Timken rm configs and designs

Rolling Mill Industry Training:

RM Configurations & Designs

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



Work Roll



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



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



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



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



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



SRNB Configurations

SRNB’s

SRNB – Seal Configurations



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



Work Roll

Axial Roll Shifting

• Alternate method of flatness/ profile

control

• Induces thrust on work rolls

• Requires an external thrust bearing



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



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



Back-up Roll



TQOW TQITS

Back-up Roll

CRB



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



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



Long Products

• Multi-Row Cylindricals (RY Type)

• Angular Contact Ball Bearings

Bar & Tube Mills



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



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



• 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



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



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



TQITS• Two single, one double

cone / four single cups

• Tapered bore

• Preadjusted with

spacers to achieve

proper setting

• “Indirect” style

mounting

Back-up Roll



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



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



Back-up Roll

TQITS Hydraulic Removal

(“Three-Hole System”)



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



Back-up Roll

Oil Film BUR Bearings



Lubrication

Basic Methods of Lubrication

(for Rolling Mill Applications)

● Grease

● Oil Mist

● Air-Oil

● Circulating Oil



● 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



● 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



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



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



● 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



Lubrication

Air-Oil Delivery

OIL FILM

OIL/AIR

STREAM

METERED OIL SUPPLY

(cc/HOUR)

COMPRESSED

AIR



Lubrication

Air-Oil Schematic

Mixing

Station

Air Oil

Air-Oil

Business

Timken rm configs and designs