Analytical study of elastically deformed polyamide journal bearing reinforced by copper strips

Elastic deformation of bearing surface is the major factor affecting load c arrying a capacity and friction coefficient of hydrodynamic journal bearing . The effect of elastic deformation of bearing surface on performance of po lyamide journal bearing reinforced by parallel and perpendicular copper str ips, uniformly distributed to the direction of shaft motion is presented. T he results presented in this study and the method of calculating hydrodynam ic pressure, load carrying capacity and friction coefficient show that the elastic deformation of bearing surface caused by hydrodynamic pressure incr eases oil film thickness and consequently results in reduction in load carr ying capacity. Also covering 29% of the bearing area by three copper strips equally distributed in the half bearing area of width-to-diameter ratio eq uals 0.3 gives optimal improvement in load capacity and remarkable reductio n in friction coefficient. Furthermore, reinforcing polyamide bearing area by single perpendicular cop per strip of width-to-diameter ratio equals to 0.3 located at theta = 135 d egrees can save copper material where only 10% of the total area can be cov ered. The length of such copper strip can be shortened to 0.75 of its lengt h without affecting bearing behaviour. This configurations represent minimu m cost and optimum performance of the proposed bearing. The reinforcement o f bearing by parallel copper strips is not recommended since more copper ma terial is required to enhance the bearing characteristics compared with per pendicular strips.