Investigation of effects of boron additives on performance of cam
mechanisms
In many applications like gears, cams, valves, the operating conditions warrant
the operation to
liein the mixed lubrication regime [1].
Besides, under very heavy loads, slow relative speed, insufficient surface area and scarcity of lubricant,
the formation of the thick film necessary for hydrodynamic lubrication become difficult and interacting surfaces contact each other at several locations and tribo–pairs operate in mixed lubrication...
... In an actual engine, the lubricating oil film thickness will range from a continuous film of oil in hydrodynamic lubrication, as in crankshaft bearings, to a trapped and thinner film in
elastohydrodynamic lubrication and boundary or mixed lubrication [4], as
in cam-follower mechanisms...
...As shown in Fig. 6,
it was observed that, reducing effect on the friction,
addition of 4% hBN and
4% BA compounds to the base oil,
was 7% and
12% at 212 N preload, and 7.7% and
13.2% at 412 N preload, respectively.
These results indicate that the
friction reduction effects of boron additives on the contact loads exist, and these additives improved the antiwear property of base engine oil..."
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