SAFETY PRECAUTIONS
-On FWE get immobilization permission and propeller clearance from bridge.
-under piston spaces and scavenge space ventilate by blower.
-Stopped engine
-Shut off starting air supply At starting air receiver
-Block the main starting valve
-Shut off starting air distributor/distributing system power supply
-Shut off safety air supply
-Shut off control air supply
-Shut off air supply to exhaust valve – Only with stopped lubricating oil pumps
-Engage turning gear
-Shut off cooling water
-Shut off fuel oil
-Stop lubricating oil supply
-Lock the turbocharger rotors
-isolate expansion tank than only drain jacket drain jacket cooling water and open purging valve so that air pressure helps in draining.
CRANKPIN BEARING CHECKING
The bottom clearance between the journal and a new bearing shell is the result of a summation of the production tolerances of the bearing assembly components.
For the bottom clearance of a specific bearing
1. Open the crankcase door at the relevant
cylinder.
2. Turn the crank concerned to BDC.
3. Measure the clearance in the crankpin
bearing by inserting a feeler gauge at the
bottom of the bearing shell in both sides.
See Data for bottom clearance.
4. The difference between the actual clear-
ance measurement and the measurement
recorded in the Adjustment Sheet (or the
clearance noted for a new bearing installed
later) must not exceed 0.1 mm. If so, the
crankpin bearing must be disassembled for
inspection.
5. The wear limit for the crankpin bearing
shells is based on an evaluation of the
bearing condition at the time of inspection.
An average wear rate of 0.01 mm per
10,000 hours is regarded as normal.
6. For further external inspection of the crank-pin bearing, see .
Now DISMANTLING OF CRANKPIN BEARING;
1. Turn the crank to BDC.
2. Suspend two tackles from the lifting brackets, in the athwartship direction.
3. Turn the crank to TDC.
Mount eye bolts in each side of the crank-
pin bearing cap and, using shackles and
wire ropes, hook on the tackles and haul
tight.Loosen the crankpin bearing stud nuts, using the hydraulic jacks.
Remove the hydraulic jacks and the nuts.
4. Lower the bearing cap while seeing care-
fully that the studs do not damage the
crankpin journal.Land the bearing cap on a couple of planks placed in the oil pan.
Inspect the bearing shell.
For evaluation of bearings, see.
5. If the bearing shell needs to be replaced,
remove the whole bearing cap from the
crankcase.Hook the tackle on to an eye bolt on one side of the bearing cap.
Mount the wire guide in the top of the
crankcase door opening.
Using the tackle from the frame box inside
wall, together with a tackle suspended from
the platform bracket, lift the bearing cap
out of the crankcase.
6. Place the bearing cap on one side on a
couple of planks.
Dismount the bearing shell lock screws and
replace the bearing shell by a new one.
7. Turn to TDC.
Mount the four supports for guide shoes
on the crosshead guides.
Carefully turn the crank down until the
guide shoes rest on the supports.
Adjust the support brackets to the guide
shoes so that the weight of the crosshead
is evenly distributed on the four supports.
8. Mount a lifting attachment for securing the connecting rod at the lower end, on one
side.Hook on the tackle to a beam under the
gallery platform and haul tight.
9. Carefully turn the crankshaft downwards,while ‘following’ with the tackle, making sure that the upper part of the bearing comes completely clear of the recess in the crankshaft when the parts begin to ‘separate’.
Continue turning the crankshaft until the
bearing surface can be freely inspected.
Inspect the bearing shell surface and the
crankpin journal.
10. If it is necessary to replace the bearing
shell, proceed as follows:
Turn the crankshaft to HORIZONTAL.
Release the tackle so that the connecting
rod is hanging freely.
11. Mount an eye bolt in the bottom of each
guide shoe.
Suspend two tackles from the eye bolts.
12. Place the lifting tool for the crankpin upper shell on the crank webs and hook the tackles on to the lifting tool.
Mount the tool on the bearing shell in the
connecting rod, using the tackles, and haul
tight.
13. Dismount the bearing shell lock screws.
Lower the lifting tool with the bearing shell,
using the tackles.
-On FWE get immobilization permission and propeller clearance from bridge.
-under piston spaces and scavenge space ventilate by blower.
-Stopped engine
-Shut off starting air supply At starting air receiver
-Block the main starting valve
-Shut off starting air distributor/distributing system power supply
-Shut off safety air supply
-Shut off control air supply
-Shut off air supply to exhaust valve – Only with stopped lubricating oil pumps
-Engage turning gear
-Shut off cooling water
-Shut off fuel oil
-Stop lubricating oil supply
-Lock the turbocharger rotors
-isolate expansion tank than only drain jacket drain jacket cooling water and open purging valve so that air pressure helps in draining.
CRANKPIN BEARING CHECKING
The bottom clearance between the journal and a new bearing shell is the result of a summation of the production tolerances of the bearing assembly components.
For the bottom clearance of a specific bearing
1. Open the crankcase door at the relevant
cylinder.
2. Turn the crank concerned to BDC.
3. Measure the clearance in the crankpin
bearing by inserting a feeler gauge at the
bottom of the bearing shell in both sides.
See Data for bottom clearance.
4. The difference between the actual clear-
ance measurement and the measurement
recorded in the Adjustment Sheet (or the
clearance noted for a new bearing installed
later) must not exceed 0.1 mm. If so, the
crankpin bearing must be disassembled for
inspection.
5. The wear limit for the crankpin bearing
shells is based on an evaluation of the
bearing condition at the time of inspection.
An average wear rate of 0.01 mm per
10,000 hours is regarded as normal.
6. For further external inspection of the crank-pin bearing, see .
Now DISMANTLING OF CRANKPIN BEARING;
1. Turn the crank to BDC.
2. Suspend two tackles from the lifting brackets, in the athwartship direction.
3. Turn the crank to TDC.
Mount eye bolts in each side of the crank-
pin bearing cap and, using shackles and
wire ropes, hook on the tackles and haul
tight.Loosen the crankpin bearing stud nuts, using the hydraulic jacks.
Remove the hydraulic jacks and the nuts.
4. Lower the bearing cap while seeing care-
fully that the studs do not damage the
crankpin journal.Land the bearing cap on a couple of planks placed in the oil pan.
Inspect the bearing shell.
For evaluation of bearings, see.
5. If the bearing shell needs to be replaced,
remove the whole bearing cap from the
crankcase.Hook the tackle on to an eye bolt on one side of the bearing cap.
Mount the wire guide in the top of the
crankcase door opening.
Using the tackle from the frame box inside
wall, together with a tackle suspended from
the platform bracket, lift the bearing cap
out of the crankcase.
6. Place the bearing cap on one side on a
couple of planks.
Dismount the bearing shell lock screws and
replace the bearing shell by a new one.
7. Turn to TDC.
Mount the four supports for guide shoes
on the crosshead guides.
Carefully turn the crank down until the
guide shoes rest on the supports.
Adjust the support brackets to the guide
shoes so that the weight of the crosshead
is evenly distributed on the four supports.
8. Mount a lifting attachment for securing the connecting rod at the lower end, on one
side.Hook on the tackle to a beam under the
gallery platform and haul tight.
9. Carefully turn the crankshaft downwards,while ‘following’ with the tackle, making sure that the upper part of the bearing comes completely clear of the recess in the crankshaft when the parts begin to ‘separate’.
Continue turning the crankshaft until the
bearing surface can be freely inspected.
Inspect the bearing shell surface and the
crankpin journal.
10. If it is necessary to replace the bearing
shell, proceed as follows:
Turn the crankshaft to HORIZONTAL.
Release the tackle so that the connecting
rod is hanging freely.
11. Mount an eye bolt in the bottom of each
guide shoe.
Suspend two tackles from the eye bolts.
12. Place the lifting tool for the crankpin upper shell on the crank webs and hook the tackles on to the lifting tool.
Mount the tool on the bearing shell in the
connecting rod, using the tackles, and haul
tight.
13. Dismount the bearing shell lock screws.
Lower the lifting tool with the bearing shell,
using the tackles.
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