Liquid metal bearing with air suction function and preparation method thereof

Abstract

The application provides a liquid metal bearing with an air absorption function and a preparation method, and belongs to the technical field of medical diagnosis equipment. The liquid metal bearing with the air absorption function comprises a mandrel and a bearing bush. The bearing bush is rotatably arranged on the mandrel and surrounds the mandrel to form a lubricating gap. A liquid lubricating medium is arranged in the lubricating gap. An air absorption coating is arranged on the inner wall of the lubricating gap. The air absorption coating is used for adsorbing the gas escaping from the inside of the liquid lubricating medium when the liquid lubricating medium flows in the lubricating gap. The technical scheme of the application can solve the technical problem that the lubricating performance of the liquid metal is reduced due to the mixing of the gas.

Description

Technical Field

[0001] This application belongs to the field of medical diagnostic equipment technology, and in particular relates to a liquid metal bearing with air intake function and its preparation method. Background Technology

[0002] CT (Computed Tomography) is a medical imaging diagnostic technique that uses X-rays to scan the human body from multiple angles and obtain cross-sectional images through computer reconstruction. It provides clearer and more detailed anatomical information than ordinary X-rays and is widely used to detect tumors, fractures, hemorrhages, or infections in areas such as the brain, chest, abdomen, and bones. It is an important tool for rapid clinical diagnosis and treatment planning. As a radiological diagnostic instrument, CT equipment is widely used in the field of medical diagnostic technology. The CT tube, as one of the core components of the CT equipment, primarily functions to generate and emit X-rays. The CT tube consists of a tube shell, a cathode electron gun, and an anode target disk; the cathode electron gun emits a high-speed electron beam, and the anode target disk receives the electron beam and generates the X-rays required for CT scanning.

[0003] To dissipate the enormous heat generated by the high-speed electron beam bombardment of the anode target disk and prevent it from burning out, the anode target disk is rotatably mounted on the tube shell via a liquid metal bearing. Its rotation relies on the liquid metal within the bearing for lubrication. During actual research and development, researchers discovered that during long-term operation, trace amounts of gas can mix into the liquid metal, forming microbubbles. These bubbles disrupt the continuity of the lubricating film formed when the liquid metal flows within the lubrication gap, reducing the hydrodynamic pressure effect of the liquid metal. This leads to a decrease in the lubrication performance of the liquid metal, affecting the normal rotation of the anode target disk and consequently impacting the service life of the CT tube. Summary of the Invention

[0004] The purpose of this application is to provide a liquid metal bearing with air suction function and a method for its preparation, aiming to solve the technical problem that the lubrication performance of liquid metal is reduced due to the mixing of gas.

[0005] To achieve the above objectives, this application proposes a liquid metal bearing with a suction function, comprising: mandrel; A bearing bush is rotatably mounted on the mandrel and surrounds the mandrel to form a lubrication gap. A liquid lubricating medium is disposed within the lubrication gap, and an air-absorbing coating is disposed on the inner wall of the lubrication gap. The air-absorbing coating is used to adsorb the gas that escapes from the interior of the liquid lubricating medium when the liquid lubricating medium flows within the lubrication gap.

[0006] In one embodiment, the thickness of the getter coating is 10 nm to 10 μm.

[0007] In one embodiment, the air-absorbing coating is a non-evaporative air-absorbing component.

[0008] In one embodiment, the air-absorbing coating has a porous structure and a microporous surface.

[0009] In one embodiment, a protective layer is provided on the side of the microporous surface facing away from the air-absorbing coating.

[0010] In one embodiment, the inner wall of the lubrication gap is provided with a wetting coating, and the suction coating is disposed on the wetting coating.

[0011] In one embodiment, a bonding layer is provided on the wetting coating, and the getter coating is disposed on the wetting coating through the bonding layer.

[0012] In one embodiment, the mandrel includes a shaft and an annular boss surrounding the shaft. The portion of the shaft located on one side of the annular boss is a first shaft body, and the portion of the shaft located on the other side of the annular boss is a second shaft body. A bearing bush is sleeved on the first shaft body and the annular boss. The inner surface of the bearing bush, the outer surface of the first shaft body, and the outer surface of the annular boss are all provided with the wetting coating. The suction coating is provided on the wetting coating of the first shaft body and the annular boss.

[0013] In addition, this application also proposes a preparation method for preparing the liquid metal bearing with air-absorbing function as described above, the preparation method comprising: Pre-treat the outer surface of the mandrel to be coated to remove surface oil and oxide layer; A getter coating is prepared on the surface of the mandrel to be coated, and the surface of the getter coating is microporousized. The bearing bush is fitted onto the mandrel, and liquid lubricating medium is injected into the lubrication gap formed by the bearing bush and the mandrel. The lubrication gap formed by the bearing bush and the spindle is sealed.

[0014] In one embodiment, the step of preparing a getter coating on the surface to be coated on the mandrel and microporousizing the surface of the getter coating includes: A getter coating is prepared on the surface of the mandrel to be coated using magnetron sputtering, and a reactive gas is introduced during the magnetron sputtering process to make the getter coating form a porous structure. After magnetron sputtering is completed, the surface of the getter coating is selectively etched with a dilute acid solution to remove the second-phase particles on the surface of the getter coating, so that the getter coating forms a microporous surface.

[0015] The technical solution of this application provides an air-absorbing coating on the inner wall of the lubrication gap to adsorb gas escaping from the interior of the liquid lubricating medium. This suppresses the decline in lubrication performance caused by gas mixing in the liquid lubricating medium, ensuring its lubrication performance and thus ensuring the normal rotation of the anode target disk and extending the service life of the CT tube. In this embodiment, the liquid metal bearing with air-absorbing function consists of a spindle and a bearing bush rotatably mounted on the spindle. The liquid lubricating medium is contained within the lubrication gap formed by the spindle and the bearing bush, thereby providing lubrication for the rotation of the bearing bush and the anode target disk. The air-absorbing coating is provided on the inner wall of the lubrication gap and is used to adsorb trace amounts of gas escaping from the interior of the liquid lubricating medium. By integrating an air-absorbing coating on the inner wall of the lubrication gap to adsorb trace amounts of gas escaping from the interior of the liquid lubricating medium when it flows within the lubrication gap, the volume proportion of gas mixed in the liquid lubricating medium can be reduced, thereby ensuring the lubrication performance of the liquid lubricating medium. Furthermore, the gas-absorbing coating is adjacent to the liquid lubricating medium within the lubrication gap, allowing it to rapidly adsorb gas escaping from the liquid lubricating medium, thus significantly improving adsorption efficiency. Specifically, during CT tube operation, the bearing rotates relative to the spindle, driving the liquid lubricating medium to flow within the lubrication gap. As the liquid lubricating medium flows, any gas mixed within it escapes from the interior of the liquid lubricating medium under compression and shearing forces. The gas-absorbing coating on the inner wall of the lubrication gap adsorbs this gas as it escapes from the liquid lubricating medium, reducing the volume percentage of gas mixed within it, ensuring the lubrication performance of the liquid lubricating medium, and consequently ensuring the normal rotation of the anode target disk and extending the service life of the CT tube. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort. In the drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0017] Figure 1 A schematic diagram of the structure of a liquid metal bearing in one embodiment provided in this application; Figure 2 A cross-sectional view of the lubrication gap in one embodiment provided in this application; Figure 3 A schematic diagram of the mandrel structure in one embodiment provided in this application; Figure 4A schematic flowchart of the preparation method in one embodiment provided in this application.

[0018] In the picture: 100, mandrel; 110, shaft; 111, first shaft body; 112, second shaft body; 120, annular boss; 200, bearing shell; 300, lubrication gap; 310, suction coating; 311, protective layer; 320, liquid lubricating medium; 330, wetting coating; 331, bonding layer. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is referred to as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0021] It should also be noted that if the embodiments of the present invention involve directional indications, such as up, down, left, right, front, back, etc., these directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. Furthermore, if the embodiments of the present invention involve descriptions such as "first," "second," "S1," "S2," "step one," "step two," etc., these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance, or implicitly indicating the number of technical features indicated or the order of method execution. Those skilled in the art will understand that anything that does not violate the inventive concept and does not contradict the inventive points should be included within the scope of protection of the present invention.

[0022] This application provides a liquid metal bearing with air suction function and a method for its preparation, aiming to solve the technical problem that the lubrication performance of liquid metal is reduced due to the mixing of gas.

[0023] Please see Figures 1 to 3This application proposes a liquid metal bearing with suction function for use in medical diagnostic equipment such as CT scanners. The CT tube, as one of the core components of a CT scanner, is mainly used to generate and emit X-rays. The CT tube includes a shell, a cathode electron gun, an anode target disk, and a liquid metal bearing. The cathode electron gun emits a high-speed electron beam. The anode target disk has a track surface inclined relative to its central axis. A portion of the annular area of ​​the track surface serves as the focal track to withstand the bombardment of the high-speed electron beam and generate X-rays for outward emission. The liquid metal bearing provides the structural basis for the rotation of the anode target disk; that is, the anode target disk is mounted on the liquid metal bearing and driven by the liquid metal bearing.

[0024] The liquid metal bearing with suction function includes a spindle 100 and a bearing bush 200. The bearing bush 200 is rotatably mounted on the spindle 100 and forms a lubrication gap 300 with the spindle 100. A liquid lubricating medium 320 is disposed within the lubrication gap 300, and a suction coating 310 is disposed on the inner wall of the lubrication gap 300. The suction coating 310 is used to adsorb the gas that escapes from the interior of the liquid lubricating medium 320 when it flows within the lubrication gap 300. In the CT tube, the rotation of the anode target disk is driven by a drive assembly, which includes a rotor and a stator. The rotor is mounted on the bearing bush 200 of the liquid metal bearing, and the stator is disposed outside the tube shell of the CT tube. During operation, by energizing the stator, the rotor and the bearing bush 200 on which the rotor is mounted can be driven to rotate using electromagnetic principles, thereby driving the anode target disk mounted on the bearing bush 200 to rotate. The rotation of the anode target disk is lubricated by a liquid lubricating medium 320 within the lubrication gap 300 of the liquid metal bearing. In this embodiment, the liquid lubricating medium 320 is liquid metal.

[0025] The technical solution of this application provides an air-absorbing coating 310 on the inner wall of the lubrication gap 300 to adsorb gas escaping from the interior of the liquid lubricating medium 320. This suppresses the decrease in lubrication performance of the liquid lubricating medium 320 caused by gas mixing, ensuring the lubrication performance of the liquid lubricating medium 320, thereby ensuring the normal rotation of the anode target disk and extending the service life of the CT tube. In this embodiment, the liquid metal bearing with air-absorbing function consists of a spindle 100 and a bearing bush 200 rotatably disposed on the spindle 100. The liquid lubricating medium 320 is contained within the lubrication gap 300 formed by the spindle 100 and the bearing bush 200, thereby providing lubrication for the rotation of the bearing bush 200 and the anode target disk. A gas-absorbing coating 310 is disposed on the inner wall of the lubrication gap 300 and is used to adsorb trace amounts of gas escaping from the interior of the liquid lubricating medium 320. By integrating the gas-absorbing coating 310 on the inner wall of the lubrication gap 300 to adsorb trace amounts of gas escaping from the interior of the liquid lubricating medium 320 when it flows within the lubrication gap 300, the volume proportion of gas mixed in the liquid lubricating medium 320 can be reduced, thereby ensuring the lubrication performance of the liquid lubricating medium 320. Furthermore, since the gas-absorbing coating 310 is adjacent to the liquid lubricating medium 320 within the lubrication gap 300, it can rapidly adsorb gas escaping from the liquid lubricating medium 320, which can greatly improve the adsorption efficiency. Specifically, during CT tube operation, the bearing 200 rotates relative to the spindle 100, causing the liquid lubricating medium 320 to flow within the lubrication gap 300. As the liquid lubricating medium 320 flows within this gap, any gas mixed in will escape from its interior under compression and shearing forces. The gas-absorbing coating 310 on the inner wall of the lubrication gap 300 adsorbs the gas as it escapes from the liquid lubricating medium 320, reducing the volume percentage of gas mixed in and ensuring the lubrication performance of the liquid lubricating medium 320. This, in turn, ensures the normal rotation of the anode target disk and extends the service life of the CT tube. This gas-absorbing liquid metal bearing is applied in the field of medical diagnostic equipment technology.

[0026] During long-term operation of the liquid metal bearing, trace amounts of gas may mix into the liquid lubricating medium 320, forming microbubbles. These bubbles disrupt the continuity of the lubricating film formed when the liquid lubricating medium 320 flows within the lubrication gap 300, reducing the hydrodynamic pressure effect of the liquid lubricating medium 320 and leading to a decline in its lubrication performance. Simultaneously, as the bubbles circulate with the liquid lubricating medium 320, they may undergo adiabatic compression in high-pressure areas, generating localized high temperatures, which further exacerbates material corrosion and wear in the liquid metal bearing. It should be noted that the sources of the trace gases mixed into the liquid lubricating medium 320 include: slow outgassing of the liquid metal bearing material under high-temperature vacuum conditions, chemical reaction products between the liquid lubricating medium 320 and the liquid metal bearing material, and microleakage, etc.

[0027] In traditional technical solutions, a separate gas-absorbing component is typically installed inside the liquid metal bearing to adsorb gas escaping from the liquid lubricating medium 320. However, due to the structural limitations of the liquid metal bearing, the gas-absorbing component is located in a region far from the lubrication gap 300. This results in the gas in the liquid lubrication medium 320 needing to travel a long diffusion path before being adsorbed by the gas-absorbing component, leading to low adsorption efficiency. Furthermore, installing a separate gas-absorbing component requires additional internal space in the liquid metal bearing, increasing its structural complexity and manufacturing cost. The technical solution of this application creatively reconstructs the gas management path inside the liquid metal bearing from its root cause. Specifically, a gas-absorbing coating 310 is installed on the inner wall of the lubrication gap 300, migrating the gas-absorbing structure from a location "far from the lubrication gap 300" to a location "where the gas escapes." This allows the gas escape and gas adsorption to highly overlap spatially, enabling rapid adsorption of gas escaping from the liquid lubrication medium 320 and improving adsorption efficiency. Meanwhile, the technical solution of this application only requires the preparation of an air-absorbing coating 310 on the inner wall of the lubrication gap 300, which does not require modification of the structure of the liquid metal bearing, thus keeping the liquid metal bearing in a simple structure and reducing the manufacturing cost of the liquid metal bearing.

[0028] In one embodiment of this application, the thickness of the getter coating 310 is 10 nm to 10 μm. In this embodiment, by designing the thickness of the getter coating 310 to 10 nm to 10 μm, it can ensure that the getter coating 310 has sufficient specific surface area and material capacity, so that the getter coating 310 can efficiently and continuously adsorb the gas overflowing from the liquid lubricating medium 320, avoiding rapid saturation failure due to the getter coating 310 being too thin. On the other hand, it can prevent the getter coating 310 from cracking and falling off due to being too thick.

[0029] In one embodiment of this application, the getter coating 310 is a non-evaporable getter component. In this embodiment, the getter coating 310 is made of a non-evaporable getter material, which is a metal or alloy material that does not require evaporation to form a thin film and only needs to be activated by heating to achieve getter function. When the CT tube is working, the heat generated by the anode target plate is transferred to the lubrication gap 300, which can activate the getter coating 310 by heat. It does not require an additional activation device, which simplifies the structure. At the same time, it can also ensure the immediacy and reliability of the getter coating 310 in adsorbing the gas escaping from the liquid lubricating medium 320.

[0030] In this embodiment, the non-evaporative getter material is selected from at least one of zirconium-based alloys, titanium-based alloys, or titanium-zirconium-vanadium alloys. The zirconium-based alloys include Zr-Al alloys, Zr-V-Fe alloys, or Zr-C alloys; the titanium-based alloys include Ti-Mo alloys; and the titanium-zirconium-vanadium alloys are Ti-Zr-V ternary alloys with a grain size of 3 nm to 5 nm and an activation temperature of 180 to 250 °C.

[0031] In one embodiment of this application, the getter coating 310 has a porous structure and a microporous surface. In this embodiment, by making the getter coating 310 a porous structure with a microporous surface, it can, on the one hand, increase the specific surface area of ​​the getter coating 310, providing more abundant adhesion sites for gas molecules, allowing the getter coating 310 to capture the escaping gas more fully and efficiently, thereby accelerating the adsorption rate and increasing the getter capacity of the getter coating 310; on the other hand, the capillary effect of the microporous surface helps guide gas molecules to diffuse into the interior of the getter coating 310, avoiding premature surface saturation and extending the effective service life of the getter coating 310. Furthermore, designing the getter coating 310 as a porous structure can, to a certain extent, buffer the shear stress generated by the flow of the liquid lubricating medium 320, enhance the adhesion between the coating and the substrate, and reduce the risk of peeling, thereby ensuring long-term getter function while maintaining the stability and reliability of the liquid metal bearing during operation. In a specific embodiment, the porosity of the porous structure formed by the getter coating 310 is 20% to 60%.

[0032] In this embodiment, the process by which the getter coating 310 adsorbs the gas escaping from the liquid lubricating medium 320 is chemical adsorption. That is, the hydrogen gas in the gas escaping from the liquid lubricating medium 320 will be physically adsorbed on the surface of the getter coating 310, then dispersed into hydrogen atoms and diffuse into the coating lattice; carbon monoxide, oxygen, and nitrogen will react with the active metal atoms of the getter coating 310 to generate stable compounds.

[0033] Please see Figure 1 and Figure 2In one embodiment of this application, a protective layer 311 is provided on the side of the microporous surface facing away from the getter coating 310. In this embodiment, the protective layer 311 is used to isolate the getter coating 310 from the liquid lubricating medium 320, so as to prevent the getter coating 310 from corroding or peeling off due to direct contact with the liquid lubricating medium 320, thereby ensuring that the getter coating 310 can perform its gas adsorption function for a long time and stably. In addition, the protective layer 311 can also promote the dissociation of hydrogen molecules into hydrogen atoms and accelerate their diffusion into the interior of the getter coating 310. In a specific embodiment, the protective layer 311 can be a nickel-based protective layer. The protective layer 311 can be prepared on the surface of the getter coating 310 by electroplating or chemical plating.

[0034] Please see Figure 1 and Figure 2 In one embodiment of this application, a wetting coating 330 is provided on the inner wall of the lubrication gap 300, and a getter coating 310 is provided on the wetting coating 330. A bonding layer 331 is provided on the wetting coating 330, and the getter coating 310 is provided on the wetting coating 330 through the bonding layer 331. In this embodiment, the wetting coating 330 is a molybdenum coating, which can improve the wettability between the liquid lubricating medium 320 and the liquid metal bearing substrate material, thereby ensuring the uniform spread and stable load-bearing of the liquid lubricating medium 320 in the lubrication gap 300. The bonding layer 331 can improve the bonding strength of the getter coating 310 when it is provided on the wetting coating 330, so as to prevent the getter coating 310 from falling off. In a specific embodiment, the bonding layer 331 can be made of active metals with good compatibility such as titanium and chromium, and is deposited on the surface of the wetting coating 330 using physical vapor deposition technology such as magnetron sputtering.

[0035] Please see Figures 1 to 3 In one embodiment of this application, the mandrel 100 includes a shaft 110 and an annular boss 120 surrounding the shaft 110. The portion of the shaft 110 located on one side of the annular boss 120 is a first shaft body 111, and the portion of the shaft 110 located on the other side of the annular boss 120 is a second shaft body 112. A bearing bush 200 is sleeved on the first shaft body 111 and the annular boss 120. A wetting coating 330 is provided on the inner surface of the bearing bush 200, the outer surface of the first shaft body 111, and the outer surface of the annular boss 120. A suction coating 310 is provided on the wetting coating 330 provided on the first shaft body 111 and the annular boss 120. In this embodiment, by preparing the suction coating 310 on the annular boss 120 of the shaft 110 and the outer surface of the first shaft body 111, the preparation difficulty of the suction coating 310 can be reduced, thereby reducing the manufacturing difficulty of the liquid metal bearing with suction function.

[0036] In this embodiment, the lubrication gap 300 is sequentially provided with a wetting coating 330, a bonding layer 331, a gas-absorbing coating 310, a protective layer 311, a liquid lubricating medium 320, and a gas-absorbing coating 330 from the mandrel 100 to the bearing bush 200. The gas-absorbing coating 310 is disposed between the bonding layer 331 and the protective layer 311. The bonding layer 331 is used to improve the bonding strength of the gas-absorbing coating 310 when it is disposed on the wetting coating 330, so as to prevent the gas-absorbing coating 310 from falling off. The protective layer 311 is used to prevent the gas-absorbing coating 310 from corroding or falling off due to direct contact with the liquid lubricating medium 320, thereby ensuring that the gas-absorbing coating 310 can perform its gas adsorption function for a long time and stably. With the above-mentioned multi-layer structure design, the gas-absorbing coating 310 is encapsulated between the bonding layer 331 and the protective layer 311, forming a "sandwich" protective structure. Through the synergistic effect of the bonding layer 331 and the protective layer 311, the structural integrity of the gas-absorbing coating 310 can be guaranteed, and the gas adsorption function of the gas-absorbing coating 310 can be maintained, thereby improving the operational reliability of the liquid metal bearing and extending the service life of the liquid metal bearing.

[0037] Please see Figure 4 , Figure 4 This is a schematic flowchart of a preparation method provided in one embodiment of this application. This preparation method is used to prepare the aforementioned liquid metal bearing with air-absorbing function. The preparation method includes: S100, Pre-treat the outer surface of the mandrel 100 to be coated, so as to remove surface oil and oxide layer from the outer surface of the mandrel 100 to be coated; wherein, the surface roughness of the outer surface of the mandrel 100 to be coated after pre-treatment is controlled within 0.1μm to 0.4μm; S200: Prepare a getter coating 310 on the surface of the mandrel 100 to be coated, and perform microporous treatment on the surface of the getter coating 310. S300, The bearing bush 200 is fitted onto the spindle 100, and the liquid lubricating medium 320 is poured into the lubrication gap 300 formed by the bearing bush 200 and the spindle 100; S400, the lubrication gap 300 formed by the bushing 200 and the spindle 100 is sealed.

[0038] In this embodiment, through steps S100 to S400, a gas-absorbing coating 310 is prepared on the inner wall of the lubrication gap 300 during the manufacturing of the liquid metal bearing. This coating adsorbs gas escaping from the interior of the liquid lubricating medium 320 during CT tube operation, thereby suppressing the decrease in lubrication performance caused by gas mixing into the liquid lubricating medium 320, ensuring the lubrication performance of the liquid lubricating medium 320, and thus ensuring the normal rotation of the anode target disk and extending the service life of the CT tube. Specifically, before step S100, a wetting coating 330 and a bonding layer 331 need to be prepared on the outer surface of the mandrel 100 to be coated, and after step S200, a protective layer 311 needs to be prepared on the surface of the gas-absorbing coating 310.

[0039] In one embodiment of this application, step S200 includes preparing a getter coating 310 on the surface of the mandrel 100 to be coated using a magnetron sputtering process, and introducing a reactive gas (such as oxygen, nitrogen, etc.) during the magnetron sputtering process to make the getter coating 310 form a porous structure; after the magnetron sputtering is completed, the surface of the getter coating 310 is selectively etched with a dilute acid solution to remove the second phase particles on the surface of the getter coating 310 so that the getter coating 310 forms a microporous surface.

[0040] In this embodiment, the getter coating 310 is formed with a porous structure and microporous surface through magnetron sputtering combined with the introduction of reactive gases and selective etching with dilute acid solution: First, during the magnetron sputtering process, reactive gases (such as oxygen or nitrogen) are introduced into the sputtering chamber. These reactive gases react chemically with the sputtered target atoms, generating dispersed second-phase particles (such as oxides or nitrides) in situ during the growth of the getter coating 310. These second-phase particles act as "site-fillers" embedded in the metal matrix of the getter coating 310, hindering the dense packing of metal atoms, thereby forming a large number of pore structures inside the getter coating 310, so that the getter coating 310 forms a columnar crystalline porous structure; subsequently, after the magnetron sputtering is completed, a process is employed... A dilute acid solution is used to selectively etch the coating surface. Since the corrosion rate of dilute acid on second-phase particles (such as metal oxides or nitrides) is significantly higher than that on the getter metal substrate, the etching process preferentially dissolves the second-phase particles on the surface of the getter coating 310. The locations previously occupied by these dissolved particles form open, recessed micropores, ultimately constructing a microporous surface with gas adsorption activity on the surface of the getter coating 310. The pore size of the surface micropores ranges from 50 nm to 2 μm, while the interconnected channels formed inside the coating due to residual or partially dissolved second-phase particles constitute pathways for gas diffusion to deeper layers. This achieves a gradient structure from surface micropores to internal pores, providing sufficient surface area and diffusion channels for efficient gas adsorption. Specifically, during magnetron sputtering, the sputtering target is a Zr-Al, Zr-V-Fe, Ti-Mo, or Ti-Zr-V alloy target, the sputtering working gas is Ar, and the sputtering pressure is 0.3 Pa.

[0041] Before step S200, the pretreated mandrel 100 is further subjected to Ar ion bombardment cleaning of the outer surface to be coated, in order to remove residual oxides and activate the surface. The bias voltage for bombardment cleaning is -500V to 800V, and the time is 5 min to 15 min.

[0042] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A liquid metal bearing with air-suction function, characterized in that, include: mandrel; A bearing bush is rotatably mounted on the mandrel and surrounds the mandrel to form a lubrication gap. A liquid lubricating medium is disposed within the lubrication gap, and an air-absorbing coating is disposed on the inner wall of the lubrication gap. The air-absorbing coating is used to adsorb the gas that escapes from the interior of the liquid lubricating medium when the liquid lubricating medium flows within the lubrication gap.

2. The liquid metal bearing with air-suction function as described in claim 1, characterized in that, The thickness of the air-absorbing coating is 10 nm to 10 μm.

3. The liquid metal bearing with air-suction function as described in claim 1, characterized in that, The air-absorbing coating is a non-evaporative air-absorbing component.

4. The liquid metal bearing with air-suction function as described in claim 1, characterized in that, The air-absorbing coating has a porous structure and a microporous surface.

5. The liquid metal bearing with air-suction function as described in claim 4, characterized in that, A protective layer is provided on the side of the microporous surface that is away from the air-absorbing coating.

6. The liquid metal bearing with air-suction function as described in claim 1, characterized in that, The inner wall of the lubrication gap is provided with a wetting coating, and the suction coating is disposed on the wetting coating.

7. The liquid metal bearing with air-suction function as described in claim 6, characterized in that, A bonding layer is provided on the wetting coating, and the air-absorbing coating is disposed on the wetting coating through the bonding layer.

8. The liquid metal bearing with air-suction function as described in claim 6, characterized in that, The mandrel includes a shaft and an annular boss surrounding the shaft. The portion of the shaft located on one side of the annular boss is a first shaft body, and the portion of the shaft located on the other side of the annular boss is a second shaft body. The bearing bush is sleeved on the first shaft body and the annular boss. The inner surface of the bearing bush, the outer surface of the first shaft body, and the outer surface of the annular boss are all provided with the wetting coating. The suction coating is provided on the wetting coating of the first shaft body and the annular boss.

9. A preparation method for preparing a liquid metal bearing with air-absorbing function as described in any one of claims 1 to 8, characterized in that, The preparation method includes: Pre-treat the outer surface of the mandrel to be coated to remove surface oil and oxide layer; A getter coating is prepared on the surface of the mandrel to be coated, and the surface of the getter coating is microporousized. The bearing bush is fitted onto the mandrel, and liquid lubricating medium is injected into the lubrication gap formed by the bearing bush and the mandrel. The lubrication gap formed by the bearing bush and the spindle is sealed.

10. The preparation method according to claim 9, characterized in that, The steps of preparing a getter coating on the surface of the mandrel to be coated and microporousizing the surface of the getter coating include: A getter coating is prepared on the surface of the mandrel to be coated using magnetron sputtering, and a reactive gas is introduced during the magnetron sputtering process to make the getter coating form a porous structure. After magnetron sputtering is completed, the surface of the getter coating is selectively etched with a dilute acid solution to remove the second-phase particles on the surface of the getter coating, so that the getter coating forms a microporous surface.

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