BEARINGS
&
LUBRICATION
PRINCIPLES OF FRICTION
TYPES OF BEARINGS
S O L ID S P L IT H A L F T IL T IN G P A D
JO U R N A L B E A R IN G(R A D IA L L O A D )
G . C Y L IN D E R &R ID E R R IN G
G U ID E B E A R ING(B A C K & F O R T H )
M O T IO N
G . V E R T IC A L F A N
T H R U S T B E A R IN G / T IL T IN G P A D(A X IA L L O A D)
(A R E A C O N T A C T )
P L A IN B E A R ING
(P O IN T O R L IN E C O N T A C T )
R O L L IN G E L E M E NTO R
A N T I F R IC T IO N B E A R IN G
B E A R IN G
BEARING ARRANGEMENT
THRUST
RADIAL
BEARING ARRANGEMENT
THRUST
RADIAL
BEARING ARRANGEMENT
ANTIFRICTION BEARINGS
• BALL BEARINGS
•RADIAL BALL BEARING
•ANGULAR CONTACT BALL BEARING
• ROLLER BEARINGS
• CYLINDRICAL ROLLER BEARING
• TAPER ROLLER BEARING
• SPHERICAL ROLLER BEARING
• NEEDLE ROLLER BEARING
BEARING NOMENCLATURE
LOAD DIRECTION
BALL BEARINGS
ROLLER BEARINGS
NEEDLE ROLLER BEARINGS
BEARING LIFE
LOAD CARRYING SURFACES
BEARING DESIGNATION
BEARING DESIGNATION
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.
FRICTION BEARINGS
TILTING PAD BEARINGSLEEVE BEARINGS
WORKING PRINCIPLE
TILTING PAD RADIAL BEARING
TILTING PAD THRUST BEARING
LUBRICATION
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
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
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
LUBE OIL PROPERTIES
Viscosity Viscosity indexFlash point Pour pointOxidation stabilityDemulsibilityLoad carrying ability (EP)DetergencyTAN / TBN
TYPES OF LUBRICANTS
• Automotive oils Engine oils Gear oils Transmission oils Other oils (preservative oils etc)
• Industrial oils Turbine oils Hydraulic oils Gear oils Refrigeration compressor oils
• Greases• Synthetic oils
LUBE OIL SELECTION
OEM recommendationViscosity & VIBearing and lubrication typeOperating temperature
LUBE OIL MONITORING
Lube oil levelOil pressureOil inlet and outlet tempLube cooler inlet & outlet tempOil filter DPBearing temp
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
WDA Methodology• Particle Size
• Composition
• Shape
• Concentration
WDA Trend Graph
• 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
Oil analysis Vs WDA
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