Objective of the Project:
· Increase of the railway transport traffic safety (prevention of the derailment) and speed, decrease of the energy losses on friction and decrease of the vehicle running gear maintenance expenses; · Decrease of the environment pollution by vibrations, noise and friction modifiers.
There are different views at present on the wear resistance, value and stability of friction forces of the rails and wheels and brake shoes. This is due to the fact that tribo-technical aspects of the interacting bodies (problems of formation of the friction forces, mechanism of wear, lubrication of the rails and wheels, selection of materials for the brake shoes, constructions of bogies and etc.) are studied insufficiently and the results of experimental researches obtained in the specific conditions are generalized unfoundedly that complicates obtaining the optimal solutions. Some shortcomings typical for this sphere:
· For estimating the possibility of derailment, they use formula of Nadal (1908) considering the limited number of parameters: vertical and lateral forces, slope of the flange and friction coefficient though a distortion of the wheel-set axle from the radial position, time of action of the lateral load and etc., are additionally considered by modifications of this formula. But the laws of variation of these parameters during operation are not well established, namely: friction coefficients, state and disposition of interacting surfaces, vertical and lateral loads and etc. All this is negatively reflected on the forecasting and determination of the ways of prevention of the derailment, decrease of the vibrations and noise, losses on the wear and expenses on the maintenance;
· The adopted practice of lubrication of the flange roots is irrational especially for the curves of small radii, since it is only acceptable for the steering surfaces but the flange root performs simultaneously the roles of both, the steering surface and rolling surface on which are imposed different tribo-technical properties – high friction coefficient (0.25-0.4) at rolling and friction coefficient as low as possible at steering the wheel. At operation of the flange root in the mode of traction or braking its lubrication promotes the decrease of the friction force, increase of the relative sliding, especially on the steering surfaces, and violation of continuity of the third body film. That leads to direct interaction of the surfaces whose properties differ from the volume properties of these materials and third body, and sharp worsening of the contact zone tribo-technical properties. As the experimental researches have shown behavior of the friction forces and wear rate greatly depend on the level of destruction of the third body. But the existence of the third body and conditions of its destruction are ignored in the methods of calculation on the friction and wear and conditions of derailment, and some efforts to consider the thickness of the lubricant film of hydro-dynamic generation for estimation of resistance of the interacting surfaces to the external impacts did not give positive results.· The existent constructions of the wheel-sets and properties of the lubricants (friction modifiers) do not provide the given values and stability of the friction coefficients at rolling and steering of the wheels, prevention of the lubricant from transfer on the rolling surface and the different purpose friction modifiers from mixing. The used rail fastening devices do not insure the constant rail cant and improvement of the brake shoes volume properties does not always provide the necessary superficial properties. All this hinders prevention of the wheel climbing up on the rail, leads to increase the destruction intensity and damageability of the interacting surfaces.
For reaching the project aims will be developed the following innovative technologies and constructions:
· The technology of obtaining ecologically compatible friction modifiers containing metallic and oxide nano-particles with different properties for the rolling surfaces (the friction modifier will also be applicable for the brake shoes) and steering surfaces of the wheels and rails. The conditions of implantation of the nano-particles on the surfaces in the process of operation will be ascertained;
· The constructions of the wagon and locomotive wheel-sets ensuring reduction of the un-sprung masses, relative sliding and stress concentrations in the joint of the wheel and axle; the wheel profile allowing the separate modification of the rolling and steering surfaces that will prevent mixing of the two different friction modifiers; the method and device for application of the friction modifiers allowing the control of friction forces and relative sliding; a device for rail fastening ensuring the constant rail cant and increased damping properties of rails.
The expected results:The new developments will promote: decrease of the derailment probability, relative sliding velocities of the wheels and rails, un-sprung masses of the wagon and locomotive running gears, the environment pollution by vibrations, noise and friction modifiers by 40-60 %, damageability of the wheels, rails and brake shoes and expenses on the maintenance; increase of the wear resistance and service life of the wheels, rails and brake shoes by 1.5-2.5 times and stability of the wheel-set axles; prevention of the rail corrugation; improvement of the rail damping property in the lateral direction; constancy of the rail cant and the wear controlling in the contact zone.
The project executers are highly skilled specialists having experience of participation in the international projects, authors of numerous scientific works and participants of various international forums.
The project collaborators are well-known experts, whose role will be review of the quarterly reports, commenting and controlling of the research results, joined publications, consultations on application of the project results, identification of the potential companies interested in the commercialization of the research results, drawing up the business plans, conducting the joined workshops.
The many-sided technical approach and methods of solution of the project problems imply development of various new technical solutions on the base of synthesis of the fundamental principles of tribo-technics, dynamics, material science, metallurgy and the results of experimental researches.
