Conductive self-lubricating polymer material for intelligent self-lubricating bushing

Abstract

The invention provides a conductive self-lubricating polymer material for an intelligent self-lubricating bushing. The conductive self-lubricating polymer material comprises a lubricating layer and a conductive layer, the lubricating layer takes polyetherimide as a matrix and polytetrafluoroethylene as a lubricating phase; the conductive layer takes graphite, graphene, carbon nanotubes, carbon black, carbon fibers and the like as a conductive phase; by monitoring the resistance value between the bushing outer ring and the self-lubricating material, the relation between the abrasion loss and the resistance value of the bushing self-lubricating material is established, the effect of monitoring the abrasion state of the self-lubricating polymer material in real time is achieved, and early warning of the service life of the self-lubricating bushing is achieved; by measuring the resistance of the friction surface of the self-lubricating polymer material, online monitoring of the wear state of the material and early warning of wear failure can be realized; according to the invention, a friction-wear test is carried out aiming at the actual use condition of the conductive self-lubricating polymer for the intelligent self-lubricating bushing, and the influence of material components, forming process parameters and the like on the conductivity and friction-wear performance of the material is researched.

Description

Technical Field

[0001] The invention relates to the technical field of self-lubricating sleeves, and in particular to a conductive self-lubricating polymer material for an intelligent self-lubricating bushing. Background Art

[0002] Self-lubricating bushings have the advantages of high load-bearing capacity, long service life, high reliability, good environmental adaptability, simple and compact structure, light weight, and maintenance-free. They have attracted extensive attention and become the core components of many equipment, especially in the equipment of national key industries such as aerospace and engineering machinery. They play a key role. Self-lubricating bushings are composed of an outer ring and a self-lubricating material bonded to the inner surface of the outer ring. Self-lubricating bushings often face severe working conditions such as heavy loads, high frequencies, and high and low temperature cycles during service. The main failure form is the wear failure of the bushing self-lubricating material. Once the self-lubricating material fails during service, it will directly lead to damage to the self-lubricating bushing, causing irreversible losses.

[0003] At present, the wear amount of self-lubricating materials is mainly obtained through two manual detection methods: stopping the machine to measure with a feeler gauge or disassembling and measuring the thickness of the bushing. The manual detection method is not only labor-intensive, but also the detection results are greatly affected by human experience factors, time-consuming, and there are large manual errors. In addition, when the bushing is stopped or disassembled and installed, it will affect the normal operation of other parts of the equipment. Therefore, the wear state monitoring and life prediction of self-lubricating bushings have always been technical difficulties that hinder the widespread application of self-lubricating bushings. Real-time monitoring of the wear amount of self-lubricating materials when the bushing is in service and prediction of the life of self-lubricating materials have become research focuses.

[0004] In order to solve the above technical problems, a conductive self-lubricating polymer material for an intelligent self-lubricating bushing is proposed. Summary of the invention

[0005] In view of this, the present invention provides a conductive self-lubricating polymer material for an intelligent self-lubricating bushing to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial option.

[0006] The technical solution of the present invention is achieved as follows: a conductive self-lubricating polymer material for an intelligent self-lubricating bushing comprises a lubricating layer and a conductive layer;

[0007] The lubricating layer is based on polyetherimide and has polytetrafluoroethylene as the lubricating phase;

[0008] The conductive layer is made of graphite, graphene, carbon nanotubes, carbon black, carbon fiber, etc. as a conductive phase;

[0009] The lubricating layer and the conductive layer form a smart self-lubricating conductive polymer material.

[0010] Further preferably, during the processing of the intelligent self-lubricating conductive polymer material, the microscopic morphology and composition of the worn surface of the self-lubricating polymer material are analyzed using characterization and analysis equipment such as a scanning electron microscope, an EDS spectrometer, and an X-ray photoelectron spectrometer to reveal the friction and wear mechanism of the intelligent self-lubricating polymer material.

[0011] More preferably, the polyetherimide is prepared by heating 4,4′-diaminodiphenyl ether or m-(or p-)phenylenediamine and 2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride in a dimethylacetamide solvent, polycondensing, pulverizing, and imidizing.

[0012] Further preferably, the mass ratio of the polyetherimide is in the range of: 30%-50% of 4,4′-diaminodiphenyl ether, 1%-6% of phenylenediamine, and 10%-40% of 2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]; and the concentration of the dimethylacetamide solvent used as a catalyst is between 35% and 50%.

[0013] Further preferably, the polytetrafluoroethylene is prepared from chloroform as raw material, chloroform is fluorinated with anhydrous hydrofluoric acid at a reaction temperature above 65° C., antimony pentachloride is used as a catalyst, and finally tetrafluoroethylene is prepared by thermal cracking.

[0014] Further preferably, an aviation self-lubricating bushing service life evaluation test machine is used to carry out intelligent self-lubricating conductive polymer material friction and wear tests under laboratory conditions, and the relationship between resistance change and wear state is determined by detecting and analyzing the resistance and wear data of the self-lubricating polymer material.

[0015] Further preferably, a tribological test is carried out on a sample of the intelligent self-lubricating conductive polymer material using a screen-display high-temperature material end face friction and wear testing machine. The test conditions are: room temperature, load 200N, sliding speed 0.12m / s. During the test, a multimeter is used to measure the online resistance change of the conductive polymer in real time, and the friction coefficient data is detected and recorded in real time through the testing machine software. The wear amount is measured by a surface profiler.

[0016] Further preferably, the lubricating layer and the conductive layer are formed into a polymer conductive layer by hot molding, and a friction-reducing and wear-resistant polymer material is solidified on the surface thereof as an insulating layer to produce an intelligent self-lubricating conductive polymer material with a layered structure.

[0017] The embodiment of the present invention has the following advantages due to the adoption of the above technical solution:

[0018] 1. The present invention establishes a connection between the wear amount and the resistance value of the bushing self-lubricating material by monitoring the resistance value between the bushing outer ring and the self-lubricating material, thereby achieving the function of real-time monitoring of the wear state of the self-lubricating polymer material and realizing early warning of the life of the self-lubricating bushing;

[0019] Second, the present invention can realize online monitoring of the wear state of the material and early warning of wear failure by measuring the friction surface resistance of the self-lubricating polymer material;

[0020] 3. The present invention conducts friction and wear tests on the actual use conditions of conductive self-lubricating polymers for intelligent self-lubricating bushings, studies the influence of material composition, molding process parameters, etc. on the conductivity and friction and wear performance of materials, determines the key influencing parameters and their weights, and establishes the mapping law between the resistance change and wear state of self-lubricating polymer materials, providing solid theoretical support for the material design, performance optimization and wear monitoring of conductive self-lubricating polymers.

[0021] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural diagram of a sample of the intelligent self-lubricating conductive polymer material in the present invention;

[0024] Figure 2 A curve diagram showing the change of resistance and friction coefficient of the intelligent self-lubricating polymer material of the present invention over time;

[0025] Figure 3 The figure is a curve diagram showing the change of resistance and wear of the intelligent self-lubricating polymer material over time. DETAILED DESCRIPTION

[0026] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] like Figure 1 As shown, an embodiment of the present invention provides a conductive self-lubricating polymer material for an intelligent self-lubricating bushing, including a lubricating layer made of polyetherimide as a matrix and polytetrafluoroethylene as a lubricating phase, and a conductive layer with graphite, graphene, carbon nanotubes, carbon black, carbon fiber, etc. as a conductive phase.

[0029] Embodiment 1

[0030] The lubricating layer and the conductive layer are formed into a polymer conductive layer by hot molding, and a friction-reducing and wear-resistant polymer material is solidified on the surface of the polymer conductive layer as an insulating layer to prepare an intelligent self-lubricating conductive polymer material with a layered structure.

[0031] In one embodiment, the polyetherimide is prepared by heating 4,4′-diaminodiphenyl ether or m-(or p-)phenylenediamine and 2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride in a dimethylacetamide solvent through polycondensation, powdering, and imidization. The mass ratio of the polyetherimide is: 45% of 4,4′-diaminodiphenyl ether, 3% of phenylenediamine, and 15% of 2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]; the concentration of the dimethylacetamide solvent used as a catalyst is 45%.

[0032] The preparation of the above-mentioned polyetherimide can be divided into a polynitro substitution method and a polycyclic condensation process. The former first undergoes a cyclization reaction to form an imide ring, and then undergoes an aromatic nucleophilic nitro substitution reaction to form a flexible ether "hinge". The latter first undergoes an aromatic nucleophilic nitro substitution reaction and then undergoes a cyclization reaction. The polymer formation process is a polycyclic condensation process.

[0033] In one embodiment, the polytetrafluoroethylene is prepared from chloroform as raw material, chloroform is fluorinated with anhydrous hydrofluoric acid, the reaction temperature is above 65° C., antimony pentachloride is used as a catalyst, and finally tetrafluoroethylene is prepared by thermal cracking.

[0034] In one embodiment, during the processing of the intelligent self-lubricating conductive polymer material, the microscopic morphology and composition of the worn surface of the self-lubricating polymer material are analyzed using characterization and analysis equipment such as a scanning electron microscope, an EDS spectrometer, and an X-ray photoelectron spectrometer to reveal the friction and wear mechanism of the intelligent self-lubricating polymer material. Microcapsules containing fluorescent agents can be added to assist in the analysis process.

[0035] In one embodiment, at the beginning of the friction process, the lubricating layer of the self-lubricating polymer material bears and achieves friction reduction and wear resistance, and the resistance value is relatively high at this time; when the self-lubricating polymer material fails due to wear, that is, the lubricating layer is completely worn out, the conductive layer of the self-lubricating polymer material is fully exposed, and the resistance value is relatively low at this time.

[0036] Embodiment 2

[0037] The lubricating layer and the conductive layer are formed into a polymer conductive layer by hot molding, and a friction-reducing and wear-resistant polymer material is solidified on the surface of the polymer conductive layer as an insulating layer to prepare an intelligent self-lubricating conductive polymer material with a layered structure.

[0038] In one embodiment, the polyetherimide is prepared by heating 4,4′-diaminodiphenyl ether or m-(or p-)phenylenediamine and 2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride in a dimethylacetamide solvent through polycondensation, powdering, and imidization. The mass ratio of the polyetherimide is: 50% of 4,4′-diaminodiphenyl ether, 2% of phenylenediamine, and 10% of 2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]; the concentration of the dimethylacetamide solvent used as a catalyst is 40%.

[0039] The preparation of the above-mentioned polyetherimide can be divided into a polynitro substitution method and a polycyclic condensation process. The former first undergoes a cyclization reaction to form an imide ring, and then undergoes an aromatic nucleophilic nitro substitution reaction to form a flexible ether "hinge". The latter first undergoes an aromatic nucleophilic nitro substitution reaction and then undergoes a cyclization reaction. The polymer formation process is a polycyclic condensation process.

[0040] In one embodiment, the polytetrafluoroethylene is prepared from chloroform as a raw material, chloroform is fluorinated with anhydrous hydrofluoric acid at a reaction temperature above 70° C., antimony pentachloride is used as a catalyst, and finally tetrafluoroethylene is prepared by thermal cracking.

[0041] In one embodiment, during the processing of the intelligent self-lubricating conductive polymer material, the microscopic morphology and composition of the worn surface of the self-lubricating polymer material are analyzed using characterization and analysis equipment such as a scanning electron microscope, an EDS spectrometer, and an X-ray photoelectron spectrometer to reveal the friction and wear mechanism of the intelligent self-lubricating polymer material. Microcapsules containing fluorescent agents can be added to assist in the analysis process.

[0042] In one embodiment, at the beginning of the friction process, the lubricating layer of the self-lubricating polymer material bears and achieves friction reduction and wear resistance, and the resistance value is relatively high at this time; when the self-lubricating polymer material fails due to wear, that is, the lubricating layer is completely worn out, the conductive layer of the self-lubricating polymer material is fully exposed, and the resistance value is relatively low at this time.

[0043] like Figure 2 and Figure 3As shown, the intelligent self-lubricating conductive polymer material is subjected to friction and wear tests of the intelligent self-lubricating bushing under laboratory conditions using an aviation self-lubricating bushing service life evaluation test machine. The relationship between the resistance change and the wear state is determined by detecting and analyzing the resistance and wear data of the self-lubricating polymer material. As the friction test proceeds, the resistance change and the friction coefficient of the intelligent self-lubricating polymer material show a strong correlation. In the early stage of wear, under the action of the load, the upper specimen directly contacts the lubricating layer of the polymer material. At this time, the friction coefficient is within 0.16 and the resistance value is greater than 120MΩ. When the friction and wear test is carried out to 1000s, the friction coefficient remains at about 0.16, the resistance value drops to about 100MΩ, and the wear amount is 0.07mm. When the friction and wear test is carried out to 1580s, the friction coefficient rises to 0.21, the resistance value drops to within 1MΩ, and the wear amount reaches 0.11mm. At this time, the lubricating layer material fails due to complete wear.

[0044] In one embodiment, a tribological test is performed on a sample of an intelligent self-lubricating conductive polymer material using a screen-displayed high-temperature material end face friction and wear tester. The test conditions are: room temperature, a load of 200 N, and a sliding speed of 0.12 m / s. During the test, a multimeter is used to measure the online resistance change of the conductive polymer in real time. The friction coefficient data is detected and recorded in real time through the test machine software, and the wear amount is measured by a surface profiler.

[0045] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A conductive self-lubricating polymer material for an intelligent self-lubricating bushing, characterized in that: including a lubricating layer and a conductive layer; The lubricating layer is based on polyetherimide and has polytetrafluoroethylene as the lubricating phase; The conductive layer is made of graphite, graphene, carbon nanotubes, carbon black, carbon fiber, etc. as a conductive phase; The lubricating layer and the conductive layer form a smart self-lubricating conductive polymer material.

2. The conductive self-lubricating polymer material for an intelligent self-lubricating bushing according to claim 1, characterized in that: During the processing of the intelligent self-lubricating conductive polymer material, the microscopic morphology and composition of the worn surface of the self-lubricating polymer material are analyzed using characterization and analysis equipment such as a scanning electron microscope, an EDS spectrometer, and an X-ray photoelectron spectrometer to reveal the friction and wear mechanism of the intelligent self-lubricating polymer material.

3. The conductive self-lubricating polymer material for an intelligent self-lubricating bushing according to claim 1, characterized in that: The polyetherimide is prepared by heating 4,4'-diaminodiphenyl ether or m-(or p-)phenylenediamine and 2,2'-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride in dimethylacetamide solvent, polycondensing, powdering and imidizing.

4. The conductive self-lubricating polymer material for an intelligent self-lubricating bushing according to claim 3, characterized in that: The mass ratio of the polyetherimide is: 30%-50% of 4,4'-diaminodiphenyl ether, 1%-6% of phenylenediamine, and 10%-40% of 2,2'-bis[4-(3,4-dicarboxyphenoxy)phenyl]; the concentration of the dimethylacetamide solvent used as a catalyst is between 35% and 50%.

5. The conductive self-lubricating polymer material for an intelligent self-lubricating bushing according to claim 1, characterized in that: The polytetrafluoroethylene is prepared by using chloroform as a raw material, fluorinating the chloroform with anhydrous hydrofluoric acid at a reaction temperature above 65° C., using antimony pentachloride as a catalyst, and finally using a thermal cracking method to prepare tetrafluoroethylene.

6. The conductive self-lubricating polymer material for an intelligent self-lubricating bushing according to claim 1, characterized in that: The intelligent self-lubricating conductive polymer material was subjected to friction and wear tests under laboratory conditions using an aviation self-lubricating bushing service life evaluation test machine. The relationship between resistance change and wear state was determined by detecting and analyzing the resistance and wear data of the self-lubricating polymer material.

7. The conductive self-lubricating polymer material for an intelligent self-lubricating bushing according to claim 1, characterized in that: A tribological test was carried out on samples of intelligent self-lubricating conductive polymer materials using a screen-display high-temperature material end face friction and wear testing machine. The test conditions were: room temperature, load 200N, sliding speed 0.12m / s. During the test, a multimeter was used to measure the online resistance change of the conductive polymer in real time. The friction coefficient data was detected and recorded in real time through the testing machine software, and the wear amount was measured by a surface profiler.

8. The conductive self-lubricating polymer material for an intelligent self-lubricating bushing according to claim 1, characterized in that: The lubricating layer and the conductive layer are formed into a polymer conductive layer by hot molding, and a friction-reducing and wear-resistant polymer material is solidified on the surface of the polymer conductive layer as an insulating layer to prepare an intelligent self-lubricating conductive polymer material with a layered structure.

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