Kubota D1803-CR-E4, Workshop Manual

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2.9 Piston ring
2.9.1 Outline of piston ring
Piston rings primarily maintain air tightness of the
combustion chamber.
2.9.2 Structure of piston ring
The piston rings are top ring (barrel face), second ring
(taper face), and oil ring.
(1) Top ring
(2) Second ring
(3) Oil ring
(4) Expander
(5) Plane (barrel face) type (for
D1803-CR-E4, and V2403-
CR-E4 model)
(6) Key-stone (barrel face) type
(for D1803-CR-TE4, -TIE4
and V2403-CR-TE4, TE4BG,
-TIE4 model)
(7) Inner bevel (taper face) type
(8) Bevel cutter type
2.9.3 Function of piston ring
1. Maintain airtightness of the combustion chamber
during the compression stroke and combustion
stroke.
2. Wipe down oil on the cylinder wall. Also prevent oil
getting into combustion chamber.
3. Transfer piston heat to the cylinder wall.
4. Support piston posture.
2.9.4 Specification of piston ring
Service speci-
fication of pis-
ton ring gap
Top ring
0.20 to
0.35 mm
0.0079 to
0.013 in.
Second ring
D1803-CR-E4
V2403-CR-E4
0.30 to
0.45 mm
0.012 to
0.017 in.
D1803-CR-
TE4, -TIE4
V2403-CR-
TE4, -TE4BG,
-TIE4
0.40 to
0.55 mm
0.016 to
0.021 in.
Oil ring
D1803-CR-E4
V2403-CR-E4
0.20 to
0.40 mm
0.0079 to
0.015 in.
D1803-CR-
TE4, -TIE4
V2403-CR-
TE4, -TE4BG,
-TIE4
0.25 to
0.45 mm
0.0099 to
0.017 in.
2.10 Connecting rod
2.10.1 Outline of connecting rod
The connecting rod connects the piston and the
crankshaft.
The connecting rod transfers the combustion pressure
received by the piston to the crankshaft.
2.10.2 Structure of connecting rod
The connecting rod is made up of a connecting rod cap
and connecting rod etc.
(1) Small end
(2) Big end
(3) Connecting rod cap (4) Small end bushing
(5) Bearing metal
MECHANISM
2. Engine body 4. ENGINE
D1803-CR-E4,D1803-CR-TE4,D1803-CR-TIE4,V2403-CR-E4,V2403-CR-TE4,V2403-CR-TE4BG,V2403-CR-TIE4
4-7
KiSC issued 12, 2018 A