Valmet 309 - Page 40

Vlbratlon
darD€r 6l
l/612
l. V lbratlon
damDer
2. Pul lsy
f.
Hub
4.
Nui
ln
slx-cyllnder englnes
ihe cranksh6f't
fron+
€nd lncorporales
a
forslonal vlbrailon
damper
of vlscous type. ThE damper
has
a caslng
fllled
l{lih vlscous slllcono
fluld,
encompasslng
the
damplng
paste
ll{lth mlnlmun clearances.
Borrlng shel I
l. lnd lum lead alloy
2. Lead bronze
l. Sieel body
4-7
Th9
crankshati boarlngs are ilxed
to l-he
cyllndsr
block on bolh sldes of
-ihe
cyllnder,
whlch
means thai therg ls one bearlng
polni
more
+han lhere are
cyllnders
ln
ihe
englne.
The cranksha{t
thrust bearlngs
(4)
are
locaied
on
ihg sldes of ihe
endmost
bearlng
Journal.
The
maln
and blg end bearlngs
are so-called
three-layer bearlngs rhlch have
on
top
of
lhe
s+Eel
body
c lead-bronze
layer wlfh
load
capacliy cnd
good
heai conductlbllliy.
The
actual slldlng surfoce ls covEred rlth o
lhln
layer
ot lead-lndlum f,hlch f6cl I l'tales
+he
runn Ing
ln.
44
P I ston
l. Combustlon
chamber
2. Casi lron
r
Ing
5.
Clrcllp
4.
Plsion
oln
5. Bearlng bush
6. Connect I ng rod
7. Chrome-p lafed
cornpresslon
rlng
8. Compresslon r Ing
9. Sprlng-loaded
oll rlng
ylth
slldlng sur{aces
chromed
The
pls+on
ls made of eutectlc olumlnlum
alloy.
The speclally
formed
cqbustlon chambar
(l)
oo
the
plston
+op end
lmproves the mlxlng
of alr
and
fuel.
In
ihe
hlgh-power englne verslons
the
groove
for the top
plston
rlng
ls
In +he
c€st lron rlng
(2)
cast onto the
plston.
There
are ihr€€
plsion
rlngs:
+he
topnpst rlng ls a
compresslon rlng
(7)
vlth a barrel-iype,
chrone
plaied
surface.
The oiher compresslon
rlng
(8)
Is a so-colled
mlnute
rlng wlih a Jor or
90r anglo.
The +hlrd
rlng ls
a sprlng-load6d
ol I
rlng
(9).
The
pls+on pln
(4)
ls Insldo +he
plston
t|l+h
accurate fliilng
and fhe
connecllng
rod small
end and
ihe
plston pln
have
a
so-called
floåtlng
fl|oun+lng bo+vreen each
other.
The
plstons
of the
612 englnes are
cooled by
dlrecilng
an
ol
I
jet
to the
boftom surface.
o