Part B Cylindrical Roller Bearing Cage Design

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Part B Part B Cylindrical Roller Bearing Cylindrical Roller Bearing

Cage DesignCage Design

Cylindrical Roller Bearing Product Overview

5/7/2007 CRB Product Overview 2

Cage Design TVP = glass fiber reinforced

nylon M = one piece, machined

bronze finger or fully milled S = one piece

stamped steel (5200 series & HJIR)

Pin type

S

Pin type

M

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PrecisionPrecision



ISO Class

ABMA Class Usual Symbol

Normal RBEC 1 No Symbol (PO)

6 RBEC 3 P6

5 RBEC 5 P5

4 RBEC 7 P4

2 RBEC 9 P2

Typical Precision Classes (Tolerance)

ISO 492 Section for metric roller bearings in increasing precision

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Application ConsiderationsApplication Considerations



Application Considerations

LubricationHeat generationSpeed/accelerationMisalignment



Lubrication Bearing features

– Lubrication grooves and holes in OD

– Face scallops / lube from bore (stationary inner / rotating outer)• Used in multi-row CRB’s

– Spiral bore groove• Improved disassembly on

roll necks



Torque & Heat Generation

Sources of bearing torque– Elastic deformation (roller-raceway contact)– Cage contact– Flange contact– Lubricant viscous forces



Heat Generation

By design, generate less heat due to minimal friction

– Bearing operating temperature must not exceed 250°F (121°C)

Heat will dissipate by oil flow and conduction/convection/radiation through housing material



Speed/Acceleration Considerations

High speeds and acceleration– Concern for large bore and eccentric

applications

Lower speeds with light loads– Skid smearing can occur due to lack of roller

traction– Min load = 2% of C1



Misalignment

Roller/race profiles– Standard roller/race profiling designed to

withstand 0.0005 in/in of misalignment (low to moderate loads)

– More complex profiles (MRD) can be used to help reduce edge stresses that develop beyond the defined drops



Misalignment

Flange modifications– Flanges can be heightened, tapered, or

include special profiles

Lubrication improvements– Increased oil flow rates to insure contact

points generate adequate lube film thickness

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Part NumberingPart Numbering



Cylindrical Roller Bearing (CRB) Part Numbering - Metric

PREFIXDIMENSION

SERIESCYLINDRICAL TYPE BEARING

BORE SIZE SUFFIX

N, NU, NF, NJ, NP, NUP, NJF, NN, NNU, NUP,

4NNU, HJ

(0)2, (0)3, (0)4, 10, 19, 22, 23, 29, 30, 49, 51, 57, 59

d = __ * 5 (mm) For d < 500mm

d = XXX (mm) For d >= 500mm

/XXX Designation

Cage Design

E.TVP, M, S



Cylindrical Roller Bearing (CRB) Part NumberingCRB Configurations

– NJ = Cylindrical roller radial bearing (2 ribs on outer ring, 1 rib on inner ring)

– NU = Cylindrical roller radial bearing (2 ribs on outer ring, cylindrical inner ring)

– NUP = Cylindrical roller radial bearing (2 ribs on outer ring,1 fixed rib and 1 loose rib/flat washer on inner

ring)– RNU = Cylindrical roller radial bearing (2 ribs on outer ring,

without an inner ring) Series

– 10 = width series 1; diameter series 0 (dimension series 10– 2 = width series 0; diameter series 2 (dimension series 02)– 22 = width series 2; diameter series 2 (dimension series 22)– 3 = width series 0; diameter series 3 (dimension series 03)– 23 = width series 2; diameter series 3 (dimension series 23)

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Timken Cylindrical Roller Timken Cylindrical Roller Bearing Product Overview Bearing Product Overview Part BPart B

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Part B Cylindrical Roller Bearing Cage Design

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