Reinforced liquid metal sliding bearing

Abstract

The invention relates to the technical field of metal bearings, in particular to a reinforced liquid metal sliding bearing. The enhanced liquid metal sliding bearing comprises a rotor, a stator and liquid metal filled in an assembling gap between the rotor and the stator. The fixed positions of the rotor and the stator are provided with a spiral groove structure, a textured microstructure, an infiltration coating and a sealing coating. By adopting the enhanced liquid metal sliding bearing provided by the invention, the wettability and the wear resistance of a bearing rotating pair can be improved, and the problems of coating falling, wear, poor lubrication and the like of the enhanced liquid metal sliding bearing in a high-vacuum, high-temperature, high-pressure, high-speed and high-load use environment are effectively solved. High-pressure sealing is formed on the gaps between the stator and the rotor and between the limiting rings of the stator and the rotor, the liquid metal is kept in the bearing, the assembled bearing does not need a vacuum environment in the transfer process, meanwhile, external gas is prevented from entering the bearing structure, and the possibility that the liquid metal leaks or gets stuck is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of hydrodynamic bearings, and in particular to a reinforced liquid metal sliding bearing. Background Art

[0002] X-ray tubes are used to generate and amplify X-rays. Ball bearings are currently widely used in X-ray tubes. However, as ball bearings wear out during use, the working noise becomes louder and louder, and the bearing capacity is weak and the life is short. It is difficult to meet the application requirements of high-end CT systems. They are gradually being replaced by enhanced liquid metal sliding bearings. Enhanced liquid metal sliding bearings are mainly composed of rotors, stators and sealing structures. Liquid metal is used as a lubricant to fill the gap of the rotating pair, and a high-pressure seal is formed on the bearing sealing surface to keep the liquid metal in the bearing. However, due to the high surface tension of liquid metal and its adhesion to the bearing surface, liquid metal often leaks, especially after the liquid metal is oxidized to gallium oxide.

[0003] In view of the above problems, the current solutions can only improve the wettability or wear resistance of the enhanced liquid metal sliding bearings, but not both at the same time. Sealing rings or other sealing materials can also be used to enhance the sealing between the liquid metal and the bearing components. In addition, the wettability of the liquid metal to the seal can be reduced by changing the material or anti-wetting surface of the seal, such as PVD or CVD coating on the surface; currently, the enhanced liquid metal sliding bearings can also be coated with a surface coating, but because the coating only exists on the surface, the wettability, sealing and wear resistance cannot be fully improved. The most important thing is that the coating has the risk of falling off, and the life and reliability of the bearing are limited. In particular, the current improved sealing ring method often cannot provide sufficient sealing, and is more likely to become a leakage point during use, bringing new risk points, further affecting the performance and life of the bearing. The Chinese patent with patent application number 202210580147.7 discloses a liquid metal hydrodynamic sliding bearing, a groove coating manufacturing method and an X-ray tube. By arranging liquid metal material between the rotating shell and the bearing core of the sliding bearing, low friction and high wear resistance of the sliding bearing are achieved, but no solution is provided for the sealing problem.

[0004] Therefore, providing a method for improving the wettability, wear resistance and sealing of liquid metal sliding bearings is a major technical problem that needs to be solved at present. Summary of the invention

[0005] A first aspect of the present invention provides a device for enhancing a liquid metal sliding bearing, the enhanced liquid metal sliding bearing comprising a rotor, a stator, and liquid metal 5, wherein the liquid metal is filled in an assembly gap between the rotor and the stator; the rotor comprises a sealing cover 4, a rotating drum 1, and a limiting ring 3.

[0006] In one embodiment, the stator comprises a support shaft 2 .

[0007] In one embodiment, the liquid metal is gallium-based liquid metal.

[0008] The inventors discovered during the experiment that, according to the enhanced liquid metal sliding bearing structure provided in the present application, a high-pressure seal can be formed between the liquid metal and the bearing surface after the bearing is filled with liquid and assembled: a high-pressure seal is formed on the gap between the stator and the rotor and between the sealing covers of the stator and the rotor to keep the liquid metal inside the bearing. During the transportation process of the assembled bearing, no vacuum environment is required, and at the same time, external gas is prevented from entering the bearing structure, thereby reducing the possibility of liquid metal leakage or jamming.

[0009] In one embodiment, the rotating drum and the limiting ring have a spiral groove structure and a textured microstructure at the fixed positions; and the stator has a spiral groove structure at the fixed position.

[0010] In one embodiment, the spiral groove structure is a groove structure, and the spiral groove structure includes a first groove, a second groove, and a third groove.

[0011] In one embodiment, the sealing area plane of the limiting ring of the rotor has a textured microstructure.

[0012] During the experiment, the inventors found that in order to improve the sealing performance of the bearing stator and rotor sealing surfaces, the inventors designed a textured microstructure in the enhanced liquid metal sliding bearing, which can effectively prevent the liquid metal from leaking to the outside of the bearing, improve the sealing and protection performance of the bearing, and further improve the service life and reliable stability of the bearing.

[0013] In one embodiment, the textured microstructure includes one or more structures selected from the group consisting of a micrometer-scale honeycomb structure, a papillary structure, a dendritic structure, and a scalene structure.

[0014] In one embodiment, the textured microstructure is a micrometer-scale honeycomb structure or a papillary structure or a dendritic structure or a scalene structure.

[0015] In one embodiment, the textured microstructure is a micrometer-scale honeycomb structure.

[0016] In one embodiment, the surface of the textured microstructure has a sealing coating.

[0017] In one embodiment, the sealing coating comprises an anti-wetting layer.

[0018] In one embodiment, the sealing coating is an anti-wetting layer.

[0019] In one embodiment, the sealing coating has a film thickness of 0.05 to 2.0 μm.

[0020] In one embodiment, the sealing coating thickness may be 0.05 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2.0 μm.

[0021] In a preferred embodiment, the sealing coating has a thickness of 0.6 μm or 0.8 μm.

[0022] In one embodiment, the component of the sealing coating is selected from any one of aluminum oxide, aluminum nitride, aluminum oxide silicon, titanium nitride, tungsten nitride, tungsten carbide, zirconium nitride, chromium nitride, titanium aluminum nitride, diamond, and graphene, and the particle size of the component of the sealing coating may be nanometer size.

[0023] In a preferred embodiment, the sealing coating component is selected from any one of aluminum oxide, aluminum nitride, aluminum oxide silicon, tungsten nitride, tungsten carbide, zirconium nitride, chromium nitride, and graphene, and the particle size of the sealing coating component can be nanometer size.

[0024] In a more preferred embodiment, the sealing coating component is more preferably any one of aluminum oxide, aluminum silicon oxide, tungsten carbide, chromium nitride, and graphene, and the particle size of the sealing coating component may be nanometer size.

[0025] In a more preferred embodiment, the sealing coating component is any one of nano-aluminum oxide, nano-chromium nitride, and graphene.

[0026] The inventors found during the experiment that the textured microstructure combined with the sealing coating can achieve optimal sealing and anti-infiltration properties.

[0027] In one embodiment, the sealing structure comprises a textured microstructure and a sealing coating.

[0028] The inventors discovered during the experiment that a textured microstructure design combined with a sealing coating is used in an enhanced liquid metal sliding bearing structure. The sealing coating has strong substrate bonding, excellent wear resistance and anti-wetting properties to reduce the adhesion or wetting of liquid metal to the surface of the bearing structure, thereby solving the problem of liquid metal leakage from the sealing surface.

[0029] In one embodiment, the rotating pairs of the rotor and the stator have a wetting coating.

[0030] In one embodiment, the rotating pair surfaces of the rotor and the stator and the groove structure surfaces thereof have a wetting coating.

[0031] In one embodiment, the infiltration coating comprises a base layer and a wetting layer.

[0032] In one embodiment, the base layer is in contact with the rotational secondary surface and the groove structure surface thereof, and the base layer is interposed between the rotational secondary surface and the wetting layer.

[0033] In one embodiment, the film thickness of the wetting coating is 0.05-1.5 μm.

[0034] In one embodiment, the base layer may have a thickness of 0.05 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, or 0.5 μm.

[0035] In a preferred embodiment, the base layer has a thickness of 0.05 μm or 0.3 μm.

[0036] In one embodiment, the wetting layer has a thickness of 0.1 to 1.0 μm.

[0037] In one embodiment, the wetting layer may have a thickness of 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1.0 μm.

[0038] In a preferred embodiment, the wetting layer has a thickness of 0.3 μm or 0.5 μm.

[0039] The inventors found during the experiment that the wetting coating provided by the present invention has super strong bonding force with the substrate, and the wetting coating has the advantages of high hardness, low friction coefficient, excellent liquid metal wettability and wear resistance.

[0040] In one embodiment, the component of the base layer is any one of titanium nitride, chromium nitride, tungsten carbide, titanium aluminum nitride, titanium carbonitride, niobium nitride, silicon boride, diamond, and graphene, and the particle size of the component of the base layer may be nanometer size.

[0041] In a preferred embodiment, the component of the base layer is any one of chromium nitride, tungsten carbide, niobium nitride, titanium carbonitride, diamond, graphene, and boron nitride, and the particle size of the component of the base layer can be nanometer size.

[0042] In a preferred embodiment, the base layer is composed of nano-boron nitride or nano-tungsten carbide; and the base layer is treated by laser pulse strengthening.

[0043] In one embodiment, the component of the wetting layer is one or more of gold, silver, copper, niobium, tantalum, rhenium, nickel, tungsten, molybdenum, indium, tin and their halides or sulfides, and the particle size of the component of the wetting layer may be nanometer size.

[0044] In a preferred embodiment, the component of the wetting layer is any one of gold, niobium, tantalum, tungsten, molybdenum, indium and their halides or sulfides, and the particle size of the component of the wetting layer may be nanometer size.

[0045] In a preferred embodiment, the wetting layer is composed of nano-tungsten and molybdenum sulfide.

[0046] During the experiment, the inventors found that in order to improve the wettability and wear resistance of the rotating pair of the enhanced liquid metal sliding bearing, by limiting the rotating pair surface and groove structure surface of the rotor and stator in the enhanced liquid metal sliding bearing to have an infiltration coating, the wettability and wear resistance of the rotating pair of the enhanced liquid metal sliding bearing can be improved, so that the wettability, lubricity and wear resistance of the rotating pair area can be taken into account, effectively solving the problems of coating shedding, wear, poor lubrication, etc. of the enhanced liquid metal sliding bearing in the high vacuum, high temperature, high pressure, high speed and high load use environment.

[0047] In the present application, in order to facilitate the distinction between the wetting coating and the sealing coating, the wetting coating included in the drum 1 is distinguished as the first wetting coating, the second wetting coating, and the third wetting coating; the sealing coating included on the drum 1 is distinguished as the first sealing coating and the second sealing coating. The wetting coating included in the support shaft 2 is distinguished as the fourth wetting coating, the fifth wetting coating, and the sixth wetting coating; the sealing coating included in the limit ring 3 is distinguished as the third sealing coating, and the wetting coating included in the limit ring 3 is distinguished as the seventh wetting coating; the wetting coating included in the sealing cover 4 is distinguished as the eighth wetting coating; and the sealing coating included in the sealing cover 4 is distinguished as the fourth sealing coating.

[0048] In one embodiment, the structural schematic diagram of the sealing structure is as follows Figure 5 As shown, the sealing structure includes a textured microstructure 3211 and an anti-wetting layer 3212 .

[0049] In one embodiment, the structural schematic diagram of the rotating drum is as follows Figure 2 As shown, the drum 1 is provided with a drum center hole 11, a first wetting coating 111, a drum inner step 12, a second wetting coating 121, a first groove 122, a first liquid storage tank 123, a drum inner step side wall 13, a third wetting coating 131, a drum large outer end surface 14, a first sealing coating 141, a drum small outer end surface 15, and a second sealing coating 151.

[0050] In one embodiment, the structural diagram of the support shaft is as follows: Figure 3 As shown, the support shaft 2 is provided with a bearing 21, a second groove 211, a second liquid storage tank 212, a fourth wetting coating 213, a third liquid storage tank 214, a flange section 22, a fifth wetting coating 221, a limiting surface 222, a fixing section 23, and a sixth wetting coating 231.

[0051] In one embodiment, the structural diagram of the limiting ring is as follows: Figure 4 As shown, the limiting ring 3 is provided with a limiting ring groove area 31, a third groove 311, a seventh wetting coating 312, a limiting ring sealing area 32, a third sealing coating 321, a textured microstructure 3211, an anti-wetting layer 3212, a first surface 33, an inner hole 34, a second surface 35, and a third surface 36.

[0052] In one embodiment, the structural diagram of the sealing cover is as follows: Figure 6 As shown, the sealing cover 4 is provided with a central area 41 , an eighth wetting coating 411 , a sealing area 42 , and a fourth sealing coating 421 .

[0053] The structural schematic diagram of the textured microstructure is as follows Figure 7 As shown, the metallographic image of the textured microstructure is as follows Figure 8 shown.

[0054] In one embodiment, the sealing coating and the wetting coating are both subjected to laser pulse strengthening treatment.

[0055] In one embodiment, the laser pulse strengthening treatment is a laser shock coating to make it nano-sized, using a stacked laser, setting the wavelength of the stacked laser to 365nm, the laser rated power to 30W, the beam quality M2 <1.1, the power output to 20%, the pulse width to 100ps, and the rotation rate to 2000mm / s.

[0056] Beneficial Effects

[0057] 1. By adopting the technical solution provided by the present invention, the wettability and wear resistance of the bearing rotating pair can be improved, and the key problems of coating shedding, wear, poor lubrication, etc. of the enhanced liquid metal sliding bearing in the use environment of high vacuum, high temperature, high pressure, high speed and high load can be effectively solved.

[0058] 2. By adopting the technical solution provided by the present invention, the sealing performance of the bearing stator and rotor sealing surfaces can be improved: the present invention provides a special textured microstructure combined with a sealing coating, which can effectively prevent liquid metal from seeping out of the bearing, thereby improving the sealing performance of the bearing and further improving the service life and reliability of the bearing.

[0059] 3. By adopting the technical solution provided by the present invention, the problems of liquid metal leakage and jamming can be effectively solved. The enhanced liquid metal sliding bearing treated by the technical solution of the present invention can prevent liquid metal from migrating along the surface of bearing components, reduce the risk of leakage into the vacuum space inside the tube, ensure that there is sufficient liquid metal lubricant inside the bearing, and effectively reduce the direct contact and wear between the stator and the rotor, thereby maintaining the pressure resistance of the CT tube, avoiding high-voltage ignition failures, reducing the risk of bearing jamming, and ensuring the safe operation of the entire CT machine.

[0060] 4. By adopting the technical solution provided by the present invention, the manufacturing cost is low, the stability is high, the durability is good, and the problems of liquid metal leakage and bearing jamming can be solved.

[0061] 5. By adopting the technical solution provided by the present invention and according to the enhanced liquid metal sliding bearing structure provided in the present application, a high-pressure seal can be formed between the liquid metal and the bearing surface after the bearing is filled with liquid and assembled: a high-pressure seal is formed on the gap between the stator and the rotor and between the limiting rings of the stator and the rotor to keep the liquid metal inside the bearing. During the transportation process of the assembled bearing, no vacuum environment is required, and external gas is prevented from entering the bearing structure, thereby reducing the possibility of liquid metal leakage or jamming. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 Schematic diagram of the cross section of the enhanced liquid metal sliding bearing.

[0063] Figure 2 Schematic diagram of the structure of the rotor drum for enhancing the liquid metal sliding bearing.

[0064] Figure 3 Schematic diagram of the structure of the stator support shaft for enhancing the liquid metal sliding bearing.

[0065] Figure 4 Schematic diagram of the structure of the rotor limit ring for enhancing the liquid metal sliding bearing.

[0066] Figure 5 This is a schematic diagram of the enlarged structure of the limit ring surface structure.

[0067] Figure 6 Schematic diagram of the structure of the rotor sealing cover for the enhanced liquid metal sliding bearing.

[0068] Figure 7 Schematic diagram of the textured microstructure.

[0069] Figure 8 Metallographic image of the textured microstructure.

[0070] Fig. 9 This is a diagram showing the contact angle state of liquid metal on the surface of the sealing structure before the sealing coating is applied.

[0071] Fig.10 This is a diagram showing the contact angle state of liquid metal on the surface of the sealing structure after the sealing coating is applied.

[0072] Fig.11 A diagram showing the contact angle of liquid metal on the surface of a bearing after a sealing structure and a sealing coating are set.

[0073] Fig.12 This is a diagram of the contact angle of liquid metal on the surface of the bearing before there is any wetting coating.

[0074] Fig.13 This is a diagram showing the contact angle state of liquid metal on the surface of the bearing after the wetting coating is set on it.

[0075] Figure 1 Middle: 1-rotating drum, 2-supporting shaft, 3-limiting ring, 4-sealing cover, 5-liquid metal.

[0076] Figure 2 In: 1-rotor, 11-rotor center hole, 111-first wetting coating, 12-rotor inner step, 121-second wetting coating, 122-first groove, 123-first liquid storage tank, 13-rotor inner step side wall, 131-third wetting coating, 14-rotor large outer end face, 141-first sealing coating, 15-rotor small outer end face, 151-second sealing coating.

[0077] Figure 3 Middle: 2-support shaft, 21-bearing, 211-second groove, 212-second liquid storage tank, 213-fourth wetting coating, 214-third liquid storage tank, 22-flange section, 221-fifth wetting coating, 222-limiting surface, 23-fixing section, 231-sixth wetting coating.

[0078] Figure 4 Middle: 3-limiting ring, 31-limiting ring groove area, 311-third groove, 312-seventh wetting coating, 32-limiting ring sealing area, 321-third sealing coating, 33-first surface, 34-inner hole, 35-second surface, 36-third surface.

[0079] Figure 5 Middle: 3211-textured microstructure, 3212-anti-wetting layer.

[0080] Figure 6 Middle: 4-sealing cover, 41-central area, 411-eighth wetting coating, 42-sealing area, 421-fourth sealing coating. DETAILED DESCRIPTION

[0081] Example 1

[0082] This embodiment provides a method for enhancing a liquid metal sliding bearing, wherein the enhanced liquid metal sliding bearing comprises a rotor, a stator, and liquid metal 5, wherein the liquid metal is filled in an assembly gap between the rotor and the stator; the rotor comprises a sealing cover 4, a rotating drum 1, and a limiting ring 3.

[0083] The stator comprises a supporting shaft 2 .

[0084] The liquid metal is gallium-based liquid metal.

[0085] The rotating drum and the limiting ring have a spiral groove structure and a textured microstructure at the fixed positions; the stator has a spiral groove structure at the fixed position.

[0086] The spiral groove structure is a groove structure, and the spiral groove structure includes a first groove 122 , a second groove 211 , and a third groove 311 .

[0087] The sealing structure comprises a textured microstructure and a sealing coating.

[0088] The sealing area plane of the limiting ring of the rotor has a textured microstructure.

[0089] The textured microstructure is a micron-scale honeycomb structure.

[0090] The micron-scale honeycomb structure has a side length of 50 μm, a side width of 20 μm, and a side height of 0.5 μm.

[0091] The surface of the textured microstructure has a sealing coating.

[0092] The sealing coating is an anti-wetting layer.

[0093] The anti-wetting layer has a thickness of 0.6 μm.

[0094] The component of the anti-wetting layer is nano-aluminum oxide.

[0095] The rotating pair surfaces of the rotor and the stator and the groove structure surfaces thereof are provided with a wetting coating.

[0096] The wetting coating includes a base layer and a wetting layer, the base layer has a thickness of 0.05 μm, and the wetting layer has a thickness of 0.3 μm.

[0097] The base layer is in contact with the rotational secondary surface and the groove structure surface thereof, and the base layer is located between the rotational secondary surface and the wetting layer.

[0098] The component of the base layer is nano boron nitride.

[0099] The component of the wetting layer is nano tungsten.

[0100] The sealing coating and the wetting coating are both subjected to laser pulse strengthening treatment.

[0101] The laser pulse strengthening process uses a stacked laser, and sets the wavelength of the stacked laser to 365nm, the laser rated power to 30W, the beam quality M2<1.1, the power output to 20%, the pulse width to 100ps, and the pulse jump rate to 2000mm / s.

[0102] The cross-sectional schematic diagram of the enhanced liquid metal sliding bearing is as follows Figure 1 shown.

[0103] The structural schematic diagram of the rotating drum is as follows Figure 2 As shown, the drum 1 is provided with a drum center hole 11, a first wetting coating 111, a drum inner step 12, a second wetting coating 121, a first groove 122, a first liquid storage tank 123, a drum inner step side wall 13, a third wetting coating 131, a drum large outer end surface 14, a first sealing coating 141, a drum small outer end surface 15, and a second sealing coating 151.

[0104] The structural schematic diagram of the support shaft is as follows Figure 3 As shown, the support shaft 2 is provided with a bearing 21, a second groove 211, a second liquid storage tank 212, a fourth wetting coating 213, a third liquid storage tank 214, a flange section 22, a fifth wetting coating 221, a limiting surface 222, a fixing section 23, and a sixth wetting coating 231.

[0105] The structural diagram of the limiting ring is as follows Figure 4 As shown, the limiting ring 3 is provided with a limiting ring groove area 31, a third groove 311, a seventh wetting coating 312, a limiting ring sealing area 32, a third sealing coating 321, a base layer 3211, an anti-wetting layer 3212, a first surface 33, an inner hole 34, a second surface 35, and a third surface 36.

[0106] The structural schematic diagram of the sealing structure is as follows Figure 5 As shown, the sealing structure includes a textured microstructure 3211 and an anti-wetting layer 3212 .

[0107] The structural schematic diagram of the sealing cover is as follows Figure 6 As shown, the sealing cover 4 is provided with a central area 41 , an eighth wetting coating 411 , a sealing area 42 , and a fourth sealing coating 421 .

[0108] The textured microstructure is as Figure 7 shown.

[0109] The metallographic image of the textured microstructure is shown in Figure 8 shown.

[0110] Example 2

[0111] This embodiment provides a method for enhancing a liquid metal sliding bearing, wherein the enhanced liquid metal sliding bearing comprises a rotor, a stator, and liquid metal 5, wherein the liquid metal is filled in an assembly gap between the rotor and the stator; the rotor comprises a sealing cover 4, a rotating drum 1, and a limiting ring 3.

[0112] The stator comprises a supporting shaft 2 .

[0113] The liquid metal is gallium-based liquid metal.

[0114] The rotating drum and the limiting ring have a spiral groove structure and a textured microstructure at the fixed positions; the stator has a spiral groove structure at the fixed position.

[0115] The spiral groove structure is a groove structure, and the spiral groove structure includes a first groove 122 , a second groove 211 , and a third groove 311 .

[0116] The sealing structure comprises a textured microstructure and a sealing coating.

[0117] The sealing area plane of the limiting ring of the rotor has a textured microstructure.

[0118] The textured microstructure is a micron-scale honeycomb structure.

[0119] The micron-scale honeycomb structure has a side length of 50 μm, a side width of 20 μm, and a side height of 0.5 μm.

[0120] The surface of the textured microstructure has a sealing coating.

[0121] The sealing coating is an anti-wetting layer.

[0122] The thickness of the anti-wetting layer is 0.8 μm.

[0123] The component of the anti-wetting layer is nano chromium nitride.

[0124] The rotating pair surfaces of the rotor and the stator and the groove structure surfaces thereof are provided with a wetting coating.

[0125] The wetting coating comprises a base layer and a wetting layer, the base layer has a thickness of 0.3 μm, and the wetting layer has a thickness of 0.5 μm.

[0126] The base layer is in contact with the rotational secondary surface and the groove structure surface thereof, and the base layer is located between the rotational secondary surface and the wetting layer.

[0127] The component of the base layer is nano tungsten carbide.

[0128] The component of the wetting layer is molybdenum sulfide.

[0129] The sealing coating and the wetting coating are both subjected to laser pulse strengthening treatment, and the laser pulse strengthening treatment method is the same as that in Example 1.

[0130] The structure of the enhanced liquid metal sliding bearing is the same as that of Example 1.

[0131] Comparative Example 1

[0132] This comparative example provides a method for enhancing a liquid metal sliding bearing, wherein the enhanced liquid metal sliding bearing comprises a rotor, a stator, and liquid metal 5, wherein the liquid metal is filled in an assembly gap between the rotor and the stator; the rotor comprises a sealing cover 4, a rotating drum 1, and a limiting ring 3.

[0133] The stator comprises a supporting shaft 2 .

[0134] The liquid metal is gallium-based liquid metal.

[0135] The rotating drum and the limiting ring have a spiral groove structure and a textured microstructure at the fixed positions; the stator has a spiral groove structure at the fixed position.

[0136] The spiral groove structure is a groove structure, and the spiral groove structure includes a first groove 122 , a second groove 211 , and a third groove 311 .

[0137] The sealing structure comprises a textured microstructure and a sealing coating.

[0138] The sealing area plane of the limiting ring of the rotor has a textured microstructure.

[0139] The textured microstructure is a micron-scale honeycomb structure.

[0140] The micron-scale honeycomb structure has a side length of 50 μm, a side width of 20 μm, and a side height of 0.5 μm.

[0141] The surface of the textured microstructure has a sealing coating.

[0142] The sealing coating is an anti-wetting layer.

[0143] The thickness of the anti-wetting layer is 0.8 μm.

[0144] The component of the anti-wetting layer is nano chromium nitride.

[0145] The rotating pair surfaces of the rotor and the stator and the groove structure surfaces thereof are provided with a wetting coating.

[0146] The wetting coating comprises a base layer and a wetting layer, the base layer has a thickness of 0.3 μm, and the wetting layer has a thickness of 0.5 μm.

[0147] The base layer is in contact with the rotational secondary surface and the groove structure surface thereof, and the base layer is located between the rotational secondary surface and the wetting layer.

[0148] The component of the base layer is nano tungsten carbide.

[0149] The component of the wetting layer is molybdenum sulfide.

[0150] The enhanced liquid metal sliding bearing structure is the same as that of Example 1.

[0151] Comparative Example 2

[0152] This comparative example provides a method for enhancing a liquid metal sliding bearing, wherein the enhanced liquid metal sliding bearing comprises a rotor, a stator, and liquid metal 5, wherein the liquid metal is filled in an assembly gap between the rotor and the stator; the rotor comprises a sealing cover 4, a rotating drum 1, and a limiting ring 3.

[0153] The stator comprises a supporting shaft 2 .

[0154] The liquid metal is gallium-based liquid metal.

[0155] The rotating drum and the limiting ring have a spiral groove structure and a textured microstructure at the fixed positions; the stator has a spiral groove structure at the fixed position.

[0156] The spiral groove structure is a groove structure, and the spiral groove structure includes a first groove 122 , a second groove 211 , and a third groove 311 .

[0157] The sealing structure comprises a textured microstructure and a sealing coating.

[0158] The sealing area plane of the limiting ring of the rotor has a textured microstructure.

[0159] The textured microstructure is a micron-scale honeycomb structure.

[0160] The micron-scale honeycomb structure has a side length of 50 μm, a side width of 20 μm, and a side height of 0.5 μm.

[0161] The surface of the textured microstructure has a sealing coating.

[0162] The sealing coating is an anti-wetting layer.

[0163] The thickness of the anti-wetting layer is 0.8 μm.

[0164] The anti-wetting layer is composed of chromium nitride.

[0165] The rotating pair surfaces of the rotor and the stator and the groove structure surfaces thereof are provided with a wetting coating.

[0166] The wetting coating is a wetting layer, and the thickness of the wetting layer is 0.5 μm.

[0167] The base layer is in contact with the rotational secondary surface and the groove structure surface thereof, and the base layer is located between the rotational secondary surface and the wetting layer.

[0168] The component of the wetting layer is molybdenum sulfide.

[0169] The sealing coating and the wetting coating are both subjected to laser pulse strengthening treatment, and the laser pulse strengthening treatment method is the same as that in Example 1.

[0170] The enhanced liquid metal sliding bearing structure is the same as that of Example 1.

[0171] Comparative Example 3

[0172] This comparative example provides a method for enhancing a liquid metal sliding bearing, wherein the enhanced liquid metal sliding bearing comprises a rotor, a stator, and liquid metal 5, wherein the liquid metal is filled in an assembly gap between the rotor and the stator; the rotor comprises a sealing cover 4, a rotating drum 1, and a limiting ring 3.

[0173] The stator comprises a supporting shaft 2 .

[0174] The liquid metal is gallium-based liquid metal.

[0175] The rotating drum and the limiting ring are provided with a spiral groove structure at the fixed positions.

[0176] The spiral groove structure is a groove structure, and the spiral groove structure includes a first groove 122 , a second groove 211 , and a third groove 311 .

[0177] The sealing area plane of the limiting ring of the rotor is provided with a sealing coating.

[0178] The sealing coating is an anti-wetting layer.

[0179] The thickness of the anti-wetting layer is 0.8 μm.

[0180] The component of the anti-wetting layer is nano chromium nitride.

[0181] The rotating pair surfaces of the rotor and the stator and the groove structure surfaces thereof are provided with a wetting coating.

[0182] The wetting coating comprises a base layer and a wetting layer, the base layer has a thickness of 0.3 μm, and the wetting layer has a thickness of 0.5 μm.

[0183] The base layer is in contact with the rotational secondary surface and the groove structure surface thereof, and the base layer is located between the rotational secondary surface and the wetting layer.

[0184] The component of the base layer is nano tungsten carbide.

[0185] The component of the wetting layer is molybdenum sulfide.

[0186] The sealing coating and the wetting coating are both subjected to laser pulse strengthening treatment, and the laser pulse strengthening treatment method is the same as that in Example 1.

[0187] The enhanced liquid metal sliding bearing structure is the same as that of Example 1.

[0188] The molybdenum sulfide, nano tungsten and chromium nitride used in the above-mentioned Examples 1-2 and Comparative Examples 1-3 are all commercially available products.

[0189] The nano-aluminum oxide, nano-boron nitride, nano-chromium nitride, nano-tungsten carbide, nano-chromium nitride, nano-chromium nitride, and nano-tungsten carbide used in the above-mentioned Examples 1-2 and Comparative Examples 1-3 are all of nano-grade, and there is no limitation on the particle size. All nano-grade ones can be used, and all are commercially available products.

[0190] Performance Testing

[0191] 1. Binding strength test: The binding strength between the sealing coating and the substrate in the enhanced liquid metal sliding bearing provided in Examples 1-2 and Comparative Examples 1-3 was tested. The test results are shown in Table 1. The specific binding strength test method and standard used was the scratch method GB / T30707-2014.

[0192] 2. Hardness test: The hardness of the sealing coating in the enhanced liquid metal sliding bearing provided in Example 1-2 and Comparative Example 1-3 was tested, and the test results are shown in Table 1; the hardness of the wetting coating in the enhanced liquid metal sliding bearing provided in Example 1-2 and Comparative Example 1-3 was tested, and the test results are shown in Table 2; the specific hardness test method and standard adopted are GB / T9790-2020.

[0193] 3. Liquid metal contact angle state test: The gallium-based liquid metal was subjected to a contact angle test on the sealing coating surface of the enhanced liquid metal sliding bearing provided in Examples 1-2 and Comparative Examples 1-3. The test results are shown in Table 1. The gallium-based liquid metal was subjected to a contact angle test on the wetting coating surface of the enhanced liquid metal sliding bearing provided in Examples 1-2 and Comparative Examples 1-3. The test results are shown in Table 2.

[0194] The contact angle of the liquid metal on the bearing surface without sealing coating and wetting coating and after sealing coating and wetting coating are set is shown in Figure 2. Figure 9-13 .

[0195] Said Fig. 9 It is a contact angle state diagram of liquid metal on the surface of the sealing structure before the sealing coating is removed; Fig.10 The contact angle state diagram of liquid metal on the surface of the sealing structure after the sealing coating is provided; Fig.11A state diagram of the contact angle of liquid metal on the surface of a bearing after a sealing structure and a sealing coating are provided; Fig.12 It is a contact angle state diagram of liquid metal on the surface of the bearing before there is no wetting coating; Fig.13 This is a diagram showing the contact angle of liquid metal on the surface of a bearing after a wetting coating is set on the bearing; Fig.13 It can be seen that the liquid metal has complete wettability on the infiltrated coating.

[0196] When the contact angle between the liquid metal and the bearing surface is <90°, the bearing surface is in a liquid-philic metal state with a wetting effect; when the contact angle between the liquid metal and the bearing surface is <10°, the bearing surface is in a super-liquid-philic metal state with an excellent wetting effect; when the contact angle between the liquid metal and the bearing surface = 0°, it means that the bearing surface can be completely wetted by the liquid metal. When the contact angle between the liquid metal and the bearing surface is >90°, the bearing surface is in a liquid-repellent metal state with anti-wetting properties; when the contact angle between the liquid metal and the bearing surface is >150°, the bearing surface is in a super-liquid-philic metal state with excellent anti-wetting properties; the test results use super-liquid-philic metal, liquid-repelling metal, super-liquid-philic metal, and liquid-philic metal to describe the contact state between the liquid metal and the sealing coating surface and the wetting coating surface.

[0197] 4. Liquid metal temperature resistance test: The sealing coatings obtained in Examples 1-2 and Comparative Examples 1-3 were placed in a vacuum furnace at 400°C for 2 hours to test whether the sealing coatings had defects such as shedding, cracking, and discoloration. The test results are shown in Table 1. The infiltration coatings obtained in Examples 1-2 and Comparative Examples 1-3 were placed in a vacuum furnace at 400°C for 2 hours to test whether the sealing coatings had defects such as shedding, cracking, and discoloration. The test results are shown in Table 2.

[0198] 5. Enhanced liquid metal sliding bearing sealing test: After the enhanced liquid metal sliding bearings obtained by assembling Examples 1-2 and Comparative Examples 1-3 were placed in an anhydrous ethanol solution after applying an atmospheric pressure of 0.6 MPa to the inside to test whether bubbles appeared in the enhanced liquid metal sliding bearings. The test results are shown in Table 1.

[0199] 6. Liquid metal shaft friction coefficient test: The wetting coatings obtained in Examples 1-2 and Comparative Examples 1-3 were tested for friction and wear performance. The test results are shown in Table 2. The specific test method and standard are ISO 22462:2020.

[0200] Table 1 mainly involves the sealing coating performance test data; Table 2 mainly involves the wetting coating performance test data.

[0201] Table 1

[0202]

[0203] Table 2

[0204] Example Friction coefficient hardness Contact angle state Temperature resistance Example 1 ＜0.08 3500HV Super-liquid metal No falling off, no cracking, no discoloration Example 2 ＜0.05 2300HV Liquid metal No falling off, no cracking, no discoloration Comparative Example 1 ＜0.05 2100HV Liquid metal No falling off, no cracking, no discoloration Comparative Example 2 ＜0.05 2300HV Liquid metal No falling off, no cracking, no discoloration Comparative Example 3 0.05 2300HV Liquid metal No falling off, no cracking, no discoloration

[0205] It can be seen from the test data in Table 1 and Table 2 that the coatings provided in Example 1 and Example 2 can be combined with the sliding bearings with excellent performance, and the enhanced liquid metal sliding bearings provided in Example 1 and Example 2 have good sealing performance and excellent high temperature resistance performance; by adopting the enhanced liquid metal sliding bearings provided by the present invention, the wettability and wear resistance of the bearing rotating pair can be improved, and the key problems such as coating shedding, wear, and poor lubrication of the enhanced liquid metal sliding bearings in the use environment of high vacuum, high temperature, high pressure, high speed, and high load can be effectively solved. A high-pressure seal is formed on the gap between the stator and the rotor and between the limiting rings of the stator and the rotor to keep the liquid metal inside the bearing. The assembled bearing does not require a vacuum environment during the transportation process, and prevents external gas from entering the bearing structure, thereby reducing the possibility of liquid metal leakage or jamming.

Claims

1. A reinforced liquid metal sliding bearing, characterized in that: The enhanced liquid metal sliding bearing comprises a rotor, a stator and liquid metal, wherein the liquid metal is filled in the assembly gap between the rotor and the stator; the rotor comprises a sealing cover, a rotating cylinder and a limiting ring.

2. The enhanced liquid metal sliding bearing according to claim 1, characterized in that: The rotating drum and the limiting ring have a spiral groove structure and a textured microstructure at the fixed positions; the stator has a spiral groove structure at the fixed position.

3. The enhanced liquid metal sliding bearing according to claim 2, characterized in that: The textured microstructure includes one or more structures of a micron-scale honeycomb structure, a papillary structure, a dendritic structure, and a scalene structure.

4. The enhanced liquid metal sliding bearing according to claim 2 or 3, characterized in that: The surface of the textured microstructure has a sealing coating.

5. The enhanced liquid metal sliding bearing according to claim 4, characterized in that: The sealing coating includes an anti-wetting layer.

6. The enhanced liquid metal sliding bearing according to claim 5, characterized in that: The film thickness of the sealing coating is 0.05 to 2.0 μm.

7. The enhanced liquid metal sliding bearing according to claim 4, characterized in that: The rotating surfaces of the rotor and the stator are provided with a wetting coating.

8. The enhanced liquid metal sliding bearing according to claim 7, characterized in that: The infiltration coating comprises a base layer and a wetting layer.

9. The enhanced liquid metal sliding bearing according to claim 7, characterized in that: The film thickness of the wetting coating is 0.05 to 1.5 μm.

10. The enhanced liquid metal sliding bearing according to any one of claims 7 to 9, characterized in that: The sealing coating and the wetting coating are both subjected to laser pulse strengthening treatment.

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