Tham khảo tài liệu 'tribology lubricants and lubrication 2012 part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 117 Methodology of Calculation of Dynamics and Hydromechanical Characteristics of Heavy-Loaded Tribounits Lubricated with Structurally-Non-Uniform and Non-Newtonian Fluids of comparison of calculated results with those obtained experimentally or during operation. On the basis of experimental studies and modern methods of calculation the criteria of performance of hydrodynamic tribounits are developed the smallest allowable film thickness hper maximum allowable hydrodynamic pressure pper minimum film thickness reduced to the diameter of the journal the maximum unit load fmax. According to calculations of crankshaft engine bearings of several dimensions the maximum permissible loading parameters listed in the table 5 are obtained. Assessment of performance of bearings is also done according to the calculated value of the relative total lengths of areas per the cycle of loading ah and ap er where the values of inf hmin are less and sup pmax are bigger than acceptable values. Experience has shown that these parameters should not exceed 20 Fig. 12 . Engine group Loading parameters Maximum specific load fmax MPa Reduced to the diameter of the journal minimum film thickness mp 100 mm The largest hydrodynamic pressure in the lubricating film sup Pmax Mpa Bearin g Type Crank Main Crank Main Crank Main Antifriction material SB - stalebronzovye inserts coated with lead bronze SA - staleallyuminievye inserts coated aluminum alloy AMO 1-20 SB SA SB SA SB 1 SA SB 1 SA SB SA SB SA Highly accelerated 55 49 41 37 2 0 1 2 448 397 336 305 Medium accelerated 52 46 34 30 5 2 3 1 5 420 377 275 245 Low accelerated 45 39 5 31 27 2 5 1 9 367 326 255 225 Table 5. Maximum permissible loading parameters of sliding bearings of a crankshaft of automotive internal combustion engines Fig. 12. The dependence of the hydromechanical characteristics on the rotation angle of crankshaft 118 Tribology - Lubricants and Lubrication 6. Conclusion Thus the methodology of calculating the dynamics and HMCh of
