The UPEC Industrial Group Entered “the World's Bearing Elite”

It is difficult to name anything more important for equipment and machinery than a bearing. Perhaps only a wheel. They have been spinning together from the times of ancient Egyptian and Roman civilizations solving the main task – reducing friction during the movement. The great Leonardo da Vinci and Galileo Galilei, many outstanding engineers and scientists were involved in the development of bearing designs at different times. Without high-quality bearings, modern engines, cars, agricultural machinery, rail transport, aircrafts, armoured vehicles, machine tools, and virtually all mechanical engineering and even space engineering would not be possible. Nevertheless, there is a wrong idea about the bearing as the simplest assembly being easily manufactured. This is a deeply erroneous view. A modern bearing requires the development of steels and other structural materials with very specific properties, complex heat treatment, optimal internal geometry of contacting elements, unique machine tools that quickly reproduce this geometry by turning, grinding and superfinishing operations with micron accuracy, special coatings, greases and seals as well as the finest technology and quality control devices. A strong bearing industry is a reliable sign of high-tech engineering.

Today, one of the most complex bearing assemblies, without which it would be impossible to develop high-speed rail passenger traffic and freight traffic of increased load capacity is a tapered cartridge bearing. Most recently, only a few world leaders in the industry was able to calculate and produce this assembly. Swedish company SKF - bearing company No. 1 in the world, the flagship of bearing innovations (founded in 1907); German company FAG (founded in 1883) being part of the famous Schaeffler Industrial Group; the dominant companies in the American market – Timken and Brenco. By the way, it is the founder of Timken, Henry Timken, who registered in 1898 a patent for a tapered bearing for wheel axles of horse-drawn transport of that time, and a year later founded a company that produces bearings for carriages of the railway transport.

Today's cartridge bearing assembly is a closed device assembled and lubricated at the manufacturing plant, fully ready for fitting and providing 800,000 to 1 million km run without any maintenance. The outer racer of a double-row tapered bearing plays the role of a traditional box body, and the loading is transferred from the side frame of the truck through a polymeric wear-resistant insertion to the adapter distributing the load along the outer racer. The cartridge assembly has smaller dimensions and is noticeably lighter than the traditional box assembly, while having a large load-bearing capacity. Due to the more complex structure and production technology, the bearing itself is considerably more expensive than two classic cylindrical bearings inserted into the traditional box assembly, but this is justified in the cost of the life cycle by the absence of an expensive and unreliable system of depot scheduled maintenance with lube replacement and overhaul of rolling elements.

A cartridge bearing comes to the world on the threshold of the new millennium in China, which is actively developing high-speed and ultra-high-speed rail transportation, after the USA and Europe. The development of TBU by SKF, which, with the support of the State, establishes a joint venture in China, becomes the state standard for a Chinese cartridge bearing. In Russia, EPK and Brenco establish a joint venture to produce cartridge bearings of American design. In the same 2000's, SKF decides to build a factory in Tver to produce its own cartridge bearings. Timken and FAG are also looking for their place in the huge market of "1,520 space" (the territory of the former USSR with a characteristic track width of 1,520 mm). As a result, despite the former power of the bearing industry (there were more than 30 gas state bearing plants in the USSR), there was no manufacturer in the market of 1,520 mm track ready for own development and production of a cartridge bearing, taking into account the specifics of the operation of "1,520 track space" (railways of the territory of the former USSR).

During the Soviet period, Kharkov Bearing Plant (HARP™), being part of the UPEC Industrial Group was the main experimental site for the development of new designs and technologies, developed mainly in All-Russian Research and Development Institute of the Bearing Industry, the leading institute of the bearing industry of the USSR. In Kharkov, bearing steels with unique properties of heat treatment, advanced designs and technologies of cylindrical and ball bearings were mastered. However, by the time of the world's "bearing giants" entering the market of 1,520 mm track with offers to assemble closed tapered bearing onto freight and passenger cars, neither HARP nor Ukrainian Bearing Industry Design and Technology Bureau (UKTBPP) - the main bearing design bureau of Ukraine, being also part of the UPEC Industrial Group, had no developments of cartridge bearing assemblies.

And in 2008 the Board of Directors of the UPEC IG decided to establish the Research and Development Center (R&D Center of the UPEC), with the first and main objective to develop energy-efficient cartridge bearings of increased service life for 1,520 mm track.

In its activities, the R&D Center of the UPEC relied on the best Kharkov scientific and engineering schools in the field of mechanical engineering and optimal design. The main emphasis was on mathematical modelling of strength and wear, three-dimensional optimization of internal geometry, modelling of basic technological processes and the creation of massive test beds for physical modelling of operating conditions. To automate the development and design processes, UPEC, jointly with the US company RTS (one of the four world leaders of software platforms for supporting engineering activities) implemented the largest in Eastern Europe project for integrated automation of developments in 2009-2010. Designers, calculators, manufacturing engineers, plant managers, Engineering Centers and the Design Bureau of the UPEC obtained advanced specialized software products related to a unified database, corporate libraries and a unified project management program. All this accelerated the development dramatically. The task was not simply to design a cartridge bearing, but to create a structure, materials and heat treatments that would be optimal in the composition of new cars and carriages accepted for use on the 1,520 mm track, and, most importantly, taking into account the specific operating conditions. For this purpose, the dynamics of the train, deformation of the car and the carriage were initially modelled and, as a consequence, the loading conditions of the bearing assembly, taking into account the heavy operating conditions on 1,520 mm track. Nonlinear mathematical models of the finite element method used to analyse and optimize the geometry of a cartridge bearing assembly contained tens of millions of degrees of freedom being record at that time.

Every advantage has its "reverse side". One of the key advantages of a cartridge bearing – an eight-year operation period without replacing the lubricant – also has its reverse side. In ordinary box bearings, during maintenance, wear products were automatically removed with the old lubricant. In a closed bearing assembly, wear should be virtually eliminated, because even the smallest particles of metal, gradually accumulating in the lubricant, will work as an abrasive, exponentially accelerating wear and outage of a bearing. This task was solved due to the optimal three-dimensional geometry and perfection of working surfaces minimizing contact stresses and wear rate, optimal arrangement of fibres in the racers and unique lubrication developed by the UPEC in 2011 in cooperation with the German company Klüber Lubrication, the world leader in special lubricants. In addition to record wear prevention indicators, Klueberplex-HARP lubricant has a very low level of hydraulic losses and performance in a wide climatic range from –60°С to +50°С. However, a new effective lubricant includes additives that are found to be incompatible with conventional elastomers used to seal the cartridge bearings. In 2012, jointly with the German company Freudenberg Sealing Technologies (Simrit) and Italian Corcos, special elastomers chemically neutral to the Klueberplex-HARP lubricant were found, and the developed original design of the cartridge seals best combines effective sealing of a cartridge bearing and low mechanical and hydraulic losses, and the performance of a sealing in the same temperature range. But no matter how perfect the theoretical and laboratory developments are, in such a responsible and innovative product as a new bearing assembly for a rolling stock the final word rests always with the running wear tests. For this purpose, the R&D Center has created unparalleled automated test beds that simulate not only standard European, American and GOST test methods, but also the very loading characteristics that are typical for the upper track structure and the flexible design of the 1,520 mm track carriages, including intense dynamic and axial loads, distortions, etc. The original design of the test beds developed at the R&D Center of the UPEC in cooperation with the UKTBPP can simulate the bearing operating conditions in any part of the trackway. To manufacture automation of these test beds, German companies Beckhoff and Bluemenbecker were involved. Bluemenbecker made the developed on the basis of classical hydraulic loaders, and Beckhoff, for the first time in civil engineering, used its unique high-precision multi-tonnage electrodynamic actuators for loading previously used only by NASA. In 2013, the test beds were certified for testing all types of railway bearings.

Since 2011, the plants of the UPEC Industrial Group have begun to develop the production of cartridge bearings. The complex optimal geometry of the racers and rollers, along with the high demands for surface perfection and machine tools performance, is the basis for the requirements for the Performance Specification for the development of special grinding and superfinishing equipment by the world's leading machine tool manufacturers: Italian Mechanika Nova (machine tools for internal and external grinding of several surfaces of racers simultaneously), as well as German Modler (roller grinding) and Nagel (roller superfinishing). Jointly with the Czech companies Roboterm and Hydroma, a modern energy-efficient induction heating and punching line for bearing racers has been developed, ensuring an optimal pattern of appearing of the metal fibres on the raceways. Technologies were also mastered and modern equipment was purchased for hard turning, superfinishing of racers, etc.

And this long path of one of the most complicated integrated developments of the company was passed - in August 2017, at the test beds of the UPEC Test Center, certified by the National Accreditation Agency of Ukraine, many-month longevity tests of TBU HARP 1520 (150×250) cartridge bearing for innovative cars of increased carrying capacity have been completed with quite successful results. After hundreds of thousands of kilometres of running on the raceways, working sides of the racers and the working surfaces of the rollers, including the convex working ends, required according to the test procedure, no signs of wear were found at all! Now, certification tests of bearing assemblies of other dimension types, including TBU HARP 130×230, in the development and production assimilation of which all the same design innovations and technologies are used that have been tested and confirmed with tests of the TBU HARP 150×250 cartridge assemblies, wait for their turn. In this context, it is necessary to mention the unique development of the UPEC – an energy-efficient closed cylindrical bearing assembly of increased service life, HARP Duplex, intended for the modernization of cars of conventional load carrying capacity. A thousand cars with HARP Duplex bearing assemblies underwent the supervised operational tests in the Russian Railways, which resulted in 2 million km of run without any signs of wear! At the same time, the working temperature of the HARP Duplex bearing assembly was by 20-25°C lower than that of the tapered bearing of the world-famous manufacturer, which reliably indicates a lower friction loss and, as a consequence, high energy efficiency with a noticeable gain in traction. Together with a new development – the plasma hardening of the bearing surfaces of the box - the box assembly with the HARP Duplex bearing now reliably ensures a repair-free run of 800 thousand km (or eight years without maintenance) and is the optimal product for the modernization of cars of conventional load carrying capacity.

Thus, the Ukrainian UPEC Industrial Group confidently entered the "elite world club" of the manufacturers of cartridge bearing assemblies of increased service life, steadily demonstrating a combination of age-old engineering traditions, its own innovative developments with the transfer of advanced European technologies.