A gas bearing and a compressor containing the same

Abstract

The present invention provides a gas bearing and a compressor including the same, which relates to the technical field of compressors and solves the technical problems that the static pressure gas bearing used in the compressor has poor bearing capacity and the dynamic pressure gas bearing is prone to instability. The gas bearing includes a bearing body, a tilting pad assembly and a shallow cavity assembly arranged on the bearing body, and an air supply assembly connected to the tilting pad assembly and the shallow cavity assembly to supply external high-pressure gas; the air supply assembly has a first air supply unit and a second air supply unit connected to the tilting pad assembly and the shallow cavity assembly for gas transportation respectively; the compressor includes a gas bearing. The present invention is used for centrifugal compressors, and has the advantages of both tilting pad static pressure bearings and shallow cavity bearings. It can ensure that during the full range of operation of the compressor, the bearing will not rub against the thrust plate, thereby affecting the bearing life, and improves the operating stability of the rotor under high speed conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular to a gas bearing and a compressor comprising the same. Background Art

[0002] A centrifugal compressor is an air-conditioning compressor that uses high-speed impeller rotation to generate centrifugal force to compress gas. Currently, there are conventional fixed-frequency, variable-frequency, magnetically suspended, and air-suspended centrifugal compressors. Among them, air-suspended centrifugal compressors have become the future development trend of centrifugal compressors due to their simple structure, oil-free, friction-free, and low cost.

[0003] Since a centrifugal compressor is a device that compresses refrigerant, the forces on both ends of the rotor are generally not the same, so the rotor will inevitably move forward or backward. At this time, a thrust bearing needs to be arranged in the rotor system to balance the forward or backward force of the rotor. The force condition and working state of the thrust bearing will be directly affected by the terminal equipment, so the role of the thrust bearing is crucial.

[0004] Air-suspended centrifugal compressors use gas bearings to support the rotor and balance the axial force. Gas bearings mainly include dynamic pressure and static pressure gas bearings. Dynamic pressure gas bearings are self-supporting bearings that do not require an additional air supply system for air supply and mainly work on the principle of dynamic pressure. Static pressure gas bearings use active ventilation to generate an air film to support the rotor. Static pressure gas bearings do not cause friction between the rotor and the bearing in the full range of operation, so they have low losses and long life. Dynamic pressure gas bearings require a certain takeoff speed. At low speeds, the rotor cannot take off. In addition, during the start-stop phase, friction will occur between the rotor and the bearing, and the load-bearing capacity of dynamic pressure gas bearings is relatively low. Static pressure gas bearings are not adaptable, so at high speeds, the rotor is prone to instability, and when the air supply pressure difference is large, the bearing will produce air hammers that can easily lead to instability.

[0005] Air suspension compressors generally have high speeds, and because centrifugal compressors have a large pressure ratio, when hydrodynamic gas bearings are used alone, the bearing's load-bearing capacity is insufficient, resulting in an inability to balance the axial force well. If hydrostatic bearings are used alone, the rotor is prone to instability at high speeds and requires a large air supply pressure. Summary of the invention

[0006] The object of the present invention is to provide a gas bearing and a compressor comprising the same, so as to solve the technical problems existing in the prior art that the static pressure gas bearing used in the compressor has poor bearing capacity and the dynamic pressure gas bearing is prone to instability.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a gas bearing, comprising a bearing body, a tilting pad assembly and a shallow cavity assembly arranged on the bearing body, and a gas supply assembly connected to the tilting pad assembly and the shallow cavity assembly to supply external pressurized gas.

[0009] As a further improvement of the present invention, the gas supply assembly comprises a first gas supply unit and a second gas supply unit which are respectively connected to the tilting pad assembly and the shallow cavity assembly for gas transportation.

[0010] As a further improvement of the present invention, the air supply assembly includes a bearing air supply plate connected to the bearing body, and the bearing air supply plate is provided with a shallow cavity air supply groove and a tilting pad air supply ring on the side facing the bearing body. The first air supply unit includes a shallow cavity air supply hole that is arranged through the bearing air supply plate and connected to the shallow cavity air supply groove; the second air supply unit includes a tilting pad air supply hole that is arranged through the bearing air supply plate and connected to the tilting pad air supply ring.

[0011] As a further improvement of the present invention, the shallow cavity air supply groove and the tilting pad air supply ring are both circular ring structures, and the centers of the two circles coincide.

[0012] As a further improvement of the present invention, the shallow cavity assembly includes a shallow cavity air intake ring arranged on one side of the bearing body and adapted to the specifications and shape of the shallow cavity air supply groove, a plurality of shallow cavities arranged on the other side of the bearing body, and shallow cavity air intake holes respectively connected to the shallow cavity air intake ring and the shallow cavity at both ends.

[0013] As a further improvement of the present invention, the height of the shallow cavity air intake ring is smaller than the depth of the shallow cavity air supply groove.

[0014] As a further improvement of the present invention, all of the shallow cavities are arranged in a circular ring shape along the center of the bearing body.

[0015] As a further improvement of the present invention, the tilting pad assembly includes a tilting pad air inlet groove arranged on one side of the bearing body and having a specification and shape that is compatible with the tilting pad air supply ring, a tilting pad block arranged in the shallow cavity, a porous block arranged above the tilting pad block, and a tilting pad air inlet hole arranged on the tilting pad block and connected to the tilting pad air inlet groove and the shallow cavity.

[0016] As a further improvement of the present invention, the tilting pad is further provided with supporting ribs for preventing the porous block from breaking.

[0017] As a further improvement of the present invention, the diameter of the shallow cavity air inlet hole is 0.6-1 mm.

[0018] The present invention provides a compressor, comprising the gas bearing.

[0019] As a further improvement of the present invention, the compressor is a centrifugal compressor.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The gas bearing provided by the present invention is a high-stability and high-load tilting pad thrust gas bearing with no friction loss in the entire range. It has the advantages of both tilting pad hydrostatic bearings and shallow cavity bearings, and can ensure that during the entire operation of the compressor, the bearing will not rub against the thrust plate, thereby affecting the bearing life, and improves the operating stability of the rotor under high speed conditions; the gas supply components in the gas bearing of the present invention are respectively connected to different gas supply pipelines, and two-way gas supply is used to supply the tilting pad component and the shallow cavity component in the gas bearing, which can supply the most suitable pressure to different gas bearing parts, thereby maximizing the bearing capacity and improving the reliability of the bearing, and under high-speed conditions, the gas supply can be reduced according to the capacity of different bearings to minimize the power consumption of the gas supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 is a front cross-sectional view of the gas bearing of the present invention;

[0024] Figure 2 is a top view of the gas bearing of the present invention;

[0025] Figure 3 is a front cross-sectional view of a bearing body in a gas bearing of the present invention;

[0026] Figure 4 is a top view of a bearing body in a gas bearing of the present invention;

[0027] Figure 5 is a front cross-sectional view of a bearing gas supply plate in a gas bearing of the present invention;

[0028] Figure 6 It is a top view of the bearing gas supply plate in the gas bearing of the present invention.

[0029] In the figure, 1, bearing body; 11, locking hole; 2, tilting pad assembly; 21, tilting pad air inlet groove; 22, tilting pad block; 23, porous block; 24, tilting pad air inlet hole; 25, supporting rib; 3, shallow cavity assembly; 31, shallow cavity air inlet ring; 32, shallow cavity; 33, shallow cavity air inlet hole; 4, air supply assembly; 41, bearing air supply plate; 42, shallow cavity air supply groove; 43, tilting pad air supply ring; 44, shallow cavity air supply hole; 45, tilting pad air supply hole; 46, locking threaded hole. DETAILED DESCRIPTION

[0030] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0031] like Figure 1 As shown, the present invention provides a gas bearing, comprising a bearing body 1, a tilting pad assembly 2 and a shallow cavity assembly 3 arranged on the bearing body 1, and a gas supply assembly 4 connected to both the tilting pad assembly 2 and the shallow cavity assembly 3 to supply external pressurized gas. It should be noted here that the supplied pressurized gas refers to a gas whose pressure is greater than the ambient atmospheric pressure.

[0032] like Figure 1 and Figure 2 As shown, as an optional embodiment of the present invention, the air supply assembly 4 has a first air supply unit and a second air supply unit connected to the tilting pad assembly 2 and the shallow cavity assembly 3 for gas transportation. It should be noted that the gas sources of the first air supply unit and the second air supply unit can be the same or different, as long as two air supplies can be used to provide gas of the required pressure to different positions of the bearing, and the air supply pressure regulation and supply of the two air supply units are independently controlled. Through the above arrangement, a bearing structure with two parts of independent air supply is formed, and different flow rates of gas are supplied to different bearing parts, so that the bearing runs in the best state and the reliability of the bearing is improved.

[0033] The gas bearing provided by the present invention is a high-stability and high-load tilting pad thrust gas bearing with no friction loss in the entire range. It has the advantages of both tilting pad hydrostatic bearings and shallow cavity bearings, and can ensure that during the entire operation of the compressor, the rotor will not rub against the thrust plate, thereby affecting the rotor life. It also improves the operating stability of the rotor under high-speed conditions and is more stable under high-speed conditions. The gas supply components in the gas bearing of the present invention are respectively connected to different gas supply pipelines, and two-way gas supply is used to supply the tilting pad component and the shallow cavity component in the gas bearing, which can supply the most suitable pressure to different gas bearing parts, thereby maximizing the bearing capacity and improving the bearing reliability. In addition, under high-speed conditions, the gas supply amount can be reduced according to the capacity of different bearings, thereby minimizing the power consumption of the gas supply system.

[0034] like Figure 5 and Figure 6 As shown, further, the air supply assembly 4 includes a bearing air supply plate 41 connected to the bearing body 1, and a shallow cavity air supply groove 42 and a tilting pad air supply ring 43 are provided on the side of the bearing air supply plate 41 facing the bearing body 1, and the first air supply unit includes a shallow cavity air supply hole 44 which is arranged through the bearing air supply plate 41 and connected with the shallow cavity air supply groove 42; the second air supply unit includes a tilting pad air supply hole 45 which is arranged through the bearing air supply plate 41 and connected with the tilting pad air supply ring 43.

[0035] Specifically, the bearing air supply plate 41 has two air inlet holes, namely the tilting pad air supply hole 45 and the shallow cavity air supply hole 44. The center positions of the two holes are different, and they are respectively arranged on the shallow cavity air supply groove 42 and the tilting pad air supply ring 43. The two air supply holes are respectively connected to different air supply pipelines, and two-way air supply is adopted; a locking threaded hole 46 is also designed on the bearing air supply plate 41.

[0036] As an optional embodiment of the present invention, the shallow cavity air supply groove 42 and the tilting pad air supply ring 43 are both annular structures, and the centers of the two circles coincide. Specifically, the shallow cavity air supply groove 42 is located outside the tilting pad air supply ring 43.

[0037] like Figure 3 and Figure 4 As shown, further, the shallow cavity assembly 3 includes a shallow cavity air intake ring 31 arranged on one side of the bearing body 1 and adapted to the specifications and shape of the shallow cavity air supply groove 42, a plurality of shallow cavities 32 arranged on the other side of the bearing body 1, and a shallow cavity air intake hole 33 connected to the shallow cavity air intake ring 31 and the shallow cavity 32 at both ends.

[0038] By providing a shallow cavity component, the gas bearing of the present invention is a thrust gas bearing structure with a shallow cavity structure. Under high-speed conditions, the dynamic pressure effect is enhanced and the bearing capacity of the bearing can be improved.

[0039] As an optional embodiment of the present invention, the height of the shallow cavity air intake ring 31 is less than the depth of the shallow cavity air supply groove 42. When the bearing body 1 and the bearing air supply plate 41 are connected together, there is a gap between the end of the shallow cavity air intake ring 31 and the bottom of the shallow cavity air supply groove 42, and the gap forms a circular shallow cavity air supply channel, and the pressurized gas flows along the channel and is sent to the shallow cavity 32 located at different positions of the bearing body 1 through the shallow cavity air intake hole 33.

[0040] Furthermore, all shallow cavities 32 are arranged in a circular shape along the center of the bearing body 1. Each shallow cavity 32 is a ring-shaped structure, and of course, the shallow cavity 32 can also be arranged in other regular or irregular shapes such as circle, triangle, rectangle, trapezoid, polygon, etc.

[0041] As an optional embodiment of the present invention, the tilting pad assembly 2 includes a tilting pad air inlet groove 21 arranged on one side of the bearing body 1 and having a specification and shape that is compatible with the tilting pad air supply ring 43, a tilting pad block 22 arranged in the shallow cavity 32, a porous block 23 arranged above the tilting pad block 22, and a tilting pad air inlet hole 24 arranged on the tilting pad block 22 and connected to the tilting pad air inlet groove 21 and the shallow cavity 32.

[0042] The gas bearing of the present invention is a porous static pressure gas bearing with a tilting pad structure, which increases the adaptability and damping characteristics of the entire bearing and improves the operating stability and reliability of the entire rotor system. Furthermore, the tilting pad 22 is also provided with support ribs 25 to prevent the porous block 23 from breaking.

[0043] like Figure 4 As shown, there are four supporting ribs 25 , which are divided into two groups and are symmetrically arranged along the symmetry center line of the tilting pad 22 .

[0044] Furthermore, the diameter of the shallow cavity air inlet hole 33 is 0.6-1 mm.

[0045] Embodiment 1:

[0046] The gas bearing includes a bearing body 1, on which a locking hole 11, a shallow cavity air intake ring 31, and a tilting pad air intake groove 21 are designed; the shallow cavity air intake ring 31, the tilting pad air intake groove 21 cooperate with the shallow cavity air supply groove 42 on the bearing air supply plate 41 and the tilting pad air supply ring 43, and are connected together by screws through the locking hole 11 and the locking threaded hole 46, thereby forming a reliable air supply component 4; the bearing body 1 is mainly composed of a shallow cavity 32 and a tilting pad 22, wherein the tilting pad 22 is also equipped with a porous block 23, and the tilting pad 22 can adjust its position as the load changes (the specific adjustment position refers to flipping along the symmetry line of the tilting pad 22), thereby improving the bearing Reliability, but the load-bearing capacity of the tilting pad bearing is low. Therefore, in the present invention, it mainly plays a role in the low speed and start-stop stages. At high speed, the dynamic pressure effect of the shallow cavity bearing is enhanced, and its static pressure load is also large. Therefore, at high speed, the shallow cavity bearing mainly plays a role. At this time, the air supply pressure can be adjusted to match different working conditions. These two types of bearings cooperate with each other, so that the bearing has a large load-bearing capacity and higher reliability; the shallow cavity 32 is also designed with a shallow cavity air supply hole 33 (generally 0.6-1mm), and the tilting pad block 22 is designed with a tilting pad air inlet hole 24 and a support rib 25. The support rib 25 is mainly used to increase the strength and prevent the porous block 23 from breaking.

[0047] The present invention also provides a compressor, comprising the above-mentioned gas bearing.

[0048] Furthermore, the compressor is a centrifugal compressor.

[0049] The present invention provides a high-load-bearing and high-stability tilting pad thrust gas bearing with zero friction loss in the entire region. The bearing has a large load-bearing capacity and is self-adaptive (according to load changes, the pad angle is automatically adjusted to adapt to rotor operation changes), so it has good reliability; the bearing has the characteristics of both a tilting pad static pressure gas bearing and a shallow cavity dynamic and static pressure gas bearing, that is, it has the stability of a tilting pad gas bearing and the large load-bearing capacity of a shallow cavity bearing, and because the bearing has a tiltable tilting pad part, the bearing has good self-adaptability. During start-stop and low-speed conditions, when the load is low, the tilting pad part of the bearing provides the main load-bearing capacity to float the rotor, so the bearing will There will be no more friction with the thrust plate, and under high-speed operation, the load increases and the rotor vibration intensifies. At this time, the tilting pad bearing part can deform freely to adapt to the operation changes of the rotor, and the dynamic pressure effect of the shallow cavity part and the tilting pad part in the bearing increases, and the bearing load capacity increases, so that the rotor can float stably. At this time, the static pressure part only needs to supplement a certain amount of load. The shallow cavity bearing of the fixed part of the bearing can provide sufficient load-bearing capacity for the bearing to make up for the disadvantage of insufficient load-bearing capacity of the tilting pad part, thereby reducing the air supply power consumption, and at this time the tilting pad part is adaptive, so it can provide additional damping for the bearing to reduce the vibration of the rotor at high speed; the bearing is simple to process and improves the bearing life.

[0050] After using the present invention, since the tilting pad static pressure gas bearing support can be used during the start-stop stage of the rotor, the rotor does not need to reach a high take-off speed, which reduces the difficulty of the inverter program control;

[0051] After using the present invention, the tilting pad static pressure gas bearing and the shallow cavity dynamic and static pressure gas bearing provide bearing capacity at the same time, and the bearing no longer needs a high gas supply pressure (the dynamic pressure effect of the shallow cavity bearing is enhanced under high-speed operation). Therefore, the load and power consumption of the external gas supply system are reduced;

[0052] After using the present invention, the bearing is easy to process, and the porous blocks therein are local porous blocks, so when one of the blocks is damaged, only the block can be replaced, thus saving material costs.

[0053] First of all, it should be explained here that “inward” refers to the direction toward the center of the accommodating space, and “outward” refers to the direction away from the center of the accommodating space.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate directions or positional relationships based on the attached Figure 1The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0056] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0059] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A gas bearing, characterized in that: It comprises a bearing body, a tilting pad assembly and a shallow cavity assembly arranged on the bearing body, and a gas supply assembly connected to both the tilting pad assembly and the shallow cavity assembly to supply external pressurized gas; The gas supply assembly comprises a first gas supply unit and a second gas supply unit which are connected to the tilting pad assembly and the shallow cavity assembly for gas delivery respectively; The air supply assembly includes a bearing air supply plate connected to the bearing body, the bearing air supply plate is provided with a shallow cavity air supply groove and a tilting pad air supply ring on one side facing the bearing body, the first air supply unit includes a shallow cavity air supply hole penetratingly arranged on the bearing air supply plate and communicating with the shallow cavity air supply groove; the second air supply unit includes a tilting pad air supply hole penetratingly arranged on the bearing air supply plate and communicating with the tilting pad air supply ring; The shallow cavity assembly includes a shallow cavity air intake ring arranged on one side of the bearing body and adapted to the specifications and shape of the shallow cavity air supply groove, a plurality of shallow cavities arranged on the other side of the bearing body, and shallow cavity air intake holes respectively connected to the shallow cavity air intake ring and the shallow cavity at both ends.

2. The gas bearing according to claim 1, characterized in that The shallow cavity air supply groove and the tilting pad air supply ring are both circular ring structures, and the centers of the two circles coincide.

3. The gas bearing according to claim 1, characterized in that The height of the shallow cavity air intake ring is smaller than the depth of the shallow cavity air supply groove.

4. The gas bearing according to claim 1, characterized in that All of the shallow cavities are arranged in a circular shape along the center of the bearing body.

5. The gas bearing according to claim 1, characterized in that The tilting pad assembly includes a tilting pad air inlet groove arranged on one side of the bearing body and having a specification and shape adapted to the tilting pad air supply ring, a tilting pad block arranged in the shallow cavity, a porous block arranged above the tilting pad block, and a tilting pad air inlet hole arranged on the tilting pad block and connected to the tilting pad air inlet groove and the shallow cavity.

6. The gas bearing according to claim 5, characterized in that The tilting pad is also provided with supporting ribs.

7. A compressor, characterized in that: Comprising a gas bearing as claimed in any one of claims 1-6.

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