Not for Senka chassis
For nearly a decade, experts have been debating whether special wheeled chassis and tractors are being developed in the right direction. It is too early to sum up the disputes, but it makes sense to talk about some intermediate results based on the available documents.
The fleet of military vehicles (BAT) has a special look - special wheeled chassis and wheeled tractors (SKShT). It is on them that mobile ground systems and weapons and military equipment systems are installed that can decide the outcome of a military operation.
Fifth generation in the cart
Unfortunately, after the collapse of the USSR, the Kurgan Wheel Tractor Plant, which produced SKShT, ceased to exist, and MZKT (Minsk) became foreign. Due to the extreme necessity, in the 2003, the MZKT-7930 chassis was adopted for the supply of the Armed Forces of the Russian Federation, and the MZKT-2004 (as part of the complex) in the 79221-m. This technique can be attributed to the fourth generation.
At present, the Strategic Missile Forces would consider it to be good to get SKShTs from domestic plants, but Russian enterprises lack production capacities for assembling serial complete chassis and military tractors with the 16X16 wheel formula. There are no key auto components, for example, hydromechanical transmissions (GMF).
Proposals for replacing Belarusian SKShTs with Russian counterparts were periodically placed on the agenda. It was proposed to create a domestic fifth-generation chassis and tractors. In the long term, the specialists of the scientific and technical committee of automobile equipment of the Main Automobile and Armored Directorate of the Ministry of Defense of Russia (STC AT GABTU) proposed to create a sixth generation SKShT. It was planned to develop two families: highly mobile modular chassis with carrying capacity from 15 to 40 tons and highly mobile modular platforms (PMF) 50 tons and more. In the design it was intended to widely use non-traditional technical solutions, which are today called innovations. The tactical and technical requirements for the families were developed by the 21-m Research Institute of the Ministry of Defense.
Everything went on as usual, but suddenly KamAZ Inc. appeared among the performers, which had never dealt with developments of this kind. The question of the participation of the auto giant in the program arose after the arrival in the management of the enterprise of new people. In response to the appeal of the plant, specialists from 21 of the Research Institute suggested that KamAZ develop a chassis with a mechanical transmission in order to prepare a TTZ for the creation of next-generation SKShT based on search R & D results. Moreover, TTT has already been agreed and approved by the Defense Ministry of the Russian Federation. But KamAZ was not satisfied.
In 2007, the baseline data for creating SKSHTs with “innovative” solutions were developed, which were later approved by the Deputy Minister of Defense of the Russian Federation - the head of armaments of the Armed Forces of the Russian Federation. The scientific and production center “Special Mechanical Engineering” (SPC SM) of the Moscow State Technical University named after Bauman, since KamAZ did not have a scientific and technical reserve. In addition, the studies that were carried out by Bauman together with 21 NIII for several decades (according to R & D “Development - GKNO-B”, “Fireman”, “Balsam”, etc.) needed to be continued. For example, during the performance of the research, Balsam (1997 – 2003) developed and substantiated the technical appearance of the electromechanical transmission (EMT), created a full-scale mockup model with the wheel formula 12х12, automated motion control system (SAUD), all-wheel steering (ARU) on the base of the chassis MAZ-547В and the superstructure of the diesel locomotive DM62М. However, the main unsolved problem was in the control system of traction motors (TED) - in Russia nobody was engaged in this, there was no bench base for full-scale tests. Specialists SPC SM MSTU. Bauman closer than the other teams came to the decision, but the work was stopped as directed from above.
New research received the code "Platform". The grounds for it were the Resolution of the Government of the Russian Federation No. 633-24 of 23 in August of 2008 and the State Contract No. 611 of 17 in October of the same year. The principal executor is OJSC KamAZ. The state did not stint on financial security. Veterans of the military automobile service said that the allocated amount was more than sufficient. For all the R & D for the creation of BAT in the GABTU line, the funds were allocated less than those that went to the Platform research and development project. The aim of the work was to identify the main directions of creating a family of unified HFMs of the next generation (new look of transport bases with a carrying capacity of up to 80 tons) for the installation and transportation of advanced weapons and military equipment that can be manufactured by domestic industry.
The sharp edges of the "Platform"
The customer wanted, as a result, the appearance of future SKSHTs with such characteristics that are far superior to the capabilities of the current production equipment. A few numbers. MZKT-79221 gives maximum 40 kilometers per hour on the highway, in Platform Research and Development for promising chassis with a similar formula, this speed was discussed as average when driving on dirt roads, and on hard surface - no less than 60 kilometers per hour. The largest angle of climb for MZKT-79221 - 10 degrees, for promising SKShT it was tripled. A significant increase was made in other parameters: the power reserve - respectively 420 and 1200 kilometers, the resource before the first overhaul - 40 thousands and 200 thousands of kilometers, the depth of the ford overcome - 1,1 and 1,8 meters. KamAZ wanted to jump over a generation.
According to the results of preliminary studies, the main collaborator of the SPC SM MSTU. Bauman was proposed to look promising SKShT with unconventional technical solutions, including a modular layout, SAUD, EMT, I LIE, long-wheel steering wheel suspension. It was supposed to produce a prototype model with EMT with a motor-wheel scheme (as part of the motor-wheels, it was planned to use the upgraded asynchronous TED used earlier in the Balsam research and development) and test it to verify the correctness of the chosen solutions.
With proper organization of work, the heads of the research work could provide for measures to study the reality of achieving the specified parameters and, based on the findings, produce several mock-up samples and conduct comparative tests. But something prevented.
Appendix No. 1 to the 20 Decision of April 2009 of the year outlined the technical design of the mockup model with a tonnage of 40 tons (wheel formula 8х8), which was to be built and tested. The individual parameters indicated were lower than intended and even already achieved for the 8 x8 chassis. So, the greatest depth of a ford for a prototype sample is written in the document 1,3 meter (for comparison: MZKT-7930 - 1,4 m), power reserve - not less than 1000 kilometers (MZKT-7930 - 1157 km in fuel consumption). It was determined that the supporting-running module would include a motor-wheel, other options were not considered. Nevertheless, this idea was vigorously discussed and approved at several scientific and technical councils of GABTU.
Why was the “motor-wheel” scheme chosen? Designers with experience can easily prove that it is otherwise impossible to fulfill customer desires. The development of a chassis with ASU and a long stroke suspension, which allows changing the ground clearance within plus or minus 400 millimeters, is an extremely difficult technical task. No one in the world has yet succeeded in solving it on serial SKShTs for military purposes.
Long-travel suspension is needed for off-road multi-axle chassis to improve throughput: hanging the wheels while driving on rough terrain can lead to a decrease in tractive effort, deformation and even destruction of the chassis frame. The use of power distribution schemes for the wheels of the gearboxes located inside the frame entails the use of cardan shafts, and long suspension strokes lead to the work of cardan gears at unacceptable angles, which leads to breakage.
There were also significant problems of a production nature: the technology and the basis for the manufacture of GMF for wheeled BAT Russia lost. On the contrary, it was clear to the main co-executor what kind of cooperation between the manufacturers of the set of traction electrical equipment (KTEO) for the motor-wheel scheme would be involved in the Platform research and development project.
The technical appearance was determined by the use on the prototype of large-size tires model VI-178AU, created in Soviet times. The mistake of the head performer was to ignore the need to develop a new tire, although designers with many years of experience in designing SKShTs have noticed long ago that without a new tire there is no new car. The speed limits for super-high-load-carrying structures of particularly large load-carrying capacity are superimposed primarily by the characteristics of the tires used. The probability of their failure at high speeds is very high.
Constructors had to look along the way.
Especially it should be said about the choice of diesel generator set. The main collaborator of works had proposals for domestic engines both for the prototype model and for the future SKShT family. However, the management of the head executor of the R & D system imposed the conditions under which the decision on the choice of the motor is made by KamAZ. As a result, a Detroit Diesel engine with a power of 675 kilowatts (918 hp) was proposed for the prototype model without alternative. The piquancy of the situation is due to the fact that the American company Detroit Diesel is part of the concern Daimler AG, which shortly before it acquired 10 percent of KamAZ shares (later this package was increased to 15%).
It is unlikely that KamAZ had plans to localize the production of the American engine in Russia, since in Naberezhnye Chelny they knew that the US State Department even during the best times of “friendship” strictly forbade the transfer of technology and licenses to products more than 400 horsepower to the Russian Federation . It would not have helped that the new strategic partner Daimler in the European Union offered Detroit Diesel under the brand of Mercedes-Benz. In the research documents “Platform” one can find mention of other foreign engines, for example MTU R1238K40-1822. Did the leaders of the research work think that foreign companies could refuse to cooperate at any moment? How did they want to solve the problem, if the main goal of R & D was to determine the directions for creating SKShTs on the domestic industrial base and develop the TTZ for the subsequent development work? The question is rhetorical.
Today, a few years later, the results of research can not be considered positive. One of the reasons is the staff hunger of the head performer. We repeat: before the start of the implementation of the Platform R & D project at KamAZ, there were no SKShT specialists at all - the designers had to be searched and trained along the way. So, until November 2009 of the year, that is, at the very height of R & D, there was not a single electric drive specialist in the division of the chief designer for the new projects of STC OJSC KamAZ, and the level of knowledge that started to work was insufficient.
Nevertheless, credit should be given to the chief designer of the project, who made every effort to find specialized specialists at the Crane Plant and the Transport Electrical Equipment Plant (OTEC) located in Naberezhnye Chelny.
At the stage of research "Platform" there was no comprehensive expert assessments. Top managers of KamAZ, who supervised the work, determined the subcontractors on their own. Although if leading scientific research institutes and design bureaus, which have had successful experience in developing traction electric drives since the USSR, would have done so, they would have completed all the tasks, including manufacturing and research tests of sets of equipment for full-scale moving mock-ups with different schemes and design solutions. The asynchronous oil-cooled TEDs proposed for the Platform R & D project had a huge mass (more than fivefold excess of the value realized in the experimental TED relative to that specified in the technical assignment) and had a low coefficient of efficiency during start-up modes. Full-scale tests of TED (heating, long-term operation at nominal power, at different temperatures, humidity, other external factors, etc.) were not carried out due to the lack of their own bench equipment and KamAZ’s unwillingness to agree with the neighboring specialized plant (TCEO). Therefore, the reliability and effectiveness of TED was not fully appreciated.
During the execution of work, there were questions to the converters of the traction generator and electric motors, to the control system, but the problems identified were also not resolved. Young specialists at the stage of research and development did not dare to require the management to conduct repeated high-grade tests. This later had a negative effect on OCD.
The decision of the “golovnik” to apply the improper Detroit engine on the KamAZ-7950 mock-up sample largely predetermined the further course of work. It was impossible to use proven solutions for the aggregation of the specified engine with any domestic traction generator, the best in design and performance. For a diesel generator set, the type of generator that had never been used as a traction machine, either in domestic or in foreign engineering, was forcedly chosen - a valve-inductor machine with independent excitation winding. The design of the generator did not allow it to be used in certain modes of operation of the diesel engine, and insufficient power was also revealed from the test results. The noise of the inductor generator (about 100 dB) significantly exceeded the requirements for BAT. But the specialists of the co-performer company and the creators of the generator found themselves in a rigid framework, which did not allow to find acceptable solutions.
In technical form, the curb weight of the prototype was indicated equal to 20 tons. Non-traditional technical solutions involve the rejection of heavy-weight cardan, so we should expect a significant reduction in mass relative to previous generations of SKShT. In fact, this parameter in the prototype model KamAZ-7950 turned out to be twice as much - about 40 tons. In addition, for the design of the prototype, KamAZ took as a basis the frame of the six-axle MAZ-547В chassis, which means many tons of excess weight. When performing research such decisions are valid. But as the further development of the ROC showed, the alarm bell of increasing the curb weight during R & D rang in vain for KamAZ - the calculation of the mass of the mockup was not entrusted to anyone.
Top secret innovations
It is regrettable to state: in the Platform R & D, not only the accompanying but also many necessary studies that would solve a number of important technical problems were not performed. There is only one excuse for this: curtailing R & D and the destruction of military science in the 2008 – 2012 period was a widespread practice.
The results of research gave food for thought to the specialists of the main collaborator and cooperation. The prototype model still went, albeit with difficulty, which is a great achievement of the performers. But KamAZ did not allow conducting research work with the layout - the developers-ideologues of these innovations were not allowed to even get closer to the test layout, and this is another mistake.
In the course of R & D, it was necessary to create new test methods for SKShT with NTR, to study the needs of general customers of weapons and military equipment, to take into account the wishes of the head developers of weapons and military equipment. These questions were not given due attention. Studies on the selection of power from the generator to ensure the operation of the add-in units in the movement of the prototype model were not carried out, which further affected the issuance of private technical specifications to manufacturers of KTEO.
All projects of technical assignments of cooperation of the ROC were SPC SM MSTU. Bauman prepared based on the results of research "Platform". However, KamAZ, in connection with the change of cooperation, did not even discuss these TK.
Issues of protection against new types of high-precision and electromagnetic are not solved in research and development. weapons, EW, reducing visibility in the infrared and radio bands. The correctness of the technical solutions in relation to the conditions of the Arctic, a humid climate, desert and mountainous terrain has not been verified. The questions on the use of energy storage devices and on their operation were not thoroughly worked out - the tests were not carried out. In full, not studied the security of the chassis from the detonation of mines - limited to the design and manufacture of the cabin.
The managers of the “Golovnik” were obviously in a hurry, and as soon as the right moment came (after showing to the Minister of Defense Serdyukov), the preparation of a feasibility study for conducting the R & D began. As a backlog, many new and refined technical solutions were developed and prepared, but, as practice has shown, none of them in the EMT part was subsequently claimed. The suspension had to be redone, diesel engines taken from another foreign company.
And when the necessary experience came to the developers, for the third time KamAZ had to start everything from scratch and develop SKSHT with schemes different from motor-wheel. And even go back a generation ago, that is, to a mechanical transmission. What will be the final result - is still unknown.
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