An essential condition to ensure an engine life having 300,000 – 1 000,000 km according to race consists in assurance of a minimum wear rate of crankshaft bearings. For such units as connectingrod bearings a maximum allowable value of bearing brass wear makes 100 mkm which corresponds to an integral linear wear intensity of 10-14 …10-13 that is possible only at a hydrodynamic mode of friction actually at all modes of engines operations. Ensuring liquid friction in all range of contact pressures is achieved both through design methods, and technological ones. To the latter belongs first of all the application of lubricants with high wearresistant properties. In this connection arises a problem to reveal a mechanism and degree of the effect of lubricant components upon a range of contact pressure where liquid friction is realized. This paper reports the experimental evidences of the increase of contact pressures at which is achieved a minimum value of a constant of friction at the introduction in lubricant a standard wear-resistant additive – dialkyldithiophosphate of zinc (ZDDP). So, at the introduction in coal oil without additives I-20A (viscosity type ISO 32) 1.25 and 2.5% ZGGP maxi-mum contact pressure at which is realized a hydrody-namic mode of friction increases by 1.8 and 2 times accordingly. Because of impossibility to explain experimental data by a chemical interaction of ZDDP with surface material of tribo-coupling there is offered and substantiated a mechanism of ZDDP influence upon rheological parameters of lubricant in a separation layer. A rheological model allowing the computation of the wearresistant additives influence upon a value of hydrodynamic pressures in a lubrication layer is of-fered. The idea of the initiation by a wearresistant additive of multimolecular adsorption of lubricant on the surface of tribocoupling may be used for the optimization of ZDDP structure and also for the prognostication of changes in pressure coefficient of viscosity in a lubrication layer.
wearresistant additives, rheological model, constant of friction, slider bearings, wear
1. Mukhortov, I. Rheological Model of a Boundary Layer of Lubricant / I. Mukhortov, E.Zadorozhnaya, I. Levanov // Society of Tribolo-gists and Lubrication Engineers Annual Meeting and Exhibition. - Hilton Atlanta, Atlanta, Georgia (USA), 2011.
2. Mukhortov, I.Multimolecular adsorption lubricants and its integration in the theory fluid friction/ I. Mukhortov, E. Zadorozhnaya, I. Levanov // Society of Tribologists and Lubrication Engineers Annual Meeting and Exhibition. - Detroit Marriott at the Renaissance Center, Detroit, Michigan (USA). - 2013. - Р. 147-149.
3. Mukhortov, I.The influence of polymolecular adsorption on the rheological behaviour of lubricating oil in a thin layer/ I. Mukhortov, E. Zadorozhnaya, I. Levanov, K. Pochkaylo // FME Transactions. - 2015. - № 43 (3). - Р. 218-222.
4. Ryk, G. Testing piston rings with partial laser surface texturing for friction reduction / G. Ryk, I. Et-sion // Wear. -2006. - № 261. - Р. 792-796.
5. Felter, C.L..Numerical simulation of piston ring lubrication. / Christian Lotz. Felter // Tribology In-ternational. - 2008. -Vol. 41. - № 9-10. - Р. 914-919.
6. Shahmohamadi, H. On the boundary conditions in multi-phase flow through the piston ringcylinder liner conjunction / H. Shahmohamadi, M. Mohammadpour, R. Rahmani, H. Rahnejat, C.P. Garner, S. Howell-Smith // Tribology International. - 2015). - № 90. - Р. 164-174.
7. Mishra, P.C. A Review of Piston Compression Ring Tribology / P.C. Mishra // Tribology in Industry. - 2014. -Vol. 36. - № 3. - Р. 269-280.
8. Bedajangam, S.K. Friction Losses between Piston Ring-Liner Assembly of Internal Combustion En-gine: A Review / S.K. Bedajangam, N.P. Jadhavb // International Journal of Scientific and Research Publications. - 2013. - Vol. 3. - Is. 6,
9. Yanzhong, Wang. Wet Friction-Elements Boundary Friction Mechanism and Friction Coefficient Pre-diction / Wang Yanzhong, Wei Bin, Wu Xiangyu // Tribology in Industry. 2012. -Vol. 34. - № 4(2012). - Р. 198-205.
10. Tasdemir, Haci Abdullah. Friction and Wear Performance of Boundarylubricated DLC/DLC Con-tacts in Synthetic base Oil / Haci Abdullah Tasde-mir, Takayuki Tokoroyama, Hiroyuki Kousaka, Noritsugu Umehara, Yutaka Mabuchi // Friction and Wear Performance of Boundary-ubricated DLC/DLC Contacts in Synthetic base Oil. - 2013. - Vol. 68. - Р. 518-524.
11. Komvopoulos, K. The mechanismof friction in boundary lubrication / K. Komvopoulos, N. Saka, N.P. Suh // Journal of Tribology. - 1985. - Vol. 107. - № 11. Р. 452- 462.
12. Liu, Y. Friction and adhesion in boundary lubrication measured by microtribometers / Y. Liu , S. Liu, W. Hild, J. Luo, J.A. Schaefer // Tribology International. - 2006. - Vol. 39. - Is. 12. - P. 1674-1681.
13. Maroto-Centeno, J-A. Prediction of fuel economy performance of engine lubricants based on laboratory bench tests. Original Research Article / José-Alberto Maroto-Centeno, Tomás Pérez-Gutiérrez, Luis Fernández-Ruíz-Morón, Manuel Quesada-Pérez // Tribology International. - 2016. - Vol. 94. - Р. 67-70.
14. Khemchandani, B. A biocompatible ionic liquid as an antiwear additive for biodegradable lubricants / Bhawna Khemchandani, A. Somers, P. Howlett, A.K. Jaiswal, E. Sayanna, Maria Forsyth // Tribolo-gy International. - 2014. - Vol. 77. - Р. 171-177.
15. Lenauer, C. Piston ring wear and cylinder liner tribofilm in tribotests with lubricants artificially altered with ethanol combustion products / Claudia Lenauer, Christian Tomastik, Thomas Wopelka, Martin Jech // Tribology International. - 2015. - Vol. 82. - Р. 415-422.
16. Xiang, Y. Measurement of lubricant viscosity and detection of boundary slip at high shear rates / Y.Xiang, Y. Meng, Y.Tian, J. Zhang, W. Liang // Tribology International,. - 2016. -Vol. 94. - Р. 20-25.
17. Otero, I. Friction and anti-wear properties of two tris (pentafluoroethyl) trifluorophosphate ionic liquids as neat lubricants /Inés Otero, Enriqueta R. López, Manuela Reichelt, JosefaFernández // Tri-bology International. - 2014. - Vol. 70. - Р. 104-111.
18. Katyal, P. Central film thickness formula for shear thinning lubricants in EHL point contacts under pure rolling / Puneet Katyal, Punit Kumar // Tribol-ogy International. - 2012. - Vol. 48. - Р.. 113-121.
19. Anuradha, P. EHL line contact central and mini-mum film thickness equations for lubricants with linear piezoviscous behavior / P. Anuradha, Punit Kumar // Tribology International. - 2011. - Vol. 44. Is. 10. - Р. 1257-1260.
20. Cho, Y-K. Molecular tribology of lubricants and additives / Yoon-Kyoung Cho, Lenore Cai, Steve Granick// Tribology International. - 1997. - Vol. 30. - Is. 12. - Р. 889-894.
21. Sinhasan, R. Static and dynamic performance cha-racteristics of an orifice compensated hydrostatic journal bearing with non-Newtonian lubricants / R. Sinhasan, P.L. Sah, // Tribology International. - 1996. - Vol. 29. - Is. 6. - Р. 515-526.
22. Waara, P. Additive influence on wear and friction performance of environmentally adapted lubricants / P.Waara, J. Hannu, T. Norrby, A. Byheden // Tribology International. - 2001. - Vol. 34. - Is. 8. - Р. 547-556.
23. Truhan, J. A rig test to measure friction and wear of heavy duty diesel engine piston rings and cylinder liners using realistic lubricants / John J. Truhan, Jun Qu, Peter J. Blau // Tribology International. - 2005. - Vol. 38. - Is. 3. - Р. 211-218.
24. Zadorozhnaya, E.A. The research of non-Newtonian properties and rheology of thin lubricant layers in hydrodynamic journal bearings / E.A. Za-dorozhnaya // Society of Tribologists and Lubrica-tion Engineers Annual Meeting and Exhibition. - 2013. - Р. 95-97.
