Study of Starting Friction during the Running of Plain Journal Bearing under Hydrodynamic Lubrication Regime

Study of starting friction during the running of the engineering application has an important role in designing them, especially working at low speed and high load conditions. A significant portion of research and development today is concentrated on saving the energy by reducing the friction. The present paper addresses the measurement technique and analysis of the starting friction during the running of the journal bearing. The experiments were performed during the hydrodynamic lubrication regime using SAE 15W-30 lubricating oil. A journal bearing having journal diameter as 22 mm, length/diameter ratio 1 and 0.027 mm radial clearance has been designed and fabricated to test the starting friction. Analysis of starting friction and average friction torque during the running of journal bearing was done at 900, 1150, 1400, 1650, 1900, 2150 and 2400 revolution per minute (rpm) speed of the journal at load values of 250, 400 and 500 N. The variation of starting friction with increasing speed of the journal is described by graphs and limiting speed is obtained at which the starting friction begin to decrease. The findings of the present work could be used by bearing user and designers to design the bearings.