A polymer sliding bearing and a method for manufacturing the same

Abstract

The application belongs to the technical field of sliding bearing manufacturing, and particularly relates to a high polymer sliding bearing and a preparation method thereof, which comprises the following steps: machining a groove on an inner shaft, filling an anchoring material in the groove, heating, cooling, forming an anchoring layer in the groove, obtaining a pretreated inner shaft, pressing a wear-resistant material on the pretreated inner shaft, temperature treatment, cooling, putting into lubricating oil of the same temperature when the temperature is cooled to a predetermined temperature, continuously cooling, forming a low friction layer on the surface of the inner shaft, and obtaining a modified inner shaft; and assembling the modified inner shaft in an outer shaft to obtain the high polymer sliding bearing. The application can improve the bonding strength between the inner shaft and the low friction layer, and improve the long-term stability of the sliding bearing under dynamic load conditions.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sliding bearing manufacturing, and particularly relates to a high polymer sliding bearing and a preparation method thereof. BACKGROUND

[0002] The sliding bearing has strong bearing capacity, stable operation and low noise, and is often used in heavy load, high speed and high precision environments. In order to improve the service life of the sliding bearing, it is necessary to reduce the friction coefficient between the bearing bush and the shaft diameter. The prior art usually sprays bronze alloy powder on the inner shaft, sintering at a high temperature of 800-950 DEG C, forming a porous surface layer attached to the inner shaft, filling the lubricating oil in the pores of the porous surface layer, and then coating a low friction layer thereon. The low friction layer penetrates into the micropores of the porous surface layer when it is in a liquid state, and after solidification, the low friction layer is attached to the porous surface layer. Although this process can reduce the friction between the sliding bearing and the shaft diameter, the porous bronze layer is attached to the inner shaft by spraying and sintering, and the porous bronze layer is mainly connected with the inner shaft by limited metallurgical bonding, so the bonding strength is not high. Once the porous layer falls off, the low friction layer on it also fails, affecting the service life of the bearing.

[0003] Chinese patent application No. CN116950998A discloses a sliding bearing bush, a manufacturing method and an application, which comprises an inner shaft and a high polymer low friction layer attached to the inner shaft. The inner shaft is provided with a groove, and the high polymer low friction layer is embedded in the groove to fix the high polymer low friction layer and the inner shaft. The patent application avoids the traditional process of relying on a sintered bronze layer as an intermediate layer, and improves the contact area between the low friction layer and the inner shaft. However, the bonding strength between the low friction layer and the inner shaft groove is low, and under dynamic load conditions, the interface is prone to relative slip due to stress concentration, resulting in delamination or peeling between the low friction layer and the inner shaft, affecting the use stability of the sliding bearing. SUMMARY

[0004] The application provides a high polymer sliding bearing and a preparation method thereof, which improves the bonding strength between the inner shaft and the low friction layer, and improves the long-term stability of the sliding bearing under dynamic load conditions.

[0005] To solve the above problems, the application adopts the following technical scheme:

[0006] A preparation method of a high polymer sliding bearing, comprising the following steps:

[0007] S1, a groove is processed on the inner shaft, the groove is filled with anchoring material, heated, cooled, and an anchoring layer is formed in the groove to complete the pretreatment of the inner shaft; the anchoring material is prepared by uniformly mixing VTES modified expanded graphite, divinylbenzene, polyethylene glycol-400, TEOS hydrolysate, VTES hydrolysate, and an initiator, and concentrated under reduced pressure to obtain the anchoring material;

[0008] S2, the pretreated inner shaft is pressed with wear-resistant material, and is subjected to temperature treatment and cooling; when the temperature reaches a predetermined temperature, the inner shaft is placed in lubricating oil at the same temperature for continuous cooling, so as to form a low-friction layer on the surface of the inner shaft to obtain a modified inner shaft; the wear-resistant material is prepared by uniformly mixing polyphenylene sulfide, molybdenum disulfide, polytetrafluoroethylene, carbon fiber, and an antioxidant;

[0009] S3, the modified inner shaft is assembled in the outer shaft to obtain a high polymer sliding bearing.

[0010] The present application first processes a groove on the inner shaft, and since the main component of the inner shaft is iron, the iron reacts with oxygen in the air to generate hydrophilic iron oxide, and a hydrolysis reaction occurs between the iron oxide and moisture in the air to form hydroxyl groups on the surface of the groove; the anchoring material contains silanol generated by the hydrolysis of TEOS and VTES, the anchoring material is filled in the groove, the silanol and the hydroxyl groups on the surface of the groove undergo condensation reaction to generate Si-O-metal covalent bond, the silanol is grafted on the surface of the groove through the covalent bond, the silanol undergoes condensation reaction to generate a silicon-oxygen network, under the thermal initiation of the initiator, the silanol generated by the hydrolysis of VTES and divinylbenzene undergoes reaction to generate an organic crosslinked network, and the silicon-oxygen network and the organic crosslinked network cooperatively form a solid skeleton embedded with polyethylene glycol-400, after heating, the polyethylene glycol-400 is removed from the solid skeleton, leaving micropores on the solid skeleton to obtain an anchoring layer, the anchoring layer and the surface of the groove are connected through Si-O-metal covalent bond, and the interfacial bonding force is strong; after the wear-resistant material contacts with the anchoring layer and is heated, the polyphenylene sulfide in the wear-resistant material is melted and has reduced viscosity, and is fully infiltrated into the micropores, and after cooling, the wear-resistant material forms a low-friction layer on the inner shaft, the low-friction layer and the anchoring layer are connected in a high-strength mode through mechanical interlocking, the anchoring layer and the groove of the inner shaft are connected through covalent bond, the bonding force between the low-friction layer and the inner shaft is strong, and the low-friction layer is not prone to peeling from the inner shaft when the sliding bearing bears dynamic load, thereby improving the service life of the sliding bearing.

[0011] The expanded graphite is modified by VTES to inhibit the agglomeration of the expanded graphite, and the dispersibility of the expanded graphite in the wear-resistant material is improved; the VTES modified expanded graphite is located in the groove, and the stress generated on the VTES modified expanded graphite is small when the sliding bearing bears dynamic load, thereby preventing the VTES modified expanded graphite from being broken.

[0012] In the process of constructing the low-friction layer on the inner shaft surface, the inner shaft is immersed in lubricating oil. Due to the rich micro-nano channels in the VTES modified expanded graphite, the lubricating oil is adsorbed and enriched in the VTES modified expanded graphite under the action of capillary adsorption effect, and the lubricating oil is stored. In the subsequent use process, the VTES modified expanded graphite continuously releases the lubricating oil to the surface of the low-friction layer, reduces the friction coefficient between the inner shaft and the outer shaft, and improves the long-term use stability of the sliding bearing.

[0013] Further, the TEOS hydrolysis solution is prepared by mixing TEOS, 15wt% hydrochloric acid solution and anhydrous ethanol, and then adding deionized water under continuous stirring, and stirring at 300 rpm for 1.5 h to obtain the TEOS hydrolysis solution; the VTES hydrolysis solution is prepared by mixing VTES, 15wt% hydrochloric acid solution and anhydrous ethanol, and then adding deionized water under continuous stirring, and stirring at 300 rpm for 2 h to obtain the VTES hydrolysis solution.

[0014] The hydroxyl groups on the surface of the expanded graphite and the silanol generated by the hydrolysis of VTES undergo condensation reaction, introducing vinyl functional groups and silicon hydroxyl groups on the surface of the expanded graphite, obtaining VTES modified expanded graphite, so that the VTES modified expanded graphite can participate in the construction of organic cross-linked network and silicon-oxygen network, effectively limiting the expanded graphite in the anchoring layer, and the anchoring layer can provide support for the expanded graphite, effectively dispersing stress and preventing the expanded graphite from breaking during the process of the sliding bearing bearing dynamic load.

[0015] Further, the VTES modified expanded graphite is prepared by adding expanded graphite into the VTES hydrolysis solution and stirring to react, and then washing with anhydrous ethanol to obtain the VTES modified expanded graphite.

[0016] Further, in the preparation process of the anchoring material, the VTES modified expanded graphite, divinylbenzene, polyethylene glycol-400, TEOS hydrolysis solution, VTES hydrolysis solution and initiator are mixed, stirred at 300 rpm for 30 min, placed in an environment of 40℃ and 10.1kPa, and stirred at 350 rpm for 3h to obtain the anchoring material.

[0017] Stirring at 40℃ and 10.1kPa for 3h removes most of the ethanol introduced in the system due to the addition of the TEOS hydrolysis solution and the VTES hydrolysis solution, concentrates the anchoring material, increases the viscosity of the anchoring material, and prevents the anchoring material from flowing after being filled into the groove.

[0018] Further, in step S1, one or more of the following methods is used to fill the anchoring material in the groove: mold pressing method, injection molding method, 3D printing method, and prepreg winding method.

[0019] Further, after filling the anchor material in the groove in step S1, the inner shaft is placed in a 50℃ environment for 1h, heated to 70℃ for 2h, heated to 120℃ for 1h, heated to 220℃ for 1h, heated to 270℃ for 1h, and cooled to room temperature, forming an anchor layer in the groove and completing the pretreatment of the inner shaft; the groove is one of a ring-shaped dovetail groove, a dovetail-shaped threaded groove, a rectangular threaded groove, and a T-shaped threaded groove.

[0020] First, the inner shaft is placed in a 50℃ environment for 1h to promote the condensation reaction between silanol and the hydroxyl group on the surface of the groove and the condensation reaction between silanols, forming a silicon-oxygen network covalently connected to the groove while introducing vinyl functional groups on the surface of the groove; the temperature is raised to 70℃ for 2h, and under the initiation of the initiator, the vinyl functional groups on the surface of the groove and divinylbenzene undergo copolymerization and crosslinking reaction, forming an organic crosslinking network interpenetrated with the silicon-oxygen network and covalently connected to the surface of the groove; the temperature is raised to 120℃ for 1h, and the polyethylene glycol-400 is softened to prepare for subsequent high-temperature migration; the temperature is raised to 220℃ for 1h, and the viscosity of the polyethylene glycol-400 is further reduced, and the migration begins; the temperature is raised to 270℃ for 1h, and the polyethylene glycol-400 is discharged from the solid skeleton, and the space occupied by the polyethylene glycol-400 forms micropores, thereby obtaining a porous structure and an anchor layer covalently connected to the groove.

[0021] Further, before filling the anchor material in the groove, a 2wt% hydrochloric acid solution is sprayed into the groove, and after 2min, the groove is washed with deionized water, and the inner shaft is dried in a 50℃ air stream for 10min.

[0022] The surface of the groove is treated with a hydrochloric acid solution and deionized water, and then the surface of the groove is blown dry with an air stream, increasing the density and reactivity of the hydroxyl groups on the surface of the groove, improving the grafting efficiency of silanol, and facilitating the improvement of the interfacial bonding strength between the anchor layer and the surface of the groove.

[0023] Further, in step S2, the wear-resistant material is pressed onto the pretreated inner shaft, the temperature is raised to 350℃ and maintained for 3h, and when the temperature naturally cools to 100℃, the inner shaft is placed in a lubricating oil with a temperature of 100℃, naturally cooled to room temperature, taken out, and a low-friction layer is formed on the surface of the inner shaft to obtain a modified inner shaft.

[0024] The inner shaft cooled to 100℃ is placed in a lubricating oil with a temperature of 100℃ and continues to be naturally cooled. Since the inner shaft and the lubricating oil are at a similar temperature, the anchor layer and the wear-resistant layer are prevented from being cracked due to a large temperature difference. At the same time, the lubricating oil at 100℃ has a low viscosity and strong flowability, which is conducive to the penetration of the lubricating oil into the wear-resistant layer and the anchor layer and the contact with the expanded graphite.

[0025] A polymer sliding bearing, comprising an outer shaft and a modified inner shaft assembled in the outer shaft; the modified inner shaft comprises an inner shaft, an anchoring layer and a low-friction layer, the anchoring layer comprises the following raw materials by mass fraction: expanded graphite 9-12 parts, divinylbenzene 13-18 parts, polyethylene glycol-400 6-8 parts, TEOS hydrolysate 18-24 parts, VTES hydrolysate 18-24 parts, initiator 0.8-1.5 parts; the low-friction layer comprises the following raw materials by mass fraction: polyphenylene sulfide 50-70 parts, molybdenum disulfide 10-15 parts, polytetrafluoroethylene 7-10 parts, carbon fiber 7-12 parts, antioxidant 0.2-0.6 parts; the initiator is AIBN, and the antioxidant is BHT.

[0026] Further, the TEOS hydrolysate comprises the following raw materials by mass fraction: TEOS 8-10 parts, 15wt% hydrochloric acid solution 0.4-0.7 parts, anhydrous ethanol 130-160 parts, deionized water 3-4.5 parts; and the VTES hydrolysate comprises the following raw materials by mass fraction: VTES 17-26 parts, 15wt% hydrochloric acid solution 0.4-0.6 parts, anhydrous ethanol 180-230 parts, deionized water 7-8.5 parts.

[0027] The beneficial effects of the present application are:

[0028] The present application prepares a modified inner shaft by means of opening a groove on the inner shaft, filling the anchoring layer in the groove, and constructing a low-friction layer on the surface of the inner shaft, assembles the modified inner shaft on the outer shaft, and obtains a sliding bearing suitable for use under dynamic load working conditions. In the preparation process of the modified inner shaft, the covalent bond between the silanol generated by the hydrolysis of TEOS and VTES and the metal hydroxyl on the surface of the groove is connected between the anchoring layer and the groove, the micropores generated after the removal of polyethylene glycol-400 in the anchoring layer, and the polyphenylene sulfide in the wear-resistant material enters the micropores after melting, and after cooling, a low-friction layer connected with the anchoring layer by mechanical interlocking is obtained, the bonding force between the low-friction layer and the inner shaft is strong, so that the low-friction layer and the inner shaft are not easy to peel off when the sliding bearing is used under dynamic load working conditions, and the service life of the sliding bearing is improved.

[0029] The present application introduces VTES modified expanded graphite in the anchoring layer, the VTES modified expanded graphite is located in the groove and is confined in the anchoring layer and is not easy to break; in the construction process of the low-friction layer, the inner shaft is soaked in lubricating oil, the lubricating oil is enriched in the expanded graphite, and is continuously released to the surface of the low-friction layer in the subsequent use process, thereby reducing the friction coefficient between the inner shaft and the outer shaft and improving the long-term use stability of the sliding bearing. DETAILED DESCRIPTION

[0030] Example one

[0031] Add 10 g TEOS (tetraethyl orthosilicate), 0.5 g 15 wt% hydrochloric acid solution into 150 g anhydrous ethanol, add 3.5 g deionized water at a speed of 0.5 g / min under the condition of 300 rpm stirring, 300 rpm stirring for 1.5 h to obtain TEOS hydrolyzate; add 20 g VTES (vinyltriethoxysilane), 0.4 g 15 wt% hydrochloric acid solution into 200 g anhydrous ethanol, add 7.5 g deionized water at a speed of 0.5 g / min under the condition of 300 rpm stirring, 300 rpm stirring for 2 h to obtain VTES hydrolyzate; add 10 g expanded graphite into 200 g VTES hydrolyzate, heat to 50℃, 300 rpm stirring for 2 h, filtration, anhydrous ethanol washing to obtain VTES modified expanded graphite; mix the VTES modified expanded graphite with 15 g divinylbenzene, 6 g polyethylene glycol-400, 20 g TEOS hydrolyzate, 20 g VTES hydrolyzate, 1 g AIBN (azobisisobutyronitrile), 300 rpm stirring for 30 min, put into 40℃, 10.1 kPa environment, 350 rpm stirring for 3 h to obtain anchoring material; mix 60 g polyphenylene sulfide, 12 g molybdenum disulfide, 8 g polytetrafluoroethylene, 8 g carbon fiber, 0.3 g BHT (2,6-di-tert-butyl-p-cresol), 300 rpm stirring for 10 min to obtain wear-resistant material.

[0032] Process a groove on the inner shaft, the groove is a dovetail thread groove, spray 2 wt% hydrochloric acid solution into the groove at a spraying amount of 0.1 g / cm2, stand for 2 min, wash the groove with deionized water, put the inner shaft into 50℃ air flow to dry for 10 min, then fill the anchoring material in the groove by using the mold pressing method: put the inner shaft into the mold, use the extruder to extrude the anchoring material into the mold, fill the anchoring material in the groove by the pressure provided by the press, put the inner shaft into the oven preheated to 50℃ and keep warm for 1 h, heat to 70℃ at a speed of 20℃ / h, keep warm for 2 h, heat to 120℃ at a speed of 20℃ / h, keep warm for 1 h, heat to 220℃ at a speed of 40℃ / h, keep warm for 1 h, heat to 270℃ at a speed of 15℃ / h, keep warm for 1 h, naturally cool to room temperature, form the anchoring layer in the groove, complete the pretreatment of the inner shaft; put the pretreated inner shaft into the mold, use the extruder to extrude the wear-resistant material into the mold, press the wear-resistant material on the pretreated inner shaft by the pressure provided by the press, heat to 350℃ and keep warm for 3 h, naturally cool to 100℃, put into the lubricating oil with a temperature of 100℃, naturally cool to room temperature, take out, form the low-friction layer on the surface of the inner shaft, obtain the modified inner shaft, assemble the modified inner shaft in the outer shaft to obtain the polymer sliding bearing.

[0033] Example Two

[0034] 8 g TEOS, 0.7 g 15 wt% hydrochloric acid solution were added into 160 g anhydrous ethanol, 3 g deionized water was added at a speed of 0.5 g / min under the condition of 300 rpm stirring, 300 rpm stirring for 1.5 h to obtain TEOS hydrolyzate; 25 g VTES, 0.5 g 15 wt% hydrochloric acid solution were added into 230 g anhydrous ethanol, 8.5 g deionized water was added at a speed of 0.5 g / min under the condition of 300 rpm stirring, 300 rpm stirring for 2 h to obtain VTES hydrolyzate; 9 g expanded graphite was added into 240 g VTES hydrolyzate, heated to 50℃, 300 rpm stirring for 2 h, filtration, anhydrous ethanol washing to obtain VTES modified expanded graphite; the VTES modified expanded graphite was mixed with 13 g divinylbenzene, 7 g polyethylene glycol-400, 19 g TEOS hydrolyzate, 22 g VTES hydrolyzate, 0.9 g AIBN, 300 rpm stirring for 30 min, placed in a 40℃, 10.1 kPa environment, 350 rpm stirring for 3 h to obtain anchoring material; 70 g polyphenylene sulfide, 11 g molybdenum disulfide, 8 g polytetrafluoroethylene, 9 g carbon fiber, 0.6 g BHT were mixed, 300 rpm stirring for 10 min to obtain wear-resistant material.

[0035] A groove was machined on the inner shaft, the groove was an annular dovetail groove, 2 wt% hydrochloric acid solution was sprayed into the groove at a spraying amount of 0.1 g / cm2, and the groove was washed with deionized water after standing for 2 min. The inner shaft was dried in a 50℃ air stream for 10 min, and then the anchoring material was filled in the groove by injection molding: the inner shaft was placed in a mold cavity and the mold was closed, the anchoring material was injected into the mold cavity using an injection molding machine, the anchoring material was filled in the groove, and after setting, the mold was opened, the inner shaft was taken out, and the inner shaft was placed in an oven preheated to 50℃ for 1 h, and then the temperature was increased to 70℃ at a rate of 20℃ / h, and then the temperature was kept for 2 h, and then the temperature was increased to 120℃ at a rate of 20℃ / h, and then the temperature was kept for 1 h, and then the temperature was increased to 220℃ at a rate of 40℃ / h, and then the temperature was kept for 1 h, and then the temperature was increased to 270℃ at a rate of 15℃ / h, and then the temperature was kept for 1 h, and then the temperature was naturally cooled to room temperature, and an anchoring layer was formed in the groove, and the pretreatment of the inner shaft was completed; the pretreated inner shaft was placed in a mold, the wear-resistant material was extruded into the mold using an extruder, and the wear-resistant material was pressed on the pretreated inner shaft by the pressure provided by a press, the temperature was increased to 350℃ and kept for 3 h, and then the temperature was naturally cooled to 100℃, and then the inner shaft was placed in a lubricating oil with a temperature of 100℃, and then the temperature was naturally cooled to room temperature, and then the modified inner shaft was taken out, and a low-friction layer was formed on the surface of the inner shaft, and then the modified inner shaft was assembled in the outer shaft to obtain a high molecular sliding bearing.

[0036] Example Three

[0037] 9g TEOS, 0.4g 15wt% hydrochloric acid solution were added into 130g anhydrous ethanol, 4.5g deionized water was added at a speed of 0.5g / min under the condition of 300rpm stirring, 300rpm stirring for 1.5h to obtain TEOS hydrolyzate; 23g VTES, 0.6g 15wt% hydrochloric acid solution were added into 180g anhydrous ethanol, 8.5g deionized water was added at a speed of 0.5g / min under the condition of 300rpm stirring, 300rpm stirring for 2h to obtain VTES hydrolyzate; 10g expanded graphite was added into 180g VTES hydrolyzate, heated to 50℃, 300rpm stirring for 2h, filtration, anhydrous ethanol washing to obtain VTES modified expanded graphite; the VTES modified expanded graphite was mixed with 16g divinylbenzene, 8g polyethylene glycol-400, 24g TEOS hydrolyzate, 18g VTES hydrolyzate, 0.8g AIBN, 300rpm stirring for 30min, placed in a 40℃, 10.1kPa environment, 350rpm stirring for 3h to obtain anchoring material; 50g polyphenylene sulfide, 12g molybdenum disulfide, 7g polytetrafluoroethylene, 12g carbon fiber, 0.5g BHT were mixed, 300rpm stirring for 10min to obtain wear-resistant material.

[0038] A groove was machined on the inner shaft, the groove was a rectangular thread groove, 2wt% hydrochloric acid solution was sprayed into the groove at a spraying amount of 0.1g / cm2, and the groove was washed with deionized water after standing for 2min. The inner shaft was dried in a 50℃ air flow for 10min, and then the anchoring material was filled in the groove by 3D printing: the inner shaft was assembled on the clamp of the 3D printer, the clamp rotated the inner shaft around its axis, and the anchoring material was filled in the groove through the nozzle. The inner shaft was placed in an oven preheated to 50℃ and kept for 1h, heated to 70℃ at a speed of 20℃ / h, kept for 2h, heated to 120℃ at a speed of 20℃ / h, kept for 1h, heated to 220℃ at a speed of 40℃ / h, kept for 1h, heated to 270℃ at a speed of 15℃ / h, kept for 1h, and naturally cooled to room temperature. An anchoring layer was formed in the groove, and the pretreatment of the inner shaft was completed. The pretreated inner shaft was placed in a mold, the wear-resistant material was extruded into the mold using an extruder, and the wear-resistant material was pressed on the pretreated inner shaft by the pressure provided by the press. The temperature was increased to 350℃ and kept for 3h, and then naturally cooled to 100℃. The inner shaft was placed in a lubricating oil at a temperature of 100℃, naturally cooled to room temperature, taken out, and a low-friction layer was formed on the surface of the inner shaft. A modified inner shaft was obtained, and the modified inner shaft was assembled in the outer shaft to obtain a high molecular sliding bearing.

[0039] Example Four

[0040] 9g TEOS, 0.6g 15wt% hydrochloric acid solution were added into 140g anhydrous ethanol, 3g deionized water was added at a speed of 0g / min under the condition of 300rpm stirring, 300rpm stirring for 1.5h, to obtain TEOS hydrolyzate; 17g VTES, 0.5g 15wt% hydrochloric acid solution were added into 200g anhydrous ethanol, 8g deionized water was added at a speed of 0.5g / min under the condition of 300rpm stirring, 300rpm stirring for 2h, to obtain VTES hydrolyzate; 11g expanded graphite was added into 180g VTES hydrolyzate, heated to 50℃, 300rpm stirring for 2h, filtration, anhydrous ethanol washing, to obtain VTES modified expanded graphite; the VTES modified expanded graphite was mixed with 18g divinylbenzene, 8g polyethylene glycol-400, 23g TEOS hydrolyzate, 22g VTES hydrolyzate, 1g AIBN, 300rpm stirring for 30min, put into 40℃, 10.1kPa environment, 350rpm stirring for 3h, to obtain anchoring material; 55g polyphenylene sulfide, 10g molybdenum disulfide, 9g polytetrafluoroethylene, 10g carbon fiber, 0.4g BHT were mixed, 300rpm stirring for 10min, to obtain wear-resistant material.

[0041] A groove was machined on the inner shaft, the groove was an annular dovetail groove, 2wt% hydrochloric acid solution was sprayed into the groove at a spraying amount of 0.1g / cm2, and the groove was washed with deionized water after standing for 2min. The inner shaft was dried in a 50℃ air stream for 10min, and then the anchoring material was filled in the groove by 3D printing: the inner shaft was assembled on the clamp of the 3D printer, the clamp rotated the inner shaft around its axis, and the anchoring material was filled in the groove through the nozzle. The inner shaft was placed in an oven preheated to 50℃ and kept for 1h, heated to 70℃ at a speed of 20℃ / h, kept for 2h, heated to 120℃ at a speed of 20℃ / h, kept for 1h, heated to 220℃ at a speed of 40℃ / h, kept for 1h, heated to 270℃ at a speed of 15℃ / h, kept for 1h, and naturally cooled to room temperature. The anchoring layer was formed in the groove, and the pretreatment of the inner shaft was completed. The pretreated inner shaft was placed in a mold, the wear-resistant material was extruded into the mold using an extruder, and the wear-resistant material was pressed on the pretreated inner shaft by the pressure provided by the press. The temperature was increased to 350℃ and kept for 3h, and then naturally cooled to 100℃. The inner shaft was placed in a lubricating oil at a temperature of 100℃, naturally cooled to room temperature, taken out, and a low-friction layer was formed on the surface of the inner shaft. The modified inner shaft was assembled in the outer shaft to obtain a high molecular sliding bearing.

[0042] Example Five

[0043] Add 10 g TEOS, 0.7 g 15wt% hydrochloric acid solution into 150 g anhydrous ethanol, add 4 g deionized water at a speed of 0.5 g / min under the condition of 300 rpm stirring, 300 rpm stirring for 1.5 h to obtain TEOS hydrolyzate; add 26 g VTES, 0.5 g 15wt% hydrochloric acid solution into 210 g anhydrous ethanol, add 7 g deionized water at a speed of 0.5 g / min under the condition of 300 rpm stirring, 300 rpm stirring for 2 h to obtain VTES hydrolyzate; add 12 g expanded graphite into 220 g VTES hydrolyzate, heat to 50℃, 300 rpm stirring for 2 h, filter, anhydrous ethanol washing to obtain VTES modified expanded graphite; mix VTES modified expanded graphite with 14 g divinylbenzene, 7 g polyethylene glycol-400, 20 g TEOS hydrolyzate, 24 g VTES hydrolyzate, 1.5 g AIBN, 300 rpm stirring for 30 min, put into 40℃, 10.1 kPa environment, 350 rpm stirring for 3 h to obtain anchoring material; mix 65 g polyphenylene sulfide, 14 g molybdenum disulfide, 10 g polytetrafluoroethylene, 7 g carbon fiber, 0.3 g BHT, 300 rpm stirring for 10 min to obtain wear-resistant material.

[0044] A groove is machined on the inner shaft, the groove is a T-shaped thread groove, 2wt% hydrochloric acid solution is sprayed into the groove at a spraying amount of 0.1 g / cm2, and the groove is washed with deionized water after standing for 2 min; the inner shaft is dried in a 50℃ air flow for 10 min, and then the anchoring material is filled in the groove by using a pre-impregnated tape winding method: 20 g of fibers, including but not limited to carbon fibers, glass fibers, aramid fibers, are added to the anchoring material and soaked for 5 h to prepare a pre-impregnated tape; the pre-impregnated tape is wound on the inner shaft through a nozzle, and the anchoring material enters the groove; the inner shaft is placed in an oven preheated to 50℃ and kept for 1 h, heated to 70℃ at a speed of 20℃ / h, kept for 2 h, heated to 120℃ at a speed of 20℃ / h, kept for 1 h, heated to 220℃ at a speed of 40℃ / h, kept for 1 h, heated to 270℃ at a speed of 15℃ / h, kept for 1 h, and naturally cooled to room temperature to form an anchoring layer in the groove, completing the pretreatment of the inner shaft; the pretreated inner shaft is placed in a mold, and the wear-resistant material is extruded into the mold using an extruder, and the wear-resistant material is pressed on the pretreated inner shaft by the pressure provided by a press; the temperature is increased to 350℃ and kept for 3 h, and then naturally cooled to 100℃ and placed in a lubricating oil at a temperature of 100℃; naturally cooled to room temperature, taken out, and a low-friction layer is formed on the surface of the inner shaft to obtain a modified inner shaft; the modified inner shaft is assembled in the outer shaft to obtain a polymer sliding bearing.

[0045] Example Six

[0046] 8g TEOS, 0.5g 15wt% hydrochloric acid solution was added to 160g anhydrous ethanol, 3.5g deionized water was added at a speed of 0.5g / min under the condition of 300rpm stirring, 300rpm stirring for 1.5h, to obtain TEOS hydrolyzate; 20g VTES, 0.6g 15wt% hydrochloric acid solution was added to 220g anhydrous ethanol, 8g deionized water was added at a speed of 0.5g / min under the condition of 300rpm stirring, 300rpm stirring for 2h, to obtain VTES hydrolyzate; 9g expanded graphite was added to 200g VTES hydrolyzate, heated to 50℃, 300rpm stirring for 2h, filtration, anhydrous ethanol washing, to obtain VTES modified expanded graphite; the VTES modified expanded graphite was mixed with 13g divinylbenzene, 6g polyethylene glycol-400, 18g TEOS hydrolyzate, 24g VTES hydrolyzate, 1g AIBN, 300rpm stirring for 30min, put into 40℃, 10.1kPa environment, 350rpm stirring for 3h, to obtain anchoring material; 60g polyphenylene sulfide, 15g molybdenum disulfide, 10g polytetrafluoroethylene, 10g carbon fiber, 0.2g BHT were mixed, 300rpm stirring for 10min, to obtain wear-resistant material.

[0047] A groove was machined on the inner shaft, the groove was a T-shaped thread groove, 2wt% hydrochloric acid solution was sprayed into the groove at a spraying amount of 0.1g / cm2, and the groove was washed with deionized water after standing for 2min; the inner shaft was dried in a 50℃ air flow for 10min, and then the anchoring material was filled in the groove by using a pre-impregnated tape winding method: 20g fibers were added to the anchoring material and soaked for 5h, the fibers included but were not limited to carbon fibers, glass fibers and aramid fibers, to prepare a pre-impregnated tape; the pre-impregnated tape was wound on the inner shaft through a nozzle, the anchoring material entered the groove, and the inner shaft was placed in an oven preheated to 50℃ for 1h, and then the temperature was increased to 70℃ at a speed of 20℃ / h, and the temperature was kept for 2h, the temperature was increased to 120℃ at a speed of 20℃ / h, and the temperature was kept for 1h, the temperature was increased to 220℃ at a speed of 40℃ / h, and the temperature was kept for 1h, the temperature was increased to 270℃ at a speed of 15℃ / h, and the temperature was kept for 1h, and then the temperature was naturally cooled to room temperature, to form an anchoring layer in the groove, and the pretreatment of the inner shaft was completed; the pretreated inner shaft was placed in a mold, the wear-resistant material was extruded into the mold by using an extruder, and the wear-resistant material was pressed on the pretreated inner shaft by the pressure provided by a press, the temperature was increased to 350℃ and kept for 3h, and then the temperature was naturally cooled to 100℃, the inner shaft was placed in a lubricating oil with a temperature of 100℃, and then the temperature was naturally cooled to room temperature, to form a low-friction layer on the surface of the inner shaft, to obtain a modified inner shaft, and the modified inner shaft was assembled in the outer shaft, to obtain a polymer sliding bearing.

[0048] The present application also provides a comparative example and carries out related tests.

[0049] Comparative Example One

[0050] The difference between the present comparative example and Example 6 is that no VTES hydrolysis solution and TEOS hydrolysis solution are added in the preparation of the anchoring material, and other operation steps and conditions are the same as those in Example 6, to obtain a modified inner shaft and a sliding bearing.

[0051] Comparative Example 2

[0052] The difference between the present comparative example and Example 6 is that no polyethylene glycol-400 is added in the preparation of the anchoring material, and other operation steps and conditions are the same as those in Example 6, to obtain a modified inner shaft and a sliding bearing.

[0053] Comparative Example 3

[0054] The difference between the present comparative example and Example 6 is that no VTES modified expanded graphite is added in the preparation of the anchoring material, and other operation steps and conditions are the same as those in Example 6, to obtain a modified inner shaft and a sliding bearing.

[0055] Anti-peeling performance test

[0056] The low friction layer on the modified inner shaft prepared in each example and each comparative example is tested by using a micron scratch tester equipped with a diamond indenter, and the initial peeling load of the low friction layer is measured, as shown in Table 1.

[0057] Table 1

[0058]

[0059] As shown in Table 1, the initial peeling load of the low friction layer on the surface of the modified inner shaft prepared in Examples 1 to 6 and Comparative Example 3 is large, indicating that the bonding strength between the low friction layer and the inner shaft connected by the anchoring material is large, and the low friction layer is not easy to peel off from the inner shaft; the initial peeling load of the low friction layer on the surface of the modified inner shaft prepared in Example 6 is greater than that in Comparative Example 1 and Comparative Example 2, indicating that the addition of VTES hydrolysis solution and TEOS hydrolysis solution, polyethylene glycol-400 in the preparation of the anchoring material can improve the interfacial bonding strength between the anchoring material and the inner shaft, the anchoring material and the low friction layer, and further improve the bonding strength between the low friction layer and the inner shaft.

[0060] Friction coefficient test

[0061] The sliding bearings prepared in each example and each comparative example are respectively assembled on a rotary friction tester, the load is set to be changed between 1000N and 3000N according to a sine law, the frequency is 0.1Hz, the rotating speed is 20rpm, and the continuous running is 50000 rotations under dry friction conditions, the torque is collected in real time during the running process, and the friction coefficient is calculated according to the formula:

[0062]

[0063] The friction coefficient between the inner shaft and the outer shaft of each sliding bearing at 5000 rounds, 10000 rounds and 50000 rounds of rotation was calculated, and the results are shown in Table 2.

[0064] Table 2

[0065]

[0066] As shown in Table 2, the friction coefficient of the sliding bearing prepared in Examples 1-6 after 50000 rounds of operation is lower than that of Comparative Examples 1-3, which indicates that the low-friction layer in the sliding bearing prepared in the application is not easy to peel off under the operation condition of long-time dynamic load, the lubricating oil stored in the expanded graphite can be continuously released between the low-friction layer and the outer shaft, and the inner shaft and the outer shaft can maintain a relatively low friction coefficient for a long time, thereby improving the service life of the sliding bearing under the dynamic load condition.

Claims

1. A method for preparing a polymer sliding bearing, characterized in that, Includes the following steps: S1. Grooves are machined on the inner shaft, anchoring material is filled into the grooves, and the mixture is heated and cooled to form an anchoring layer within the grooves, thus completing the pretreatment of the inner shaft. The anchoring material is prepared as follows: VTES-modified expanded graphite, divinylbenzene, polyethylene glycol-400, TEOS hydrolysate, VTES hydrolysate, and initiator are mixed and concentrated under reduced pressure to obtain the anchoring material. The TEOS hydrolysate is prepared as follows: TEOS, 15wt% hydrochloric acid solution, and anhydrous ethanol are mixed, and deionized water is added under continuous stirring. The mixture is stirred at 300 rpm for 1.5 h to obtain the TEOS hydrolysate. The VTES hydrolysate is prepared as follows: VTES, 15wt% hydrochloric acid solution, and anhydrous ethanol are mixed, and deionized water is added under continuous stirring. The mixture is stirred at 300 rpm for 2 h to obtain the VTES hydrolysate. The VTES-modified expanded graphite is prepared as follows: expanded graphite is added to the VTES hydrolysate, stirred to react, and washed with anhydrous ethanol to obtain the VTES-modified expanded graphite. S2. Press wear-resistant material onto the pre-treated inner shaft, heat it, cool it, and when it cools to a predetermined temperature, immerse it in lubricating oil at the same temperature and continue cooling to form a low-friction layer on the surface of the inner shaft, thus obtaining a modified inner shaft; the wear-resistant material is prepared by mixing polyphenylene sulfide, molybdenum disulfide, polytetrafluoroethylene, carbon fiber, and antioxidant. S3. Assemble the modified inner shaft into the outer shaft to obtain a polymer sliding bearing.

2. The method for preparing a polymer sliding bearing according to claim 1, characterized in that, In the preparation process of the anchoring material, VTES modified expanded graphite, divinylbenzene, polyethylene glycol-400, TEOS hydrolysate, VTES hydrolysate and initiator are mixed, stirred at 300 rpm for 30 min, and placed in an environment of 40℃ and 10.1 kPa, stirred at 350 rpm for 3 h to obtain the anchoring material.

3. The method for preparing a polymer sliding bearing according to claim 2, characterized in that, In step S1, one or more of the following methods are used to fill the groove with anchoring material: molding, injection molding, 3D printing, and prepreg wrapping.

4. The method for preparing a polymer sliding bearing according to claim 3, characterized in that, In step S1, after filling the groove with anchoring material, the inner shaft is placed in an environment of 50°C and kept at that temperature for 1 hour, then heated to 70°C and kept at that temperature for 2 hours, then heated to 120°C and kept at that temperature for 1 hour, then heated to 220°C and kept at that temperature for 1 hour, then heated to 270°C and kept at that temperature for 1 hour, and finally cooled to room temperature, forming an anchoring layer in the groove, thus completing the pretreatment of the inner shaft; the groove is one of annular dovetail groove, dovetail threaded groove, rectangular threaded groove, or T-shaped threaded groove.

5. The method for preparing a polymer sliding bearing according to claim 4, characterized in that, Before filling the groove with anchoring material, spray a 2wt% hydrochloric acid solution into the groove, clean the groove with deionized water after 2 minutes, and dry the inner shaft in a 50°C airflow for 10 minutes.

6. The method for preparing a polymer sliding bearing according to claim 5, characterized in that, In step S2, the wear-resistant material is pressed onto the pretreated inner shaft, heated to 350°C and kept at that temperature for 3 hours, and then naturally cooled to 100°C before being placed in lubricating oil at 100°C. After naturally cooling to room temperature, the shaft is removed, and a low-friction layer is formed on the surface of the inner shaft, thus obtaining the modified inner shaft.

7. A polymer sliding bearing, characterized in that, The polymer sliding bearing, prepared using the method described in any one of claims 2-6, comprises an outer shaft and a modified inner shaft assembled within the outer shaft. The modified inner shaft includes an inner shaft, an anchoring layer, and a low-friction layer. The anchoring layer comprises the following parts by weight of raw materials: 9-12 parts expanded graphite, 13-18 parts divinylbenzene, 6-8 parts polyethylene glycol-400, 18-24 parts TEOS hydrolysate, 18-24 parts VTES hydrolysate, and 0.8-1.5 parts initiator. The low-friction layer comprises the following parts by weight of raw materials: 50-70 parts polyphenylene sulfide, 10-15 parts molybdenum disulfide, 7-10 parts polytetrafluoroethylene, 7-12 parts carbon fiber, and 0.2-0.6 parts antioxidant. The initiator is AIBN, and the antioxidant is BHT.

8. A polymer sliding bearing according to claim 7, characterized in that, The TEOS hydrolysate comprises the following raw materials in parts by weight: 8-10 parts TEOS, 0.4-0.7 parts 15wt% hydrochloric acid solution, 130-160 parts anhydrous ethanol, and 3-4.5 parts deionized water; the VTES hydrolysate comprises the following raw materials in parts by weight: 17-26 parts VTES, 0.4-0.6 parts 15wt% hydrochloric acid solution, 180-230 parts anhydrous ethanol, and 7-8.5 parts deionized water.

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