Water-lubricated bearing and preparation method thereof

Abstract

The invention provides a water lubricated bearing and a preparation method thereof, and belongs to the technical field of sliding bearings, the preparation method comprises the following steps: heating and melting 90-100 parts by weight of a polyurethane prepolymer to obtain a liquid polyurethane matrix; adding 0.1-1 part by weight of functional filler into the liquid polyurethane matrix, and mixing to obtain a solution A; heating and melting 20-27 parts by weight of a chain extender to obtain a solution B; the solution A and the solution B are mixed and then injected into a pretreated mold; the mold is put into a centrifugal machine, and curing forming is carried out in a centrifugal rotation state; and after curing, demolding to obtain a blank profile, and processing the blank profile to obtain the water-lubricated bearing. The water-lubricated bearing prepared through the method is free of oil contamination leakage risk, safe, environmentally friendly, simple in structure, low in cost and excellent in abrasion resistance and heat resistance.

Description

Technical Field

[0001] This invention relates to the field of sliding bearing technology, and in particular to a water-lubricated bearing and its manufacturing method. Background Technology

[0002] Sliding bearings are core components in mechanical transmissions that support the shaft through surface contact and reduce friction by relying on lubricating media. With their high load-bearing capacity and smooth operation, they are widely used in industrial fields such as metallurgy, mining, petrochemicals, construction machinery, and machine tool motors. They are also indispensable in scenarios such as water treatment and ship propulsion systems.

[0003] Currently, the vast majority of sliding bearings in industry use oil lubrication. While this meets the basic requirements of heavy-load and high-speed operation, it has many drawbacks and is difficult to adapt to the stringent requirements of various industries. First, oil lubrication systems are prone to oil leaks and discharges, which not only pollute water bodies and damage the ecosystems of sensitive water areas such as drinking water sources, nature reserves, and inland rivers and lakes, but also contaminate the working medium. This is especially problematic in industries with extremely high purity requirements, such as food and pharmaceuticals, where oil contamination directly affects product quality and safety. Second, in flammable and explosive environments such as coal mines, oil fields, and chemical plants, the oil itself is flammable. Leaks can cause fires or explosions, significantly increasing safety risks. Furthermore, oil-lubricated bearings require complex auxiliary equipment such as oil tanks, oil pumps, coolers, precision sealing devices (such as stern shaft seals), oil filters, and monitoring systems. This not only occupies a large amount of equipment space but also significantly increases procurement, installation, and subsequent maintenance costs.

[0004] Given the multiple shortcomings of oil-lubricated bearings in terms of environmental protection, safety, cost, and system adaptability, various industries urgently need an alternative that is environmentally friendly, safe, structurally simple, and more cost-effective. Summary of the Invention

[0005] In view of this, the present invention provides a water-lubricated bearing and a method for preparing the same, aiming to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A distributed address allocation method based on CAN bus, the method comprising the following steps: S1. Heat and melt 90-100 parts by weight of polyurethane prepolymer to obtain liquid polyurethane matrix; S2. Add 0.1-1 parts by weight of functional filler to the liquid polyurethane matrix and mix to obtain solution A; S3. Melt 20-27 parts by weight of the chain extender by heating to obtain solution B; S4. Mix the solution A and the solution B and then inject the mixture into the pretreated mold; S5. Place the mold into a centrifuge and solidify it under centrifugal rotation. S6. After curing, demold to obtain a blank profile, process the blank profile to obtain the water-lubricated bearing.

[0007] Optionally, Step S1 includes: Add 90-100 parts by weight of the polyurethane prepolymer into tank A of the casting machine; The polyurethane prepolymer in tank A is heated to 70-90°C to obtain the liquid polyurethane matrix, and then continuously stirred.

[0008] Optionally, step S2 includes: While maintaining a temperature of 70-90°C inside container A, 0.1-1 parts by weight of the functional filler are added to container A and continuously stirred to obtain solution A.

[0009] Optionally, step S3 includes: Add 20-27 parts by weight of the chain extender into tank B of the casting machine; The chain extender is heated to 110-120°C and stirred continuously to obtain solution B.

[0010] Optionally, step S4 includes: Solution A in tank A and solution B in tank B are mixed through the mixing head of the casting machine and then injected into the mold.

[0011] Optionally, in S2, the functional filler is polyimide powder.

[0012] Optionally, in S3, the chain extender is MOCA.

[0013] Optionally, in S4, the inner wall of the mold is coated with a release agent, and the mold is preheated before injection.

[0014] Optionally, in step S5, the centrifugal rotation time is 20-30 minutes.

[0015] In addition, to achieve the above objectives, the present invention also provides a water-lubricated bearing, which is prepared by the preparation method described in any of the preceding claims. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0018] Figure 1 This is a schematic flowchart illustrating a method for preparing a water-lubricated bearing as described in an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application 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 this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0022] Please refer to Figure 1 , Figure 1 A flowchart illustrating a method for preparing a water-lubricated bearing according to an embodiment of the present invention, the method comprising: Step S1: Heat and melt 90-100 parts by weight of polyurethane prepolymer to obtain liquid polyurethane matrix.

[0023] Preferably, step S1 includes: Step S11: Add 90-100 parts by weight of the polyurethane prepolymer into tank A of the casting machine; Step S12: Heat the polyurethane prepolymer in tank A to 70-90°C to obtain a liquid polyurethane matrix and stir continuously.

[0024] Specifically, 90-100 parts by weight of solid polyurethane prepolymer raw material are added to tank A of the casting machine. The heating and stirring system of tank A is then activated to stably heat the internal temperature of tank A to 70-90°C. This temperature range is set according to the melting point of the selected polyurethane prepolymer to ensure complete melting. In this embodiment, the heating method is the tank's built-in electric heating, with real-time temperature control achieved through a temperature sensor. Under continuous heating at 70-90°C, the solid polyurethane prepolymer completely melts, resulting in a liquid polyurethane matrix. Continuous stirring is maintained during the melting process to prevent localized overheating, agglomeration, or adhesion to the tank wall. The stirring speed can be dynamically adjusted according to the molten state of the polyurethane prepolymer. For example, when the material is solid or semi-solid, a stirring speed of 30-50 rpm is used to prevent motor overload and avoid large pieces of material impacting the stirring paddle; when the material becomes liquid, the speed can be adjusted to 60-100 rpm to ensure uniform temperature distribution and promote heat transfer.

[0025] Understandably, in this embodiment, through steps S11 to S12, the polyurethane prepolymer is added to the casting machine A tank to complete heating, melting, and stirring. Compared with manual operation, the resulting liquid polyurethane matrix has higher quality stability.

[0026] Step S1 transforms the polyurethane prepolymer from a solid state into a liquid matrix, providing a basis for subsequent mixing with functional fillers.

[0027] Step S2: Add 0.1-1 parts by weight of functional filler to the liquid polyurethane matrix and mix to obtain solution A.

[0028] Preferably, step S2 includes: While maintaining a temperature of 70-90°C inside container A, 0.1-1 parts by weight of the functional filler are added to container A and continuously stirred to obtain solution A.

[0029] Specifically, while maintaining a temperature of 70-90°C inside container A, 0.1-1 parts by weight of functional filler are added to container A to mix with the liquid polyurethane matrix obtained in step S1. During the mixing process, the stirring system is started and continuously stirred at a stirring speed of 100-300 rpm to ensure that the functional filler is fully wetted and dispersed in the liquid polyurethane matrix until the system reaches a stable state with uniformity and no visible particle agglomeration, thus obtaining solution A. Simultaneously, the temperature inside the container is continuously monitored during the mixing process to ensure it is maintained within the range of 70-90°C. This constant temperature condition stabilizes the viscosity and flowability of the liquid polyurethane matrix, prevents changes in the viscosity of the polyurethane prepolymer due to temperature fluctuations, and ensures that the functional filler is continuously and uniformly dispersed in the matrix, achieving sufficient wetting and coating, and avoiding defects such as agglomeration and uneven dispersion of the functional filler.

[0030] Preferably, the functional filler in this embodiment is polyimide (PI) powder. PI powder has excellent thermal stability, wear resistance, mechanical strength and self-lubricating properties. When mixed with liquid polyurethane matrix, it can improve the wear resistance, heat resistance and structural strength of composite material, so that the final water-lubricated bearing has better service stability and service life in water environment.

[0031] Step S2 ensures that the PI powder is fully and uniformly dispersed in the liquid polyurethane matrix, giving full play to the reinforcing, toughening, wear-resistant and heat-resistant properties of the PI powder, while providing a material basis for the subsequent in-situ polymerization reaction with the chain extender.

[0032] Step S3: Heat and melt 20-27 parts by weight of the chain extender to obtain solution B.

[0033] Preferably, step S3 includes: Step S31: Add 20-27 parts by weight of the chain extender into tank B of the casting machine; Step S32: Heat the chain extender to 110-120°C and stir continuously to obtain solution B.

[0034] Specifically, 20-27 parts by weight of the chain extender are added to tank B of the casting machine. The heating and stirring system of tank B is then started to stably heat the internal temperature of tank B to 110-120℃. This temperature range is set according to the melting point of the chain extender to ensure that the chain extender is fully melted. The heating method uses the tank's own electric heating, and real-time monitoring and closed-loop temperature control are achieved through temperature sensors. Continuous heating at 110-120℃ allows the solid chain extender to completely melt into a liquid state, obtaining solution B. During the melting process, continuous stirring is maintained to prevent local overheating, agglomeration, or adhesion of the material to the tank wall. The stirring speed is controlled at 50-80 rpm to ensure uniform melt temperature.

[0035] Preferably, the chain extender in this embodiment is 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA).

[0036] Step S3 allows the chain extender to be fully melted into a liquid state, ensuring rapid reaction and full cross-linking when mixed with solution A, thus providing a stable reaction component for the in-situ polymerization and curing of polyurethane composite materials.

[0037] Step S4: Mix the solution A and the solution B and then inject the mixture into the pretreated mold.

[0038] Preferably, step S4 includes: Solution A from tank A and solution B from tank B are mixed through the mixing head of the casting machine and then injected into the mold.

[0039] Specifically, solution A, maintained at 70-90℃ in tank A, and solution B, maintained at 110-120℃ in tank B, are simultaneously transported to the mixing head of the casting machine through independent insulated pipelines. The mixing head is activated, causing the two components to undergo an in-situ mixing reaction within the mixing chamber, yielding a polyurethane reaction mixture. This polyurethane reaction mixture is then injected into the pretreated mold cavity.

[0040] Understandably, this embodiment uses a mixing head on a casting machine to mix solution A and solution B. Compared to manual stirring or pre-mixing in a single tank, this improves the uniformity of mixing and the stability of reactivity between the two components, ensuring consistent quality across different production batches. By delivering the two components through independent insulated pipelines, the preset temperatures of solutions A and B can be maintained, preventing temperature fluctuations from causing decreased material flowability and mismatch in reactivity between the two components. Simultaneously, the simultaneous mixing and casting operation avoids the problem of incomplete cavity filling caused by pre-mixing, providing a uniform and stable casting system for subsequent curing and molding, ensuring the structural uniformity and performance stability of the resulting water-lubricated bearing.

[0041] Preferably, the mold pretreatment specifically involves: first, cleaning the mold cavity; then, uniformly coating the inner wall of the mold with a release agent; and finally, preheating the mold after the release agent has fully dried and formed a film. The preheating is preferably performed using an electric heating constant-temperature forced-air oven. The mold, after the release agent coating and drying, is placed inside the oven, and the preheating temperature is set to 70-90°C, consistent with the temperature of solution A. The constant-temperature preheating time is 30-60 minutes to ensure uniform heating of the entire mold cavity without localized temperature differences. In other embodiments, preheating can also be achieved using a built-in embedded electric heating module or a circulating hot air tunnel, as long as the mold is uniformly preheated to the target temperature of 70-90°C.

[0042] The above preheating treatment can significantly reduce the temperature difference impact when the polyurethane reaction mixture comes into contact with the mold, avoid problems such as decreased fluidity, incomplete cavity filling or uneven curing caused by sudden cooling of the material, and at the same time ensure the stability of the release agent film formation, avoid sticking defects caused by release agent failure, and further improve the molding quality and surface finish of the bearing blank.

[0043] In other embodiments, the two components can be thoroughly mixed by other mixing methods, such as manual stirring, as long as the mixing is uniform and does not affect the reactivity.

[0044] Step S4 allows solution A and solution B to be mixed in the mixing head, ensuring that the two components are in full contact before entering the mold. This provides a casting system for subsequent centrifugal curing and ensures that the internal structure of the water-lubricated bearing is uniform and its performance is stable.

[0045] Step S5: Place the mold into a centrifuge and solidify it under centrifugal rotation.

[0046] Specifically, the mold containing the polyurethane reaction mixture is placed in a centrifuge, and the centrifuge is turned on to rotate and centrifuge. Under the action of centrifugal force, the polyurethane reaction mixture is fully compacted and evenly distributed inside the mold cavity, and curing is completed in the rotating state.

[0047] Preferably, the centrifugal rotation time is 20-30 minutes, the centrifugal speed is controlled at 500-1500 rpm, and the centrifugal ambient temperature is maintained at 80-100℃ to ensure full curing and dense molding during in-situ polymerization.

[0048] In step S5, the polyurethane reaction mixture is cured and molded under the action of a centrifugal force field.

[0049] Step S6: After curing, demold to obtain a blank profile, process the blank profile to obtain the water-lubricated bearing.

[0050] Specifically, after centrifugal curing in step S5 is completed, the centrifuge is turned off, and the mold containing the bearing blank is removed from the centrifuge and allowed to cool naturally to room temperature. Alternatively, air cooling can be used to accelerate cooling, ensuring the blank is fully shaped and free from shrinkage or deformation. After the mold and blank have cooled to room temperature, demolding is performed. The blank is removed using a demolding tool to obtain the rough profile. During demolding, defects such as scratches and cracks are prevented from occurring on the rough profile. Subsequently, the rough profile is machined. The machining process is as follows: first, rough turning is performed to remove excess material and correct the dimensions, making the rough profile dimensions close to the finished product design dimensions; then, finish turning is performed, strictly controlling key dimensions such as the inner diameter, outer diameter, length, and wall thickness of the water-lubricated bearing to ensure dimensional tolerances meet design standards; finally, the bearing's inner hole, end face, and outer surface are polished and deburred to achieve a surface finish of Ra≤0.8μm, reducing frictional resistance during water lubrication. After processing, the finished water-lubricated bearing is cleaned and dried to remove surface machining debris and impurities. After passing inspection, a water-lubricated bearing that meets the usage requirements can be obtained.

[0051] Step S6 is used to transform the solidified preform into a finished water-lubricated bearing.

[0052] The water-lubricated bearing produced through steps S1 to S6 eliminates the oil leakage and discharge problems common in oil lubrication systems. It does not pollute the aquatic environment, damage the ecosystem of sensitive water areas, or contaminate the working medium. It is suitable for industries with extremely high purity requirements, such as food and pharmaceuticals, ensuring product quality and safety. Furthermore, the water medium is non-flammable, preventing fires or explosions caused by leakage in flammable and explosive environments such as coal mines, oil fields, and chemical plants, thus improving safety. In addition, this water-lubricated bearing does not require complex auxiliary equipment such as oil tanks, oil pumps, and coolers, occupying less equipment space and reducing procurement, installation, and subsequent maintenance costs. Its mechanical strength, wear resistance, and heat resistance are significantly improved, reducing frictional resistance during water lubrication and meeting the requirements for use in aquatic environments. The manufacturing process is simple and controllable, cost-effective, and highly practical.

[0053] The following detailed description of one or more optional embodiments of the present invention will be provided through specific examples. Those skilled in the art should understand that the following embodiments are merely illustrative of the technical concept and implementation of the present invention and are not intended to limit the scope of protection of the present invention.

[0054] Example Group 1: A method for preparing a water-lubricated bearing includes the following steps: Step a: Add 90 parts by weight of polyurethane prepolymer into tank A of the casting machine, heat to 70°C to melt the polyurethane prepolymer, and stir continuously during the heating process to obtain liquid polyurethane matrix. Step b: While maintaining the temperature of 70°C inside container A, add different weight parts of PI powder to the liquid polyurethane matrix in container A and mix to obtain solution A. Stir continuously during the mixing process. Step c: Add 20 parts by weight of MOCA into the B container of the casting machine, and heat the MOCA to 110°C to melt it. Stir continuously during the heating process to obtain solution B. Step d: Mix solution A in tank A and solution B in tank B through the mixing head of the casting machine, and then inject the mixture into the pretreated mold. The pretreatment method is to apply a release agent to the inner wall of the mold and preheat the mold to 70°C before injection.

[0055] Step e: Place the mold into a centrifuge and solidify it under centrifugal rotation. The centrifugal rotation time is 20 minutes, the centrifugal speed is controlled at 800 rpm, and the centrifugal ambient temperature is maintained at 100℃.

[0056] Step f: After curing, demold to obtain a blank profile, process the blank profile to obtain a water-lubricated bearing.

[0057] Performance testing: Friction coefficient and wear rate were tested in accordance with GB / T12444-2006.

[0058] The water-lubricated bearings prepared in Example Group 1 were subjected to the above performance tests, and the test results are shown in Table 1.

[0059] Table 1

[0060] Tests showed that the product performance was better when the PI powder content was between 0.1 and 1 part by weight; the overall effect was even better when the PI powder content was between 0.5 and 0.8 parts by weight; when the PI powder content was higher than 1 part by weight or lower than 0.1 parts by weight, the product performance deteriorated significantly, with the best overall performance when the PI powder content was 0.7 parts by weight.

[0061] Example Group 2: The preparation method of the water-lubricated bearing in this embodiment is the same as that in Example 1, except that the PI powder used is 0.7 parts by weight and the MOCA used is different.

[0062] The water-lubricated bearings prepared in Example Group 2 were subjected to the above performance tests, and the test results are shown in Table 2.

[0063] Table 2

[0064] Tests showed that the product performed well when the MOCA content was between 20 and 27 parts by weight; the overall effect was even better when it was between 24 and 26 parts by weight; the product performance deteriorated significantly when it was above 27 parts by weight or below 20 parts by weight, while the overall performance was optimal when the MOCA content was between 25 and 26 parts by weight.

[0065] Example Group 3: The preparation method of the water-lubricated bearing in this embodiment is the same as that in Example 1, except that the PI powder used is 0.7 parts by weight, the MOCA used is 25 parts by weight, and the polyurethane prepolymer used is different.

[0066] The water-lubricated bearings prepared in Example Group 3 were subjected to the above performance tests, and the test results are shown in Table 3.

[0067] Table 3

[0068] Tests showed that the product performance was better when the polyurethane prepolymer content was between 90 and 100 parts by weight; the overall effect was even better when it was between 95 and 100 parts by weight; the product performance deteriorated significantly when it was above 100 parts by weight or below 90 parts by weight, while the overall performance was optimal when the polyurethane prepolymer content was 100 parts by weight.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing a water-lubricated bearing, characterized in that, The preparation method includes the following steps: S1. Heat and melt 90-100 parts by weight of polyurethane prepolymer to obtain liquid polyurethane matrix; S2. Add 0.1-1 parts by weight of functional filler to the liquid polyurethane matrix and mix to obtain solution A; S3. Melt 20-27 parts by weight of the chain extender by heating to obtain solution B; S4. Mix the solution A and the solution B and then inject the mixture into the pretreated mold; S5. Place the mold into a centrifuge and solidify it under centrifugal rotation. S6. After curing, demold to obtain a blank profile, process the blank profile to obtain the water-lubricated bearing.

2. The method for preparing a water-lubricated bearing as described in claim 1, characterized in that, Step S1 includes: Add 90-100 parts by weight of the polyurethane prepolymer into tank A of the casting machine; The polyurethane prepolymer in tank A is heated to 70-90°C to obtain the liquid polyurethane matrix, and then continuously stirred.

3. The method for preparing a water-lubricated bearing as described in claim 2, characterized in that, Step S2 includes: While maintaining a temperature of 70-90°C inside container A, 0.1-1 parts by weight of the functional filler are added to container A and continuously stirred to obtain solution A.

4. The method for preparing a water-lubricated bearing as described in claim 3, characterized in that, Step S3 includes: Add 20-27 parts by weight of the chain extender into tank B of the casting machine; The chain extender is heated to 110-120°C and stirred continuously to obtain solution B.

5. The method for preparing a water-lubricated bearing as described in claim 4, characterized in that, Step S4 includes: Solution A in tank A and solution B in tank B are mixed through the mixing head of the casting machine and then injected into the mold.

6. The method for preparing a water-lubricated bearing as described in claim 1, characterized in that, In S2, the functional filler is polyimide powder.

7. The method for preparing a water-lubricated bearing as described in claim 1, characterized in that, In S3, the chain extender is MOCA.

8. The method for preparing a water-lubricated bearing as described in claim 1, characterized in that, In step S4, the inner wall of the mold is coated with a release agent, and the mold is preheated before injection.

9. The method for preparing a water-lubricated bearing as described in claim 1, characterized in that, In step S5, the centrifugal rotation time is 20-30 minutes.

10. A water-lubricated bearing, characterized in that, The water-lubricated bearing is prepared by the preparation method according to any one of claims 1-9.

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