Fig. 6 Distributions of mean hydrodynamic pressure on Pad2(θc=15°)
Fig. 7 Pressure Distributions (θc=42°)
On the other bearing is quite severe since both the film thickness and its hand, pmax increases with small slope and then decreases. The decrease in pmax is due to the increase in the asperity interaction. The rough surfaces make lubrication condition severe. The hmin value for the longitudinally oriented surface (γ>1) is smaller than that for the isotropic surface (γ=1).Patir and Cheng reported that different roughness structures have varying effects on the load carrying capacity depending on the ratio of bearing width to bearing length [20]. The load carrying capacity depends on whether the main flow or the side flow is dominant. In the present calculations, the ratio of bearing width to length of bearing pad arc is greater than 1.The isotropic surface, therefore, restricts the main flow more than the longitudinally oriented surfaces.pmax value for γ=1 is greater than for γ>1.
4. Conclusion
The theoretical analysis on the mixed lubrication of the crosshead-pin bearing is made. The journal center locus and the pressure distributions at representative crank angles are calculated. The lubrication condition of the crosshead-pin bearing is quite sever since both the film thickness and its fluctuation during one cycle is small. The eccentricity ratio of rough bearing is smaller than that of perfectly smooth bearing. With an increase in surface roughness, the film paiameter decreases and the lubrication condition becomes severe. The load carried by the asperity contact pressure is comaratively small in the present study. Tlle surface pattern parameter affects the minimum film thickness and the maximum pressure.
The authors would like to acknowledge Mr. F. Shimada of his kind cooperation.
