Dynamic pressure gas suspension centrifugal refrigeration compressor bearing gas seal structure and compressor

Abstract

The present application discloses a dynamic pressure gas suspension centrifugal refrigeration compressor bearing gas seal structure and a compressor, the dynamic pressure gas suspension centrifugal refrigeration compressor bearing gas seal structure comprises: a motor housing; a motor rotor, which is arranged in the motor housing; and an impeller, a bearing body and a comb-tooth seal structure which are arranged in sequence from the outside to the inside; wherein the impeller is arranged at the end of the motor rotor, and the air intake part is located on the side of the impeller away from the motor rotor; the comb-tooth seal structure and the bearing body are both sleeved on the motor rotor, and the bearing body is provided with a plurality of axial air supply grooves along the circumferential direction, and an axial gap which is connected to the axial air supply groove is provided between the bearing body and the comb-tooth seal structure, so as to form an air seal structure located in the axial gap. The present application achieves the technical effect of effectively preventing the liquid refrigerant in the motor housing from entering the bearing body, thereby solving the problem in the related art that the liquid refrigerant in the motor cavity is easy to enter the dynamic pressure gas suspension bearing from the motor cavity, causing the bearing to become unstable.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular to a bearing gas seal structure and a compressor of a dynamic pressure gas suspension centrifugal refrigeration compressor. Background Art

[0002] Traditional dynamic pressure gas suspension centrifugal refrigeration compressors have gas leakage problems when working. The gas leakage problem comes from the axial gap behind the impeller. There are many tiny axial gaps behind the impeller leading to the motor cavity, and the leaked gas will eventually flow into the motor cavity. The leaked gas will increase the power consumption of the compressor and reduce the efficiency. To solve this problem, the relevant technology uses a comb tooth structure for sealing. The leaked gas is throttled many times in the process of passing through the comb tooth structure, and the pressure is reduced.

[0003] like Figure 1 As shown, the hydrodynamic air suspension bearing is located near the motor cavity, and the radial comb seal is located near the impeller. The high-pressure gas behind the impeller passes through the comb seal and the pressure drops to a lower level. Then, it passes through the hydrodynamic bearing and enters the motor cavity. The refrigerant pressure and flow rate are low at the entire hydrodynamic air suspension bearing. Since the motor needs liquid refrigerant cooling during operation, there is a large amount of liquid refrigerant in the motor cavity, which is easier to enter the hydrodynamic air suspension bearing from the motor cavity, causing the bearing to become unstable. Summary of the invention

[0004] The main purpose of the present application is to provide a dynamic pressure gas suspension centrifugal refrigeration compressor bearing air seal structure and compressor, so as to solve the problem in the related art that the liquid refrigerant in the motor cavity can easily enter the dynamic pressure gas suspension bearing from the motor cavity, causing bearing instability.

[0005] In order to achieve the above-mentioned purpose, the present application provides a dynamic pressure gas suspension centrifugal refrigeration compressor bearing air seal structure, which includes: a motor housing; a motor rotor, which is arranged in the motor housing; and an impeller, a bearing body and a comb tooth sealing structure arranged in sequence from the outside to the inside; wherein the impeller is arranged at the end of the motor rotor, and the air intake part is located on the side of the impeller away from the motor rotor; the comb tooth sealing structure and the bearing body are both sleeved on the motor rotor, and the bearing body is provided with a plurality of axial air supply grooves along the circumferential direction, and an axial gap connected to the axial air supply groove is provided between the bearing body and the comb tooth sealing structure, which is used to form an air seal structure located in the axial gap.

[0006] Furthermore, the bearing body is configured as a hydrodynamic air suspension bearing, and the axial air supply groove is provided on the outer ring of the hydrodynamic air suspension bearing.

[0007] Furthermore, the circumferential angle between adjacent axial air supply grooves is 30° to 60°.

[0008] Furthermore, the axial gap is 20 to 50 μm.

[0009] Furthermore, the diameter of the axial air supply groove is 20-100 μm.

[0010] Furthermore, the end face of the comb-tooth sealing structure is fixedly connected to the end face of the motor housing; an installation hole matching the bearing body is provided at one end of the comb-tooth sealing structure close to the bearing body, and the bearing body is arranged in the installation hole.

[0011] Furthermore, the mounting hole is arranged as a countersunk hole, and the annular side of the bearing body is arranged closely against the annular side of the countersunk hole.

[0012] Furthermore, the bearing air seal structure of the dynamic pressure gas suspension centrifugal refrigeration compressor includes: the two impellers, as the first-stage impeller and the second-stage impeller, are respectively connected to the two ends of the motor rotor along the axial direction; the two comb tooth sealing structures, as the left-end comb tooth sealing structure and the right-end comb tooth sealing structure, are respectively located on the side of the first-stage impeller and the second-stage impeller adjacent to the motor rotor, and are fixedly connected to the two ends of the motor housing; the two bearing bodies, as the left-end bearing body and the right-end bearing body, are respectively arranged in the mounting holes of the left-end comb tooth sealing structure and the right-end comb tooth sealing structure.

[0013] According to another aspect of the present application, a compressor is provided, which includes a dynamic pressure gas suspension centrifugal refrigeration compressor bearing gas seal structure.

[0014] In the embodiment of the present application, a motor housing is provided; a motor rotor is provided in the motor housing; and an impeller, a bearing body and a comb-tooth sealing structure are provided in sequence from the outside to the inside; wherein the impeller is provided at the end of the motor rotor, and the air intake part is located on the side of the impeller away from the motor rotor; the comb-tooth sealing structure and the bearing body are both sleeved on the motor rotor, the bearing body is provided with a plurality of axial air supply grooves along the circumferential direction, and an axial gap connected to the axial air supply groove is provided between the bearing body and the comb-tooth sealing structure, which is used to form an air seal structure located in the axial gap. The purpose of allowing the high-pressure gas behind the impeller to enter the axial gap through the axial air supply groove on the bearing body and forming an air seal structure in the axial gap is achieved, thereby achieving the technical effect of effectively blocking the liquid refrigerant in the motor housing from entering the bearing body, thereby solving the problem in the related art that the liquid refrigerant in the motor cavity is easier to enter the dynamic pressure air suspension bearing from the motor cavity, causing the bearing to become unstable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The schematic embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0016] Figure 1 It is a structural schematic diagram of a compressor in the related art;

[0017] Figure 2 is a schematic diagram of the structure according to an embodiment of the present application;

[0018] Figure 3 yes Figure 2 A schematic diagram of the enlarged structure of the local A in the middle;

[0019] Among them, 1 is an impeller, 2 is a bearing body, 3 is an axial air supply groove, 4 is an axial gap, 5 is a comb seal structure, 6 is a motor rotor, 7 is a motor housing, 8 is a motor stator, and 9 is a groove. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0021] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so as to describe the embodiments of the present application described herein.

[0022] In this application, the terms "upper", "lower", "inner", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0023] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0024] In addition, the terms "disposed", "provided with", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0025] In addition, the term "plurality" shall mean two or more.

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] like Figures 2 to 3 As shown, an embodiment of the present application provides a dynamic pressure gas suspension centrifugal refrigeration compressor bearing air seal structure, which includes: a motor housing 7, which can be an irregular cavity part and can be formed by casting, and plays the role of support, protection, shock absorption, etc.; a motor rotor 6, which is arranged in the motor housing 7; and an impeller 1, a bearing body 2 and a comb-tooth sealing structure 5 arranged in sequence from the outside to the inside; wherein the impeller 1 is arranged at the end of the motor rotor 6, and the air intake part is located on the side of the impeller 1 away from the motor rotor 6; the comb-tooth sealing structure 5 and the bearing body 2 are both sleeved on the motor rotor 6, and the bearing body 2 is provided with a plurality of axial air supply grooves 3 along the circumferential direction, and an axial gap 4 connected to the axial air supply groove 3 is provided between the bearing body 2 and the comb-tooth sealing structure 5, which is used to form an air seal structure located in the axial gap 4.

[0028] In this embodiment, in order to drive the motor rotor 6 to rotate, a motor stator 8 including a winding can be arranged in the motor housing 7, which can provide a magnetic field to the motor rotor 6, so that the motor rotor 6 rotates at high speed in the magnetic field. The motor stator 8 and the motor rotor 6 can be cooled by a refrigerant liquid inside the motor housing 7. Compared with the dynamic pressure gas suspension centrifugal refrigeration compressor structure in the related art, in this embodiment, an axial air supply groove 3 is opened on the bearing body 2, and the positions of the bearing body 2 and the comb-tooth sealing structure 5 are adjusted so that the comb-tooth sealing structure 5 is located behind the bearing body 2, and an axial gap 4 is provided between the bearing body 2 and the comb-tooth sealing structure 5.

[0029] In order to facilitate the rotation of the impeller 1, there is a gap between the side of the impeller 1 close to the motor housing 7 and the bearing body 2 and the comb-tooth sealing structure 5, and the gap is connected to the axial air supply groove 3 and the axial gap 4 in the bearing body 2. Therefore, the high-pressure gas generated by the impeller 1 during the rotation process flows into the axial air supply groove 3 of the bearing body 2 through the gap, and flows into the axial gap 4 between the bearing body 2 and the comb-tooth sealing structure 5, forming an annular air seal structure in the axial gap 4. The air seal structure isolates the end face of the comb-tooth sealing structure 5 from the bearing body 2, that is, the liquid refrigerant inside the motor housing 7 cannot pass through the comb-tooth sealing structure 5 and enter the bearing body 2. In addition, the air seal structure can act on the bearing body 2 to offset the axial force that causes axial movement, so that the motor rotor 6 and the impeller 1 are balanced in the axial direction.

[0030] like Figures 2 to 3 As shown, the bearing body 2 is configured as a hydrodynamic air suspension bearing, and the axial air supply groove 3 is provided on the outer ring of the hydrodynamic air suspension bearing. While ensuring the structural stability of the hydrodynamic air suspension bearing, the air seal structure in the axial gap 4 is stable. In this embodiment, the circumferential angle between adjacent axial air supply grooves 3 is 30° to 60°, preferably 45°, the axial gap 4 is 20 to 50 μm, and the diameter of the axial air supply groove 3 is 20 to 100 μm.

[0031] like Figures 2 to 3 As shown, the end face of the comb-teeth seal structure 5 is fixedly connected to the end face of the motor housing 7; to improve the structural compactness of the compressor, a mounting hole matching the bearing body 2 is provided at one end of the comb-teeth seal structure 5 close to the bearing body 2, and the bearing body 2 is arranged in the mounting hole. To make the operation of the bearing body 2 more stable, the mounting hole is arranged as a countersunk hole, and the bearing body 2 as a whole has a countersunk structure matching the countersunk hole, and the ring side of the bearing body 2 is arranged closely to the ring side of the countersunk hole.

[0032] Furthermore, in this embodiment, an annular groove 9 is also provided on the side of the comb-tooth seal structure 5 close to the impeller 1, and the motor rotor 6 passes through the groove 9, and the end face of the bearing body 2 close to the impeller 1 is flush with the bottom face of the groove 9. Part of the structure of the impeller 1 is located in the groove 9, and there is a gap between the end face of the impeller 1 adjacent to the bearing body 2 and the bottom face of the groove 9, and there is also a gap between the partial annular surface of the impeller 1 and the annular surface of the groove 9. Therefore, when the impeller 1 rotates, the high-pressure gas first enters the gap between the groove 9 and the impeller 1, and forms a first-layer gas-sealing structure, and then the gas enters the axial gap 4 between the bearing body 2 and the comb-tooth seal structure 5 through the axial gas supply groove 3, forming a second-layer gas-sealing structure. Both the first-layer gas-sealing structure and the second-layer gas-sealing structure have the technical effect of reducing the entry of external gas into the motor housing 7, and the second-layer gas-sealing structure also has the technical effect of preventing the liquid refrigerant in the motor housing 7 from entering the bearing body 2.

[0033] like Figures 2 to 3As shown, the bearing air seal structure of the dynamic pressure gas suspension centrifugal refrigeration compressor includes: the two impellers, as the first-stage impeller and the second-stage impeller, are respectively connected to the two ends of the motor rotor along the axial direction; the two comb tooth sealing structures, as the left-end comb tooth sealing structure and the right-end comb tooth sealing structure, are respectively located on the side of the first-stage impeller and the second-stage impeller adjacent to the motor rotor, and are fixedly connected to the two ends of the motor housing; the two bearing bodies, as the left-end bearing body and the right-end bearing body, are respectively arranged in the mounting holes of the left-end comb tooth sealing structure and the right-end comb tooth sealing structure.

[0034] According to another aspect of the present application, a compressor is provided, which includes a dynamic pressure gas suspension centrifugal refrigeration compressor bearing gas seal structure.

[0035] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Within the spirit and principle of the present application, any modification, equivalent replacement, improvement, etc. made shall be included in the protection scope of the present application.

Claims

1. A dynamic pressure gas suspension centrifugal refrigeration compressor bearing gas seal structure, characterized in that: include: Motor housing; The motor rotor is arranged in the motor housing; and the impeller, the bearing body and the comb seal structure are arranged in sequence from the outside to the inside; wherein, The impeller is arranged at the end of the motor rotor, and the air intake part is located at a side of the impeller away from the motor rotor; The comb-teeth sealing structure and the bearing body are both sleeved on the motor rotor, the bearing body is provided with a plurality of axial air supply grooves along the circumferential direction, and an axial gap connected to the axial air supply groove is provided between the bearing body and the comb-teeth sealing structure, so as to form an air sealing structure located in the axial gap; The bearing body is configured as a dynamic pressure air suspension bearing, and the axial air supply groove is disposed on the outer ring of the dynamic pressure air suspension bearing; The end surface of the comb-tooth sealing structure is fixedly connected to the end surface of the motor housing; an installation hole matching the bearing body is provided at one end of the comb-tooth sealing structure close to the bearing body, and the bearing body is arranged in the installation hole.

2. The dynamic pressure air suspension centrifugal refrigeration compressor bearing air seal structure according to claim 1 is characterized in that: The circumferential angle between adjacent axial air supply grooves is 30° to 60°.

3. The dynamic pressure air suspension centrifugal refrigeration compressor bearing air seal structure according to claim 1, characterized in that: The axial gap is 20-50 μm.

4. The dynamic pressure air suspension centrifugal refrigeration compressor bearing air seal structure according to claim 3 is characterized in that: The diameter of the axial air supply groove is 20-100 μm.

5. The dynamic pressure air suspension centrifugal refrigeration compressor bearing air seal structure according to claim 1, characterized in that: The mounting hole is configured as a countersunk hole, and the annular side of the bearing body is configured to be tightly attached to the annular side of the countersunk hole.

6. The dynamic pressure air suspension centrifugal refrigeration compressor bearing air seal structure according to claim 1, characterized in that: include: The two impellers, serving as a primary impeller and a secondary impeller, are respectively connected to two ends of the motor rotor along the axial direction; The two comb-tooth sealing structures, as a left-end comb-tooth sealing structure and a right-end comb-tooth sealing structure, are respectively located on one side of the first-stage impeller and the second-stage impeller adjacent to the motor rotor, and are fixedly connected to both ends of the motor housing; The two bearing bodies, serving as the left-end bearing body and the right-end bearing body, are respectively arranged in the mounting holes of the left-end comb-tooth sealing structure and the right-end comb-tooth sealing structure.

7. A compressor, characterized in that: It comprises the bearing gas seal structure of the dynamic pressure gas suspension centrifugal refrigeration compressor as described in any one of claims 1 to 6.

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