Influence of micro asperity contact and radial clearance on the tribological properties of crankpin bearings

A new hybrid numerical method that couples the dynamic slider-crank mechanism(SCM)and crankpin bearing(CB)lubrication models is proposed to analyze the effect of micro asperity contact on the tribological properties of a CB.In the hybrid model,the dynamic equations of the SCM are established based on the Newton method,while the lubrication equations of the CB are established on the basis of the Reynolds equation.Experimental data of the engine are also used in simulation analyses to enhance the reliability of the results.The load-bearing capacity(LBC)and friction force of the CB are selected as objective functions.Results show that the LBC has a negligible effect on the tribological properties of the CB,but the friction force greatly affects the resistance of the bearing under different radial clearances and surface roughness values.In particular,the maximum friction force in the asperity contact region accounts for 40.5%of the maximum total friction force at a radial clearance of 5μm and 77.7%of the maximum total friction of the CB with a surface roughness of 10μm.

Kinematic Analysis and Test Study of Elliptic-Gear and Crank-Rocker Beating-Up Mechanism

In order to analyze the kinematic performances of elliptic-gear and crank-rocker(EGCR) beating-up mechanism, kinematic mathematic models of the mechanism were established, and an aided analysis and simulation software were compiled. This software can display the kinematic characteristics and simulation motion of the mechanism according to different parameters. It also supplies a platform for human-computer interaction. A group of satisfactory parameters were selected by the software. A test bed of EGCR beating-up mechanism was developed according to these parameters. The kinematic performances of the mechanism were verified by high-speed video tape recorder.