Valmet 309 - Page 39

CRANKCASE
I
10
Crankcaso
fl I
l.
Crarksha
f+
2.
Key
3.
Ma In bear Ing
4. Thrust bear lng
5. F lytrheel
6. Gear rlm
7. Hexagon screr
8. Hub
9. Dust cover foi
shaft sea I
l0.0lldeflector
12.
Gear
13. Pu
I
ley
i4. Nuf
15. Hexagon socks+
screw
16. Plston
17. Plston
r Ings
18. Pls+on
pln
19.
Clrcllp
20. Connectlng
rod
2l . Bear Ing bush
22.
Screw
2f. Nu+
24. Blg end bearlng
The crankshafl'
(l)
ls fq-ged
out of chrome-
alloyed
speclal s+eel
and
ls
I nduct I on
-hardened
at ihe bearlng and
seallng
poln+s.
Thls
makes
ll
posslble
to
grlnd
the shafi
to four under-
slzes wlihout new heai
ireainent. The
gears
(ll
and 12) nhlch drlve +he ldler
gear
and +he ol I
Dump
have been
flxed
+o +he crankshaf+
fron+
end
vrl+h
pressed-on
flt.
The
crankshafi
froni
end also
has
grooves
for fl++lng
the
hub
plece
(8)
and ihe
oulley
(13)
ls flxed to
ihe
hub.
Between the
hub
plece
and ihe
gears
there ls an
ol
I deflec+or
(10)
and
ihe dust cover tor the
shaff
seal
(9)
is
locaied
on
ioo
of the hub.
The flyrheel
(5)
wlih the
gear
rlm
(6)
flxed io
I-i wlth pressed-on
fli ls fastened io ihs
crankshaf+ rear end. The
conn6c+lng rod
(20)
transfers
+he
gas
forces
generated
by th9
combustlon
of luel from the
Dlston
to
the
crankshafl.
The
cross-sectlon of
ihe
lorqad
connecilng
rod ls an
l-proflle. The
bearing
houslng ln the
connec+lng rod blg end
ls spll+
horlzonially and the bearlng
cap ls flxed trl+h
fvro
speclal
screyis
(22)
and nuts
(21).
The
small
end
has
an
Iniegral be€rlng
houslng
yhlch
has +he
plsion
pln
bearlng
bush
(21
) flxed +o
li
wlth
pressed-on
fli.
The
connectlng rod blg
end of ihe 612 englne
has
a
bearlng houslng oJ angle
spllt deslgn and
the
bearlng cap
ls flxed wlth tl{o
rrelongaflon
scretsrr.