3
1. Why Bearing Wear Monitoring?
1) In 2-stroke engine, approx. 20% of all damages reported to classification
societies relate to bearings.
Based on statistics from Det Norske Veritas in the period from 1990 to 1996
Slow speed engines damages
0 5 10 15 20 25
Others
Main Bearing & Journal
Crank Bearing & Pin
Fuel pump, camshaft & drives
Crosshead bearing & guides
Cylinder cover & valves
Cylinder liner
Cylinderblock, frame & bedplate
Piston
Turbo charger
Percentage of all damages
• Low speed engines damages
4
1. Why Bearing Wear Monitoring?
2) Bearing damages
70% of all bearing damages happen shortly after overhaul or open-up inspections.
It may result in repair periods counted in weeks or even months! With crankshaft related failures, which can result in notations in the class book,
influencing the market value of the vessel negatively!
5
1. Why Bearing Wear Monitoring?
Open-up inspection is main fact of bearing damage.
Bearing accident case caused by open-up inspection. Engine type : 6S70MC-C Main bearing wrongly assembled after open-up inspection. Required 3months for repair.
6
1. Why Bearing Wear Monitoring?
3) Why BWM?
BWM system to be recommended to omit regular open-up inspections of any three crank-train bearings.
All vessels having DOOSAN-MAN engines (bore 46cm and above) ordered after 1.NOV.2008, have BWM system as standard.
BWM system safely protects bearing shell before steel to steel contact occurs at bearing shell.
7
2. What is DOOSAN BWM?
1) Working principles
Measure how far down the crosshead guide shoe comes in bottom dead center (BDC) at each cylinder.
Providing data from any of the three crank train bearing.
Sensing module is installed at each cylinder for diagnosis.
BWM system shall be connected to alarm monitoring and safety system.
BDC POSITION
8
2. What is DOOSAN BWM?
2) Lay-out
SAU
Engine side
ECR
Junction Box
Converter
DC 24V
Monitoring PC
SM
#1 #2 #3 #5#4
SCU
Inductive sensor
Crosshead
Liner
9
2. What is DOOSAN BWM?
3) Main component
RTD (Resistance Temperature Detector)
Inductive proximity sensor : Displacement sensor
SCU (Signal Capture Unit) : A/D conversion of sensor signal.
Extraction of BDC value.
Communication to SAU.
SM (Sensing Module)
Installed on each cylinder for diagnosis. Calculate BDC value per engine revolution by inductive proximity sensor. Self diagnostic function using internal temperature sensor.
SM (Sensing Module)
10
2. What is DOOSAN BWM?
3) Main component
SAU (Signal Analyze Unit)
Monitoring PC
SAU (Signal Analyze Unit) Installed on each engine for analyzing of data
from SM. Communication to computer for monitoring. Signal processing.
Display each cylinder’s sensing data.
Trend function.
Monitoring PC
13
3) Tuning of gap between sensor and crosshead
3mm shim for tuning
4) Monitoring PC in ECR
5) Installation of SAU
3. How to Retrofit
14
3. How to Retrofit
Engine side
ECR
Junction Box
Converter
#1 #2 #3 #5#4
Crosshead
Liner
Monitoring PCSAU
SM
16
Contact Point
H. P. ParkDirector / Head OfficeTel: 82-51-601-0802
E-mail: [email protected]
Kenny ParkBranch Manager / Hamburg
BranchTel : 49-40-2385-7710
E-mail : [email protected] Mermiris
Sales Manager / Greece OfficeTel : 30-210-418-7010
E-mail : [email protected]
Bosung Engineering Co.,Ltd.
www.bosung.com
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