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Tuesday, December 13, 2011

Removing and Installing Push Rod

Tools Required
  1. Lifting device
  2. Open end wrenches

STARTING POSITIONS
Rocker arm/swing lever with associated bearings compl. removed or inlet valve rocker arm with bearing removed.

Push rod and Swing arm

SEQUENCE OF OPERATION
Removal
  1. Clamp lifting device onto upper pushrod end.
  2. Pull out the push rod to the top.
  3. Clean the pushrod and inspect ball seat.
Installing
  1. Oil the pushrod ball seats.
  2. Insert pushrod and have it seated on the thrust piece of the can follower arm.
  3. Detach lifting device.
Note: In order to facilitate installation of rocker arms/swing lever, its recommend to loosen the screws. Thus the sleeve can align with the rocker casing.  



Tuesday, December 6, 2011

Checking, Removing and Installing Swing Arms(Cam follower Levers)


Tools Required
  1. Torque Wrench
  2. Screwdriver bit
  3. Adapter
  4. Circlip pliers
SEQUENCE OF OPERATION 1: Checking

Starting Position
Covers of cam shaft shell been removed.
  1. Check that fillister head have been tightened to the specified torque loading.
  2. Check running surfaces of all rollers for damage.
  3. Switch on lube oil pump and check that all lubricating points are adequately supplied with oil.
scratch in roller
scratch in cam shaft
 SEQUENCE OF OPERATION 2: Removal o swing arms for inlet and exhaust valves

Starting Position
Cam shaft shells, lube oil lines and push rods have been removed, and the relevant fuel oil pumps turned to TDC.
  1. In order to remove a shaft with swing arms, first of all the adjacent short shafts together with swing arms must be removed in accordance with work card.
  2. Remove the fillister head screws and take off shaft complete with swing arms and bearing brackets.
  3. Pull the bearing brackets, spacer tube and butting disk off from the shaft, for doing so, remove circlips at the fixed bearing.
  4. Check clearance between bushes of swing arms and shaft.
  5. Clean and check bearing points, contact surface on thrust piece, and the running surface of the roller. Check O ring at the shaft bearing points. Clean all drilled oil passage in shaft and swing arms.
SEQUENCE OF OPERATION 3: Installing of swing arm
push rod operation by swing arm

swing arm installation


The installation takes place in reverse order to that of removal. During installation, the following points must be sbserved:
  1. Take care not to damage the O rings in the shaft when fitting the bearing bracket.
  2. The fillister head screw are to be tightened to the specified torque loading.

Note: When mounting the bearing, it is the upper fillister head screws which are to be tightened first. 



Monday, December 5, 2011

Removal of Compressor Wheel


Tools Required
  1. Oil pump
  2. Bush
  3. Clamping piece
  4. Hexagonal screw
  5. High pressure pipe
  6. Sealing sleece
  7. Seal ring
  8. Open end wrenchs
STARTING POSITION
Either the silencer or the intake casing and oil tank and compressor casing have been removed.

Caution! Check the flexible high-pressure pipe for damage every time before it is used. Under no circumstances whatsoever is an even lightly damage high-pressure pipe to be used.

hydraulic pressure applying to unlock compressor wheel
Oil pump

SEQUENCE OF OPERATION
  1. Unscrew and remove the magnet shaft in order to prevent it being damaged. Unscrew nut, take off the claw sleeve and remove the fitted feather key.
  2. Refit the claw sleeve and screw on the nut far enough until gap between compressor wheel and claw sleeve is about 10-15 mm(for MAN B&W 9L 58/64). The claw sleeve serves as a stop when pressing off the compressor wheel. Screw sealing sleeve into the center bore of the shaft and secure oil pump with bush, clamping piece and hexagonal screws to the bearing casing.
  3. Connect high pressure pipe to bush and sealing sleeve.
  4. Unscrew the cylindrical feeder of the oil pump, immerse the mouthpiece in clean lube oil and pull out the piston using the eyebolt. For venting, hold up the mouthpiece and press the ball inwards, then screw the oil feeder back onto the pump.
  5. With the T-screw in pump open, pump unit bubble free oil exits. After closing the T-screw again continue pumping unit pumping becomes noticeably more difficult. If the compressor wheel does not jump off immediately, wait a couple of minutes in order that the oil can spread in between shaft and conical sleeve. Then continue pumping again until the compressor wheel and the conical sleeve. Then continue pumping again until the compressor wheel and the conical sleeve jump off against the claw sleeve. When this happens, they are released.
  6. Remove nut and claw sleeve. Remove feather keys if applicable.
  7. Using the lifting device, firmly secure compressor wheel and conical sleeve to the rope and hang the rope onto hoist.
  8. Pull off the compressor wheel with the conical sleeve in an axial direction and deposit on a wooden base.
Now the bearing casing is accessible for inspection of the guide bearing(locating bearing).

Saturday, December 3, 2011

Removing and Installing Piston Pin and Bush


Tools Required
  1. Lifting device for control had 
  2. Removing/Installing tool
  3. Circlip pliers
  4. Double open end wrench
  5. Lifting gear and rope
Connecting rod head
Piston pin with removal tool

SEQUENCE OF OPERATION
Removal
  1. Mount lifting device to connecting rod head, hang device onto lifting gear and raise slightly in order to relieve the piston pin.
  2. Remove the circlips and push out piston pin. Before doing so, secure the piston against canting.
  3. Carefully lift out connection rod head from the piston and lower  it which care onto a suitable support.
  4. Install device in piston pin and clamp it with hexagonal screw.
  5. Hang device onto the lifting gear and carefully push out the piston pin the full way.
Note: In case replacement of bush is required,this work should be carried out in a service workshop as the bush is to be cooled down before being installed. In the meantime and if possible, install spare connecting rod head. Rescraping the running surface must neither be made with new nor with used bushes.

Installing
Check to see that the slipper is free to move, supply pipe fully pressed into the piston skirt.
Installing the piston pin is a reversal of the removal procedure. When installing, attention should be paid no to damage the piston with the device during insertion.>

Checking and Disassembling Piston


Tools Required
  1. Piston ring expanding pliers.
  2. Adapter
  3. Extension
  4. T-handle
  5. Wrench socket
  6. Ratchet
  7. Feeler gauge
  8. Lifting gear and hemp rope
  9. Note pad
MAINTENANCE  

Remove and check piston at specified intervals. The length of periods between overhauls depends upon operating conditions, i.e in engine load, fuel used, quality of combustion, on engine lubrication and cooling. Compression rings should normally not be removed for checking, as rings are subjected to severe stress during removal and refitting. Check pistons and liner wall for effectiveness of lubrication.
The compression ring and oil control ring are to be replaced every 10.000 operating hours, unless damage as per work card necessitates replacement at an earlier stage.

Carbon deposits on piston crown
Clean piston ring grooves
Starting Position
Piston has been removed and placed on wooden support.

SEQUENCE OF OPERATION
Checking
  1. Check condition of the piston and piston ring.
  2. Clean piston of carbon deposits, taking care not to roughen the surface of the piston crown. Cautiously clean running surface.
  3. Measure axial clearance of ring in their grooves, note down measurement and enter them in the engine log.
  4. Measure shoulder clearance between piston crown and piston skirt at 4 point evenly distributed over entire circumference and note them down. For admissible shoulder clearance rates and admissible deviation of tares from amount the various measuring points.
  5. Using piston ring expanding pliers, remove  the piston rings, inspect them closely and renew if required.
  6. Carefully clean groove in piston and check wear.
  7. Install rings on piston, using piston ring expander pliers, measure groove clearance and record in engine operation log.
Note: While installing a used piston in a cylinder liner from the original, new compression rings and a new oil control ring must be used at any rate.The engine must then be run in again.

Dismantling
Piston has been removed and cleaned on outside, shoulder clearance has been measured.
  1. Remove piston pin an connection rod head.
  2. Loosen four nuts and unscrew.
  3. Slip hemp rope through piston pin bore in piston skirt and attach, lift off and cautiously deposit. When lifting off, attention has to be paid to the stud bolts and the thrust pieces.
  4. Carefully clean piston crown and piston skirt. Inside of cooling spaces must be cleaned to be metallic-bright. Oil passages are to be cleaned with compressed air. Check parts for damage (cracks).
  5. If required unscrew studs form piston crown.
Note: Operation of engine with intensely contaminated lubricating oil results in increased coke deposits in the cooling space of the piston.  

Friday, December 2, 2011

Removing and Installing Locating Bearing


Tools Required
  1. Protection Sleeve
  2. Bracket
  3. Hexagonal nut
  4. Threated rod
  5. Open end wrench
Starting Position

Either silencer or aint-intake casing and compressor casing are removed or only the air-intake socket, spacer ring and insert, impeller, cover and locating ring are taken off.

Threaded rod screwed in locating bearing
Locating bearing pulling out

SEQUENCE OF OPERATION
Removing
  1. Screw protection sleeve onto rotor shaft to protect the shaft and the bearing bore.
  2. Screw 2 threaded rods into locating bearing.
  3. Fasten bracket with hexagonal nuts to bearing casing and screw two hexagonal nuts onto threaded rods.
  4. Extract locating bearing from casing by tightened the two nuts evenly.
Note:The two nuts should be tightened equally at the same time.

Installing
  1. Screw protection sleeve onto turbine shaft, unless it has been left in place.
  2. Cautiously insert locating bearing in axial direction into bearing casing.
  3. Screw off protection sleeve.

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