Short Course 5
An Introduction to Babbitt Bearings as Used in Industrial Turbomachinery
- Monday, September 8, 8:30-5:00, Room 361B
- Limited Seating reserved on first-money-received basis!
- Register for this short course online
Instructors:
John K. Whalen, TCE, Houston, TX, Scan DeCamillo, Kingsbury, Inc., Philadelphia, PA, Barry Blair, Waukesha Bearings Corp., and Paul Allaire, University of Virginia, Charlottesville, VA
Introduction:
● What we ARE covering
- Common babbitted oil film bearings as typically found in critical rotating equipment in process plants
● What we are NOT covering
- Rolling element bearings
- Materials other than babbitt
- Lubricants other than turbine oils
- Magnetic bearings
Introduction to Hydrodynamic Lubrication and General Bearing Design (Paul Allaire)
● Towers experiments
● Stribeck curve
- Boundary lubrication
- Mixed film
- Full film
● Petroffs equation
● The hydrodynamic wedge
- Shear flow and pressure flow
- Reynolds equation
- Pressure profiles
● Plain journal bearing concepts
- Eccentricity ratio and attitude angle
- Shaft centerline path
- L/D ratio
- Unit loading
● Fixed geometry journal bearings
- Axial groove
- Multilobe
- Offset half
- Pressure dam
- Oil ring
- Pressure profiles and load capacity
● Fixed geometry bearing stiffness and damping
- Stiffness properties
- Damping properties
- Oil whirl/whip
Introduction to Journal Bearings (Barry Blair)
● Titling pad journal bearings
- Concepts
- L/D ratio
- Number of pads
- LOP versus LBP
- Preload
- Pivot offset
- Lubrication
- Orifices
- End seal bores
- Bearing housing pressure
● Journal bearing "rules of thumb"
- Clearances
- Minimum film thickness
- Maximum pad temperature
- Maximum peak pressure
- Typical unit loading
- Bearing "crush"
● Other journal bearing topics
- Breakaway torque
- Turning gear operation
- High pressure lift provisions
- Pad flutter
- Turbulence
- Squeeze film dampers
● Lubricant
- Viscosity
- Oil types
- Additive packages
● Babbitt
- Types
- Application
Introduction to Thrust Bearings (Scan DeCamillo)
● Terms and concepts
- Unit load
- Float
- Thrust collar design
- Hardness
- Finish
- Fit to shaft
● Types of thrust bearings
- Flat plate
- Taper land
- Tilting pad
- Equalized
● Oil flow
- Typical flow paths
- Losses
- Flooded versus nonflooded designs
● Load capacity (and ways to increase)
- Pad backing materials
- Offset pivots
● Influence of materials on performance
● Machine specifics
- Horizontal motors/generators
- Bearing insulation
- Turbines/compressors
- Vertical applications
- Gearboxes
- Etc.
● Thrust bearing "rules of thumb"
- Float
- Minimum film thickness
- Maximum pad temperature
- Maximum peak pressure
- Typical unit loading
● Other thrust bearing topics
- Pad flutter
Miscellaneous Bearing Topics (John Whalen)
● Installation
- Journal bearing
- Lift check
- Crush check
- Thrust bearing
- Rotor position
- Float
● Instrumentation
- API 670
- TCs versus RTDs
- Sealing
● Inspection
- Checking bearings
- Things to look for
- "Bump" check of TPJs
- UT/PT
● Failure analysis
- Fatigue
- Electrostatic discharge
- Varnish
- Etc.
