Page 71 - The Tribology Handbook

AI 1 Crankshaft bearings

Recommended groove configurations Undesirable grooving features

With thin shells the groove can take the form of a slot, Rows of holes in oil groove, communicating with
communicating if necessary with a corresponding groove corresponding groove in bearing housing, can promote
round the housing. The two halves of the shell are con- local recirculation of oil, leading to excessive temperatures.
nected by bridge pieces as at A.

Abrupt endings to partial oil grooves can cause erosion
of the surface downstream of the groove end.
, CRACKS!!, /DEPRESSION ,

Any hole, slot or groove in the housing behind a bearing
is dangerous because it promotes undesirable deflection,
fretting and, in extreme cases, cracking of the bearing.

In order to leave a heavily loaded area of a bearing Any flat or depression in a journal surface, other than
uninterrupted, a circumferential groove may be partial a blended hole in line with the bearing oil groove, is liable
rather than continuous. The ends of such a groove must to cause severe local overheating.
be blended gently into the plain surface to avoid sudden
starting or stopping of the oil flow into or out of the groove
and consequent erosion of the bearing.
A11.5