Uneak White's Personal Brand Exploration Presentation
Timken bearing fundamentals
1. Rolling Mill Industry Training:
Bearing Fundamentals
WORLDWIDE LEADER IN BEARINGS AND STEEL
2. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Bearing Types and Features
Tapered Roller Bearing Details
TRB Setting
TRB Mounting
Bearing Metallurgy & Fatigue
Mechanism
TRB Fitting Practice
Lubrication
Agenda
3. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Bearing Types
Friction bearings
Plain
Bushing
Oil sleeve
Anti-friction bearings
Ball bearings
Needle roller bearings
Spherical roller bearings
Cylindrical roller bearings
Tapered roller bearings
4. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Angular Ball
Spherical Ball
Needle
Plain
Cylindrical
Bearing Types
5. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Spherical Roller Bearings
Features
Self aligning… suitable for
misalignment
Large diameter rollers
provide high load rating
Mounted internal clearance
is determined by fit and
factory setting… C2, C0(N),
C3, C4
Easy inspection
Repairable
6. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Outer Ring
Inner Ring
Lubrication
Hole and
Groove
Cage
Roller
Flange
SRB Nomenclature
7. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Cylindrical Roller Bearings
Features
High radial load capability
Separable races - this
facilitates mounting &
dismounting when
interference fits are desired
on inner and/or outer rings
Mounted internal clearance is
determined by fit and factory
setting… C2, C0(N), C3, C4
Thrust capability with 3
flanges
Repairable
8. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
CRB Nomenclature
Outer
Ring
Inner Ring
Cage
Roller
Flange
(optional)
Flange
(optional)
Flange Designations: N, NU, NJ, NF, NP, NUP, NJF, NU+HJ, NJ+HJ
9. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Ball Bearings
Features
Most popular roller bearing
Simple design
Non-separable races
High speed capability due to
point
surface contact
Capacity based on point
contact
Controlled internal clearances,
adjustment achieved through
interference fits
Grooves in the raceways allow
ball bearings to handle axial
loads
10. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Ball Bearing Nomenclature
Outer
Ring
Inner RingCage
Ball
11. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Needle Roller Bearings
Features
Thin cross sections - suitable
where radial space is limited
Good radial load capability
Marginal thrust load capability
Nomenclature
Same as for cylindrical
12. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Tapered Roller Bearings
Features
Line contact
True rolling motion
Combined load capability
Adjustable internal
clearance
Positive roller alignment
Increased system rigidity
Easy inspection
Repairable
13. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
TRB Components
Cup
Cone
Cage
Roller
Rib
14. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
2-Row Bearing Types
TDITDO
• 2 single
cones/ Double
cup
• Set w/ cone
spacer (cone
adjusted)
• Lube hole/
groove in cup
• “Indirect”
mounting
• Float through
outer race
• Double cone/ 2
single cups
• Set with
cup spacer (cup
adjusted)
• “Direct”
mounting
•Float through
inner race
15. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Roller Bearing Comparison
TRB TRB CRB CRB CRB SRB
CHARACTERISTIC RADIAL THRUST CAGED FULL THRUST RADIAL
DOUBLEROW SINGLEROW COMPLEMENT DOUBLEROW
SINGLEROW
Pure Radial Load Excellent Unsuitable Excellent Excellent Unsuitable Excellent
Pure Axial Load Good Excellent Unsuitable Unsuitable Good Fair
CombinedLoad Excellent Fair *Fair Poor Unsuitable Excellent
Moment Load Fair Poor Unsuitable Unsuitable Unsuitable Unsuitable
High Stiffness Excellent Excellent Good Excellent Excellent Good
QuietRunning Fair Fair Good Poor Poor Fair
LowFriction Fair Fair Good Poor Poor Fair
Misalignment Poor Poor Poor Poor Unsuitable Excellent
Locating Position (Fixed) Excellent Good *Fair Fair Fair Good
Non-Locating Position (Floating) Good Unsuitable **Excellent Fair Unsuitable Fair
* Fair with Flanges on Inner andOuter Ring / Unsuitable Without
16. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Point vs. Line Contact
Less friction and heat
Higher Speeds
Lower stress
Higher load capacity
17. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
True Rolling Motion
On apex design provides true rolling motion along race
Apex
18. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
K = 1.5 - 2.2 K = 0.6 - 1.2
Combined Radial & Thrust
K = dynamic radial load rating
dynamic thrust load rating
19. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Positive Roller Alignment
The small seating force ensures
positive roller alignment
Cup Resultant
Cone Resultant
Seating Force
Cup Resultant
Cone Resultant
20. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Setting = Axial Clearance
Endplay provides axial clearance
Preload is a compression force measured as axial overlap
21. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
TRB Setting
22. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
TRB Mounting Arrangements
Direct mount is less
sensitive to misalignment
Adjustment through cups
Prevalent for centered
loads
Indirect mount provides
more rigidity
Adjustment through cones
Prevalent for overhung
loads
23. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Single Row vs. Two Row
Single row
mounting requires
adjustment
Two row mounting is
typically non-adjustable
24. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Bearing Material & Metallurgy
Steel quality is a major
factor in bearing life
Quality is determined by
cleanness
Alloy / Chemistry affects
properties of steel
25. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Cyclic Fatigue Mechanism
Non-metallic inclusions
can limit bearing life
Spall will eventually
occur over non-metallic
inclusions
Load ratings based on
bearing life before spall
occurs
26. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Bearing Life Improvement
1
10
100
1000
Total Length of Inclusion Stringers (mm/cm3)
0.00010.0010.010.1110
Time Line
1988198619831982pre-1980
0.00010.0010.010.1110
Time Line
1988198619831982pre-1980
L15.91
Life Estimates
(million revs)
Bottom Poured
Precipitation Shrouded
Precipitation Deoxidation
Super Clean Airmelt (MAP)
Vacuum Carbon Deoxidation
Vacuum-Arc Remelted (1980)
Bottom Poured
Precipitation Shrouded
Precipitation Deoxidation
Super Clean Airmelt (MAP)
Vacuum Carbon Deoxidation
Vacuum-Arc Remelted (1980)
27. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Fitting Practice
Tight fits for rotating race
Exceptions: low speed applications,
TQO work and back-up rolls, keyed
bores
Heavy duty tight fits for heavy loads
and high speed (Limits for TH product)
Loose or split fits suggested when
adjustment is necessary and for
stationary races
28. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Purpose of Lubrication
Reduction of friction,
wear and fatigue
Corrosion prevention
Transfer of heat
Remove debris
29. WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Bearing Fundamentals
Oil Flow Through the Bearing
Direct flow
between
cage I.D.
and small
cone rib
Direction of
oil flow
High Speed
High Speed
Low Speed
Low Speed
Rolling Mill Speed
Guidelines
Max Rib Speed (FPM) Min System Lube
1,500 Grease
3,000 Oil Level
5,000 Ciculating Oil
5,500 Air/Oil or Oil Mist
6,000 Oil Jets
Special High Speed
Bearings with
Ciculating Oil
10,000
Rib Speed = ∏∏∏∏ x Cone Rib Dia. X RPM
12 in/ft
* Note: Work Roll Bearings are an exception to the rule
*