Gas bearing and compressor

Abstract

The invention provides a gas bearing and a compressor. The gas bearing comprises a bearing support; the first bearing shell is arranged in the bearing support, and a first-stage damping structure is arranged between the outer wall of the first bearing shell and the inner wall of the bearing support; and the second bearing shell is arranged in the first bearing sleeve shell, and a secondary damping structure is arranged between the outer wall of the second bearing shell and the inner wall of the first bearing shell. According to the gas bearing and the compressor, the first-stage damping structure and the second-stage damping structure are arranged, so that impact, loads and the like borne by the rotor can be buffered, and the influence of the impact and the loads on the bearing and the compressor is reduced; in addition, the problem of local abrasion caused by uneven stress at the two ends of the bearing due to inclination of the rotor can be further reduced, and the reliability and stability of the gas bearing and the compressor are further improved.

Description

Technical Field

[0001] The invention relates to the technical field of compression equipment, in particular to a gas bearing and a compressor. Background Art

[0002] Centrifugal chillers are widely used in large public buildings, comfort air conditioning, data centers, district energy and heat pumps, and their energy efficiency has a significant impact on the energy consumption of public buildings. Compressors, as a general power source, are widely used in centrifugal chillers.

[0003] For air-suspended centrifugal compressors, air-suspended bearings are the core components that determine whether they can operate safely and stably. The stability and reliability of air-suspended bearings directly affect the performance of centrifugal compressors. Compared with dynamic pressure air-suspended bearings, static pressure air-suspended bearings have received extensive attention for their strong bearing capacity. The reliability and stability of static pressure air suspension are affected by many factors, such as support method, rotation speed, air supply flow rate, etc., among which the structure of the bearing has an important influence on its performance. The rotor assembly will receive certain loads and radial impacts during operation. Large impact loads will affect the operating performance and reliability of the bearings. In severe cases, the shaft will get stuck and the motor will burn out, which will affect the operating performance and life of the compressor. Summary of the invention

[0004] In order to solve the technical problem in the prior art that static pressure air suspension bearings may get stuck when subjected to impact or load, thus affecting the reliability of the compressor, a gas bearing and a compressor are provided with a secondary damping structure for buffering to improve the impact resistance and reliability.

[0005] A gas bearing, comprising:

[0006] Bearing support;

[0007] A first bearing shell, wherein the first bearing shell is disposed in the bearing support, and a primary damping structure is disposed between an outer wall of the first bearing shell and an inner wall of the bearing support;

[0008] The second bearing shell is arranged in the first bearing sleeve shell, and a secondary damping structure is arranged between the outer wall of the second bearing shell and the inner wall of the first bearing shell.

[0009] The primary damping structure includes a wave foil structure, which is annularly surrounded on the first bearing shell, and the wave crest of the wave foil structure abuts and cooperates with the bearing support, and the wave trough of the wave foil structure abuts and cooperates with the first bearing shell.

[0010] The corrugated foil structure has a first end and a second end in a length direction, the first end is arranged on the bearing support, and the second end is movably located between the bearing support and the first bearing shell.

[0011] The thickness L3 of the corrugated foil structure has a numerical range of 0.1 mm to 0.5 mm; and / or the pitch L4 between two adjacent wave crests of the corrugated foil structure has a numerical range of 2 mm to 8 mm; and / or the single wave height L5 between the wave crest and the wave trough of the corrugated foil structure has a numerical range of 1.5 mm to 3 mm.

[0012] The number of the bump foil structures is at least two, and all the bump foil structures are arranged in parallel along the axial direction of the gas bearing.

[0013] There is a seam spacing between two adjacent bump foil structures, and the relationship among the seam spacing L6, the number n of the bump foil structures and the axial length L2 of the gas bearing is: L2=L6*n*(20-50).

[0014] The secondary damping structure includes a damping ring, which surrounds the outer wall of the second bearing shell, and the outer wall of the damping ring is in abutment with the first bearing shell.

[0015] The number of the damping rings is at least two, and all the damping rings are arranged in parallel along the axial direction of the gas bearing.

[0016] The gas bearing has a first portion, a middle portion, and a second portion distributed in an axial direction, at least one damping ring is located at the first portion, and at least one damping ring is located at the second portion.

[0017] The thickness L1 of the damping ring has a value ranging from 2.6 mm to 5.3 mm.

[0018] The gas bearing further includes a porous structure disposed in the second bearing housing.

[0019] The gas bearing further comprises a retaining ring, which is arranged at the end of the first bearing shell and abuts against the second bearing shell; or, the retaining ring is arranged at the end of the second bearing shell and abuts against the first bearing shell.

[0020] A compressor comprises the above-mentioned gas bearing.

[0021] The gas bearing and compressor provided by the present invention can buffer the impact, load, etc. exerted on the rotor by providing a primary damping structure and a secondary damping structure, thereby reducing the impact and load on the bearing and the compressor, and can further reduce the problem of local wear caused by uneven force on both ends of the bearing due to the inclination of the rotor, thereby further improving the reliability and stability of the gas bearing and the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A cross-sectional view of a gas bearing provided by an embodiment of the present invention;

[0023] Figure 2 A side view of a gas bearing provided by an embodiment of the present invention;

[0024] Figure 3 A schematic structural diagram of a corrugated foil structure provided in an embodiment of the present invention;

[0025] Figure 4 Another schematic structural diagram of a corrugated foil structure provided by an embodiment of the present invention;

[0026] In the figure:

[0027] 1. Bearing support; 2. First bearing housing; 3. Second bearing housing; 4. Corrugated foil structure; 5. Damping ring; 6. Porous structure; 7. Retaining ring. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention 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 terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0032] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] For air-suspended centrifugal compressors, air-suspended bearings are the core components that determine whether they can operate safely and stably. The stability and reliability of air-suspended bearings directly affect the performance of centrifugal compressors. Compared with dynamic pressure air-suspended bearings, static pressure air-suspended bearings have received extensive attention for their strong bearing capacity. The reliability and stability of static pressure air suspension are affected by many factors, such as support method, rotation speed, air supply flow rate, etc., among which the structure of the bearing has an important influence on its performance. The rotor assembly will receive certain loads and radial impacts during operation. Large impact loads will affect the operating performance and reliability of the bearings. In severe cases, the shaft will get stuck and the motor will burn out, which will affect the operating performance and life of the compressor.

[0034] To this end, the present application provides a Figures 1 to 4The gas bearing shown comprises: a bearing support 1; a first bearing shell 2, wherein the first bearing shell 2 is arranged in the bearing support 1, and a primary damping structure is arranged between the outer wall of the first bearing shell 2 and the inner wall of the bearing support 1; and a second bearing shell 3, wherein the second bearing shell 3 is arranged in the first bearing sleeve shell, and a secondary damping structure is arranged between the outer wall of the second bearing shell 3 and the inner wall of the first bearing shell 2. By arranging the primary damping structure and the secondary damping structure, the impact and load on the rotor can be buffered, and the impact of the impact and load on the bearing and the compressor can be reduced. In addition, the problem of local wear caused by uneven force on both ends of the bearing due to the inclination of the rotor can be further reduced, and the reliability and stability of the gas bearing and the compressor can be further improved.

[0035] When the gas bearing is used, the gas bearing can generate an air film between its second bearing shell 3 and the rotor, thereby supporting the rotor. When the rotor is subjected to an impact load, the impact load on the rotor can act on the second bearing shell 3 through the air film, and the primary damping structure and the secondary damping structure can be deformed accordingly, thereby buffering and offsetting the impact load. In particular, when the rotor is subjected to an overturning load, axial tilt will occur. The axial tilt will cause local contact between the rotor and the gas bearing at the end of the gas bearing and cause severe wear. At this time, the primary damping structure and the secondary damping structure can be deformed accordingly, so that the gas bearing can adapt to the inclination of the rotor, avoiding further rigid contact between the rotor and the gas bearing to increase the degree of wear, thereby achieving the purpose of ensuring the reliability and stability of the gas bearing and the compressor.

[0036] As an embodiment, the primary damping structure includes a wave foil structure 4, which is annularly wrapped around the first bearing shell 2, and the wave crest of the wave foil structure 4 abuts and fits with the bearing support 1, and the wave trough of the wave foil structure 4 abuts and fits with the first bearing shell 2. The shape of the wave foil structure 4 allows it to deform with the change of the wave crest and the wave trough when subjected to a force, thereby producing a damping buffering effect, achieving the effect of buffering and offsetting the impact and load on the rotor. Among them, the wave foil structure 4 is annularly wrapped around the first bearing shell 2, so that when the wave foil structure 4 is subjected to the impact and load transmitted from the rotor, the wave foil structure 4 can extend along the annular shape, thereby ensuring that the deformation of the wave foil structure 4 is reliable and the buffering of the impact and load is reliable.

[0037] The bump foil structure 4 has a first end and a second end in the length direction, the first end is arranged on the bearing support 1, and the second end is movably located between the bearing support 1 and the first bearing housing 2. The free movement of the second end enables the bump foil structure 4 to be reliably deformed to ensure the damping effect of the bump foil structure 4. When the bump foil structure 4 is deformed, the second end will approach the first end, and after the force on the bump foil structure 4 disappears, the second end moves away from the first end.

[0038] The thickness L3 of the bump foil structure 4 has a numerical range of 0.1 mm to 0.5 mm. When the thickness L3 of the bump foil structure 4 is too large, the force required for the bump foil structure 4 to deform is large, and the reaction rate to the rotor being subjected to an impact load is low. When the thickness L3 of the bump foil structure 4 is too small, the structural strength of the bump foil structure 4 is poor, and at the same time, the structural strength between the bearing support 1 and the first bearing housing 2 cannot reliably support the rotor, which will affect the working reliability of the gas bearing and the compressor. Only when the thickness L3 of the bump foil structure 4 is between 0.1 mm and 0.5 mm, can the deformation reliability and structural strength of the bump foil structure 4 be guaranteed, thereby ensuring the structural reliability of the gas bearing and the compressor.

[0039] The pitch L4 between two adjacent wave crests of the wave foil structure 4 has a numerical range of 2 mm to 8 mm. When the pitch L4 of the wave foil structure 4 is too large, the bearing capacity of the wave foil structure 4 is reduced; and when the pitch L4 of the wave foil structure 4 is too small, the force required for the wave foil structure 4 to deform is large, and the reaction rate to the impact load on the rotor is low. Only when the pitch L4 of the wave foil structure 4 is between 2 mm and 8 mm, can the deformation reliability and structural strength of the wave foil structure 4 be guaranteed, thereby ensuring the reliability of the gas bearing and the compressor mechanism.

[0040] The value range of the single wave height L5 between the wave crest and the wave trough of the wave foil structure 4 is 1.5 mm to 3 mm. When the single wave height L5 of the wave foil structure 4 is too large, the deformation that the wave foil structure 4 can produce is large, but the thickness of the wave foil structure 4 is too large to affect the overall volume of the gas bearing; and when the single wave height L5 of the wave foil structure 4 is too small, the deformation that the wave foil structure 4 can produce is small, so that the bearing capacity of the wave foil structure 4 is reduced. Only when the single wave height L5 of the wave foil structure 4 is between 1.5 mm and 3 mm, can the deformation reliability and structural strength of the wave foil structure 4 be guaranteed, thereby ensuring the reliability of the gas bearing and the compressor.

[0041] The number of the bump foil structures 4 is at least two, and all the bump foil structures 4 are arranged in parallel along the axial direction of the gas bearing. By providing a plurality of bump foil structures 4, it is possible to ensure that the plurality of bump foil structures 4 are mutually redundant, thereby improving the reliability of the gas bearing, and the plurality of bump foil structures 4 can be used to increase the contact area, thereby absorbing more impact and load.

[0042] There is a joint spacing between two adjacent bump foil structures 4. By setting the joint spacing, structural interference between the two adjacent bump foil structures 4 is avoided, and the relative independence of the bump foil structures 4 is ensured, thereby improving the reliability of the gas bearing.

[0043] The relationship between the joint spacing L6, the number n of the bump foil structures 4 and the axial length L2 of the gas bearing is: L2 = L6*n*(20-50); when the joint spacing L6 is too large, the number of bump foil structures 4 and the size of a single bump foil structure 4 will be reduced, and the bearing capacity of the bump foil structure 4 will be reduced; when the joint spacing L6 is too small, structural interference is easily generated between two adjacent bump foil structures 4, resulting in reduced reliability of the gas bearing; when the number n of the bump foil structures 4 is too large, the reliability of the bump foil structures 4 will be reduced. The number and size of a single bump foil structure 4 are set to reduce the bearing capacity of the bump foil structure 4. When the number n of the bump foil structures 4 is too small, the width of a single bump foil structure 4 is too large, which makes the reaction rate of the bump foil structure 4 to impact and load lower. Only when the relationship between the joint spacing L6, the number n of the bump foil structures 4 and the axial length L2 of the gas bearing meets the condition L2=L6*n*(20~50), that is, even if the joint spacing L6 and the number n of the bump foil structures 4 are inversely proportional, can the reliability and bearing capacity of the gas bearing be guaranteed.

[0044] The secondary damping structure includes a damping ring 5, which surrounds the outer wall of the second bearing housing 3, and the outer wall of the damping ring 5 is in abutment with the first bearing housing 2. The damping ring 5 is used to achieve a certain relative movement between the first bearing housing 2 and the second bearing housing 3, further improving the gas bearing's adaptability to the impact and load on the rotor, and improving the supporting effect of the gas bearing.

[0045] The number of the damping rings 5 ​​is at least two, and all the damping rings 5 ​​are arranged in parallel along the axial direction of the gas bearing. By providing multiple damping rings 5, the damping effect of the secondary damping structure can be further improved. At the same time, the relative movement accuracy between the first bearing housing 2 and the second bearing housing 3 can be improved by different deformations of the damping rings 5 ​​at different positions, thereby ensuring the reliability and load-bearing capacity of the gas bearing.

[0046] Preferably, the gas bearing has a first portion, a middle portion, and a second portion distributed in the axial direction, at least one damping ring 5 is located at the first portion, and at least one damping ring 5 is located at the second portion. When the rotor is impacted, loaded, and tilted, the rotor will inevitably tilt relative to the axial direction. For example, when the left end of the rotor tilts downward, the lower part of the damping ring 5 in the first portion on the left side is squeezed and deformed, and the upper part of the damping ring 5 in the second portion is also squeezed and deformed. However, the damping ring 5 in the first portion and the damping ring 5 in the second portion are located at both ends of the gas bearing, which further avoids direct rigid contact between the rotor and the gas bearing, thereby improving the support reliability of the gas bearing.

[0047] The thickness L1 of the damping ring 5 has a numerical range of 2.6 mm to 5.3 mm. When the thickness L1 of the damping ring 5 is too small, the damping effect of the damping ring 5 is poor, and when the thickness L1 of the damping ring 5 is too large, the size of the gas bearing is too large, and the deformation allowed by the gas bearing is exceeded. Only when the thickness L1 of the damping ring 5 is between 2.6 mm and 5.3 mm, the reliability and load-bearing capacity of the gas bearing can be guaranteed.

[0048] like Figure 2 As shown, a receiving groove is provided on the inner wall of the first bearing shell 2, and the damping ring 5 is arranged in the receiving groove, and part of the damping ring 5 protrudes from the receiving groove. The receiving groove is used to fix the setting position of the damping ring 5 to ensure that the damping ring 5 is reliably fixed, thereby ensuring the structural reliability of the gas bearing.

[0049] The gas bearing further includes a porous structure 6, which is arranged in the second bearing housing 3. External pressure gas supplies gas to the porous structure 6 through gas channels arranged on the bearing support 1, the first bearing housing 2, and the second bearing housing 3, thereby forming an air film between the porous structure 6 and the rotor, achieving the purpose of supporting the rotor with the air film, and the porous structure 6 can form a reliable air film on the surface of the rotor, thereby improving the support reliability of the rotor. Preferably, the porous structure 6 can be selected from graphite, ceramics, sintered materials, etc.

[0050] The porous structure 6 and the second bearing housing 3 are fixedly connected by glue.

[0051] The gas bearing further includes a retaining ring 7, which is disposed at the end of the first bearing housing 2 and abuts against the second bearing housing 3. The retaining ring 7 is used to restrict the second bearing housing 3 to prevent the first bearing housing 2 and the second bearing housing 3 from axially moving relative to each other, thereby ensuring the structural reliability of the gas bearing.

[0052] The retaining ring 7 is arranged at the end of the second bearing housing 3, and the retaining ring 7 is in abutment with the first bearing housing 2. The retaining ring 7 is used to restrict the first bearing housing 2 to prevent the first bearing housing 2 and the second bearing housing 3 from axially moving relative to each other, thereby ensuring the structural reliability of the gas bearing.

[0053] A compressor comprises the above-mentioned gas bearing.

[0054] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A gas bearing, characterized in that: include: Bearing support (1); A first bearing shell (2), wherein the first bearing shell (2) is arranged in the bearing support (1), and a primary damping structure is arranged between an outer wall of the first bearing shell (2) and an inner wall of the bearing support (1); A second bearing shell (3), wherein the second bearing shell (3) is arranged inside the first bearing sleeve shell, and a secondary damping structure is arranged between the outer wall of the second bearing shell (3) and the inner wall of the first bearing shell (2).

2. The gas bearing according to claim 1, characterized in that: The primary damping structure comprises a wave foil structure (4), which is annularly surrounded on the first bearing shell (2), and the wave crest of the wave foil structure (4) is in abutment with the bearing support (1), and the wave trough of the wave foil structure (4) is in abutment with the first bearing shell (2).

3. The gas bearing according to claim 2, characterized in that: The corrugated foil structure (4) has a first end and a second end in a length direction, the first end being arranged on the bearing support (1), and the second end being movably located between the bearing support (1) and the first bearing housing (2).

4. The gas bearing according to claim 2, characterized in that: The thickness L3 of the corrugated foil structure (4) has a numerical range of 0.1 mm to 0.5 mm; and / or the pitch L4 between two adjacent wave crests of the corrugated foil structure (4) has a numerical range of 2 mm to 8 mm; and / or the single wave height L5 between the wave crest and the wave trough of the corrugated foil structure (4) has a numerical range of 1.5 mm to 3 mm.

5. The gas bearing according to claim 2, characterized in that: The number of the bump foil structures (4) is at least two, and all the bump foil structures (4) are arranged in parallel along the axial direction of the gas bearing.

6. The gas bearing according to claim 5, characterized in that: There is a seam spacing between two adjacent bump foil structures (4), and the relationship between the seam spacing L6, the number n of the bump foil structures (4) and the axial length L2 of the gas bearing is: L2 = L6*n*(20-50).

7. The gas bearing according to claim 1, characterized in that: The secondary damping structure comprises a damping ring (5), the damping ring (5) surrounds the outer wall of the second bearing shell (3), and the outer wall of the damping ring (5) is in abutment with the first bearing shell (2).

8. The gas bearing according to claim 7, characterized in that: The number of the damping rings (5) is at least two, and all the damping rings (5) are arranged in parallel along the axial direction of the gas bearing.

9. The gas bearing according to claim 8, characterized in that: The gas bearing comprises a first portion, a middle portion and a second portion distributed in the axial direction, at least one damping ring (5) is located at the first portion, and at least one damping ring (5) is located at the second portion.

10. The gas bearing according to claim 7, characterized in that: The thickness L1 of the damping ring (5) has a value ranging from 2.6 mm to 5.3 mm.

11. The gas bearing according to claim 1, characterized in that: The gas bearing further comprises a porous structure (6), wherein the porous structure (6) is arranged in the second bearing housing (3).

12. The gas bearing according to claim 1, characterized in that: The gas bearing further comprises a retaining ring (7), wherein the retaining ring (7) is arranged at the end of the first bearing shell (2), and the retaining ring (7) is in abutment with the second bearing shell (3); or, the retaining ring (7) is arranged at the end of the second bearing shell (3), and the retaining ring (7) is in abutment with the first bearing shell (2).

13. A compressor, characterized in that: A gas bearing comprising the gas bearing according to any one of claims 1 to 12.

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