hydrostatic gas bearings

Abstract

This invention discloses a hydrostatic gas bearing, comprising: a bearing base with an installation space; an elastic foil installed within the installation space; and a cooling inlet on the bearing base, communicating with the installation space and supplying cooling fluid into the installation space. The hydrostatic gas bearing of this invention effectively solves the problem of vibration suppression failure in existing hydrostatic gas bearings.

Description

Technical Field

[0001] This invention relates to the field of gas bearing technology, and more specifically, to a hydrostatic gas bearing. Background Technology

[0002] Bearings are one of the core components of rotating machinery, used to support the rotor's rotation. Based on the lubrication method, bearings are generally classified into oil-lubricated bearings and oil-free bearings. Gas bearings belong to the category of oil-free bearings. Gas bearings offer a range of advantages, including high operating speed, good stability, low vibration, and oil-free lubrication, making them ideal for light-load, high-speed rotating machinery such as air compressors, gas turbines, and centrifugal compressors.

[0003] Based on different lubricating gas film formation mechanisms, gas bearings can be classified into hydrodynamic gas bearings, hydrostatic gas bearings, and extrusion-type gas bearings. Hydrostatic gas bearings utilize gas supplied at a certain pressure by an external gas supply system. The gas is then delivered to the gap between the bearing and the rotor via a bearing throttle, forming a high-pressure gas film at the gap to support the rotor and suspend it. The throttle orifice of hydrostatic gas bearings can take various forms, including porous, pinhole, micro-orifice, and shallow cavity structures. Figure 1 This diagram illustrates the working phenomenon of a porous hydrostatic gas bearing. The porous material can be graphite, sintered metal, or sintered powder, etc. Its characteristic feature is the distribution of a certain proportion of pores within the bearing, which act as throttling devices. During operation, high-pressure gas is introduced. After passing through the throttling devices, the gas forms a uniform gas film with a certain pressure on the bearing surface, which supports the levitation of the object. Figure 1 The bubbles are actually formed by the dispersion of air films.

[0004] Besides porous gas hydrostatic bearings, small-bore gas hydrostatic bearings are also widely used, and their general structure is as follows: Figure 1 As shown, a hydrostatic gas bearing supports the rotor 101. The hydrostatic gas bearing consists of a bearing body 102, an O-ring 103, a housing 104, and a high-pressure gas inlet 105. The rotor 101 is a simplified structure in the figure, showing only the shaft diameter that mates with the bearing. During operation, the rotor 101 rotates under the drive of the stator magnetic field or the coupling. The radial support force for this rotation comes from the hydrostatic gas bearing. The load-bearing capacity of the hydrostatic gas bearing is directly proportional to the viscosity and pressure of the gas supplied. Generally, the relative pressure of the supplied high-pressure gas does not exceed 0.6 MPa. Therefore, in practical applications, the appropriate gas film pressure is obtained by changing the type and relative pressure of the gas supply medium, thereby providing load-bearing capacity for the rotor. However, the damping of the gas film is poor, resulting in poor vibration resistance of the bearing during application. When applied to high-speed rotating machinery, the rotor vibrates significantly under the influence of unbalanced forces and aerodynamic forces. Due to its low damping, the bearing has poor vibration suppression capability, which can easily lead to rotor instability. Therefore, O-rings are generally used, on the one hand to increase bearing damping, and on the other hand to provide a seal.

[0005] Since the 1980s, with the increasingly widespread application of gas bearings, Figure 1 The hydrostatic gas bearing structure exhibits limitations, primarily constrained by the reliability of the O-rings. For example, in high-temperature environments, the O-rings must withstand high temperatures; in refrigerant environments, they are susceptible to corrosion; since rotor vibration is unavoidable during operation, the O-rings are constantly subjected to reciprocating vibration excitation transmitted through the bearing, requiring them to withstand fatigue failure; when the rotor is subjected to impact, the O-rings cannot undergo permanent deformation; and to perform their sealing function, the O-rings require a groove fit structure, but due to the small groove space, heat dissipation is poor during long-term operation, easily leading to thermal failure, etc.

[0006] In summary, the vibration suppression structure of hydrostatic gas bearings in the prior art is prone to failure. Summary of the Invention

[0007] This invention provides a hydrostatic gas bearing to solve the problem that vibration suppression in existing hydrostatic gas bearings is prone to failure.

[0008] To achieve the above objectives, the present invention provides a hydrostatic gas bearing, comprising: a bearing base having an installation space; an elastic foil installed within the installation space; and a cooling inlet on the bearing base communicating with the installation space, wherein a cooling fluid is introduced into the installation space through the cooling inlet.

[0009] Further, the bearing base includes: a housing, on which the cooling inlet is provided, the housing being a cylindrical structure; a connecting ring, the connecting ring passing through the housing, the inner wall of the housing and the outer wall of the connecting ring forming the mounting space, the mounting space being annular, the mounting space having annular openings at both ends along the axis of the bearing base; and an elastic foil connected to the inner wall of the housing, the elastic foil also being connected to the outer wall of the connecting ring.

[0010] Furthermore, the bearing base also includes a bearing ring for mounting on the rotor, the bearing ring having multiple throttling holes; a connecting ring is mounted on the outer circumference of the bearing ring, the inner wall of the connecting ring and the outer wall of the bearing ring forming a sealed hollow cavity, the throttling holes communicating with the hollow cavity; the inlet pipe of the hydrostatic gas bearing communicating with the hollow cavity, the inlet pipe introducing high-pressure gas into the hollow cavity.

[0011] Furthermore, the intake pipe passes through the housing, the mounting space, and the connecting ring simultaneously.

[0012] Furthermore, the cooling inlet is located at the intake pipe position.

[0013] Furthermore, the housing is provided with a mounting hole, the air inlet pipe of the hydrostatic gas bearing passes through the mounting hole and has a gap with the inner wall of the mounting hole; the air inlet pipe is fixedly connected to the connecting ring.

[0014] Furthermore, the bearing base also includes a sealing ring, which is sealed at the connection end face between the bearing ring and the connecting ring.

[0015] Furthermore, a cooling outlet is provided on the housing, and the cooling outlet is connected to the installation space, through which cooling fluid from the installation space can flow out.

[0016] Furthermore, there are multiple cooling inlets and multiple cooling outlets, with one cooling outlet corresponding to one cooling inlet.

[0017] Furthermore, all of the cooling inlets are located in the middle of the housing, and at least two of the cooling outlets are located at both ends of the housing in the axial direction.

[0018] When a gas hydrostatic bearing is operating, it vibrates due to the rotor load. The elastic foil deforms to absorb this vibration, thus improving the bearing's stability. The elastic foil increases the damping of the gas hydrostatic bearing, enhancing its ability to suppress rotor vibration, resulting in a high-damping gas hydrostatic bearing structure that further improves its vibration suppression capabilities.

[0019] When the rotor vibrates, the elastic foils undergo relative motion within the mounting space, converting vibrational energy into heat through Coulomb friction, thus providing damping. However, the elastic foils may fail due to excessively high temperatures during prolonged friction. Therefore, this invention incorporates a cooling channel and a cooling inlet. Cooling fluid is introduced into the mounting space through this inlet, cooling the elastic foils and carrying away heat during its flow. This maintains the temperature of the elastic foils and the surrounding space within a stable range, preventing thermal failure during long-term operation and ensuring the long-term vibration suppression capability of the hydrostatic gas bearing. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram of a hydrostatic gas bearing in the prior art;

[0021] Figure 2 This is a cross-sectional schematic diagram of a hydrostatic gas bearing according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the external structure of the hydrostatic gas bearing according to an embodiment of the present invention;

[0023] Figure 4 This is a cross-sectional schematic diagram of a hydrostatic gas bearing according to an embodiment of the present invention;

[0024] Figure 5 This is a side view of a hydrostatic gas bearing according to an embodiment of the present invention;

[0025] Figure 6 yes Figure 4 A partial enlarged view of a hydrostatic gas bearing;

[0026] Figure 7 This is a schematic diagram of the housing of the hydrostatic gas bearing according to an embodiment of the present invention;

[0027] Figure 8 yes Figure 7 A cross-sectional schematic diagram of the shell;

[0028] Figure 9 This is a schematic diagram of the bearing ring structure of the hydrostatic gas bearing according to an embodiment of the present invention;

[0029] Figure 10 This is a schematic diagram of the structure of the elastic foil of the hydrostatic gas bearing according to an embodiment of the present invention. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0031] See Figures 2 to 10 As shown, according to an embodiment of the present invention, a hydrostatic gas bearing is provided, the hydrostatic gas bearing including a bearing base 10 and an elastic foil 20, wherein an installation space A is provided on the bearing base; the elastic foil 20 is installed in the installation space A;

[0032] The bearing base 10 is provided with a cooling inlet 11, which is connected to the installation space A, and cooling fluid is introduced into the installation space A through the cooling inlet 11.

[0033] When a gas hydrostatic bearing is operating, it vibrates due to the rotor load. The elastic foil deforms to absorb this vibration, thus improving the bearing's stability. The elastic foil increases the damping of the gas hydrostatic bearing, enhancing its ability to suppress rotor vibration, resulting in a high-damping gas hydrostatic bearing structure that further improves its vibration suppression capabilities.

[0034] When the rotor vibrates, the elastic foils move relative to each other within the mounting space, converting vibrational energy into heat through Coulomb friction, thus providing damping. However, the elastic foils may fail due to excessively high temperatures during prolonged friction. Therefore, this invention incorporates a cooling channel and a cooling inlet. Cooling fluid (cooling gas) is introduced into the mounting space A through this inlet, cooling the elastic foils and carrying away heat during its flow. This maintains the temperature of the elastic foils and the surrounding space within a stable range, preventing thermal failure during long-term operation and ensuring the long-term vibration suppression capability of the hydrostatic gas bearing.

[0035] Combination Figures 2 to 4 As shown, the bearing base 10 includes a housing 12 and a connecting ring 13. The cooling inlet 11 is provided on the housing 12, and the housing 12 has a cylindrical structure. The connecting ring 13 passes through the housing 12, and the mounting space A is formed between the inner wall of the housing 12 and the outer wall of the connecting ring 13. The mounting space A is an annular space, and both ends of the mounting space A along the axis of the bearing base 10 are annular openings. The elastic foil 20 is connected to the inner wall of the housing 12, and the elastic foil 20 is also connected to the outer wall of the connecting ring 13.

[0036] The cooling fluid (cooling gas) introduced through the cooling inlet flows within the annular installation space A, carrying away heat. Afterward, the cooling fluid can flow out from the annular openings at both ends of the bearing base axis within installation space A and enter the unit containing rotor 40. This structural design allows the heat from the elastic foil to be quickly dissipated, rapidly reducing the temperature and ensuring the damping effect remains effective over a long period.

[0037] The bearing base 10 further includes a bearing ring 14, which is fitted onto the rotor 40. The bearing ring 14 has multiple throttling holes 14a. A connecting ring 13 is fitted around the outer circumference of the bearing ring 14, and a sealed hollow cavity 15 is formed between the inner wall of the connecting ring 13 and the outer wall of the bearing ring 14. The throttling holes 14a communicate with the hollow cavity 15. The inlet pipe 30 of the hydrostatic gas bearing communicates with the hollow cavity 15, and the inlet pipe 30 introduces high-pressure gas into the hollow cavity 15.

[0038] Multiple throttling orifices 14a are provided on the bearing ring 14, and the hollow cavity 15 is arranged along the circumferential direction. The hollow cavity is mainly used to store high-pressure gas from the intake pipe. During operation, the high-pressure gas enters the hollow cavity through the intake pipe 30, then passes through the multiple throttling orifices, and forms a gas film on the inner wall of the bearing ring, supporting the rotor 40 to suspend.

[0039] The inner diameter surface of the connecting ring and the outer diameter surface of the bearing ring are interference-fitted, which is beneficial for sealing and improving the assembly accuracy of the parts. The connecting ring serves to connect the elastic foil and the bearing ring, thus achieving a multi-functional purpose.

[0040] Preferably, the air intake pipe 30 passes through the housing 12, the mounting space A, and the connecting ring 13 simultaneously.

[0041] This design of the intake pipe utilizes the structural space of the bearing base without occupying other space, resulting in a more compact structure.

[0042] Preferably, the cooling inlet 11 is located at the position of the intake pipe 30. In this embodiment, a cooling inlet is provided on each side of the intake pipe 30. The cooling inlet 11 and the intake pipe 30 are located at the same position, which increases the structural compactness. Simultaneously, the cooling gas from the cooling inlet can cool the high-pressure gas inside the intake pipe 30 through heat conduction, achieving overall cooling of the bearing and providing auxiliary cooling.

[0043] Combination Figure 2 As shown, the bearing base 10 also includes a sealing ring 16, which is sealed and connected at the connection end face of the bearing ring 14 and the connecting ring 13.

[0044] The sealing ring 16 can be made of metal sealant, mainly used to seal the two connecting end faces of the extractor 14 and the connecting ring 13 to prevent high-pressure gas from leaking after entering the intake pipe. In addition to metal sealant, other types of sealing gaskets can also be used.

[0045] Preferably, see Figure 6 and Figure 8 The housing 12 has a mounting hole 12a. The air inlet pipe 30 of the hydrostatic gas bearing passes through the mounting hole 12a and has a gap with the inner wall of the mounting hole 12a. The air inlet pipe 30 is fixedly connected to the connecting ring 13 (by welding or threading). The outer diameter of the air inlet pipe 30 is D1, and the diameter of the mounting hole 12a is D2, where D1 < D2. See also... Figure 7 The mounting holes 12a are multiple and are evenly arranged along the circumference of the shell. The mounting holes 12a are located in the middle and serve as a partition corresponding to the middle part of the shell.

[0046] The aforementioned gap allows components such as bearing rings, sealing rings, connecting rings, and elastic foils to make slight movements relative to the housing in the axial direction, giving the elastic foils more room to move. The gap value is generally 0.1 to 1 mm.

[0047] Considering the installation environment and fit of the hydrostatic gas bearing, preferably, see [reference needed]. Figure 4 and Figure 8 The housing 12 is provided with a cooling outlet 17, which is connected to the installation space A, and the cooling fluid of the installation space A can flow out from the cooling outlet 17.

[0048] The purpose of providing cooling outlet 17 is to discharge the cooling fluid (cooling air) from the installation space. The cooling fluid entering from the cooling inlet flows through the installation space, carrying away heat, and then flows out through cooling outlet 17. Because the hydrostatic gas bearing will be installed inside the unit, if it is integrated with other structures, it is highly likely to block the annular openings at both ends of the A-axis of the installation space, or the air pressure may not allow the cooling fluid to flow out effectively. Therefore, cooling outlet 17 is provided as a safety outlet to discharge excess cooling fluid, ensuring efficient flow in the cooling channel and guaranteeing long-term cooling effectiveness.

[0049] Preferably, there are multiple cooling inlets 11 and multiple cooling outlets 17, with one cooling outlet 17 corresponding to one cooling inlet 11. The cooling outlets are generally located diagonally opposite (or symmetrically along the axis of the corresponding cooling inlet) to maximize the flow of cooling fluid, thereby cooling the elastic foils at various locations within the installation space A.

[0050] Preferably, in this embodiment, all the cooling inlets 11 are located in the middle of the housing 12, and at least two cooling outlets 17 are located at both ends of the housing 12 in the axial direction.

[0051] See Figure 4 Cooling gas enters from one cooling inlet (left side of inlet pipe 30 in the figure) and flows out from the cooling outlet (lower left side of the figure), cooling the elastic foil along the way and carrying away heat. Cooling gas enters from another cooling inlet (right side of inlet pipe 30 in the figure) and flows out from the cooling outlet (lower right side of the figure), cooling the elastic foil along the way and carrying away heat.

[0052] Combination Figure 5 and Figure 10 As shown, the elastic foil consists of three parts: a folded edge, a convex corrugated surface, and a convex corrugated bottom surface. The function of the folded edge is to assemble it to... Figure 3 The axial groove shown is used to partially fix the elastic foil to the housing using a fixing pin. The corrugated convex surface flexibly engages with the outer wall of the connecting ring. Similarly, the corrugated bottom surface also flexibly engages with the inner wall of the housing. When the rotor vibrates, the corrugated bottom surface and the inner wall of the housing move relative to each other, converting the vibration energy into heat through Coulomb friction, thus providing a damping effect. The surface roughness of the inner wall of the housing is generally Ra3.2 to Ra12.5.

[0053] The aforementioned flexible fit refers to the flexible convex surface of the elastic foil freely overlapping the outer wall of the connecting ring. The two are not fixed. The significance of this design is that when the rotor vibrates, the vibration is transmitted to the bearing ring via the air film. Since the connecting ring and bearing ring are an interference-fitted unit, the vibration is also transmitted to the elastic foil, causing it to vibrate as well. Under the influence of this vibration, the convex surface of the elastic foil moves relative to the outer wall of the connecting ring, generating Coulomb friction and converting the vibration energy into heat, thus providing a damping effect. To ensure the effectiveness of the Coulomb friction, the surface roughness of the outer wall of the connecting ring is generally Ra3.2 to Ra12.5.

[0054] Elastic foil structure such as Figure 10 As shown, high-strength high-temperature alloy steel is used, making it suitable for various harsh environments. The material thickness is between 0.05-0.3mm; too thin a material can lead to difficulties in foil processing, while too thick a material can result in excessively high foil stiffness, thus losing its damping effect.

[0055] There are six elastic foils in the hydrostatic gas bearing. They are evenly distributed at three points along the circumference on the left end, with adjacent foils spaced θ apart, rather than forming a full circle. This is to allow the foils some free deformation space during deformation. Figure 5 As shown. Similarly, at the right end, the elastic foil is also evenly distributed in three places along the circumference. The advantage of this design is that it reduces the total axial length of the elastic foil, which on the one hand helps to improve the processing accuracy of the elastic foil, and on the other hand reduces the concentration of heat generated by the elastic foil.

[0056] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0057] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0058] Of course, the above are preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the basic principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A hydrostatic gas bearing, characterized in that, include: Bearing base (10), on which an installation space (A) is provided; An elastic foil (20) is installed within the mounting space (A); The bearing base (10) is provided with a cooling inlet (11), which is connected to the installation space (A) and the cooling inlet (11) supplies cooling fluid to the installation space (A); The bearing base (10) includes a housing (12), a connecting ring (13), and a bearing ring (14). The housing (12) has a cooling inlet (11). The connecting ring (13) passes through the housing (12), and the inner wall of the housing (12) and the outer wall of the connecting ring (13) form the installation space (A). The bearing ring (14) is used to be fitted onto the rotor (40), and the bearing ring (14) has multiple throttling holes (14a). A connecting ring (13) is sleeved on the outer circumference of the bearing ring (14), and a sealed hollow cavity (15) is formed between the inner wall of the connecting ring (13) and the outer wall of the bearing ring (14). The throttling orifice (14a) is connected to the hollow cavity (15). The air inlet pipe (30) of the hydrostatic gas bearing is connected to the hollow cavity (15), and the air inlet pipe (30) introduces high-pressure gas into the hollow cavity (15). The cooling inlet (11) is located at the position of the air inlet pipe (30).

2. The hydrostatic gas bearing according to claim 1, characterized in that, The housing (12) is a cylindrical structure; the mounting space (A) is an annular space, and the two ends of the mounting space (A) along the axis of the bearing base (10) are annular openings; The elastic foil (20) is connected to the inner wall of the housing (12), and the elastic foil (20) is also connected to the outer wall of the connecting ring (13).

3. The hydrostatic gas bearing according to claim 1, characterized in that, The intake pipe (30) passes through the housing (12), the mounting space (A), and the connecting ring (13).

4. The hydrostatic gas bearing according to claim 1, characterized in that, The housing (12) has a mounting hole (12a), and the air inlet pipe (30) of the hydrostatic gas bearing passes through the mounting hole (12a) and has a gap with the inner wall of the mounting hole (12a); The air intake pipe (30) is fixedly connected to the connecting ring (13).

5. The hydrostatic gas bearing according to claim 2, characterized in that, The bearing base (10) also includes a sealing ring (16), which is sealed to the end face of the bearing ring (14) and the connecting ring (13).

6. The hydrostatic gas bearing according to claim 2, characterized in that, The housing (12) is provided with a cooling outlet (17), which is connected to the installation space (A), and the cooling fluid of the installation space (A) can flow out from the cooling outlet (17).

7. The hydrostatic gas bearing according to claim 6, characterized in that, There are multiple cooling inlets (11) and multiple cooling outlets (17), with one cooling outlet (17) corresponding to one cooling inlet (11).

8. The hydrostatic gas bearing according to claim 7, characterized in that, All of the cooling inlets (11) are located in the middle of the housing (12), and at least two of the cooling outlets (17) are located at both ends of the housing (12) in the axial direction.

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