, the second thrust bearing is provided on the side of the bearing support facing the diffuser, and the bearing support is also used to support the main shaft through the radial bearing.

[0017] Furthermore, the centrifugal compressor further includes a housing and a radial bearing. The support assembly includes a bearing support. The first end of the bearing support abuts against the diffuser, the second end is connected to the housing, and is used to support the main shaft through the radial bearing. The outer contour dimension of the bearing support gradually increases from the first end to the second end.

[0018] Furthermore, the centrifugal compressor further includes a radial bearing. The support assembly includes a bearing support, which is used to support the main shaft through the radial bearing. The bearing support is provided with a vent hole, which is used to make the working environment of the radial bearing consistent with that of the first thrust bearing and the second thrust bearing.

[0019] Furthermore, the first thrust bearing is directly fixed at the bottom of the first groove.

[0020] Furthermore, the centrifugal compressor further includes an impeller and a locking component. A cavity is provided in the main shaft and a shaft core is provided at the center. The end of the shaft core extends out of the end of the main shaft; the impeller is sleeved on the outer end of the shaft core, and the impeller is locked on the shaft core through the locking component, and the impeller is located outside the diffuser.

[0021] Furthermore, the thrust disc further includes a connecting portion, the connecting portion is connected to the thrust portion and is sleeved on the main shaft. A through hole is provided at the bottom of the first groove, and the connecting portion is embedded in the through hole.

[0022] Furthermore, the centrifugal compressor further includes an impeller provided at the end of the main shaft, and the impeller is located outside the diffuser.

[0023] The side wall of the through hole is provided with a first axial comb tooth seal structure; and / or

[0024] The end of the impeller facing the diffuser is provided with a radial comb tooth seal structure; and / or

[0025] The impeller has an embedding portion embedded in the diffuser, and a second axial comb tooth seal structure is provided along the length direction on the embedding portion.

[0026] Further, the first axial comb tooth seal structure, the radial comb tooth seal structure, and the second axial comb tooth seal structure are provided simultaneously, and the radial comb tooth seal structure is located radially between the first axial comb tooth seal structure and the second axial comb tooth seal structure.

[0027] Further, the centrifugal compressor further includes a radial bearing for supporting the main shaft, and the first thrust bearing, the second thrust bearing, and / or the radial bearing is an air suspension bearing.

[0028] According to the second aspect of the present invention, an air conditioning device is provided, including the centrifugal compressor of the above embodiment.

[0029] Based on the above technical solution, in the centrifugal compressor of the embodiment of the present invention, the thrust disk cooperates with the thrust bearings on both sides, and can withstand the axial forces in the left and right directions to ensure the stability of the compressor during full-condition operation and reverse operation; moreover, through the mutual abutment of the support assembly and the diffuser for combined limiting, the position of the thrust disk can be limited, and the gap between the thrust disk and the thrust bearings on both sides can be accurately limited, thereby reducing the assembly difficulty, improving the assembly efficiency and assembly accuracy, and ensuring the working performance of the thrust bearings and improving the operation stability of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 is a schematic structural diagram of an embodiment of the centrifugal compressor of the present invention;

[0032] Figure 2 is a schematic installation structure diagram of the diffuser, thrust disk, and fixing plate in the centrifugal compressor of the present invention;

[0033] Figure 3 is a schematic installation structure diagram of the diffuser, thrust disk, fixing plate, and bearing support in the centrifugal compressor of the present invention;

[0034] Figure 4 is a schematic diagram of the integrated structure of the fixing plate and bearing support in the centrifugal compressor of the present invention;

[0035] Figure 5 is a schematic installation structure diagram of the bearing support and the housing in the centrifugal compressor of the present invention;

[0036] Figure 6 is a schematic structural diagram of an embodiment of the seal structure in the centrifugal compressor of the present invention.

[0037] DESCRIPTION OF THE REFERENCE NUMERALS

[0038] 1. Main shaft; 2. Impeller; 3. Diffuser; 4. Thrust disk; 5. Support assembly; 6. Housing; 7. Stator assembly; 8. Radial bearing; 9. Locking component; 10. First thrust bearing; 10'. Second thrust bearing;

[0039] 11. Cavity; 12. Shaft core; 13. Magnet; 21. Radial comb tooth seal structure; 22. Embedded part; 23. Second axial comb tooth seal structure; 31. First groove; 32. Fastener; 33. Positioning spigot; 34. Through hole; 35. First axial comb tooth seal structure; 41. Thrust part; 42. Connecting part; 51. Fixed plate; 511. Positioning ring; 512. Inner wall; 52. Bearing support; 521. Second groove; 522. Mounting hole; 523. Operation hole; 524. Weight reduction groove; 525. Flange; 526. Vent hole; 527. Spigot; 61. First volute; 62. Intermediate housing; 63. Second volute. Detailed implementation mode

[0040] The present invention will be described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Each aspect so defined can be combined with any other one or more aspects, unless explicitly stated that they cannot be combined. In particular, any feature considered to be preferred or advantageous can be combined with one or more other features considered to be preferred or advantageous.

[0041] The terms "first", "second", etc. used in the present invention are only for convenient description to distinguish different components with the same name, and do not indicate the order or primary-secondary relationship.

[0042] The present invention provides a centrifugal compressor. In order to enable those skilled in the art to more clearly understand the improvement points of the present invention, first in combination with Figure 1 the overall structure of the centrifugal compressor will be described.

[0043] As Figure 1 shown, taking a two-stage centrifugal compressor as an example, it includes a first volute 61, a second volute 63 and an intermediate housing 62. The first volute 61 and the second volute 63 are respectively arranged at both ends of the intermediate housing 62 along the axial direction, jointly forming the compressor housing 6. The main shaft 1 is arranged at the central position of the compressor housing. A impeller 2 is respectively arranged at both ends of the main shaft 1. A diffuser 3 is arranged at the inner end of the impeller 2. When the impeller 2 rotates at a high speed, the gas rotates along with it. Under the action of centrifugal force, the gas is thrown into the rear diffuser 3 for pressure increase, converting the velocity energy of the medium at the outlet of the impeller 2 into pressure energy. The gas with increased pressure is discharged from the volute.

[0044] To support the main shaft 1, radial bearings 8 are provided at both ends of the main shaft 1. The radial bearings 8 are supported by bearing supports 52, and the bearing supports 52 are connected to the intermediate housing 62. A stator assembly 7 is provided between the main shaft 1 and the intermediate housing 62. Since the impeller 2 generates an axial force during operation, a thrust bearing is provided at one end of the main shaft 1 to balance the axial force generated by the impeller 2.

[0045] The working principle of this compressor is as follows: During the operation of the compressor, the main shaft 1 rotates at a high speed. Gas enters the diffuser 3 through the impeller 2 on the left side. After the gas is compressed at the first stage, it enters the first volute 61. The exhaust passage on the first volute 61 guides the compressed gas into the impeller 2 on the right side. After the centrifugal action of the impeller 2 on the right side, the gas enters the diffuser 3 on the right side. After the gas is compressed at the second stage, it enters the second volute 63 and is discharged from the compressor through the exhaust passage on the second volute 63.

[0046] Next, the bearing support assembly in the centrifugal compressor will be described in detail. In some embodiments, as Figure 2 shown, the centrifugal compressor includes: a main shaft 1, an impeller 2, a diffuser 3, a thrust disk 4, and a support assembly 5.

[0047] Among them, a magnetic steel 13 may be provided in the middle of the main shaft 1. The diffuser 3 is fixed to the housing 6. A first thrust bearing 10 is provided at one end of the diffuser 3 away from the diffusing surface, and the diffusing surface is the end face close to the impeller 2. The support assembly 5 is provided at one end of the diffuser 3 away from the diffusing surface. One end of it is fixed to the housing 6 of the compressor, and the other end abuts against the end face of the diffuser 3. A second thrust bearing 10' is provided on the side of the support assembly 5 facing the diffuser 3. The thrust disk 4 is configured to rotate together with the main shaft 1. The thrust disk 4 has a thrust portion 41, for example, a disk-shaped structure. The gaps between the two sides of the thrust portion 41 and the first thrust bearing 10 and the second thrust bearing 10' are defined by the mutual abutment of the diffuser 3 and the support assembly 5. The two sides of the thrust portion 41 form working surfaces with the thrust bearings on both sides, which can bear bidirectional axial forces to ensure the stable and reliable operation of the compressor under all working conditions and during reverse rotation.

[0048] For example, the first thrust bearing 10 and the second thrust bearing 10' can be static pressure or dynamic pressure gas thrust bearings, or they can also be magnetic suspension bearings.

[0049] Take Figure 2 as an example. Since there is a gap between the thrust bearing and the thrust disk 4, the gas will form a gas film with pressure in this gap to play a thrust and lubrication role. Since the thrust bearing itself is in the compressor cavity, the gas comes from the cavity environment. During the rotation of the rotor, the gas can be brought into the gap to form a dynamic pressure gas thrust bearing.

[0050] In the centrifugal compressor of this embodiment, the thrust disc can cooperate with the thrust bearings on both sides and can withstand axial forces in both the left and right directions to ensure the stability of the compressor during full-condition operation and reverse operation. The operating conditions of the compressor refer to the evaporation temperature and condensation temperature of the system where the compressor is located. Full-condition means that the compressor operates within a certain evaporation temperature range and condensation temperature range. When the compressor stops, due to the exhaust pressure being higher than the suction pressure, reverse rotation may occur after shutdown.

[0051] Moreover, since both the diffuser 3 and the support assembly 5 need to be fixed to the housing 6 of the compressor, their positions are fixed. The diffuser 3 and the support assembly 5 are combined and limited by abutting against each other, which limits the position of the thrust disc 4 and the clearance between the thrust bearings on both sides. Thereby, the clearance of the thrust bearings can be accurately guaranteed, the assembly difficulty can be reduced, the assembly efficiency and assembly accuracy can be improved, and the working performance of the thrust bearings can be ensured, thus improving the operation stability of the compressor.

[0052] As Figure 2 shown, a first groove 31 is provided at one end of the diffuser 3 away from the diffusing surface. A first thrust bearing 10 is provided at the bottom of the first groove 31 along the axial direction. The thrust portion 41 is located within the first groove 31, and there are clearances between both sides of the thrust portion 41 and the first thrust bearing 10 and the second thrust bearing 10'.

[0053] Since the diffuser 3 and the support assembly 5 abut against each other, the clearances of the thrust bearings on both sides can be accurately guaranteed through the axial depth of the first groove 31. The assembly accuracy can be improved, the assembly difficulty can be reduced, the assembly efficiency can be improved, and at the same time, the performance of the thrust bearings can be ensured, preventing the performance of the thrust bearings from being reduced or even failing due to inaccurate clearance control, thus improving the operation stability of the compressor.

[0054] As Figure 2 shown, the depth of the first groove 31 includes: the thickness of the thrust portion 41, the thicknesses of the thrust bearings on both sides, and the clearances of the thrust bearings on both sides. Therefore, in order to ensure the clearances of the thrust bearings on both sides, the clearances can be controlled by increasing the depth of the first groove 31, the thickness of the thrust portion 41, and the thicknesses of the thrust bearings on both sides. The specific method is: based on the clearance range required for the thrust bearings, the thickness tolerance range of the thrust portion 41, and the thickness tolerance range of the thrust bearings, the designed depth and tolerance range of the first groove 31 are inversely deduced. Thus, the clearance of the thrust bearings can be guaranteed by improving the machining accuracy of the depth of the first groove 31, the assembly accuracy can be improved, and the assembly difficulty can be reduced, thereby improving the assembly efficiency.

[0055] In some embodiments, such as Figure 2 and Figure 3As shown, the centrifugal compressor further includes a housing 6 and a radial bearing 8 for bearing the radial force of the rotor, mainly from the gravity of the rotor itself. For example, the radial bearing 8 can be a hydrostatic or hydrodynamic gas radial bearing, or it can also be a magnetic levitation bearing.

[0056] The support assembly 5 includes a fixing plate 51 and a bearing support 52. Among them, the fixing plate 51 abuts against the diffuser 3, and the second thrust bearing 10' is arranged on one side of the fixing plate 51 facing the diffuser 3; the bearing support 52 is arranged on the side of the fixing plate 51 away from the diffuser 3. The first end of the bearing support 52 is connected to the fixing plate 51, and the second end is connected to the housing 6 for supporting the main shaft 1 through the radial bearing 8.

[0057] In this embodiment, the support assembly 5 adopts a split structure. The second thrust bearing 10' is installed through the fixing plate 51, and the radial bearing 8 is installed on the bearing support 52, which is beneficial to improving the installation position accuracy of the radial bearings 8 at both ends of the main shaft 1 and the thrust bearing, including the coaxiality of the two radial bearings 8 and the perpendicularity of the thrust bearing, and can improve the working stability of the rotor system.

[0058] Specifically, as Figure 5 shown, it can be achieved in the following way. The second end of the bearing support 52 is provided with a flange 525, and a stop 527 is provided at the outer end of the flange 525. The bearing support 52 is installed in the intermediate housing 62 through the flange 525 and fixed by fasteners. At the same time, the bearing support 52 relies on the stop 527 for radial positioning.

[0059] During processing, first, the two bearing supports 52 are first repositioned through the stop 527 and matched with the intermediate housing 62. Then, the flange 525 is fixed to the intermediate housing 62 through fasteners, and then a pin is driven for fixation. Subsequently, the intermediate housing 62 and the two bearing supports 52 are positioned as an integral component on the processing equipment, and the end faces of the two bearing supports 52 that cooperate with the fixing plate 51 are processed to ensure the perpendicularity of the thrust bearing and the radial bearing 8. Then, the installation holes 522 of the two bearing supports 52 are processed in sequence from one side to ensure the coaxiality of the two radial bearings 8.

[0060] After processing, the bearing support 52 is removed, and the radial bearing 8 is installed in the installation hole 522 of the bearing support 52 by hot fitting. Then, the fixing plate 51 is installed at the first end of the bearing support 52. The bearing support 52 can be fixedly installed on the housing 6 according to the pin position determined during processing.

[0061] Since the processing of each key positioning part is completed in one clamping process, the coaxiality of the two radial bearings 8 and the perpendicularity of the thrust bearing can be ensured, thereby improving the working stability of the rotor system.

[0062] As Figure 3As shown, the fixing plate 51 is also used to limit the displacement of the radial bearing 8 along the axial direction towards the diffuser 3. Thus, the fixing plate 51 can not only mount the second thrust bearing 10', but also axially limit the radial bearing 8, making the structure of the bearing support assembly more compact, and facilitating the guarantee of the parallelism between the mounting surface of the second thrust bearing 10' and the axial limiting surface of the radial bearing 8 through the machining parallelism on both sides of the fixing plate 51, thereby improving the mounting accuracy of the thrust bearing and the radial bearing 8.

[0063] Further, a positioning ring 511 is provided at one end of the fixing plate 51 facing the bearing support 52, and an annular second groove 521 is provided on the bearing support 52. The positioning ring 511 is embedded in the second groove 521 to radially position the fixing plate 51, and there is a gap between the fixing plate 51 and the main shaft 1. Moreover, the inner wall of the positioning ring 511 matches the outer wall of a partial length section of the radial bearing 8, which is used to support a partial length section of the radial bearing 8 and simultaneously play a role in axial thrust prevention for the radial bearing 8.

[0064] In a specific structure, as Figure 2 shown, the first thrust bearing 10 is fixed on the diffuser 3 through a fastener 32, the second thrust bearing 10' is fixed on the fixing plate 51 through a fastener 32, the fixing plate 51 and the diffuser 3 are in mutual abutment, and a positioning stop 33 is provided on the outer periphery of the diffuser 3 for positioning and mounting with the housing 6.

[0065] In some embodiments, as Figure 4 shown, the fixing plate 51 and the bearing support 52 form an integral structure. The support assembly 5 adopting an integral structure can simplify the structure, reduce the assembly difficulty, and is easy to ensure the perpendicularity between the radial bearing 8 and the thrust bearing through the machining accuracy of the support assembly 5.

[0066] In some embodiments, not shown in the figure, the centrifugal compressor further includes a housing 6 and a radial bearing 8. Among them, the support assembly 5 includes a bearing support 52. The first end of the bearing support 52 abuts against the diffuser 3, the second end is connected to the housing 6, the second thrust bearing 10' is provided on the side of the bearing support 52 facing the diffuser 3, and the bearing support 52 is also used to support the main shaft 1 through the radial bearing 8. A thrust platform is reserved when machining the mounting hole 522 of the bearing support 52 to axially limit the radial bearing 8.

[0067] Compared with Figure 4 the embodiment shown, the fixing plate 51 is omitted, which can further reduce the axial dimension of the bearing support assembly, simplify the structure, reduce the assembly difficulty, and is easy to ensure the perpendicularity between the radial bearing 8 and the thrust bearing through the machining accuracy of the support assembly 5.

[0068] As Figure 3 and Figure 4As shown, the centrifugal compressor further includes a housing 6 and a radial bearing 8. The support assembly 5 includes a bearing support 52. The first end of the bearing support 52 abuts against the diffuser 3, and the second end is connected to the housing 6 for supporting the main shaft 1 through the radial bearing 8. Since the outer diameter of the thrust bearing is smaller than the inner diameter of the housing 6, correspondingly, the outer profile dimensions of the bearing support 52 gradually increase from the first end to the second end. For weight reduction, as Figure 5 shown, a weight reduction groove 524 can also be provided on the side of the bearing support 52 away from the thrust bearing. For example, the weight reduction groove 524 is arranged in a ring shape, the inner wall is parallel to the axis, and the outer wall is consistent with the outer profile shape of the bearing support 52.

[0069] By adopting a structure with a gradually changing cross-sectional area for such a V-shaped bearing support 52, the overall structural strength of the bearing support 52 can be improved, the force distribution at each part is uniform, the load-bearing capacity can be optimized, and the outer side wall is an inclined surface which is easy to achieve through casting and has a draft angle when casting through a mold.

[0070] Furthermore, as Figure 5 shown, the bearing support 52 is provided with a vent hole 526 for making the working environment of the radial bearing 8 the same as that of the first thrust bearing 10 and the second thrust bearing 10', for example, making the working back pressure of the radial bearing 8 the same as that of the first thrust bearing 10 and the second thrust bearing 10'. There are refrigerant for cooling the motor entering and leaving in the motor cavity. When the compressor is running normally, the overall pressure and temperature in the motor cavity are stable. The working environment of the thrust bearing and the radial bearing is the same as that of the motor cavity, that is, to ensure gas circulation and relatively stable back pressure. If the back pressure fluctuates too much, it will cause fluctuations in the bearing gas film and affect the bearing performance.

[0071] As Figure 3 shown, the bearing support 52 is provided with an operation hole 523 along the radial direction for installing a vibration sensor or a temperature sensor on the outer wall of the radial bearing 8 through the operation hole 523 to monitor the working state of the radial bearing 8. The hole section on the outer side along the radial direction of the operation hole 523 can be used as a bypass hole to ensure that the pressure and temperature of the thrust bearing, the radial bearing 8 and the motor cavity are all the same. The hole section on the inner side along the radial direction of the operation hole 523 plays a role in dissipating heat from the radial bearing 8.

[0072] In some embodiments, as Figure 3 shown, the first thrust bearing 10 is directly fixed at the bottom of the first groove 31 of the diffuser 3. For example, the first thrust bearing 10 adopts a hydrodynamic thrust bearing and is a thin plate structure. This hydrodynamic thrust bearing can be directly fixed at the bottom of the first groove 31. This structure integrates the diffuser 3 and the thrust bearing fixing plate into one part. The bottom of the first groove 31 can be used as the fixing plate of the first thrust bearing 10 without additionally setting a thrust bearing fixing plate, which can further reduce the axial dimension of the bearing support assembly and make the structure more compact.

[0073] In some embodiments, such as Figure 1 shown, the centrifugal compressor further includes an impeller 2 and a locking member 9. A cavity 11 is provided in the main shaft 1 and a shaft core 12 is provided at the center. The end of the shaft core 12 extends beyond the end of the main shaft 1. The impeller 2 is sleeved on the outer end of the shaft core 12, and the impeller 2 is locked on the shaft core 12 by the locking member 9, and the impeller 2 is located outside the diffuser 3.

[0074] This embodiment enables the impeller 2 to be detachably arranged relative to the main shaft 1, which can reduce the difficulty of disassembling and assembling the impeller, simplify the assembly process and the required equipment of the impeller, improve the assembly efficiency, and the operability of disassembly, inspection and maintenance work. Moreover, this installation method can not only prevent the main shaft or the impeller from deforming, but also ensure the installation strength of the impeller, avoid stress concentration, and thus improve the compression capacity of the compressor. In addition, by providing a cavity in the main shaft, the weight of the main shaft can be reduced to increase the critical speed of the rotor, and further improve the ultimate working ability of the compressor.

[0075] Still referring to Figure 1 , the shaft core 12 is directly formed when machining the cavity 11, so that the shaft core 12 and the rest of the main shaft 1 are machined into one body, without the need to additionally install the shaft core 12 in the cavity of the main shaft 1, which can further reduce the assembly difficulty, increase the connection strength between the shaft core 12 and the main shaft 1, and ensure the position accuracy of the shaft core 12, effectively solve the jumping problem at the front end of the rotor, reduce the length of the cantilever end, and thus improve the working stability and reliability of the compressor. For example, the cavity 11 can be an annular groove or a plurality of holes symmetrically arranged with respect to the axis center.

[0076] Such as Figure 3 shown, the thrust disk 4 further includes a connecting portion 42. The thrust disk 4 is connected to the thrust portion 41 and is sleeved on the main shaft 1. A through hole 34 is provided at the bottom of the first groove 31, and the connecting portion 42 is embedded in the through hole 34. The connecting portion 42 can be in interference fit with the main shaft 1 so that the thrust disk 4 can rotate together with the main shaft 1. The diffuser 3 and the fixing plate 51 are fixedly arranged and have gaps with the main shaft 1 respectively. For example, the thrust disk 4 can be a cylindrical stepped structure.

[0077] Such as Figure 6As shown, the centrifugal compressor further includes an impeller 2 provided at the end of the main shaft 1. The impeller 2 is located outside the diffuser 3. A first axial comb seal structure 35 is provided on the side wall of the through hole 34 to form a shaft seal with the thrust disk 4, which can reduce the refrigerant from entering the motor chamber through the gap between the diffuser 3 and the thrust disk 4 along with the impeller exhaust. And / or a radial comb seal structure 21 is provided at the end of the impeller 2 facing the diffuser 3, which can reduce the refrigerant from flowing outward along the gap between the impeller 2 and the diffuser 3. And / or the impeller 2 has an embedded portion 22 embedded in the diffuser 3. For example, the embedded portion 22 can be an elongated strip structure extending axially. A second axial comb seal structure 23 is provided on the radial inner side of the embedded portion 22 along the length direction to reduce the refrigerant from flowing outward along the gap between the impeller 2 and the diffuser 3.

[0078] Specifically, the inclined surface of the comb teeth slopes from the high-pressure side to the low-pressure side, and the tip of the comb teeth can be trapezoidal.

[0079] This embodiment can reduce the refrigerant leakage between the impeller 2 and the diffuser 3 and between the diffuser 3 and the thrust disk 4. It can not only ensure the required gap during the operation of the main shaft 1 and the impeller 2, but also prevent refrigerant leakage caused by too large a gap, effectively solving the compressor sealing problem and being beneficial to improving the compressor energy efficiency.

[0080] Moreover, this structure integrates the diffuser 3, the thrust bearing fixing plate and the shaft seal into one part, which can simplify the installation structure, make the structure more compact, and improve the assembly efficiency. As Figure 2 shown, a positioning stop 33 is provided on the outer periphery of the diffuser 3 for positioning and installing with the housing 6, and then accurately positioned with a pin. Thus, the coaxiality of the shaft seal part on the diffuser and the perpendicularity of the thrust bearing fixing surface are ensured on one part. This not only reduces the processing difficulty, but also greatly reduces the assembly cumulative error. The shaft seal with high coaxiality requirements and the thrust bearing with high perpendicularity requirements share the positioning stop 33 and the pin for positioning, unifying the assembly reference, reducing the assembly difficulty, and improving the assembly accuracy. It can not only improve the perpendicularity of the thrust bearing fixing surface to ensure the working performance of the thrust bearing, but also improve the coaxiality of the first axial comb seal structure 35 to prevent the comb teeth from wearing and affecting the sealing performance.

[0081] In terms of material selection, the material of the diffuser 3 should be softer than that of the thrust disk 4. Generally, aluminum can be selected for the diffuser 3, and 45 steel or 40Cr can be selected for the thrust disk. In this way, if the first axial comb seal structure 35 on the diffuser 3 wears with the main shaft 1, the comb teeth will wear first to prevent the main shaft 1 from wearing.

[0082] Still referring to Figure 6, the first axial labyrinth seal structure 35, the radial labyrinth seal structure 21 and the second axial labyrinth seal structure 23 are arranged simultaneously, and the radial labyrinth seal structure 21 is located radially between the first axial labyrinth seal structure 35 and the second axial labyrinth seal structure 23. This arrangement can make the air flow form a tortuous flow path, optimize the air flow deceleration and pressure reduction effect, and improve the sealing performance.

[0083] Specifically, a boss is provided at one end of the impeller 2 facing the diffuser 3, the boss extends into the groove of the diffuser 3, and the radial labyrinth seal structure 21 is arranged at the end of the boss, so as to further extend the gas flow path while achieving radial sealing, optimize the air flow deceleration and pressure reduction effect, and improve the sealing performance.

[0084] In addition, the present invention also provides an air conditioning device, including the centrifugal compressor of the above embodiment. The centrifugal compressor of the present invention can withstand axial forces in two directions, ensure the operation stability of the compressor under all working conditions and during reverse rotation; moreover, it can accurately ensure the assembly clearance of the thrust bearing, ensure the performance of the thrust bearing, thereby improving the operation stability of the compressor. These two factors can both improve the working stability and reliability of the air conditioning device.

[0085] The above has introduced in detail a centrifugal compressor and an air conditioning device provided by the present invention. Specific embodiments are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A centrifugal compressor, characterized in that, Comprising: A housing (6), including an intermediate housing (62); A main shaft (1), with radial bearings (8) provided at both ends thereof; A diffuser (3), with a first thrust bearing (10) provided at one end of the diffuser (3) away from the diffusing surface; Two support assemblies (5), with a second thrust bearing (10') provided at one end of the support assembly (5) facing the diffuser (3); And A thrust disc (4), configured to rotate together with the main shaft (1), and axially located between the diffuser (3) and the support assembly (5). The thrust disc (4) has a thrust portion (41), and the gaps between both sides of the thrust portion (41) and the first thrust bearing (10) and the second thrust bearing (10') are defined by the mutual abutment of the diffuser (3) and the support assembly (5); Wherein, the support assembly (5) includes: A fixing plate (51), with the second thrust bearing (10') provided on the side of the fixing plate (51) facing the diffuser (3), and the fixing plate (51) is further used to limit the axial displacement of the radial bearing (8) towards the diffuser (3) side; and A bearing support (52), provided on the side of the fixing plate (51) away from the diffuser (3). The first end of the bearing support (52) is connected to the fixing plate (51), and the second end is connected to the intermediate housing (62) by a pin, for supporting the main shaft (1) through the radial bearing (8). The bearing support (52) and the fixing plate (51) adopt a split structure; During processing, first fix the two bearing supports (52) to the intermediate housing (62), then position the intermediate housing (62) and the two bearing supports (52) as an integral assembly on the processing equipment, and machine the end faces of the two bearing supports (52) that cooperate with the fixing plate (51) to ensure the perpendicularity of the second thrust bearing (10') and the radial bearing (8). Then, starting from one side, machine the mounting holes (522) of the two bearing supports (52) in sequence to ensure the coaxiality of the two radial bearings (8).

2. The centrifugal compressor according to claim 1, characterized in that, A first groove (31) is provided at one end of the diffuser (3) away from the diffusing surface. The first thrust bearing (10) is provided at the bottom of the first groove (31) along the axial direction, and the thrust portion (41) is located in the first groove (31).

3. The centrifugal compressor according to claim 1, characterized in that, A positioning ring (511) is provided at one end of the fixing plate (51) facing the bearing support (52). An annular second groove (521) is provided on the bearing support (52). The positioning ring (511) is embedded in the second groove (521), and the inner wall (512) of the positioning ring (511) cooperates with the outer wall of a partial length section of the radial bearing (8).

4. The centrifugal compressor according to claim 1, characterized in that, The outer profile dimensions of the bearing support (52) gradually increase from the first end to the second end.

5. The centrifugal compressor according to claim 1, characterized in that, A vent hole (526) is provided on the bearing support (52) to make the working environment of the radial bearing (8) the same as that of the first thrust bearing (10) and the second thrust bearing (10').

6. The centrifugal compressor according to claim 1, characterized in that, It further includes an impeller (2) and a locking component (9). A cavity (11) is provided in the main shaft (1) and a shaft core (12) is provided at the center. The end of the shaft core (12) extends out of the end of the main shaft (1). The impeller (2) is sleeved on the outer end of the shaft core (12), and the impeller (2) is locked on the shaft core (12) by the locking component (9), and the impeller (2) is located outside the diffuser (3).

7. The centrifugal compressor according to claim 2, characterized in that, The first thrust bearing (10) is directly fixed to the bottom of the first groove (31).

8. The centrifugal compressor according to claim 2, wherein, The thrust disc (4) further includes a connecting portion (42). The connecting portion (42) is connected to the thrust portion (41) and is sleeved on the main shaft (1). A through hole (34) is provided at the bottom of the first groove (31), and the connecting portion (42) is embedded in the through hole (34).

9. The centrifugal compressor according to claim 8, characterized in that, It further includes an impeller (2) provided at the end of the main shaft (1), and the impeller (2) is located outside the diffuser (3). The side wall of the through hole (34) is provided with a first axial comb tooth sealing structure (35); and / or The end of the impeller (2) facing the diffuser (3) is provided with a radial comb tooth sealing structure (21); and / or The impeller (2) has an embedding portion (22) embedded in the diffuser (3), and a second axial comb tooth sealing structure (23) is provided along the length direction on the embedding portion (22).

10. The centrifugal compressor according to claim 9, characterized in that, The first axial comb tooth sealing structure (35), the radial comb tooth sealing structure (21) and the second axial comb tooth sealing structure (23) are provided simultaneously, and the radial comb tooth sealing structure (21) is located radially between the first axial comb tooth sealing structure (35) and the second axial comb tooth sealing structure (23).

11. The centrifugal compressor according to claim 1, characterized in that, The first thrust bearing (10), the second thrust bearing (10') and / or the radial bearing (8) is an air suspension bearing.

12. An air conditioning device, characterized in that, It includes the centrifugal compressor according to any one of claims 1 to 11.

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