3. TYPES OF BEARINGS
B E A R IN G
P L A IN B E A R IN G R O L L IN G E L E M E N T
OR
A N T I F R IC T IO N B E A R IN G
(A R E A C O N T A C T ) (P O IN T O R L IN E C O N T A C T )
J O U R N A L B E A R IN G G U ID E B E A R IN G T H R U S T B E A R IN G / T IL T IN G P A D
(R A D IA L L O A D ) (B A C K & F O R T H ) (A X IA L L O A D )
M O T IO N
S O L ID S P L IT HALF T IL T IN G P A D G . C Y L IN D E R & G . V E R T IC A L F A N
R ID E R R IN G
17. BEARING FAILURE ANALYSIS
A SURVEY REVEALS :
• 9% FAILURE DUE TO FATIGUE.
• 27% FAILURES DUE TO IMPROPER MOUNTING &
DISMOUNTING.
• 43% FAIL DUE TO IMPROPER LUBRICATION.
• 21% FAILURES DUE TO OTHER CAUSES.
OBJECTIVE:
• 100% FAILURES DUE TO NORMAL FATIGUE.
23. WHY LUBRICATION??
• Formation of protective film to
Reduce friction
Prevent corrosion
Remove wear particles and debris
Provide efficient cooling
Reduce wear
Shock absorption
Overall life improvement
24. LUBRICATION THEORY
• Full film
• Static
• Hydrodynamic
• Elastohydrodynamic
• Application of pressure / load
• Depends upon speeds, loads, lubricant viscosity
• Boundary layer
• Layer separation not complete
• Results from insufficient lube, incorrect lube
25. GREASE Vs OIL
When greases?
Normal speed and temp conditions
Simpler / cheaper installation
Better adhesion
Protection against impurities
Less frequent application required
When Oils?
High Speed and temp
Excellent cleaning and flushing characteristics
Can be used in recirculative systems
Can serve better in excessive dirt environment
More stable than greases
30. WDA Concept
Every lubricated wear surface generates particles
There is a gradual build up of small particles in a normal system
When abnormal wear begins, there is no sharp instantaneous increase in the
concentration of small particles present in the system
Large particles, however, reach a dynamic equilibrium in a normal system
(filtration)
When abnormal wear begins, there is a dramatic increase in the
concentration of large particles
Therefore, detection, measurement and analysis of these large wear particles
can provide early and accurate information about the condition of the
machine
33. Oil analysis Vs WDA
• Lubricant Analysis
– Monitoring of the lubricant
– Condition of the lubricant
– Viscosity, TAN, TBN, Water content, Insolubles
• Wear debris Analysis
– Monitoring of wear particles
– Condition of the machine
– Quantity of wear particles in ppm
34. WDA : Advantages and disadvantages
Advantages:
Provides early warning
Identifies lubricant contamination
Identifies specific failing components
Helps monitor component deterioration
Disadvantages:
Trending is necessary
Accuracy depends on sampling point, skill
