GUDGEON PIN BEARING LUBRICATION• Compression & power stroke –heavyCompression & power stroke heavy

downward load• Exhaust stroke Low downward load• Exhaust stroke – Low downward load• Suction stroke - Load reversal• Lubrication hydrostatic and hydrodynamic- at

Heavy loading• Oil flow and cooling – at low loads and load

reversalCONCLUSION :sufficient time for efficient lubrication & coolinglubrication & cooling

X-HEAD BEARING LUBRICATION• Heavy load for most part of cycleHeavy load for most part of cycle• Low load during scavenging –no load reversal

Sh i d f L O l & li• Short period for L.O. supply & cooling• Lubrication regime combination of elasto-

hydrodynamic ,hydrostatic & hydrodynamic• Slow speed , small oscillations – poor p , p

hydrodynamic effect

X-HEAD BEARING DESIGN CHANGES

NO DESIGN CHANGES ADVANTAGENO DESIGN CHANGES ADVANTAGE1 Flat Palm top end Better X‐head pin support

2 Reduced Pin length 1.Reduced bending2 Reduced Pin length 1.Reduced bending2.Better support

3 Hollow Pin Greater stiffness‐ resistance to bending

4 Increased Pin dia 1. More Load bearing area2 Better hydrodynamic lubrication2. Better hydrodynamic lubrication

5 Extremely fine & hard Pin surface

1. Reduced metal to metal contact2. Better wear resistance

6 Bearing metal‐Lowfriction & high 

1. Better lubrication2. Increased bearing life

fatigue strength