front of engine. As assembling piston ring,first it should
be
put
in
cylinder liner,then
be
checked with clearance gauge to find out if the opening clearance is
in
the
speci-
fied
scopy.lf
clearance
is
too small ,repair with file. Piston rings should be staggered
-120OC
with
each
other,and meanwhile avoid the direction
of
piston pin hole.
See
to
Fig.
3.
When assemble the piston into engine,the piston ring, piston pin,connecting
rod liner
and
connecting rod bearing should
be
coated with enough grease. R series
diesel engine
has
'(a)' type combustion chamber at the top
of
piston,with the sur-
face
of
spraying coating graphite ·of tin - coated. The piston
of
R series strengthen
diesel engine
is
controllable heat expansion piston with the skirt inlaid by steel
sheet. the first
is
direct
to
cooling nozzle.
The piston pin
is
full floating type,
and
can
be
rotate
in
piston pin hole
as
it getting
to
certain working temperature,to make wearing .evenly. But it
is
cool,it·
is
interference
fit
between piston pin
and
the piston pin hole.
So
when assemble and disassemble
the piston pin,the piston should
be
preheated to
80
-
90OC.
Assemble piston pin by
..
force at cool temperature
is
prohibited, othervise the pinhole may be ruined. Piston
..
pin should stagger 1
mm
to non - pressure plane relative to piston center,
to
de-
crease piston knock.
Connecting rod body
and
connecting
rod
cap
are positioned by single - tooth,
and
hav~
marking numbers at same side, when assembled, the number must be
regisered. The small end bushing of connecting
rod
is
wrapped bush by bimetal ma-
terial
;the oil holes
on
the bushing should
be
right alingned to the oil gathering hole at
the top of connecting
rod
small end,to lubricate piston pin and bushing. Connecting
rod
bolts should
be
tightened evenly with specified torque strictly, connecting
rod
bolts
are
self - locked by friction force.
The
mass difference
of
connecting
rod
for
one same diesel engine
is
less than 12g,
and
that of piston and connecting
rod
as-
sembly for one same diesel engine
is
not bigger than 20g.
Connecting
rod
bearing
of
R series diesel engine
is
usually made
of
steel - backed
a-
luminum alloy material. Connecting
rod
bearing of strengthen diesel engine
is
made
of steel - backed copper - lead alloy. It
is
unadjustable for the gap between shaft
bearing shell
ad
shaft neck
,when
wearing capacity is over limited value,the bearing
shell must
be
changed.
5. Crankshaft
and
flywheel assembly
The crankshaft
is
made
of
OT800
- 3 high strength modular cast iron t
and
is
full sup-
• 31 •
To Next Page