Self-lubricating composite material, method for manufacturing same and water-lubricated bearing

Abstract

The application relates to a self-lubricating composite material, a preparation method thereof and a water-lubricated bearing, the self-lubricating composite material comprising a base material and microcapsules dispersed in the base material, the base material comprising a first polymer, the microcapsules comprising first microcapsules and second microcapsules, the first microcapsules comprising a first core material and a first wall material covering the first core material, the first core material comprising a calcium salt, the second microcapsules comprising a second core material and a second wall material covering the second core material, the second core material comprising one or more of sodium alginate and polyvinyl alcohol, so that the friction loss of the water-lubricated bearing can be reduced, and the service life of the water-lubricated bearing can be prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tribology, in particular to a self-lubricating composite material, a preparation method thereof and a water-lubricated bearing. BACKGROUND

[0002] With the increasing demand for transportation, the number of ships sailing on the sea and rivers is also rising. The pollution caused by ship operations seriously threatens the marine ecosystem and has attracted widespread attention. As an important part of the ship propulsion system, the water-lubricated bearing uses water as a lubricant to protect and lubricate the friction surface, effectively solving the problem of oil-based lubricant leakage caused by the failure of the sealing element of the traditional oil-lubricated bearing. The water-lubricated bearing is a key component of the ship transmission system, which operates under low speed and heavy load conditions, and it is difficult to form fluid dynamic pressure lubrication, which leads to serious wear and failure, which has become a prominent problem affecting the normal operation of the ship. SUMMARY

[0003] The present application provides a self-lubricating composite material, a preparation method thereof and a water-lubricated bearing, which aims to reduce the friction loss of the water-lubricated bearing and prolong its service life.

[0004] In a first aspect, the present application provides a self-lubricating composite material, which comprises a base material and microcapsules dispersed in the base material, the base material comprises a first polymer, the microcapsules comprise first microcapsules and second microcapsules, the first microcapsules comprise a first core material and a first wall material covering the first core material, the first core material comprises a calcium salt, and the second microcapsules comprise a second core material and a second wall material covering the second core material, the second core material comprises one or more of sodium alginate and polyvinyl alcohol.

[0005] In some embodiments, the mass ratio of the calcium salt to at least one of the sodium alginate and the polyvinyl alcohol is 1:2 to 1:1.

[0006] In some embodiments, the calcium salt comprises one or more of calcium carbonate, calcium chloride and calcium lactate.

[0007] In some embodiments, the mass ratio of the microcapsules to the base material is (3-10):100.

[0008] In some embodiments, the mass fraction of the calcium salt in the first microcapsules is 15% to 50%.

[0009] In some embodiments, the mass fraction of at least one of the sodium alginate and the polyvinyl alcohol in the second microcapsules is 33% to 50%.

[0010] In some embodiments, the first polymer comprises one or more of polyether ether ketone, polyurethane, ultra-high molecular weight polyethylene, nylon, and polytetrafluoroethylene, the ultra-high molecular weight polyethylene having a molecular weight of 1.5 million to 8 million Daltons.

[0011] In some embodiments, the first core material and the second core material each independently comprises a second polymer, the second polymer comprising one or more of polysulfone and polymethyl methacrylate.

[0012] In a second aspect of the present application, a method for preparing a self-lubricating composite material is provided, comprising the following steps:

[0013] mixing a base material with microcapsules to obtain a mixture, the base material comprising a first polymer, the microcapsules comprising first microcapsules and second microcapsules, the first microcapsules comprising a first core material and a first wall material covering the first core material, the first core material comprising a calcium salt, the second microcapsules comprising a second core material and a second wall material covering the second core material, the second core material comprising one or more of sodium alginate and polyvinyl alcohol;

[0014] vacuum sintering the mixture to obtain the self-lubricating composite material.

[0015] In some embodiments, the step of vacuum sintering the mixture comprises: applying a pressure of 1 MPa to 10 MPa to the mixture to remove air in the mixture, and then keeping the mixture at a temperature of 140°C to 330°C for 20 minutes to 60 minutes, and then keeping the mixture at a temperature of 120°C to 250°C for 10 minutes to 30 minutes.

[0016] In some embodiments, the mass ratio of the calcium salt to at least one of the sodium alginate and the polyvinyl alcohol is 1:2 to 1:1.

[0017] In some embodiments, the calcium salt comprises one or more of calcium carbonate, calcium chloride, and calcium lactate.

[0018] In some embodiments, the mass ratio of the microcapsules to the base material is (3 to 10):100.

[0019] In a third aspect of the present application, a water-lubricated bearing is provided, comprising at least one of the self-lubricating composite material of the first aspect of the present application and the self-lubricating composite material prepared by the method of the second aspect of the present application.

[0020] Compared with the conventional technology, the self-lubricating composite material has at least the following advantages:

[0021] The calcium salt capable of quickly forming a gel is compounded with at least one of sodium alginate and polyvinyl alcohol in the first microcapsule and the second microcapsule respectively, and then the first microcapsule and the second microcapsule are dispersed in the matrix material including the first polymer. With the progress of friction and wear, the first microcapsule and the second microcapsule are broken, releasing the first core material and the second core material, so that the gel formed by the calcium salt and at least one of sodium alginate and polyvinyl alcohol is continuously generated on the worn surface. Since the gel has both adhesion and lubricity, the water molecule layer can still be maintained on the worn surface under low-speed heavy-load working conditions, significantly reducing the friction coefficient, thereby greatly reducing the friction loss and prolonging the service life of the equipment. The self-lubricating composite material can be applied to water-lubricated bearings to effectively solve the problems of wear, corrosion, noise, reliability and service life of the shafting (such as the thrust shaft, transmission shaft and stern shaft) of a ship in a seawater environment. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 SEM (scanning electron microscope) diagram of the microcapsule prepared in Example 1 of the present application.

[0023] Figure 2 Schematic diagram of the mold, the mixture and the press head in the sintering treatment of Example 1 of the present application.

[0024] Figure 3 Sintering schedule for sintering treatment of the mixture in Example 1 of the present application.

[0025] Figure 4 Mechanism diagram of the first microcapsule and the second microcapsule in the self-lubricating composite material prepared in Example 1 of the present application.

[0026] Figure 5 Column chart of the friction coefficient changing with the rotation speed of Example 1 to 4 and Comparative Example 1 of the present application.

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 1. mold; 2. press head; 3. mixture. DETAILED DESCRIPTION

[0029] To make the above objectives, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are described in detail below. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0030] In the present application, "first aspect", "second aspect", "third aspect" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or quantity, nor can it be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third" and the like only serve the purpose of non-exhaustive enumeration description, and should be understood as not constituting a closed limitation on the quantity.

[0031] In the present application, "optionally", "optional" and "optional" mean optional, i.e. selected from "have" or "no" two parallel schemes. If there are multiple "optional" in a technical solution, unless otherwise specified, and there is no contradiction or mutual restriction relationship, each "optional" is independent of each other.

[0032] In the present application, if there is no special description, the above numerical interval is regarded as continuous, and includes the minimum value and the maximum value of the range, and every value between the minimum value and the maximum value. Further, when the range is an integer, every integer between the minimum value and the maximum value of the range is included. In addition, when multiple ranges are provided to describe characteristics or properties, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges included therein.

[0033] In the present application, the technical features described in an open manner include closed technical solutions composed of listed features, and also include open technical solutions containing listed features.

[0034] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as understood by a person skilled in the art to which the present application belongs. The terms used in the present application in the specification of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The term "and / or" used in the present application includes any and all combinations of one or more related listed items. In the present application, the term "plurality" means at least two, for example, two, three, etc., unless otherwise specifically limited.

[0035] The commonly used materials for water-lubricated bearings include iron, wood, ceramic, rubber, polymer and the like. In recent decades, polymer materials have been widely used in the manufacture of water-lubricated tail pipe bearings due to their corrosion resistance and good chemical stability, but have also brought serious vibration and wear problems. Under low-speed heavy-load conditions, the serious wear and noise problems of water-lubricated wear parts are particularly troublesome. Although polymer materials are widely used to prepare water-lubricated bearings due to their good corrosion resistance, wear resistance and self-lubricating properties, it is difficult to further improve the friction-reducing and wear-resistant properties of high polymer materials in a water-lubricated environment due to the difficulty in adding lubricants. There are still problems of difficulty in forming a stable water film at low speed and possible extrusion of the lubricating water film under high pressure, resulting in boundary lubrication.

[0036] Based on this, the first aspect of the present application provides a self-lubricating composite material, which comprises a base material and microcapsules dispersed in the base material, the base material comprising a first polymer, the microcapsules comprising first microcapsules and second microcapsules, the first microcapsules comprising a first core material and a first wall material covering the first core material, the first core material comprising a calcium salt, the second microcapsules comprising a second core material and a second wall material covering the second core material, the second core material comprising sodium alginate.

[0037] In the above self-lubricating composite material, the calcium salt capable of rapidly forming a gel is respectively compounded with at least one of sodium alginate and polyvinyl alcohol in the first microcapsules and the second microcapsules, and then the first microcapsules and the second microcapsules are dispersed in the base material comprising the first polymer. With the progress of friction and wear, the first microcapsules and the second microcapsules are worn out, releasing the first core material and the second core material, so that the gel formed by the calcium salt and at least one of sodium alginate and polyvinyl alcohol is continuously generated on the worn surface. Since the gel has both adhesion and lubricity, the water molecule layer can still be maintained on the worn surface under low-speed heavy-load working conditions, significantly reducing the friction coefficient, thereby greatly reducing the friction loss and prolonging the service life of the equipment. The application of the self-lubricating composite material to water-lubricated bearings can effectively solve the problems of wear, corrosion, noise, reliability and service life of ship shafting (such as thrust shaft, transmission shaft and stern shaft) in seawater environment.

[0038] Compared with the traditional gel coating technology, the self-lubricating composite material in the present application composites the base material, the first microcapsule and the second microcapsule, wherein the base material provides rigid support, and the first microcapsule and the second microcapsule provide lubrication, and can continuously generate gel during the friction process to achieve sustainable lubrication. Further, the first microcapsule and the second microcapsule are uniformly dispersed in the base material, and can achieve ordered and uniform release during the friction process. In addition, the two types of materials (calcium salt and sodium alginate) that make up the gel are respectively encapsulated in the first microcapsule and the second microcapsule in the self-lubricating composite material in the present application, rather than being directly compounded in the base material or being compounded in the same microcapsule, which effectively avoids the failure of the gel during the hot pressing process, or the destruction of the mechanical properties of the base material due to the swelling of the gel in the base material.

[0039] In some embodiments, the mass ratio of the calcium salt to the at least one of sodium alginate and polyvinyl alcohol is 1:2-1:1. That is, the mass ratio of the at least one of sodium alginate and polyvinyl alcohol to the calcium salt is 1:1-2:1. Adjusting the mass ratio of the calcium salt to the at least one of sodium alginate and polyvinyl alcohol in the above range is beneficial to further reduce the friction coefficient. As non-limiting examples, the mass ratio of the calcium salt to the at least one of sodium alginate and polyvinyl alcohol includes but is not limited to 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, or a range between any two of the foregoing.

[0040] In some embodiments, the calcium salt includes one or more of calcium carbonate, calcium chloride, and calcium lactate.

[0041] In some embodiments, the mass ratio of the microcapsule to the base material is (3-10):100. Thus, it is beneficial to further reduce the friction coefficient. As non-limiting examples, the mass ratio of the microcapsule to the base material includes but is not limited to 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, or a range between any two of the foregoing.

[0042] In some embodiments, the mass percentage of the calcium salt in the first microcapsule is 15%-50%. As non-limiting examples, the mass percentage of the calcium salt in the first microcapsule includes but is not limited to 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or a range between any two of the foregoing.

[0043] In some embodiments, the mass percentage of the at least one of sodium alginate and polyvinyl alcohol in the second microcapsule is 33% to 50%. That is, the mass percentage of the at least one of sodium alginate and polyvinyl alcohol in the second microcapsule is 33% to 50%. As non-limiting examples, the mass percentage of the at least one of sodium alginate and polyvinyl alcohol in the second microcapsule includes, but is not limited to, 33%, 35%, 37%, 40%, 42%, 45%, 47%, 50%, or a range between any two of the foregoing.

[0044] Controlling the mass percentage of the calcium salt in the first microcapsule or controlling the mass percentage of the at least one of sodium alginate and polyvinyl alcohol in the second microcapsule within the above ranges is conducive to coating the calcium salt or the at least one of sodium alginate and polyvinyl alcohol.

[0045] In some embodiments, the first polymer includes one or more of polyether ether ketone, polyurethane, ultra-high molecular weight polyethylene, nylon, and polytetrafluoroethylene. In some of these embodiments, the ultra-high molecular weight polyethylene has a molecular weight of 1.5 million to 8 million Daltons.

[0046] In some embodiments, the first core material and the second core material each independently includes a second polymer, and the second polymer includes one or more of polysulfone and polymethyl methacrylate.

[0047] In some embodiments, the average particle size of the microcapsule is 1 μm to 10 μm. As non-limiting examples, the average particle size of the microcapsule includes, but is not limited to, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or a range between any two of the foregoing.

[0048] In a second aspect, the present application provides a method for preparing a self-lubricating composite material, including the following steps:

[0049] Mixing the base material with the microcapsule to obtain a mixture; the base material includes a first polymer, and the microcapsule includes a first microcapsule and a second microcapsule; the first microcapsule includes a first core material and a first wall material coating the first core material, and the first core material includes a calcium salt; the second microcapsule includes a second core material and a second wall material coating the second core material, and the second core material includes one or more of sodium alginate and polyvinyl alcohol;

[0050] Performing vacuum sintering treatment on the mixture to obtain the self-lubricating composite material.

[0051] The calcium salt capable of quickly generating a gel is compounded with at least one of sodium alginate and polyvinyl alcohol in the first microcapsule and the second microcapsule respectively, and then the first microcapsule and the second microcapsule are dispersed in the matrix material including the first polymer. With the progress of friction and wear, the first microcapsule and the second microcapsule are broken to release the first core material and the second core material, so that the gel is continuously generated on the worn surface. Since the gel has adhesion and lubricity, the water molecule layer can be maintained on the worn surface under low-speed heavy-load working conditions, the friction coefficient is significantly reduced, the friction loss is greatly reduced, and the service life of the equipment is prolonged. The self-lubricating composite material is applied to a water-lubricated bearing, which can effectively solve the problems of wear, corrosion, noise, reliability and service life of a ship shaft system (such as a thrust shaft, a transmission shaft and a stern shaft) in a seawater environment.

[0052] In some embodiments, the step of vacuum sintering the mixture includes: applying a pressure of 1 MPa to 10 MPa to the mixture to remove air in the mixture, and then heat preserving at 140°C to 330°C for 20 minutes to 60 minutes, and then heat preserving at 120°C to 250°C for 10 minutes to 30 minutes. Removing air in the mixture is to make the mixture in a vacuum environment, and the pressure applied to the mixture and the vacuum sintering treatment are beneficial to improve the density and bonding strength of the mixture, thereby improving the forming quality of the mixture. Taking polyether ether ketone as the first polymer, for example, polyether ether ketone has a high crystallization rate at 250°C, and the heat preserving process can improve the crystallinity of polyether ether ketone, thereby improving the mechanical properties and wear resistance of polyether ether ketone.

[0053] In some embodiments, the mass ratio of the calcium salt to at least one of sodium alginate and polyvinyl alcohol is 1:2 to 1:1.

[0054] In some embodiments, the calcium salt includes one or more of calcium carbonate, calcium chloride and calcium lactate.

[0055] In some embodiments, the mass ratio of the microcapsule to the matrix material is (3 to 10):100.

[0056] In some embodiments, the mass percentage of the calcium salt in the first microcapsule is 15% to 50%.

[0057] In some embodiments, the mass percentage of at least one of sodium alginate and polyvinyl alcohol in the second microcapsule is 33% to 50%.

[0058] It should be noted that the self-lubricating composite material described above can be obtained by adjusting the process conditions of the preparation method of the self-lubricating composite material described above.

[0059] In a third aspect of the present application, a water-lubricated bearing is provided, comprising at least one of the self-lubricating composite material according to the first aspect of the present application and the self-lubricating composite material prepared by the method according to the second aspect of the present application.

[0060] In order to further illustrate the present application, the technical solutions of the present application are described in detail below in combination with specific examples. If a specific technology or condition is not specified in the examples, it is implemented according to the technology or condition described in the literature in the field or according to the product manual. If the manufacturer of the reagent or instrument is not specified, it is a conventional product that can be obtained from the market.

[0061] Example 1

[0062] The method for preparing the self-lubricating composite material comprises the following steps:

[0063] (1) Preparation of microcapsules

[0064] (1.1) 3 g of calcium carbonate was dissolved in 100 mL of deionized water to prepare component A; 10 g of component A and 1 g of emulsifier Span 80 were mixed, and then subjected to cell crushing for 10 minutes, followed by mixing with 100 mL of dichloromethane containing 3 g of polysulfone to obtain a mixed solution A;

[0065] (1.2) 3 g of sodium alginate was dissolved in 100 mL of deionized water to prepare component B; 10 g of component B was mixed with 100 mL of dichloromethane containing 3 g of polysulfone, and 1 g of Span 80 was added, followed by cell crushing for 10 minutes to obtain a mixed solution B; the mass ratio of calcium carbonate to sodium alginate was 1:1;

[0066] (1.3) A 1 wt% polyvinyl alcohol aqueous solution was prepared as a dispersion liquid, and the mixed solution A and the mixed solution B were added to the dispersion liquid under the condition of 42°C and stirring speed of 300 r / min, and the stirring was continued for 4 h. By solvent evaporation method, dichloromethane was evaporated during the heating and stirring process, and the wall material polysulfone was condensed to form a shell to prepare the microcapsules;

[0067] The microcapsules include first microcapsules and second microcapsules, the first microcapsules include a first core material and a first wall material covering the first core material, the first core material includes calcium carbonate, and the first wall material includes polysulfone; the second microcapsules include a second core material and a second wall material covering the second core material, the second core material includes sodium alginate, and the second wall material includes polysulfone; the mass fraction of calcium carbonate in the first microcapsules is 25%, and the mass fraction of sodium alginate in the second microcapsules is 25%.

[0068] Figure 1 The SEM image of the microcapsules prepared in Example 1 is shown in Figure 1. Figure 1 It can be seen that the average particle size of the microcapsules is about 2 μm.

[0069] (2) Microcapsules and matrix material composite

[0070] Referring to Figure 2 The microcapsules and matrix material polyether ether ketone powder were mixed in a mass ratio of 5:100 to obtain a mixture 3. The mixture 3 was placed in a graphite mold 1, and graphite paper was used to separate the mixture 3 from the graphite mold 1 to reduce cross contamination. The mixture 3 was sintered according to the following sintering process: a pre-pressing force of 1 MPa was applied to the mixture 3 by using a press head 2, and the air between the powders was pumped out by a vacuum pump to increase the compactness. Referring to Figure 2 and Figure 3 Then, a pressure of 10 MPa was applied to the mixture 3, the temperature was heated from 20°C to 330°C within 50 min, and the temperature was kept for 60 min. Next, the temperature was cooled from 330°C to 250°C within 20 min, and the temperature was kept for 30 min. Finally, the temperature was cooled from 250°C to 20°C within 30 min. After the sintered sample was treated by sandpaper, polishing cloth, and polishing liquid, a smoother surface was obtained, and a self-lubricating composite material was obtained.

[0071] Example 2

[0072] The preparation method of the self-lubricating composite material was basically the same as that of Example 1, except that in step (2), the microcapsules and matrix material polyether ether ketone powder were mixed in a mass ratio of 7:100 to obtain a mixture.

[0073] Example 3

[0074] The preparation method of the self-lubricating composite material was basically the same as that of Example 1, except that in step (2), the microcapsules and matrix material polyether ether ketone powder were mixed in a mass ratio of 10:100 to obtain a mixture.

[0075] Example 4

[0076] The preparation method of the self-lubricating composite material was basically the same as that of Example 1, except that in step (1.2), 3 g of sodium alginate was replaced by 6 g of sodium alginate, 3 g of polysulfone was replaced by 6 g of polysulfone, the mass ratio of calcium carbonate to sodium alginate was 1:2, the mass fraction of calcium carbonate in the first microcapsule was 16.7%, and the mass fraction of sodium alginate in the second microcapsule was 33.3%.

[0077] Comparative Example 1

[0078] The preparation method of the self-lubricating composite material included the following steps:

[0079] The polyether ether ketone powder was placed in a graphite mold, and graphite paper was used to separate the polyether ether ketone powder from the graphite mold to reduce cross-contamination. The polyether ether ketone powder was sintered according to the following sintering process: a pre-pressure of 1 MPa was applied to the polyether ether ketone powder, and the air between the powders was pumped out by a vacuum pump to increase the compactness. Subsequently, a pressure of 10 MPa was applied to the polyether ether ketone powder, the temperature was heated from 20°C to 330°C within 50 min, and the temperature was maintained for 60 min. Next, the temperature was cooled from 330°C to 250°C within 20 min, and the temperature was maintained for 30 min. Finally, the temperature was cooled from 250°C to 20°C within 30 min. After the sintered sample was treated with sandpaper, polishing cloth, and polishing liquid, a smoother surface was obtained, and a self-lubricating composite material was obtained.

[0080] Test Example

[0081] Tribological tests were performed using a UMT tribometer. Specifically, a silicon nitride ball with a diameter of 10 mm was used as the top surface, and the self-lubricating composite material disc prepared in each example or Comparative Example 1 was used as the bottom surface. The normal force in the test was 15 N, and the rotational speed was selected to be 30 rpm (r / min), 60 rpm, 120 rpm, 180 rpm, and 240 rpm, respectively.

[0082] The mechanism diagram of the first microcapsule and the second microcapsule in the self-lubricating composite material prepared in Example 1 is shown in Figure 4 . The test results are shown in Table 1 and Figure 5 .

[0083] Table 1

[0084]

[0085] As shown in Figure 4 , during the process of friction and wear, the first microcapsule with calcium carbonate as the first core material and the second microcapsule with sodium alginate as the second core material in Example 1 were broken, releasing the first core material and the second core material therein. Calcium carbonate and sodium alginate quickly formed a hydrogel on the friction surface under the action of water lubrication, fixed the water molecule layer, and separated the rough peaks in the heavy load area, thereby reducing the friction and wear.

[0086] From Table 1 and Figure 5It can be seen that, under the same rotation speed condition, the friction coefficient of the self-lubricating composite material of Examples 1 to 4 is smaller compared with that of Comparative Example 1, which indicates that the self-lubricating composite material provided by the application, which comprises a base material and microcapsules, the base material comprising a first polymer, and the microcapsules comprising first microcapsules and second microcapsules, the first microcapsules comprising a first core material and a first wall material covering the first core material, the first core material comprising a calcium salt, and the second microcapsules comprising a second core material and a second wall material covering the second core material, the second core material comprising one or more of sodium alginate and polyvinyl alcohol, can effectively reduce the friction loss of a water-lubricated bearing and prolong the service life thereof.

[0087] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not exist in contradiction, they should be considered as falling within the scope of the present disclosure.

[0088] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all fall within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims, and the description can be used to explain the content of the claims.

Claims

1. A water-lubricated bearing characterized by, The self-lubricating composite material comprises a base material and microcapsules dispersed in the base material, the base material comprises a first polymer, the first polymer comprises one or more of polyether ether ketone, polyurethane, ultra-high molecular weight polyethylene, nylon and polytetrafluoroethylene, the microcapsules comprise first microcapsules and second microcapsules, the first microcapsules comprise a first core material and a first wall material covering the first core material, the first core material comprises a calcium salt, the second microcapsules comprise a second core material and a second wall material covering the second core material, the second core material comprises one or more of sodium alginate and polyvinyl alcohol, the mass ratio of the calcium salt to at least one of the sodium alginate and the polyvinyl alcohol is 1:2-1:1, the first wall material and the second wall material each independently comprise a second polymer, the second polymer comprises polysulfone, the mass ratio of the microcapsules to the base material is (7-10):100; the water-lubricated bearing is used for a ship shafting.

2. The water-lubricated bearing of claim 1, wherein The calcium salt comprises one or more of calcium carbonate, calcium chloride and calcium lactate.

3. A water-lubricated bearing according to claim 1 or 2, characterised in that The mass ratio of the microcapsules to the base material is 10:

100.

4. The water-lubricated bearing according to claim 1 or 2, characterized in that The self-lubricating composite material has one or more of the following characteristics: (1) the mass percentage of the calcium salt in the first microcapsules is 15%-50%; (2) the mass percentage of at least one of the sodium alginate and the polyvinyl alcohol in the second microcapsules is 33%-50%.

5. The water-lubricated bearing according to claim 1 or 2, characterized in that The molecular weight of the ultra-high molecular weight polyethylene is 1.5 million-8 million Daltons.

6. The water-lubricated bearing according to claim 1 or 2, characterized in that, characterized in that, The preparation method of the self-lubricating composite material comprises the following steps: mixing the base material and the microcapsules to obtain a mixture; and performing vacuum sintering treatment on the mixture to obtain the self-lubricating composite material.

7. The water-lubricated bearing of claim 6, wherein The step of performing vacuum sintering treatment on the mixture comprises: applying a pressure of 1 MPa-10 MPa to the mixture to remove air in the mixture, and then keeping the mixture at 140°C-330°C for 20 min-60 min and then keeping the mixture at 120°C-250°C for 10 min-30 min.

8. The water-lubricated bearing of claim 1 or 2, wherein The calcium salt is calcium carbonate.

9. The water-lubricated bearing of claim 8, wherein, The mass percentage of the calcium carbonate in the first microcapsules is 25%.

10. The water-lubricated bearing of claim 1 or 2, wherein The average particle size of the microcapsules is 1-10 μm.

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