CN-122007819-A - Integral manufacturing method of ultra-large self-lubricating radial spherical plain bearing

CN122007819ACN 122007819 ACN122007819 ACN 122007819ACN-122007819-A

Abstract

The invention discloses an overall manufacturing method of an oversized self-lubricating radial spherical plain bearing, and belongs to the technical field of spherical plain bearing manufacturing. The invention constructs a full-flow collaborative manufacturing system of inner ring integral forging strengthening-spherical ultrasonic chromeplating-liner plasma modification-precise closed-loop assembly, realizes defect-free forming of an oversized inner ring through a three-section temperature-control integral forging process, improves the binding force of a plating layer through ultrasonic rolling extrusion strengthening and precise chromeplating collaborative, realizes the ultra-high peel strength of a PTFE liner through a four-step full-flow process, and realizes precise assembly of a bearing through a double closed-loop tool. The invention solves the problem that the prior art cannot realize the industrial pain point of the domestic manufacturing of the oversized heavy-duty knuckle bearing, the core performance index completely surpasses imported products, fills the blank of the domestic technology, and can be widely applied to the fields of heavy-duty engineering equipment such as oversized piling equipment, heavy-duty hoisting equipment and the like.

Inventors

ZHANG YONGTAO
XIAO HAO
HUANG JIAN
FAN CHENYANG
LIU XIUCHENG
LI TAO
Guan Zhenglin
JI XIAOYU
Tu Tonghang

Assignees

中交第二航务工程局有限公司

Dates

Publication Date: 20260512
Application Date: 20260320

Claims (17)

1. The integral manufacturing method of the ultra-large self-lubricating radial spherical plain bearing is characterized by comprising the following steps of: s1, performing integral forging and heat treatment on an inner ring, namely selecting GCr15 bearing steel as a blank, sequentially performing three-section type temperature-control integral forging of a hydraulic machine blank, a saddle reaming and a horizontal ring rolling, and then performing quenching and tempering treatment; s2, performing ultrasonic strengthening and accurate chromium plating on the spherical surface of the inner ring obtained in the step S1 by adopting an ultrasonic rolling extrusion process to strengthen the spherical surface of the inner ring so that the surface roughness Ra of the spherical surface is less than or equal to 0.4 mu m, and improving the surface activity of a matrix; s3, preparing a PTFE self-lubricating liner, namely sequentially performing four steps of synergy processes of single yarn twisting, epoxy resin sizing, plasma activation, weaving and pasting on PTFE yarns to prepare the PTFE self-lubricating liner; s4, accurate closed-loop assembly, namely placing the inner ring and the outer ring into a special assembly tool, integrating a pre-tightening force sensor and a laser displacement sensor, setting an assembly pre-tightening force of 5-8 kN, and performing press fitting at a speed of 1+/-0.1 mm/min to finish assembly.
2. The integral manufacturing method of the oversized self-lubricating radial spherical plain bearing according to claim 1, wherein the hydraulic machine blank in the step S1 is characterized in that the blank is sent into a continuous heating furnace, the temperature is raised to 1150-1200 ℃, the temperature is kept for 1-5 hours to ensure the internal temperature of the blank to be uniform, then the blank is transferred to a 5000t hydraulic machine, the blank is pre-pressed under the pressure of 450-500 MPa and then is gradually raised to 1150-1200 MPa by adopting a stepped upsetting process, the blank is upsetted to the diameter of 1200-1215 mm, the height of 500-510 mm, and the upsetting deformation is controlled to be less than or equal to 50%.
3. The method for integrally manufacturing the ultra-large self-lubricating radial spherical plain bearing according to claim 1, wherein the step S1 is characterized in that the saddle reaming is carried out, specifically, a blank which is subjected to upsetting by a hydraulic press is transferred to a saddle reamer, and is gradually reamed to an inner diameter of 690-700 mm and an outer diameter of 1100-111mm at a reaming rate of 10+/-1 mm/min, and the wall thickness deviation is monitored in real time to be less than or equal to 2mm.
4. The method for integrally manufacturing the oversized self-lubricating radial spherical plain bearing according to claim 1 or 3, wherein the blank temperature in the process of reaming the horse frame is 1050-1100 ℃.
5. The integral manufacturing method of the oversized self-lubricating radial spherical plain bearing according to claim 1 is characterized in that in the step S1, a blank subjected to horse reaming is fed into a horizontal ring rolling machine, a stepped temperature control ring rolling process is adopted, the initial temperature of the ring rolling is controlled to 1090-1100 ℃, the middle stage of the ring rolling is gradually cooled to 1070-1090 ℃, the final stage of the ring rolling is cooled to 1055-1070 ℃, the whole temperature reduction rate is less than or equal to 10 ℃ per minute, the spindle rotating speed is set to 20-30r/min, the core roller feeding speed is set to 5mm/min, the blank is finished to an inner ring blank with the inner diameter of 790-800 mm, the wall thickness of 100-105 mm and the outer diameter of 1000-1010 mm through radial and axial rolling, the roundness of the inner ring is detected in real time in the rolling process, and the deviation control is less than or equal to 0.1mm.
6. The method for integrally manufacturing an oversized self-lubricating radial spherical plain bearing according to claim 1, wherein the quenching temperature in step S1 is 800-850 ℃, and the tempering temperature is 150-180 ℃.
7. The method for integrally manufacturing an oversized self-lubricating radial spherical plain bearing according to claim 1, wherein the hardness of the inner ring after heat treatment in the step S1 is 60-64 HRC, and the hardness uniformity deviation is less than or equal to 1HRC.
8. The method for integrally manufacturing the ultra-large self-lubricating radial spherical plain bearing according to claim 1, wherein the working pressure of the ultrasonic rolling extrusion process in the step S2 is 50-80 MPa, and the ultrasonic frequency is 20kHz.
9. The method for integrally manufacturing an oversized self-lubricating radial spherical plain bearing according to claim 1, wherein in the chromium plating solution of the sulfate chromium plating system in step S2, the concentration of chromium sulfate is 280-300 g/L, the concentration of sulfuric acid is 18-20 g/L, and the concentration of rare earth additive is 4.8-5 g/L.
10. The method for integrally manufacturing the oversized self-lubricating radial spherical plain bearing of claim 1, wherein the plating solution temperature is controlled to be 55-60 ℃ and the current density is controlled to be 50-60A/dm 2 in the chromium plating process in the step S2.
11. The method for integrally manufacturing an oversized self-lubricating radial spherical plain bearing according to claim 1, wherein the thickness of the chromium coating in step S2 is not less than 10 μm.
12. The method for integrally manufacturing the ultra-large self-lubricating radial spherical plain bearing according to claim 1, wherein the single yarn twisting in the step S3 is specifically characterized in that PTFE yarns are put into a yarn twisting machine, the twisting density is set to 80 twists/m, a tensile testing machine is adopted to detect that the single yarn strength is more than or equal to 5N/yarn after twisting, and unqualified yarns are removed.
13. The method for integrally manufacturing the oversized self-lubricating radial spherical plain bearing according to claim 1, wherein the step S3 is characterized in that the step S3 is performed with sizing of epoxy resin, specifically, absolute ethyl alcohol is used as a solvent, the epoxy resin E-51 and a curing agent are mixed according to a mass ratio of 10:1 to prepare epoxy resin slurry with the epoxy resin E-51 and the curing agent accounting for 12wt% of the slurry, the twisted PTFE yarn is immersed in the slurry to ensure complete infiltration of the yarn, and then the slurry is dried until the slurry is completely cured.
14. The method for integrally manufacturing the ultra-large self-lubricating radial spherical plain bearing according to claim 1, wherein the plasma activation in the step S3 is specifically that the PTFE yarn after sizing is sent into plasma treatment equipment, the power is set to be 450-550W, the treatment time is set to be 2-5 min, the argon flow is set to be 8-12L/min, the surface activity of the yarn is improved through plasma bombardment, and the yarn is sealed and stored immediately after the treatment.
15. The method for integrally manufacturing the ultra-large self-lubricating radial spherical plain bearing according to claim 1, wherein the weaving and pasting step S3 is characterized in that the activated PTFE yarns are fed into a rapier loom to be woven into a lining fabric, the density of the fabric is controlled to be 25-35 warp yarns/cm and 20-30 weft yarns/cm, polyurethane adhesive is coated on the inner wall of an outer ring of the bearing, the lining fabric is uniformly pasted on the outer ring, and the lining fabric is put into a press for compression curing.
16. The method for integrally manufacturing an oversized self-lubricating radial spherical plain bearing according to claim 1, wherein the peel strength of the pad and the outer ring in step S3 is not less than 1.55N/mm.
17. The method for integrally manufacturing the ultra-large self-lubricating radial spherical plain bearing according to claim 1, wherein the pre-tightening force and the fit clearance are monitored in real time in the press-fitting process in the step S4, and the fit clearance is controlled to be 0.05-0.1 mm.

Description

Integral manufacturing method of ultra-large self-lubricating radial spherical plain bearing Technical Field The invention belongs to the technical field of joint bearing manufacturing, in particular to an integral manufacturing method of an ultra-large self-lubricating centripetal joint bearing, and particularly relates to an integrated manufacturing technology of the ultra-large self-lubricating centripetal joint bearing for a main oil cylinder of ultra-large piling equipment and 5000t heavy-load engineering equipment, which is suitable for severe working conditions of 5000t heavy load, 30-degree swing angle and long-term continuous operation, and can be accurately adapted to the domestic production requirements of the ultra-large bearing with the inner diameter of more than 800mm and the weight of over 2000 kg. Background The main oil cylinder joint bearing of heavy load equipment such as ultra-large pile driving ships, heavy hoisting equipment and the like is a core component for transmitting heavy load and realizing swinging function and needs to bear the combined action of 5000 t-level extreme load and +/-30-degree frequent swinging angle. At present, the ultra-large self-lubricating centripetal joint bearing (with the inner diameter of 800mm, the spherical diameter of 1022mm and the weight of over 2000 kg) required by the ultra-large pile driving ship of 150 meters is the largest specification product of the global wide-series joint bearing. The related equipment manufacturers in China need to import the bearing at high price, the single set of purchasing cost is over 200 ten thousand yuan, and the supply period is as long as 4 months, so that the manufacturing cost of the equipment is greatly increased, and the domestic localization process and delivery efficiency of the ultra-large pile driving equipment in China are severely restricted. With the upgrade of the foundation engineering of China to ultra-large tonnage and ultra-long distance, the requirement of ultra-large heavy-duty equipment is greatly increased, and the ultra-large specification self-lubricating radial spherical plain bearing manufacturing technology with independent intellectual property is developed. A plurality of technical bottlenecks which are difficult to surmount exist on oversized products in the traditional domestic joint bearing manufacturing technology, namely, firstly, an inner ring forming process is immature, defects such as looseness, shrinkage cavity, welding cracks and the like are easy to generate in the inner ring due to adoption of a segmented forging and welding mode, mechanical properties are unevenly distributed, hardness deviation is more than or equal to 5HRC and 5000t heavy load cannot be borne, secondly, a domestic PTFE yarn liner has obvious short performance plate, peeling strength of the liner and the outer ring is less than or equal to 0.8N/mm, peeling and abrasion are easy to occur under heavy load swing working conditions, service life is only less than or equal to 500h, and is far lower than service indexes of imported products above 800h, thirdly, the spherical chromium plating quality of the inner ring is poor, plating thickness is uneven, bonding force with a base body is weak, peeling and peeling are easy to occur after long-term heavy load friction, so that bearing sealing failure is caused, fourthly, the ultra-large-size bearing assembly lacks special tools, the pre-tightening force control precision is low, so that bearing swing flexibility is poor, and swing resistance exceeds 80NAnd fifthly, the overall dimensional accuracy of the bearing is difficult to control, the fit clearance deviation between the inner ring and the outer ring exceeds 0.2mm, and the sealing performance and the swing stability are affected. The systematic short plate of the existing domestic ultra-large-size knuckle bearing manufacturing technology is quite outstanding in that the integral forming of an inner ring of a 800mm inner diameter bearing cannot be realized by traditional forging equipment and technology from the aspect of forging technology, the integral strength of the inner ring is reduced by more than 30% by a sectional welding technology, a welding area is easy to become a stress concentration source, the surface active treatment technology of domestic PTFE yarns is immature from the aspect of gasket preparation, the targeted twisting, sizing and modification design is lacking, the adhesive strength of the gasket and the outer ring is low, the wear resistance is insufficient, the chromium plating technological parameters (temperature and current density) are empirically set from the aspect of surface treatment, the precise control system is lacking, the thickness deviation of a plating layer is more than or equal to 1 mu m, the pretreatment strengthening is not carried out on a spherical surface, the bonding force of the plating layer is inherently insufficient, the special life test platform of the domes