Abstract

Design parameters of the CB (crankpin bearing), including c,r_b, r_s, and B (radial clearance, bearing radius, shaft radius, and width) can affect lubrication-friction in the engine, thus, friction loss can be increased, and tribological performance can be reduced. To clarify this issue, an integrated framework combining slider-crank dynamics and crankpin-bearing mixed lubrication analysis is established to evaluate in detail under various changes of c, r_b, r_s, and B based on the Reynolds equation and MATLAB software. The p, F, and μ (oil pressures, force of friction, and friction-coefficients) of CB are selected as evaluating indexes. The study shows that all design parameters of CB greatly affect the friction loss and tribological performance of the engine. To improve the tribological performance of the engine, the optimal ranges of 2025c≤≤ μm, 1520r_b≤≤ mm, and 1520B≤≤ mm should be selected in the engine design process. These ranges are proposed based on numerical trend analysis rather than formal optimization.

Keywords:Crankpin bearing; Tribological performance; Friction loss; Slider-crank mechanism