Crankcase; Baseplate; Crankshaft And Connecting Rod Assy; Piston - Robin EC05-2 Service Manual

4-2 CRANKCASE
All parts related with crankcase assy are aluminium alloy diecastings, which removed all unnecessary excess thickness for
extreme lightness, consist of split-type front crankcase, rear crankcase and crankcase cover (for Model D) or reduction cover
(for Model B) depending upon the model as per the following table,
Model
Reduction Cover Crankcase Cover Rear Crankcase
Front Crankcase
EC05-2
D
B
B
Exclusive for D D
Exclusive for B
Exclusive for
B
for D type
~
EC07-2 for D type
Exclusive for B Exclusive for B
D
Exclusive for
D
Exclusive for
D
-
EC10 for
D
type Exclusive for B
B
~
v
Exclusive for D Exclusive for D D
Exclusive for D Exclusive for V
~-
EC17 for D type Exclusive for
B
/
Exclusive for B
B
v
Exclusive for
D
Exclusive for
V
I
EC25-2
D
for DS type
DS
for D type
Exclusive for D Exclusive for D.DS
Model EClOD, V. EC17D, V. EC25-2D. DS:
The rear crankcase forms a governor chamber and provided with crankcase cover. As front, rear crankcase cover hasone ball bearing respective-
ly,
the crankshaft is supported by 3 ball bearings.
Model EClOB, EC17B
The rear crankcase forms a part of the reduction gear chamber and after installing the reduction gear and governor, reduction cover is to be
fitted. The reduction cover has two ball bearings, one is supporting the crankshaft and the other one is supporting the driving shaft.
4-3 BASE PLATE
The base plate made of aluminum alloy diecasting is to be attached to the front and rear crankcase .with
4
bolts.
4-4 CRANKSHAFT and CONNECTING ROD ASSY.
The crankshaft is separable into the front crankshaft, rear crankshaft and crank pin.
Crankshaft is made of forged carbon steel; Crank pin is made of chromium-molybdenum steel, hardened and
precision machined.
Connecting rod is a forged chromium-molybdenum piece which is equipped with needle-bearings at both large and
small ends. Both rod ends
has an oil grooves to deliver lubricant t o prevent burning and wearing.
The front, rear crankshafts and the crank pin are assembled together and force fitted in exact alignment with the
special assembling fixture after fitted the needle-bearing and connecting rod on the crank pin. Generally, they can
not disassembled. In case of replacing the crankshaft, it is requested to replace crankshaft and connecting rod in
assembled manner.
4-5 PISTON
The piston is made of precision-casted heat-resistant aluminum alloy which machined precisely into oval section in order t o
prevent from burning and slapping. It is attached to the connecting rod small end by means of a piston and a needle bearing.
Near the top of the piston, there are two grooves for compression rings. In order to prevent the rotating the rings during the
operation and damaging the cylinder port, lock-pins are inserted.
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