timken rm configs and designs
TRANSCRIPT
Rolling Mill Industry Training:
RM Configurations & Designs
WORLDWIDE LEADER IN BEARINGS AND STEEL
WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Configurations & Designs
� Work Roll Bearings
� TQO
� Thrust Bearings
� Back-up Roll Bearings
� Cylindrical Roller Bearings (CRB)
� TQO
� TQIT
� Lubrication
Agenda
WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Configurations & Designs
Work Roll
WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Configurations & Designs
TQOW
Work Roll
• Two double cones/ two single/ one
double cup
• Straight bore
• Preadjusted with spacers to achieve
proper setting
• Inner cone spacer piloted & hardened
• Lubrication entries in the cup spacers
• “Direct” style mounting
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Rolling Mill Industry Training Configurations & Designs
2TDIW
Work Roll
• Two double cones/ four
single cups
• Can be supplied with or
without center spacers
• Can provides tighter
OAW tolerance (822 Code)
• All other properties
similar to TQO
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Rolling Mill Industry Training Configurations & Designs
Work Roll
Typical Mounting
• Loose fit cones/ cups for
ease of assembly
• Cups must be clamped
• Cones must be unclamped
• Drive Side - Float
• Operator Side - Fixed
(via keepers)
Thrust Ring
Split-hinged
Ring
Threaded
RingsFillet
Ring
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Rolling Mill Industry Training Configurations & Designs
Work Roll
Chock Sealing
• Two seals on inboard side
• One seal on outboard side
• Additional sealing often
used at fillet ring
• Seal orientation is criticalFillet
Ring
ContaminationBearing
Oil
Grease
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Rolling Mill Industry Training Configurations & Designs
Work Roll
Sealed Roll Neck Bearings (SRNB)
• Sealed version of standard WR
bearings
• Provides an additional seal
against contaminant ingress &
helps to retain grease
• Designed to have nearly the
same capacity as the unsealed
bearing
• 2TDI Configuration featuring
spiral bore grooves, faces slots
and no center spacers
• Solid or Relube Cup Spacers
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Rolling Mill Industry Training Configurations & Designs
SRNB Configurations
SRNB’s
SRNB – Seal Configurations
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Rolling Mill Industry Training Configurations & Designs
Work Roll
Work Roll Bending
• Used to maintain proper profile
(HSM) and flatness (CSM)
• Radial load taken by WR bearings
• Bearing enhancements may be
required
Negative P
ositive
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Rolling Mill Industry Training Configurations & Designs
Work Roll
Axial Roll Shifting
• Alternate method of flatness/ profile
control
• Induces thrust on work rolls
• Requires an external thrust bearing
WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Configurations & Designs
Work Roll
• External thrust bearing
• Takes thrust in both directions
• Inner race keyed to roll neck
• Additional radial clearance
added over cups
• Spring loaded cups
(can be integrated into bearing)
TDIK
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Rolling Mill Industry Training Configurations & Designs
Work Roll
TTDWK
• Required for high thrust loads
(ex. Structural & Beam mills)
• Takes thrust in each direction
• Spring loaded outer races
• Alternate Double Directional
V-Flat Assembly
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Rolling Mill Industry Training Configurations & Designs
Back-up Roll
WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Configurations & Designs
TQOW TQITS
Back-up Roll
CRB
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Rolling Mill Industry Training Configurations & Designs
Back-up Roll
Cold Rolling Mills • Thinner gauge product
(sheet and foil gauges)
• Typically rolled at higher
speeds
• Final product – requires
good flatness/ gauge
control
• Requires improved
bearing/ mill precision
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Rolling Mill Industry Training Configurations & Designs
4-row CRB - BUR Bearings
Back-up Roll
RY Type RX Type
- Two outer races with triple flanges
- Machined bronze cages
- Bore Range: 6.3” – 13.8” (160 – 350 mm)
- OD Range: 9.0” – 19.6” (230 – 500 mm)
- Two single flange outer races
- Pin type normally used
- Bore Range: 12” – 47” (300 – 1200 mm)
- OD Range: 16.5” – 62.5” (420 – 1590 mm)
- Also offered with tapered ID (RYK, RXK)
- Inner Rings normally customer finished after mounting
- Standard envelope tolerance: P6
- Standard running tolerance: P5
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Rolling Mill Industry Training Configurations & Designs
Long Products
• Multi-Row Cylindricals (RY Type)
• Angular Contact Ball Bearings
Bar & Tube Mills
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Rolling Mill Industry Training Configurations & Designs
Back-up Roll
4-row CRB Mounting – Operator Side
Thrust Bearing- absorbs external thrust
- stabilizes axial roll position
Most popular anti-friction BU Roll bearing…high capacity / high precision capability
Note: Drive side chock may use locator bearing, such as deep groove ball bearing
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Rolling Mill Industry Training Configurations & Designs
CRB - BUR Bearing Installation
• Outer race and roller assemblies are
loaded into the chock.
• Inner rings are mounted independent of
outer ring/ roller sets.
• Inner rings are mounted with an
interference fit on the roll neck.
• Inner rings can be supplied to finished
“OD” size or can be finish ground on the
roll neck.
Back-up Roll
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Rolling Mill Industry Training Configurations & Designs
• Minimizes eccentricity of the Roll Neck to the Roll Body
• Minimizes Inner Race Wall Section Variation Contribution to Eccentricity
• Provides Tighter Control of Bearing Radial Internal Clearance ( R.I.C. )
• Provides More Consistent Inner Race OD Size Control ( on each neck )
Benefits of Finish Grinding Inner Race OD
After Mounting on the Roll Neck
Back-up Roll
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Rolling Mill Industry Training Configurations & Designs
Installing the Chock Assembly:
• Suggested Mounting Methods:
• Chocking/ Dechocking Machine
• Piloting Sleeve
• Overhead Crane
- Care must be taken when using
a crane to align the chock prior to
installation.
• Regardless of mounting method, care
must be taken not to damage the inner
races during assembly.
Back-up Roll
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Rolling Mill Industry Training Configurations & Designs
Key Points for CRB Back-Up Roll Bearings:
• Inner Races Stay with Rolls
• Outer Assembly Stay with Chocks
• Chock Assemblies Interchangeable from
Roll to Roll
• Inner Race OD’s Can be “Skin Ground”
to Extend Useful Life in the Mill
(however RIC will be affected)
Back-up Roll
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Rolling Mill Industry Training Configurations & Designs
TQITS• Two single, one double
cone / four single cups
• Tapered bore
• Preadjusted with
spacers to achieve
proper setting
• “Indirect” style
mounting
Back-up Roll
WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Configurations & Designs
Back-up Roll
• Tight fit cones/ loose fit cups
• Cones must be clamped
• Float through cups on drive side /
Fix cups on operator side
• Fillet ring length critical to control
fit (Ring Gauge)
• Roll neck taper must match cone
bore taper (Sine Bar)
TQITS Mounting
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Rolling Mill Industry Training Configurations & Designs
Back-up Roll
• Hydraulic jack used to push
assembly up tight
• Inspection hole suggested to
check for gap between lead cone
& fillet ring
TQITS Mounting Device
Hydraulic Jack
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Rolling Mill Industry Training Configurations & Designs
Back-up Roll
TQITS Hydraulic Removal
(“Three-Hole System”)
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Rolling Mill Industry Training Configurations & Designs
Back-up Roll
• Similar to mounting used
for work rolls
• Used for mill speeds less
than 2500 fpm
• Typically used for lower
precision applications
(HSM/ Roughing Mill)
TQOW Configuration and Mounting
WORLDWIDE LEADER IN BEARINGS AND STEEL
Rolling Mill Industry Training Configurations & Designs
Back-up Roll
Oil Film BUR Bearings
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Rolling Mill Industry Training Configurations & Designs
Lubrication
Basic Methods of Lubrication
(for Rolling Mill Applications)
● Grease
● Oil Mist
● Air-Oil
● Circulating Oil
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Rolling Mill Industry Training Configurations & Designs
● Commonly used for work roll bearing position
● TQO & SRNB’s
● Applicable to BUR bearings in medium and slow speed mills (<2,500 FPM/250 RPM)
● Venting required
● Grease fill recommendation:
● 30 to 50% of Total Bearing Free Volume
● Suggested grease properties:
● Base Oil Viscosity @ 40C: 320-460 cSt
● Additives: Corrosion and Oxidation Inhibitors, EP Additives
● Petroleum Or Synthetic Oil
Lubrication
Grease
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Rolling Mill Industry Training Configurations & Designs
● Atomized at Mist Generator and conveyed to nozzles
● Ideal mist velocity: 12-15 ft/s
● Piping sized to achieve desired velocity
● Gravity feed required from mist generator
● Internal Chock Pressure ≈≈≈≈ 0.75 psi
● Venting required for proper distribution of oil
● Oil Viscosity should not exceed 460cSt
● Air and Oil are typically pre-heated
●10% of oil mist may remain airborne (Stray Mist)
Lubrication
Oil Mist
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Rolling Mill Industry Training Configurations & Designs
Lubrication
● Spray-type nozzles recommended
● No. of holes in nozzles selected based on desired flow (CFM)
● Suggested oil flow rates calculated from:
● CFM = DR/14 (Bearings - Rolling Mill Service)
● CFM = D/40 (Seals)
Oil Mist Nozzles
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Rolling Mill Industry Training Configurations & Designs
a. oil entries
b. combination vent
and oil level
c. oil drainage
d. combine vent and
oil drainage for inner
seal at bottom dead
center
Lubrication
Oil Mist - Chock Schematic
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Rolling Mill Industry Training Configurations & Designs
● Oil transported along inside wall of pipe
● Oil distribution cartridges mounted in chock
● Not limited to oil viscosity range
● Chock’s internal pressure (3-5 psi) helps prevent
contaminant ingress
● Oil Consumption is ≈≈≈≈ 25% of an oil mist system
Lubrication
Air-Oil
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Rolling Mill Industry Training Configurations & Designs
Lubrication
Air-Oil Delivery
OIL FILM
OIL/AIR
STREAM
METERED OIL SUPPLY
(cc/HOUR)
COMPRESSED
AIR
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Rolling Mill Industry Training Configurations & Designs
Lubrication
Air-Oil Schematic
Mixing
Station
Air Oil
Air-Oil