CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.
-
Upload
brice-bennett -
Category
Documents
-
view
231 -
download
6
Transcript of CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.
![Page 1: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/1.jpg)
CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT
LESSON TWO
![Page 2: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/2.jpg)
1. CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT
1.1 DEFINITION OF A CRANKSHAFT
The crankshaft converts reciprocating motion in the cylinder into rotary motion of the propeller shaft.
![Page 3: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/3.jpg)
![Page 4: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/4.jpg)
1. CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT
1.1 DEFINITION OF A CRANKSHAFT
The crankshaft converts reciprocating motion in the cylinder into rotary motion of the propeller shaft.
1.2 PARTS
The crankshaft is made up of throws and jurnals. A throw consists a pin ( secured or attached to big / bottom end bearings ) and two webs or crancks. Jurnals rest or lie in the main bearings.
![Page 5: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/5.jpg)
![Page 6: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/6.jpg)
1. CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT
1.1 DEFINITION OF A CRANKSHAFT
The crankshaft converts reciprocating motion in the cylinder into rotary motion of the propeller shaft.
1.2 PARTS
The crankshaft is made up of throws and jurnals. A throw consists a pin ( secured or attached to big / bottom end bearings ) and two webs or crancks. Jurnals rest or lie in the main bearings.
1.3 STRESSES ( fluctuating )
Bending ( when the piston is at TDC );
Sheer stress ( in operation );
Torsion ( due to speed change, i.e. acceleration & deceleration )
![Page 7: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/7.jpg)
1.4 MANUFACTURING
Solid forged built in a single piece ( small-slow speed engines )
![Page 8: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/8.jpg)
![Page 9: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/9.jpg)
![Page 10: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/10.jpg)
1.4 MANUFACTURING
Solid forged built in a single piece ( small-slow speed engines )
Semi-built design ( large medium-speed engines ). Crankpins & webs are forged or cast in one piece and shrunk on to the journals.
Fully-built ( cast in single piece – webs are shrunk on to the crankpins and journals
![Page 11: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/11.jpg)
![Page 12: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/12.jpg)
![Page 13: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/13.jpg)
1.4 MANUFACTURING
Solid forged built in a single piece ( small-slow speed engines )
Semi-built design ( large medium-speed engines ). Crankpins & webs are forged or cast in one piece and shrunk on to the journals.
Fully-built ( cast in single piece – webs are shrunk on to the crankpins and journals
1.5 MATERIALS
Carbon steel
![Page 14: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/14.jpg)
1.4 MANUFACTURING
Solid forged built in a single piece ( small-slow speed engines )
Semi-built design ( large medium-speed engines ). Crankpins & webs are forged or cast in one piece and shrunk on to the journals.
Fully-built ( cast in single piece – webs are shrunk on to the crankpins and journals
1.5 MATERIALS
Carbon steel
Alloy of nickel, chromium & molibdenum
Specialy alloyed grey cast steel
![Page 15: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/15.jpg)
1.4 MANUFACTURING
Solid forged built in a single piece ( small-slow speed engines )
Semi-built design ( large medium-speed engines ). Crankpins & webs are forged or cast in one piece and shrunk on to the journals.
Fully-built ( cast in single piece – webs are shrunk on to the crankpins and journals
1.5 MATERIALS
Carbon steel
Alloy of nickel, chromium & molibdenum
Specialy alloyed grey cast steel
1.6 ARRANGEMENT OF CRANKS
Multi-throw shaft to provide for the engine firing order
![Page 16: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/16.jpg)
2. MAIN BEARINGS / CRANKSHAFT BEARINGS
2.1 LOCATION
In the transverse saddles of the bedplate.
![Page 17: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/17.jpg)
![Page 18: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/18.jpg)
2. MAIN BEARINGS / CRANKSHAFT BEARINGS
2.1 LOCATION
In the transverse saddles of the bedplate.
2.2 PURPOSE
To provide support for the crankshaft
![Page 19: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/19.jpg)
2. MAIN BEARINGS / CRANKSHAFT BEARINGS
2.1 LOCATION
In the transverse saddles of the bedplate.
2.2 PURPOSE
To provide support for the crankshaft
2.3 MATERIAL ( multilayer bearings )
Used for crankshaft bearings and connecting rod big end bearings ( 4 stroke engines )
![Page 20: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/20.jpg)
![Page 21: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/21.jpg)
![Page 22: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/22.jpg)
![Page 23: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/23.jpg)
![Page 24: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/24.jpg)
2. MAIN BEARINGS / CRANKSHAFT BEARINGS
2.1 LOCATION
In the transverse saddles of the bedplate.
2.2 PURPOSE
To provide support for the crankshaft
2.3 MATERIAL ( multilayer bearings )
Used for crankshaft bearings and connecting rod big end bearings ( 4 stroke engines )
Steel support shell ( basic element );
![Page 25: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/25.jpg)
![Page 26: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/26.jpg)
2. MAIN BEARINGS / CRANKSHAFT BEARINGS
2.1 LOCATION
In the transverse saddles of the bedplate.
2.2 PURPOSE
To provide support for the crankshaft
2.3 MATERIAL ( multilayer bearings )
Used for crankshaft bearings and connecting rod big end bearings ( 4 stroke engines )
Steel support shell ( basic element );
Bearing metal ( white metal, copper-lead or aluminium-tin alloy, leaded bronze );
![Page 27: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/27.jpg)
2. MAIN BEARINGS / CRANKSHAFT BEARINGS
2.1 LOCATION
In the transverse saddles of the bedplate.
2.2 PURPOSE
To provide support for the crankshaft
2.3 MATERIAL ( multilayer bearings )
Used for crankshaft bearings and connecting rod big end bearings ( 4 stroke engines )
Steel support shell ( basic element );
Bearing metal ( white metal, copper-lead or aluminium-tin alloy, leaded bronze );
Nickel barrier ( separating the two layers );
![Page 28: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/28.jpg)
2. MAIN BEARINGS / CRANKSHAFT BEARINGS
2.1 LOCATION
In the transverse saddles of the bedplate.
2.2 PURPOSE
To provide support for the crankshaft
2.3 MATERIAL ( multilayer bearings )
Used for crankshaft bearings and connecting rod big end bearings ( 4 stroke engines )
Steel support shell ( basic element );
Bearing metal ( white metal, copper-lead or aluminium-tin alloy, leaded bronze );
Nickel barrier ( separating the two layers );
Galvanized layer ( good running-in and dry running properties )
![Page 29: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/29.jpg)
2. MAIN BEARINGS / CRANKSHAFT BEARINGS
2.1 LOCATION
In the transverse saddles of the bedplate.
2.2 PURPOSE
To provide support for the crankshaft
2.3 MATERIAL ( multilayer bearings )
Used for crankshaft bearings and connecting rod big end bearings ( 4 stroke engines )
Steel support shell ( basic element );
Bearing metal ( white metal, copper-lead or aluminium-tin alloy, leaded bronze );
Nickel barrier ( separating the two layers );
Galvanized layer ( good running-in and dry running properties )
Anti-corrosion layer ( lead or indium )
![Page 30: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/30.jpg)
![Page 31: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/31.jpg)
![Page 32: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/32.jpg)
2.4 PARTS
Upper & lower shells (fitted in bedplate seating / saddle )
![Page 33: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/33.jpg)
![Page 34: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/34.jpg)
![Page 35: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/35.jpg)
![Page 36: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/36.jpg)
![Page 37: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/37.jpg)
![Page 38: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/38.jpg)
2.4 PARTS
Upper & lower shells (fitted in bedplate seating / saddle )
Thrust bolts
Covers
Shims ( for adjusting vertical bearing play )
![Page 39: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/39.jpg)
2.4 PARTS
Upper & lower shells (fitted in bedplate seating / saddle )
Thrust bolts
Covers
Shims ( for adjusting vertical bearing play )
2.5 LUBRICATION
Pressure lubricated ( low pressure )
![Page 40: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/40.jpg)
2.4 PARTS
Upper & lower shells (fitted in bedplate seating / saddle )
Thrust bolts
Covers
Shims ( for adjusting vertical bearing play )
2.5 LUBRICATION
Pressure lubricated ( low pressure )
2.6 CLEARANCE
2.6.1 Measurement
lead wire
wear gauge / bridge gauge
feeler gauge
“ kjaer “ feeler
![Page 41: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/41.jpg)
2.6.2 Adjustment
This can be taken up by reducing the thickness of shims between the bearing butts and the housing.
![Page 42: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/42.jpg)
2.6.2 Adjustment
This can be taken up by reducing the thickness of shims between the bearing butts and the housing.
2.7 BEARING DAMAGES
2.7.1 Indications
![Page 43: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/43.jpg)
2.6.2 Adjustment
This can be taken up by reducing the thickness of shims between the bearing butts and the housing.
2.7 BEARING DAMAGES
2.7.1 Indications
increased temperature
slight oil pressure drop ( sometimes followed by noise )
![Page 44: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/44.jpg)
2.6.2 Adjustment
This can be taken up by reducing the thickness of shims between the bearing butts and the housing.
2.7 BEARING DAMAGES
2.7.1 Indications
increased temperature
slight oil pressure drop ( sometimes followed by noise )
2.7.2 Kinds
Squeezing of the overlay / white metal ( problems with oil film formation );
Fatigue cracking ( due to poor quality, shaft misaligment or local overload );
Dislodgement of overlay or white metal ( due to cracking );
![Page 45: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/45.jpg)
Scoring ( striation due to presence of hard particles );
Wiping ( misshaped overlay or white metal due to high temperature )
![Page 46: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/46.jpg)
![Page 47: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/47.jpg)
3. CRANKSHAFT ALIGNMENT
Crankshafts are aligned to determine load reactions on each bearing. This is done by laser tehnicques and computer calculations.
![Page 48: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/48.jpg)
3. CRANKSHAFT ALIGNMENT
Crankshafts are aligned to determine load reactions on each bearing. This is done by laser tehnicques and computer calculations.
3.1 CHECKS
![Page 49: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/49.jpg)
3. CRANKSHAFT ALIGNMENT
Crankshafts are aligned to determine load reactions on each bearing. This is done by laser tehnicques and computer calculations.
3.1 CHECKS
3.1.1 Frequency
Once a year
After replacing the main bearing
If the ship has grounded
![Page 50: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/50.jpg)
3. CRANKSHAFT ALIGNMENT
Crankshafts are aligned to determine load reactions on each bearing. This is done by laser tehnicques and computer calculations.
3.1 CHECKS
3.1.1 Frequency
Once a year
After replacing the main bearing
If the ship has grounded
3.1.2 Techniques
The deflections are measured through one revolution of the crankshaft by inserting a dial gauge / dial indicator gauge betwee the webs.
![Page 51: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/51.jpg)
![Page 52: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/52.jpg)
![Page 53: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/53.jpg)
3. CRANKSHAFT ALIGNMENT
Crankshafts are aligned to determine load reactions on each bearing. This is done by laser tehnicques and computer calculations.
3.1 CHECKS
3.1.1 Frequency
Once a year
After replacing the main bearing
If the ship has grounded
3.1.2 Techniques
The deflections are measured through one revolution of the crankshaft by inserting a dial gauge / dial indicator gauge betwee the webs.
Measurements are taken at TDC, BDC and two horizontal web positions.
![Page 54: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/54.jpg)
![Page 55: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/55.jpg)
![Page 56: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/56.jpg)
3.1.3 Misalignment
Wear of main bearings;
Distortion of engine bedplate transverse members;
Damage to supporting ship’s structure.
![Page 57: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/57.jpg)
3.1.3 Misalignment
Wear of main bearings;
Distortion of engine bedplate transverse members;
Damage to supporting ship’s structure.
3.1.4 Consequences
Hogging is closing of the crank throw at TDC.
![Page 58: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/58.jpg)
![Page 59: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/59.jpg)
3.1.3 Misalignment
Wear of main bearings;
Distortion of engine bedplate transverse members;
Damage to supporting ship’s structure.
3.1.4 Consequences
Hogging is closing of the crank throw at TDC.
Sagging is opening of the crank throw at TDC.
![Page 60: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/60.jpg)
![Page 61: CRANKSHAFT,MAIN BEARINGS & SHAFT ALIGNMENT LESSON TWO.](https://reader036.fdocuments.in/reader036/viewer/2022081501/56649ee75503460f94bf77c7/html5/thumbnails/61.jpg)
3.1.3 Misalignment
Wear of main bearings;
Distortion of engine bedplate transverse members;
Damage to supporting ship’s structure.
3.1.4 Consequences
Hogging is closing of the crank throw at TDC.
Sagging is opening of the crank throw at TDC.
3.1.5 Reports
Main engine crankshaft deflection report;
Main / auxiliary engine crankshaft deflection record;
Crankshaft and engine bearing data sheet.