The heating of journals and reciprocating parts of an engine may be
attributed to the following causes:
Improper proportions and fitting, unsuitable material, want of
homogeneity between the metals of which the journals and bearings are
composed, the revolving or reciprocating parts not being in line,
the boxes being keyed up too tight, sand or grit getting into the
journals, improper lubricating, etc. The last mentioned cause is very
complicated, as the conditions of weight of load, area of surface
subject to pressure, velocity of movement, etc., must be taken into
consideration.
To remedy the heating of journals which is caused by the revolving or
reciprocating parts not being in line, the engine or shaft must be put
in line.
When caused by the boxes or bearings being too tight, they must be
loosened a very little at a time until bearings run cool. Apply plenty
of good oil.
Clean the boxes and journals thoroughly, and see that the oil holes are
not stopped up; also see that the oil-cups are clean, to assure of the
oil getting to the bearings freely.
Oiling frequently, using a little oil at a time, gives the best results
and is the most economical.