Development of rolling bearing remanufacturing
In 1954, Schaeffler proposed the bearing remanufacturing of its brand FAG. The complete bearing remanufacturing technical data that can be found at present is the summary of the bearing repair process carried out by the Changsha Bearing Repairing Factory in 1972. Changsha Bearing Repairing Factory was once a professional factory for the remanufacturing of rolling bearings. The remanufactured object is the agricultural machinery bearing. In the process of bearing remanufacturing, the factory has compiled inspection rules for parts and finished products and formulated relevant enterprise standards. In addition to the conventional cleaning and polishing, the process includes the chrome plating process, the raceway grinding process, the cage shaping process and the matching process in the assembly process. Under the social and economic conditions at that time, the implementation of these processes And the application is very advanced. Due to the lack of a sound theoretical foundation at the time, the drawback was that the remanufacturing scheme was more random, but because the repair object was an agricultural machinery bearing with low reliability requirements, its solution could meet the application requirements.
The earliest system documentation for rolling bearing remanufacturing was the Bearing Grinding Repair Report (USAAVSCOM-TR-76-27) issued by the US Army Aviation Systems Command, and the report stated that the US military used the polishing method to remanufacture bearings. It has a history of 20 years. In September 1974, Stanley DC published a report entitled "Field Testing and Repair of Bearings" at the Symposium on Propulsion Systems Structural Interconnection and Engine Interconnection at the Naval Training School in Monterey. The report drew the attention of the US Army Aviation Systems Command (USAAVSCOM) and conducted a two-year special study with the National Aeronautics and Space Administration (NASA). On May 20-21, 1976, the US Army Aviation Systems Command held the Bearing Grinding Repair Symposium in St. Louis, Hanau H from Industrial Tectonics Inc, Parker RJ, Corpus at NASA Lewis Research Center. Bull HL at the Christi Army Warehouse and Hein GF at the NASA Lewis Research Center made independent reports on manufacturing, performance assessment, testing, application and economics. After the meeting, the US Army Aviation Systems Command summarized the reports and released USAAVSCOM-TR-76-27, marking the re-manufacturing of rolling bearings as a systematic project. In 1976, NASA released the first official report on bearing remanufacturing, TM-X-73440, which became the starting point for NASA's research on bearing remanufacturing. In 1977, NASA released the life analysis report for bearing remanufactured TN D- 8486; In 1987, an analysis report on the effect of metal layer removal on the raceway surface on fatigue life was released. TM87887; after that, NASA's bearing remanufacturing project was stagnant with an interruption time of nearly 20 years.
Although the basic research on bearing remanufacturing has stagnated, the industrial development has not stopped. The fast-developing remanufacturing projects are mainly concentrated in high-value products such as aviation or railway. Industrial bearing remanufacturing also entered major bearing manufacturers during this period. Vision. In terms of aerospace bearings, Timken has established Bearing Inspection Inc (BII) to provide services for the inspection and remanufacturing of aero-engine bearings; Schaeffler has established an aero-engine bearing remanufacturing center in Australia; SKF organizes four interdependent service centers It specializes in the inspection, repair and overhaul of aerospace engine bearings. In terms of railway bearings, bearing manufacturers of major brands have their own professional remanufacturing factories, such as: Beijing Nankou SKF Railway Bearing Co., Ltd., Schaeffler (Ningxia) Co., Ltd., Luoyang LYC Bearing Co., Ltd. Railway Bearing Division, etc. Various types of rolling bearings used in the heavy-duty industry, due to their high value, many domestic and foreign bearing manufacturers have carried out remanufacturing services for large and extra large bearings during this period, which are also due to the bearing manufacturers. Bearing production capacity, business dispersion, so there is no large-scale professional bearing remanufacturing factory, and no relevant technical system documents. In 1991, the literature put forward the value and significance of large-scale bearing remanufacturing for the actual situation that the bearing working environment in the metal rolling mill was easy to cause abnormal early bearing failure, and proposed a more detailed bearing remanufacturing scheme from the application point of view.
Rolling mill bearings before and after remanufacturing
After entering the 21st century, the problem of ecological deterioration caused by massive carbon dioxide emissions has received increasing attention. Large-scale bearing manufacturing process uses many materials, high energy consumption, large carbon emissions, theoretical research on rolling bearing remanufacturing and rapid development of industrial scale. In terms of theoretical research, NASA has once again suspended research for nearly 20 years, and has released a number of research reports on rolling bearing remanufacturing. Among them, TM-2005-212966 released in 2005 gives a clear classification of bearing remanufacturing. The remanufacturing process and the reliability of remanufactured bearings are specified; TP-2007-214463, released in 2007, proposes remanufacturing specifications for aircraft engine bearings; TM 2012-217445, released in 2012, reviews the history of bearing steel development. With the prospect, it is proposed that the rolling bearing remanufacturing industry should consider the original material of the bearing; Zaretsky re-summarized the life calculation of the remanufactured bearing at the annual meeting of the Institute of Tribology and Lubrication Engineers in 2014. Many scholars have also begun to pay attention to the technical problems of bearing remanufacturing. For example, the combination of test and theoretical analysis is used to analyze the rolling contact fatigue problem of polished remanufactured bearings. Based on the remanufacturing of large radial bearing rolling elements, a new design is proposed. A five-stage remanufacturing method under conditions; the problem of prolonging life and improving performance through bearing remanufacturing; and analyzing the relationship between remanufacturing process and fatigue life for spherical roller bearings. On the industrial scale, the bearing manufacturers of various well-known brands have set up specialized remanufacturing factories. Among them, SKF, Schaeffler and Timken have 9, 7 and 6 professional remanufacturing factories in the world respectively. The main object of the remanufacturing plant is industrial bearings. Due to the rapid progress of the remanufacturing industry during this period, more and more heavy industry companies have begun to pay attention to the value of bearing remanufacturing, and have a practical test of the reliability of remanufactured bearings.
Reprinted from the network