edwardh1, a crankpin is a rod journal.
Originally Posted By: ZeeOSix
Thought you'd like this part on page 29.
Crankpin Bearing Lubrication
All engines described in this paper had pressure lubricated
crankpin and main bearings. Oil was supplied either directly
to the crankshaft or through an oil galley to the main
bearings and from there to the crankpin. The lube oil
serves to establish a film that prevents metal to metal contact
between the journal and bearing and to provide cooling.
The splash system that persisted in automotive practice
for a number of years could not provide an oil flow rate that
was adequate to keep the bearing temperature at an acceptable
level in the higher specific power ratings of aircraft engines.
The variables that affect the flow rate of oil are: supply
pressure, bearing clearance, and the length to diameter ratio
of the bearing. The clearance and the length to diameter
ratio are under the control of the designer and require a
very tricky balance between oil flow rate and minimum oil
film thickness.
Because you know how fervently Shannow's been arguing the case for splash lubrication
But seriously, the variables mentioned in the quoted text all affect
side leakage. Yes pressure is mentioned. Nevertheless it remains true that only adequate make-up supply volume has 'bearing' on the lubrication integrity in the journal, and that excess flow via excess pressure serves no constructive purpose. Can you agree on that before this turns into a massive circular debate?