DU Sliding Material Specifications

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Technical specifications of DU sliding material

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  • DU/DUBDry Bearings

    Designers Handbook

  • IQualityAll the products described in this handbook are manufactured under DIN EN ISO 9001, ISO/TS 16949 and ISO 14001approved quality management systems.In addition GGB North America has been certified AS9100 revision B complying with the requirements of aerospaceindustrys quality management system for the manufacture of metal-backed bearings and filament wound bearings andwashers.

    AMERICA

    FRANCE

    GERMANY

    BRAZIL SLOVAKIA

    CHINA

    Technical approvals:Tested and approved by MPA Stuttgart (for DUB) for structural bearings for civil engineering applications.

  • II

    Formula Symbols and Designations

    FormulaSymbol Unit Designation

    A mm Surface Area of DU bearing

    AM mm Surface Area of mating surface in con-tact with DU bearing (slideway)

    aB - Bearing size factor

    aC - Application factor for bore burnishing or machining

    aE - High load factor

    aE1 - Specific load factor (slideways)

    aE2 - Speed, temperature and material factor (slideways)

    aE3 - Relative contact area factor (slideways)

    aL - Life correction constant

    aM - Mating surface material factor

    aT - Temperature application factor

    B mm Nominal bush width

    C 1/min Dynamic load frequency

    CD mm Installed diametral clearance

    Ci mm ID chamfer length

    Co mm OD chamfer length

    CT - Total number of dynamic load cycles

    DC mm Diameter of burnishing tool

    Dfl mm Nominal bush flange OD

    DH mm Housing Diameter

    Di mm Nominal bush and thrust washer ID

    Di,a mm Bush ID when assembled in housing

    DJ mm Shaft diameter

    DNth nvt Max. thermal neutron dose

    Do mm Nominal bush and thrust washer OD

    D Gy Max. Gamma radiation dose

    dch,1 mm Checking block diameter

    dD mm Dowel hole diameter

    dL mm Oil hole diameter

    dP mm Pitch circle diameter for dowel hole

    F N Bearing load

    Fch N Test force

    Fi N Insertion force

    f - friction

    Ha mm Depth of Housing Recess(e.g. for thrust washers)

    Hd mm Diameter of Housing Recess(for thrust washers)

    L mm Strip length

    LH h Bearing service life

    LS mm Length of stroke (slideway)

    N 1/min Rotational speed

    Nosz 1/min Oscillating movement frequency

    p N/mm Specific load

    plim N/mm Specific load limit

    psta,max N/mm Maximum static load

    pdyn,max N/mm Maximum dynamic load

    Q - Permissible number of cycles

    Ra mm Surface roughness (DIN 4768, ISO/DIN 4287/1)

    ROB Electrical resistance

    s3 mm Bush wall thickness

    sfl mm Flange thickness

    sS mm Strip thickness

    sT mm Thrust washer thickness

    T C Temperature

    Tamb C Ambient temperature

    Tmax C Maximum temperature

    Tmin C Minimum temperature

    U m/s Sliding speed

    W mm Strip width

    WU min mm Minimum usable strip width

    ZT - Total number of cycles

    1 1/106K Coefficient of linear thermal expansion parallel to surface

    2 1/106K Coefficient of linear thermal expansion normal to surface

    c N/mm Compressive Yield strength

    W/mK Thermal conductivity

    Angular displacement

    Ns/mm Dynamic Viscosity

    FormulaSymbol Unit Designation

  • III

    HistoricalThe development of a polytetrafluoroethylene (PTFE) lined composite dry bearing material was first begun by the GlacierMetal Company Ltd in 1948 and patents were subsequently granted for the material during the 1950's. Today DU is the most successful of composite bearing materials, combining the excellent dry bearing properties of PTFEwith the mechanical properties of conventional metallic bearings, and has a wider range of performance and greater num-ber of applications than probably any other bearing material.

  • 3Content

    Content

    Quality . . . . . . . . . . . . . . . . . . . . . IFormula Symbols andDesignations . . . . . . . . . . . . . . . . IIHistorical . . . . . . . . . . . . . . . . . . III

    1 Introduction . . . . . . . . . . . 51.1 Applications . . . . . . . . . . . . . . . . 51.2 Characteristics and

    Advantages . . . . . . . . . . . . . . . . 51.3 Basic Forms Available . . . . . . . 51.4 Materials . . . . . . . . . . . . . . . . . . . 6

    2 Material . . . . . . . . . . . . . . . 72.1 Structure . . . . . . . . . . . . . . . . . . . 72.2 Dry Wear Mechanism . . . . . . . . 72.3 Physical, Mechanical

    and Electrical Properties . . . . . . 92.4 Chemical Properties . . . . . . . . 10

    Electrochemical Corrosion . . . . . 102.5 Frictional Properties . . . . . . . . 10

    3 Performance . . . . . . . . . 123.1 Design Factors . . . . . . . . . . . . . 12

    Calculation . . . . . . . . . . . . . . . . . 123.2 Specific Load p . . . . . . . . . . . . 123.3 Specific Load Limit plim . . . . . . 133.4 Sliding Speed U . . . . . . . . . . . . 13

    Continuous Rotation . . . . . . . . . 13Oscillating Movement . . . . . . . . 13

    3.5 pU Factor . . . . . . . . . . . . . . . . . 143.6 Application Factors . . . . . . . . . 14

    Temperature . . . . . . . . . . . . . . . 14Mating Surface . . . . . . . . . . . . . . 15Bearing Size . . . . . . . . . . . . . . . 15Bore Burnishing . . . . . . . . . . . . . 16Type of Load . . . . . . . . . . . . . . . 16

    3.7 Calculation of Bearing Size . . 17Calculation for Bushes . . . . . . . . 17Calculation for Thrust Washers 17Calculation for Slideways . . . . . 17

    3.8 Calculation of BearingService Life . . . . . . . . . . . . . . . . 18Specific load p . . . . . . . . . . . . . . 18High load factor aE . . . . . . . . . . 18Modified pU Factor . . . . . . . . . . 18Estimation of bearing life LH . . . . 19Bore Burnishing . . . . . . . . . . . . . 19Slideways . . . . . . . . . . . . . . . . . . 19

    3.9 Worked Examples . . . . . . . . . . 20

    4 Data Sheet . . . . . . . . . . . 224.1 Data for bearing design

    calculations . . . . . . . . . . . . . . . 22

    5 Lubrication . . . . . . . . . . . 235.1 Lubricants . . . . . . . . . . . . . . . . . 235.2 Tribology . . . . . . . . . . . . . . . . . . 23

    Hydrodynamic lubrication . . . . . . 23Mixed film lubrication . . . . . . . . . 24Boundary lubrication . . . . . . . . . 24

    5.3 Characteristics ofLubricated DU bearings . . . . . . 24

    5.4 Design Guidance forLubricated Applications . . . . . 24

    5.5 Clearances forlubricated operation . . . . . . . . . 26

    5.6 Mating Surface Finish forlubricated operation . . . . . . . . . 26

    5.7 Grooving forlubricated operation . . . . . . . . . 26

    5.8 Grease Lubrication . . . . . . . . . 26

    6 Bearing Assembly . . . . . 27Dimensions and Tolerances . . . . 27

    6.1 Allowance forThermal Expansion . . . . . . . . . 27

    6.2 Tolerances forminimum clearance . . . . . . . . . 27Sizing . . . . . . . . . . . . . . . . . . . . . 28

    6.3 Counterface Design . . . . . . . . . 286.4 Installation . . . . . . . . . . . . . . . . 29

    Fitting of cylindrical bushes . . . . 29Fitting of flanged bushes . . . . . . 29Insertion Forces . . . . . . . . . . . . . 29Alignment . . . . . . . . . . . . . . . . . . 30Sealing . . . . . . . . . . . . . . . . . . . . 30

    6.5 Axial Location . . . . . . . . . . . . . . 30Fitting of Thrust Washers . . . . . . 30Slideways . . . . . . . . . . . . . . . . . . 31

    7 Modification . . . . . . . . . . 327.1 Cutting and Machining . . . . . . 32

    Drilling Oil Holes . . . . . . . . . . . . . 32Cutting Strip Material . . . . . . . . . 32

    7.2 Electroplating . . . . . . . . . . . . . . 32DU Components . . . . . . . . . . . . . 32Mating Surfaces . . . . . . . . . . . . . 32

  • 4 Content

    8 Standard Products . . . . 338.1 DU Cylindrical Bushes . . . . . . 338.2 DU Flanged Bushes . . . . . . . . 388.3 DU Flanged Washers . . . . . . . 408.4 DU Thrust Washer . . . . . . . . . 418.5 DUB Cylindrical Bushes . . . . . 428.6 DUB Flanged Bushes . . . . . . . 448.7 DU Cylindrical Bushes -

    Inch sizes . . . . . . . . . . . . . . . . . 458.8 DU Thrust Washers -

    Inch sizes . . . . . . . . . . . . . . . . . 49

    8.9 DU Strip . . . . . . . . . . . . . . . . . . 508.10 DUB Strip . . . . . . . . . . . . . . . . . 508.11 DU Strip - Inch sizes . . . . . . . . 50

    9 Test Methods . . . . . . . . . 519.1 Measurement of

    Wrapped Bushes . . . . . . . . . . . 51Test A of ISO 3547 Part 2 . . . . . 51Test B (alternatively to Test A) . 51Test C . . . . . . . . . . . . . . . . . . . . 51Measurement of Wall Thickness(alternatively to Test C) . . . . . . . 51Test D . . . . . . . . . . . . . . . . . . . . 51

  • 51Introduction

    1 IntroductionThe purpose of this handbook is to providecomprehensive technical information onthe characteristics of DU bearings. The information given permits designers toestablish the correct size of bearing requi-red and the expected life and performance. GGB Research and Development servicesare available to assist with unusual designproblems.Complete information on the range of DUstandard stock products is given togetherwith details of other DU products.

    GGB is continually refining and extendingits experimental and theoretical knowledgeand, therefore, when using this brochure itis always worth-while to contact the Com-pany should additional information berequired. As it is impossible to cover all conditions ofoperation which arise in practice, custo-mers are advised to carry out prototypetesting wherever possible.

    1.1 ApplicationsDU is suitable for rotating, oscillating, reciprocating and sliding movements.Also available are DU related materialcompositions for specific applications, for

    example when increased corrosion resi-stance of the bearing material is requireddue to atmospheric or environmental consider-

    ations food safety regulations

    1.2 Characteristics and Advantages DU requires no lubrication Provides maintenance free operation DU has a high pU capability DU exhibits low wear rate Seizure resistant Suitable for temperatures from

    -200 to +280 C High static and dynamic load capacity Good frictional properties with negli-

    gible stick-slip

    Resists solvents No water absorption and therefore

    dimensionally stable DU is electrically conductive and

    shows no electrostatic effects DU has good embedability and is tol-

    erant of dusty environments Compact and light DU bearings are prefinished and

    require no machining after assembly

    1.3 Basic Forms AvailableStandard Components available from stock. These products are manufactured to Inter-national, National or GGB standarddesigns.

    Metric and Imperial sizes Cylindrical Bushes Flanged Bushes * Thrust Washers

    Flanged Washers * Strip Material* Metric sizes only

  • 61 Introduction

    Fig. 1: Standard Components

    Non-Standard Components not available from stock. These products are manufactured tocustomers' requirements with or withoutGGB recommendations, and include forexample Modified Standard Components

    Half Bearings Flat Components Deep Drawn Parts Pressings Stampings

    Fig. 2: Non-Standard Components

    1.4 Materials

    Table 1: Characteristics of DU and DUB

    Material Backing Bearing Lining

    Operating Temperature [C] Maximum Load plim

    [N/mm2]Minimum Maximum

    DU Steel PTFE+Lead -200 +280 250

    DUB Bronze PTFE+Lead -200 +280 140

  • 72Material

    2 Material2.1 Structure

    DUDU and DUB take advantage of the out-standing dry bearing properties of Polyte-trafluoroethylene (PTFE) and combinesthem with strength, stability and good wearresistance, excellent heat conductivity andlow thermal expansion.DU consists of three bonded layers: a steelbacking strip and a porous bronze matrix,impregnated and overlaid with the PTFE/lead bearing material.

    Fig. 3: DU Microsection

    DUBDUB also consists of three layers, with abronze backing replacing the steel backingstrip. The structure is otherwise the sameas that of DU. The bronze backing provides a high corro-sion resistance, anti magnetic propertiesand a good thermal conductivity.

    Fig. 4: DUB Microsection

    2.2 Dry Wear Mechanism

    Fig. 5: Effect of wear on the DU bearing surface under dry operating conditions.

    Rad

    ial w

    ear [

    mm

    ]

    Life LH [h]

    0.01

    0.02

    0.04

    0 2000 3000 4000

    0.03

    0

    1000 5000

    0.05

    6000 7000

    Bronze beginning to smear near end of material lifeFig. 8

    Typical appearance after half material life Fig. 7

    Running-in completed low wear rate starts when bronze is exposed Fig. 6

  • 82 Material

    Running-inDuring normal operation, a DU bearingquickly beds in and the PTFE/lead overlaymaterial removed during this period, typi-cally 0.015 mm, is transferred to themating surface and forms a physically bon-ded lubricant film. The rubbing surface of the bearing oftenacquires a grey-green colour and thebronze matrix can be seen exposed overabout 10 % of the bearing surface. Any

    excess of the PTFE/lead surface layer willbe shed as fine feathery particles.

    Fig. 6: Running-in

    After 50 % of useful lifeFollowing the running-in period the wearrate reduces to a minimum and the per-centage of bronze exposed graduallyincreases.

    Fig. 7: After 50 % of useful life

    End of useful lifeAfter an extended period of operation thewear rate increases as the componentapproaches the end of its useful life as aself-lubricating bearing. At this stage atleast 70 % of the bearing surface will beexposed bronze, and approximately0.06 mm wear will have occurred.

    Fig. 8: End of useful life

    Wear of Mating SurfacesThere is no measurable wear of matingsurfaces made from recommended materi-als unless a DU bearing is operated

    beyond its useful life or becomes contami-nated with abrasive dirt.

  • 92Material

    2.3 Physical, Mechanical and Electrical Properties

    Table 2: Properties of DU and DUB

    Characteristic SymbolValue

    Unit CommentsDU DUB

    Physical Properties

    Thermal Conductivity 40 60 W/mK after running in.

    Coefficient of linear thermal expansion : measured on strip 1.9 mm thick.

    parallel to surface 1 11 18 1/106K

    normal to surface 2 30 36 1/106K

    Maximum Operating Temperature

    Tmax +280 +280 C

    Minimum Operating Temperature

    Tmin 200 200 C

    Mechanical Properties Compressive Yield Strength c 350 300 N/mm

    measured on disc 25 mm diameter x 2.44 mm thick.

    Maximum Load

    Static psta,max 250 140 N/mm

    Dynamic pdyn,max 140 140 N/mm

    Electrical Properties Surface Resistance

    ROB 1 10 1 12 depends on applied pressure and contact area

    Nuclear Radiation Resistance

    Maximum Thermal Neutron dose

    DNth 2 x 1015 2 x 1015 nvtnvt = thermal neutron flux

    Maximum gamma ray dose D 106 106 Gy = J/kg 1 Gray = 1 J/kg

  • 10

    2 Material

    2.4 Chemical PropertiesThe following table provides an indicationof the chemical resistance of DU and DUBto various chemical media. It is recommen-

    ded that the chemical resistance is confir-med by testing if possible.

    Table 3: Chemical Resistance of DU and DUB

    Electrochemical CorrosionDUB should not be used in conjunctionwith aluminium housings due to the risk of

    electrochemical corrosion in the presenceof water or moisture.

    2.5 Frictional PropertiesDU bearings show negligible 'stick-slip'and provide smooth sliding between adja-cent surfaces. The coefficient of friction ofDU depends upon: The specific load p [N/mm] The sliding speed U [m/s] The roughness of the mating running

    surface Ra [m]

    The bearing temperature T [C].A typical relationship is shown in Fig. 9,which can be used as a guide to establishthe actual friction under clean, dry conditi-ons after running in. Exact values may vary by 20 % depen-ding on operating conditions.

    Chemical % C DU DUB

    Strong Acids Hydrochloric Acid 5 20 - -Nitric Acid 5 20 - -Sulphuric Acid 5 20 - -

    Weak Acids Acetic Acid 5 20 - oFormic Acid 5 20 - o

    Bases Ammonia 10 20 o -Sodium Hydroxide 5 20 o o

    Solvents Acetone 20 + +Carbon Tetrachloride 20 + +

    Lubricants and Fuels

    Paraffin 20 + +Gasolene 20 + +Kerosene 20 + +Diesel Fuel 20 + +Mineral Oil 70 o oHFA-ISO46 High Water Fluid 70 o oHFC-Water-Glycol 70 - -HFD-Phosphate Ester 70 o oWater 20 o +Sea Water 20 - o

    + Satisfactory: Corrosion damage is unlikely to occur.

    oAcceptable: Some corrosion damage may occur but this will not be sufficient to impair either the structural integrity or the tribological performance of the material.

    -Unsatisfactory: Corrosion damage will occur and is likely to affect either the structural integrity and/or the tribo-logical performance of the material.

  • 11

    2Material

    Before running in, the friction may be up to50 % higher.With frequent starts and stops, the staticcoefficient of friction is approximately equalto, or even slightly less than the dynamiccoefficient of friction.After progressively longer periods of dwellunder load (e.g. hours or days) the static

    coefficient of friction on the first movementmay be between 1.5 and 3 times greater,particularly before running in.Friction increases at bearing temperaturesbelow 0 C. Where frictional characteristics are criticalto a design they should be established byprototype testing.

    Fig. 9: Variation of friction coefficient f with specific load p and sliding speed U at temperature T = 25 C

    Fig. 10: Variation of friction coefficient f with specific load p and temperature T at sliding speed U = 0.01 m/s

    0.30

    0.25

    0.20

    0.15

    0.10

    0.05

    00.1

    1.0

    10

    100 0.00001

    0.0001

    0.001

    0.01

    0.1

    1.0

    1.5

    2.0

    2.5

    0.25-0.30

    0.20-0.25

    0.15-0.20

    0.10-0.15

    0.05-0.10

    0.00-0.05

    Example

    Specific loadp = 2.5 N/mmSliding speedU = 0.003 m/sFriction coefficientf = 0.14

    Sliding speed U [m/s]

    Specific load p [N/mm]

    Friction coefficient f

    0.25

    0.20

    0.15

    0.10

    0.05

    00.1

    1.0

    10

    100 0

    25

    50

    75

    100

    125

    150

    200

    250

    Example

    Specific loadp = 2.5 N/mmTemperatureT= 40 CFriction coefficientf = 0.125

    Specific load p [N/mm]

    Friction coefficient f

    Temperature T [C]

    0.25-0.30

    0.20-0.25

    0.15-0.20

    0.10-0.15

    0.05-0.10

    0.00-0.05

  • 12

    3 Performance

    3 Performance3.1 Design FactorsThe main parameters when determiningthe size or calculating the service life for aDU bearing are: Specific Load Limit plim pU Factor

    Mating surface roughness Ra Mating surface material Temperature T Other environmental factors e.g. hous-

    ing design, dirt, lubrication

    CalculationTwo design procedures are provided asfollows: A bearing service life calculation based

    on the permitted bearing dimensions

    A calculation of the necessary bearingdimensions based on the required bear-ing service life

    3.2 Specific Load p For the purpose of assessing bearing per-formance the specific load p is defined asthe working load divided by the projected

    area of the bearing and is expressed inN/mm.

    Cylindrical Bush

    Thrust Washer

    Flanged Bush (Axial Loading)

    Slideway

    Permanent deformation of the DU bearinglining may occur at specific loads above140 N/mm and under these conditions DUshould only be used with slow intermittentmovements.

    The permissible maximum load on a thrustwasher is higher than that on the flange ofa flanged bush, and under conditions ofhigh axial loads a thrust washer should bespecified.

    p FDi B---------------=

    (3.2.1) [N/mm]

    [N/mm]

    p 4F Do

    2 Di2

    ( )------------------------------=

    (3.2.2)

    p F0 04, Dfl

    2 Di2

    ( )-----------------------------------------=

    (3.2.3) [N/mm]

    0.04

    p FL W--------------=

    (3.2.4) [N/mm]

  • 13

    3Performance

    3.3 Specific Load Limit plim The maximum load which can be appliedto a DU bearing can be expressed in termsof the Specific Load Limit, which dependson the type of the loading. It is highestunder steady loads. Conditions of dynamicload or oscillating movement which pro-duce fatigue stress in the bearing result ina reduction in the permissible SpecificLoad Limit.In general the specific load on a DU bea-ring should not exceed the Specific LoadLimits given in Table 4.The values of Specific Load Limit specifiedin Table 4 assume good alignment bet-ween the bearing and mating surface(Fig. 29).

    Fig. 11: Projected Area

    Maximum specific load plim

    Table 4: Maximum specific load plim

    3.4 Sliding Speed USpeeds in excess of 2.5 m/s sometimeslead to overheating, and a running in pro-cedure may be beneficial.

    This could consist of a series of short runsprogressively increasing in duration froman initial run of a few seconds.

    Calculation of Sliding Speed U [m/s]

    Continuous RotationCylindrical Bush Thrust Washer

    Oscillating MovementCylindrical Bush Thrust Washer

    BDi

    Projected Area

    A = Di x B

    Type of loading plim [N/mm2]

    steady load, rotating movement 140

    steady load, oscillating movement

    plim 140 140 115 95 85 80 60 44 30 20

    No. of movement cycles Q 1000 2000 4000 6000 8000 104 105 106 107 108

    dynamic load, rotating or oscillating movement

    plim 60 60 50 46 42 40 30 22 15 10

    No. of load cycles Q 1000 2000 4000 6000 8000 104 105 106 107 108

    U Di N 60 103------------------------=

    (3.4.1) [m/s]

    U

    Do Di+2

    ---------------- N

    60 103-----------------------------------=

    (3.4.2) [m/s]

    UDi

    60 103--------------------- 4 Nosz

    360----------------------=

    (3.4.3) [m/s]

    U

    Do Di+2

    ----------------

    60 103------------------------- 4 Nosz

    360----------------------=

    (3.4.4) [m/s]

  • 14

    3 Performance

    3.5 pU FactorThe useful operating life of a DU bearing isgoverned by the pU factor, the product ofthe specific load p [N/mm2] and the slidingspeed U [m/s].For thrust washers and flanged bush thrustfaces the rubbing velocity at the mean dia-meter is used.pU factors up to 3.6 N/mm2 x m/s can beaccommodated for short periods, whilst forcontinuous rating.

    pU factors up to 1.8 N/mm2 x m/s can beused, depending upon the operating liferequired.

    Table 5: Typical data p, U and pU

    Calculation of pU Factor [N/mm x m/s]

    3.6 Application FactorsThe following factors influence the bearingperformance of DU and must be conside-red in calculating the required dimension

    or estimating the bearing life for a particu-lar application.

    Temperature The useful life of a DU bearing dependsupon the operating temperature.Under dry running conditions frictional heatis generated at the rubbing surface of thebearing dependent on the pU condition.For a given pU factor the operating tempe-rature of the bearing depends upon thetemperature of the surrounding environ-

    ment and the heat dissipation properties ofthe housing. Intermittent operation affectsthe heat dissipation from the assembly andhence the operating temperature of thebearing.The effect of temperature on the operatinglife of DU bearings is indicated by the fac-tor aT shown in Table 6.

    Table 6: Temperature application factor aT

    DU Unit

    p 140 N/mm

    U 2.5 m/s

    pU continuous 1.8 N/mm x m/s

    pU intermittent 3.6 N/mm x m/s

    pU p U=

    (3.5.1) [N/mm x m/s]

    Mode of Operation Nature of housing

    Temperature of bearing environment Tamb [C]and Temperature application factor aT

    25 60 100 150 200 280

    Dry continuous operation Average heat dissipating qualities 1.0 0.8 0.6 0.4 0.2 0.1

    Dry continuous operation Light pressings or isolated housing with poor heat dissipating qualities 0.5 0.4 0.3 0.2 0.1 -

    Dry continuous operation Non-metallic housings with bad heat dissi-pating qualities 0.3 0.3 0.2 0.1 - -

    Dry intermittent operation (duration less than 2 min, followed by a longer dwell period)

    Average heat dissipating qualities 2.0 1.6 1.2 0.8 0.4 0.2

    Continuously immersed in water 2.0 1.5 0.6 - - -

    Alternately immersed in water & dry 0.2 0.1 - - - -

    Continuously immersed in non lubricant liquids other than water 1.5 1.2 0.9 0.6 0.3 0.1

    Continuously immersed in lubricant 3.0 2.5 2.0 1.5 - -

  • 15

    3Performance

    Mating SurfaceThe effect of the mating surface materialtype on the operating life of DU bearings isindicated by the mating surface factor aMand the life correction constant aL shown inTable 7.

    Table 7: Mating surface factor aM and life correction constant aL

    Note:The factor values given assume a matingsurface finish of 0.4 m Ra A ground surface is preferred to fine

    turned Surfaces should be cleaned of abrasive

    particles after polishing

    Cast iron surfaces should be ground to

  • 16

    3 Performance

    Fig. 13: Bearing size factor aB

    Bore BurnishingBurnishing or machining the bore of a DUbearing results in a reduction in the wearperformance. The application factor aC

    given in Table 8 is used in the design cal-culations to allow for this effect.

    Table 8: Bore burnishing or machining application factor aC

    Type of Load

    Fig. 14: Steady load, Bush stationary, Shaft rotating

    Fig. 15: Rotating load, Shaft stationary, Bush rotating

    Bea

    ring

    size

    fact

    or a

    B

    Shaft diameter DJ [mm]

    0.2

    0.3

    1.0

    1

    0.5

    0.1

    0.4

    5

    0.60.7

    0.90.8

    2.0

    6 7 8 9 10 50 100 500

    1.5

    Degree of sizingApplication factor

    aCBurnishing:Excess of burnishing tool diameter over mean bore size

    0.025 mm 0.8

    0.038 mm 0.6

    0.050 mm 0.3

    Boring: Depth of cut

    0.025 mm 0.6

    0.038 mm 0.3

    0.050 mm 0.1

    F2---

    F2---

    F F2---

    F2---

    F

  • 17

    3Performance

    3.7 Calculation of Bearing Size In designing all bearings, the shaft diame-ter is usually determined by considerationsof physical stability or stiffness and themain variable to be determined is thelength of the bush or the land width of thethrust washer.The formulae given below enable desi-gners to calculate the length or width

    necessary to satisfy both the Specific LoadLimit and the pU/Life relationship.If it is found that the total length exceedstwice the diameter of the shaft, this indica-tes that the conditions envisaged are toosevere for DU material and considerationshould be given to repositioning the bea-rings in order to reduce the load.

    Calculation for BushesBush Stationary, Shaft Rotating

    Bush Rotating, Shaft Stationary

    Calculation for Thrust Washers

    Calculation for Slideways

    Fig. 16: Slideway

    B F N LH aL+( ) 1 25 107 aT aM aB ,--------------------------------------------------------------- F

    plim Di-------------------+=

    (3.7.1) [mm]

    1.25

    B F N LH aL+( ) 2 5 107 aT aM aB ,------------------------------------------------------------ F

    plim Di-------------------+=

    (3.7.2) [mm]

    2.5

    Do DiF N LH aL+( )

    1 25, 107 aT aM aB --------------------------------------------------------------- Di

    2 1 3 F,plim--------------++= Di

    (3.7.3) [mm]

    1.251.3

    A 238F U LH aL+( ) ,

    103 aT aM ------------------------------------------------------ L LS+( )

    L------------------ F

    plim--------+=

    (3.7.4) [mm]2.38

    L

    LS

    W

    DU/DUB Strip

    Mating Surface

  • 18

    3 Performance

    3.8 Calculation of Bearing Service LifeWhere the size of a bearing is governedlargely by the space available the followingcalculation can be used to determine whe-

    ther its useful life will satisfy the require-ments. If the calculated life is inadequate,a larger bearing should be considered.

    Specific load pBushes

    Flanged Bushes

    Thrust Washers

    High load factor aE

    If aE is negative then the bearing is over-loaded. Increase the bearing diameterand/or length.

    Modified pU Factor Bushes

    Flanged Bushes

    Thrust Washers

    For oscillating movement, calculate theaverage rotational speed.

    Fig. 17: Oscillating cycle

    p FDi B---------------=

    (3.8.1) [N/mm]

    p F0 04, Dfl

    2 Di2

    ( )-----------------------------------------=

    (3.8.2) [N/mm]

    0.04

    p 4Fp Do

    2 Di2

    ( )------------------------------=

    (3.8.3) [N/mm]

    aEplim pplim--------------=

    (3.8.4) []

    plim see Table 4, Page 13

    pU 5 25 105

    , F NaE B aT aM aB --------------------------------------------------=

    (3.8.5) [N/mm x m/s]

    5.25

    pU 6 5 104

    , F NaE Dfl Di( ) aT aM aB -------------------------------------------------------------------=

    (3.8.6) [N/mm x m/s]

    6.5

    pU 3 34 105

    , F NaE Do Di( ) aT aM aB -------------------------------------------------------------------=

    (3.8.7) [N/mm x m/s]

    3.34

    N 4 Nosz360

    ----------------------=

    (3.8.8) [1/min]

    123 4

  • 19

    3Performance

    Estimation of bearing life LH Bushes (Steady load)

    Bushes (Rotating load)

    Flanged Bushes (Axial load)

    Thrust Washers

    Bore BurnishingIf the DU bush is bore burnished then thismust be allowed for in estimating the bea-

    ring life by the application factor aC(Table 8, Page 16).

    Estimated Bearing Life

    SlidewaysSpecific load factor

    If negative the bearing is overloaded andthe bearing area should be increased.

    Speed temperature and materialapplication factors

    Relative contact area factor

    Estimated bearing life

    Estimated bearing lives greater than4000 h are subject to error due to inaccu-racies in the extrapolation of test data.

    For Oscillating Movements or Dynamicload: Calculate estimated number of cyclesZT.

    ZT = LH x Nosz x 60 (for Oscillating Move-ments) (3.8.18).ZT = LH x C x 60 (for dynamic load)(3.8.19).Check that ZT is less than total number ofcycles Q for the operating specific load p(Table 4, Page 13).

    If ZT Q, LH will be limited by fatigue afterZT cycles.

    LH615pU---------- aL=

    (3.8.9) [h]

    LH1230pU------------- aL=

    (3.8.10) [h]

    LH410pU---------- aL=

    (3.8.11) [h]

    LH410pU---------- aL=

    (3.8.12) [h]

    LH LH aC=

    (3.8.13) [h]

    aE1 AF

    plim--------=

    (3.8.14) []

    aE2420 aT aM

    F U---------------------------------=

    (3.8.15) []

    aE3AAM-------=

    (3.8.16) []

    LH aE1 aE2 aE3 aL =

    (3.8.17) [h]

  • 20

    3 Performance

    3.9 Worked ExamplesCylindrical BushGiven:Load Details Steady Load Inside Diameter Di 40 mm

    Continuous Rotation Length B 30 mmShaft Steel Bearing Load F 5000 N

    Unlubricated at 25 C Rotational Speed N 50 1/min

    Calculation Constants and Application FactorsSpecific Load Limit plim 140 N/mm (Table 4, Page 13)Temperature Application Factor aT 1.0 (Table 6, Page 14)Material Application Factor aM 1.0 (Table 7, Page 15)Bearing Size Factor aB 0.85 (Fig. 13, Page 16)Life Correction Constant aL 200 (Table 7, Page 15)

    Calculation Ref ValueSpecific Load p [N/mm]

    (3.2.1), Page 12

    Sliding Speed U [m/s]

    (3.4.1), Page 13

    pU Factor (Calculate from Table 5, Page 14)

    (3.5.1), Page 14

    High Load FactoraE [-] (must be >0)

    (3.8.4), Page 18

    Modified pU Factor [N/mm x m/s]

    (3.8.5), Page 18

    LifeLH [h]

    (3.8.9), Page 19

    p FDi B-------------- 5000

    40 30------------------ 4 17,= = = 4.17

    U Di N

    60 103----------------------- 40 3 14, 50

    60 103------------------------------------- 0 105,= = =0.1053.14

    pU p U 4 17 0 105 0 438,=,,= = 4.17 0.105 0.438

    aEplim pplim--------------- 140 4 17,

    140-------------------------- 0 97,= = =0.974.17

    pU 5 25 105

    , F NaE B aT aM aB ------------------------------------------------- 0 53,= =5.25 0.53

    LH615pU---------- aL

    6150 53,-------------= 200 960== 0.53

    Cylindrical BushGiven:Load Details Dynamic Load Inside Diameter Di 30 mm

    Continuous Rotation Length B 30 mmShaft Steel Bearing Load F 25000 N

    Unlubricated at 25 C Rotational Speed N 15 1/min

    Calculation Constants and Application FactorsSpecific Load Limit plim 60 N/mm (Table 4, Page 13)Temperature Application Factor aT 1.0 (Table 6, Page 14)Material Application Factor aM 1.0 (Table 7, Page 15)Bearing Size Factor aB 1 (Fig. 13, Page 16)Life Correction Constant aL 200 (Table 7, Page 15)

    Calculation Ref ValueSpecific Load p [N/mm]

    (3.2.1), Page 12

    Sliding Speed U [m/s]

    (3.4.1), Page 13

    pU Factor (Calculate from Table 5, Page 14)

    (3.5.1), Page 14

    High Load FactoraE [-] (must be >0)

    (3.8.4), Page 18

    Modified pU Factor [N/mm x m/s]

    (3.8.5), Page 18

    LifeLH [h]

    (3.8.9), Page 19

    Calculate total load cycles

    Table 4, Page 13

    Q for 27.78 N/mm = bearing will fatigue after 105 cycles (= 28 h)

    p FDi B-------------- 25000

    30 30------------------ 27 78,= = = 27.78

    U Di N

    60 103----------------------- 30 3 14, 15

    60 103------------------------------------- 0 024,= = =3.14 0.024

    pU p U 27 87 0 024 0 669,=,,= = 0.024 0.66927.78

    aEplim pplim--------------- 60 27 87,

    60-------------------------- 0 54,= = =27.78 0.54

    pU 5 25 105

    , F NaE B aT aM aB ------------------------------------------------- 1 23,= =5.25 1.23

    LH615pU---------- aL

    6151 23,-------------= 200 350== 1.23

    ZT 300 60 60 300 106

    = =

    Cylindrical BushGiven:Load Details Steady Load

    Load RotatingInside Diameter Di 50 mm

    Continuous Rotation Length B 50 mmShaft Steel Bearing Load F 10000 N

    Unlubricated at 100 C Rotational Speed N 50 1/min

    Calculation Constants and Application FactorsSpecific Load Limit plim 60 N/mm (Table 4, Page 13)Temperature Application Factor aT 0.6 (Table 6, Page 14)Material Application Factor aM 1.0 (Table 7, Page 15)Bearing Size Factor aB 0.78 (Fig. 13, Page 16)Life Correction Constant aL 200 (Table 7, Page 15)

    Calculation Ref ValueSpecific Load p [N/mm]

    (3.2.1), Page 12

    Sliding Speed U [m/s]

    (3.4.1), Page 13

    pU Factor (Calculate from Table 5, Page 14)

    (3.5.1), Page 14

    High Load FactoraE [-] (must be >0)

    (3.8.4), Page 18

    Modified pU Factor [N/mm x m/s]

    (3.8.5), Page 18

    LifeLH [h]

    (3.8.9), Page 19

    p FDi B-------------- 10000

    50 50------------------ 4 0,= = =4.0

    U Di N

    60 103----------------------- 50 3 14, 50

    60 103------------------------------------- 0 131,= = =0.1313.14

    pU p U 4 0 0 131 0 524,=,,= = 0.5420.1314.0

    aEplim pplim--------------- 60 4 0,

    60-------------------- 0 93,= = =4.0 0.93

    pU 5 25 105

    , F NaE B aT aM aB ------------------------------------------------- 1 20,= = 1.205.25

    LH1230pU------------- aL

    12301 2,-------------= 200 825== 1.20

    Cylindrical BushGiven:Load Details Steady Load Inside Diameter Di 45 mm

    Oscillating Movements Length B 40 mmShaft Stainless Steel Bearing Load F 40000 N

    Unlubricated at 25 C Frequency C 150Continuous operation Amplitudes 20

    Calculation Constants and Application FactorsSpecific Load Limit plim 140 N/mm (Table 4, Page 13)Temperature Application Factor aT 1.0 (Table 6, Page 14)Material Application Factor aM 2.0 (Table 7, Page 15)Bearing Size Factor aB 0.81 (Fig. 13, Page 16)Life Correction Constant aL 200 (Table 7, Page 15)

    Calculation Ref ValueSpecific Load p [N/mm]

    (3.2.1), Page 12

    Sliding Speed U [m/s]

    (3.4.1), Page 13

    Average speedN [1/min]

    (3.8.8), Page 18

    pU Factor (Calculate from Table 5, Page 14)

    (3.5.1), Page 14

    High Load FactoraE [-] (must be >0)

    (3.8.4), Page 18

    Modified pU Factor[N/mm x m/s]

    (3.8.5), Page 18

    LifeLH [h]

    (3.8.9), Page 19

    Calculate total load cycles

    Table 4, Page 13

    Q for 22.22 N/mm = 108 bearing o.k.!

    p FDi B-------------- 40000

    45 40------------------ 22 22,= = = 22.22

    U 45 3 14, 33 33, 60 103

    ----------------------------------------------- 0 078,= =3.14 33.33 0.078

    N 4 Nosz360

    ---------------------- 4 20 150 360

    ------------------------------ 33 33,= = = 33.33

    pU p U 22 22 0 078 1 733,=,,= =22.22 0.078 1.733

    aEplim pplim--------------- 140 22 22,

    140------------------------------ 0 84,= = =22.22 0.84

    pU 5 25 105

    , F NaE B aT aM aB ------------------------------------------------- 1 29,= =5.25 1.29

    LH615pU---------- aL

    6151 29,-------------= 200 277==1.29

    ZT 277 150 60 2 5, 106

    = = 2.5

  • 21

    3Performance

    Thrust WasherGiven:Load Details Axial Load, Outside Diameter Do 62 mm

    Continuous Rotation Inside Diameter Di 38 mmShaft Steel Bearing Load F 6500 N

    Unlubricated at 25 C Rotational Speed N 60 1/min

    Calculation Constants and Application FactorsSpecific Load Limit plim 140 N/mm (Table 4, Page 13)Temperature Application Factor aT 1.0 (Table 6, Page 14)Material Application Factor aM 1.0 (Table 7, Page 15)Bearing Size Factor aB 0.85 (Fig. 13, Page 16)Life Correction Constant aL 200 (Table 7, Page 15)

    Calculation Ref ValueSpecific Loadp [N/mm]

    (3.8.3), Page 18

    Sliding Speed U [m/s]

    (3.4.2), Page 13

    pU Factor (Calculate from Table 5, Page 14)

    (3.5.1), Page 14

    High Load Factor aE [-]

    (3.8.4), Page 18

    Modified pU Factor [N/mm x m/s]

    (3.8.7), Page 18

    Life LH [h]

    (3.8.12), Page 19

    p 4 65003 14, 622 382( )-------------------------------------------- 3 45,= =3.14

    3.45

    U62 38+( )

    2--------------------- 3 14, 60

    60 1000---------------------------------------------------- 0 157,= =

    3.140.157

    pU p U 3 45 0 157 0 541,=,,= = 3.45 0.157 0.541

    aE140 3 45,

    140-------------------------- 0 98,= =3.45 0.98

    pU 3 34, 105

    6500 600 87, 62 38( ) 1 1 0 85, ---------------------------------------------------------------------------- 0 65,= =

    3.340.87 0.85 0.650.87

    LH410

    0 65,------------- 200 431== 0.65

    Flanged BushGiven:Load Details Axial Load Flange outside Diameter

    Dfl23 mm

    Continuous Rotation Inside Diameter Di 15 mmShaft Steel Bearing Load F 250 N

    Unlubricated at 25 C Rotational Speed N 25 1/min

    Calculation Constants and Application FactorsSpecific Load Limit plim 140 N/mm (Table 4, Page 13)Temperature Application Factor aT 1.0 (Table 6, Page 14)Material Application Factor aM 1.0 (Table 7, Page 15)Bearing Size Factor aB 1.0 (Fig. 13, Page 16)Life Correction Constant aL 200 (Table 7, Page 15)

    Calculation Ref ValueSpecific Load p [N/mm]

    (3.2.2), Page 12

    Sliding Speed U [m/s]

    (3.4.2), Page 13

    pU Factor (Calculate from Table 5, Page 14)

    (3.5.1), Page 14

    High Load Factor aE [-]

    (3.8.4), Page 18

    Modified pU Factor [N/mm x m/s]

    (3.8.6), Page 18

    Life LH [h]

    (3.8.11), Page 19

    p 2500 04, 232 152( )-------------------------------------------- 20 55,= =0.04

    20.55

    U23 15+( )

    2--------------------- 3 14, 25

    60 1000---------------------------------------------------- 0 025,= =

    3.140.025

    pU p U 20 55 0 025 0 513,=,,= = 20.55 0.025 0.513

    aE140 20 55,

    140------------------------------ 0 85,= =20.55 0.85

    pU 6 5, 105 250 50

    0 85, 23 15( ) 1 1 1 ----------------------------------------------------------------- 0 59,= =6.5

    0.850.59

    LH410

    0 59,------------- 200 495== 0.59

  • 22

    4 Data Sheet

    4 Data Sheet4.1 Data for bearing design calculations

    Quantity

    Dimensions in mm

    Inside Diameter Di

    Length BOutside Diameter Do

    Flange Diameter DflFlange Thickness sflLength of slideplate LWidth of slideplate WThickness of slideplate sS

    Radial load F [N]or specific load p [N/mm2]

    Axial load F [N]or specific load p [N/mm2]

    Oscillating frequency Nosz [1/min]

    Rotational speed N [1/min]Speed U [m/s]Length of Stroke LS [mm]Frequency of Stroke [1/min]Oscillating cycle []

    Continuous operation

    Load

    Service hours per day

    Days per yearOperating timeIntermittent operation

    Movement

    Shaft DJBearing Housing DH

    Fits and Tolerances

    Ambient temperature Tamb []

    Operating Environment

    Non metal housing with poor heat transfer properties

    Light pressing or insulated housing which poor heat transfer properties

    Housing with good heat transferproperties

    Material

    Mating surface

    Surface finish Ra [m]Hardness HB/HRC

    Process FluidLubricant

    Alternate operation in water and dry

    Dry

    Lubrication

    Process fluid lubrication

    Continuous lubrication

    Initial lubrication only

    Hydrodynamic conditions

    Dynamic viscosity

    Required service life LH [h]

    Service life

    Rotational movement Steady load Rotating load Oscillating movement

    Cylindrical Bush Flanged Bush Thrust Washer Slideplate

    Existing Design New Design

    Special(Sketch)

    Linear movement

    B

    Di (

    Di,a

    )

    Do

    Di (D

    i,a)

    Dfl

    DiDo Do

    Ws S

    Bsfl sT

    L

    Customer DataCompany: City:Street: Post Code:

    Project:Name:Tel.:

    Date:Signature:Fax:

    Application:

  • 23

    5Lubrication

    5 LubricationAlthough DU was developed as a dry selflubricating bearing material, DU also provi-des excellent performance in lubricatedapplications.

    The following sections describe the basicsof lubrication and provide guidance on theapplication of DU in such environments.

    5.1 LubricantsDU can be used with most fluids including water lubricating oils engine oil turbine oil hydraulic fluid solvent refrigerantsIn general, the fluid will be acceptable if itdoes not chemically attack the PTFE/leadoverlay or the porous bronze interlayer.Where there is doubt about the suitabilityof a fluid, a simple test is to submerge a

    sample of DU material in the fluid for two tothree weeks at 15-20 C above the opera-ting temperature. The following will usually indicate that thefluid is not suitable for use with DU: A significant change in the thickness of

    the DU material, A visible change in the bearing surface

    other than some discolouration or stain-ing

    A visible change in the microstructure ofthe bronze interlayer

    5.2 TribologyThere are three modes of lubricated bea-ring operation which relate to the thicknessof the developed lubricant film between thebearing and the mating surface.These three modes of operation dependupon:

    Bearing dimensions Clearance Load Speed Lubricant Viscosity Lubricant Flow

    Hydrodynamic lubricationCharacterised by: Complete separation of the shaft from

    the bearing by the lubricant film Very low friction and no wear of the bear-

    ing or shaft since there is no contact. Coefficients of friction of 0.001 to 0.01Hydrodynamic conditions occur when Fig. 18: Hydrodynamic lubrication

    p U 75------------ B

    Di-----

    (5.2.1) [N/mm]

  • 24

    5 Lubrication

    Mixed film lubricationCharacterised by: Combination of hydrodynamic and

    boundary lubrication. Part of the load is carried by localised

    areas of self pressurised lubricant andthe remainder supported by boundarylubrication.

    Friction and wear depend upon thedegree of hydrodynamic support devel-oped.

    DU provides low friction and high wearresistance to support the boundary lubri-cated element of the load.

    Fig. 19: Mixed film lubrication

    Boundary lubrication Characterised by: Rubbing of the shaft against the bearing

    with virtually no lubricant separating thetwo surfaces.

    Bearing material selection is critical toperformance

    Shaft wear is likely due to contactbetween bearing and shaft.

    The excellent self lubricating propertiesof DU material minimises wear underthese conditions.

    The coefficient of friction with DU is typi-cally 0.02 to 0.06 under boundary lubri-cation conditions.

    Fig. 20: Boundary lubrication

    5.3 Characteristics of Lubricated DU bearingsDU is particularly effective in the mostdemanding of lubricated applications

    where full hydrodynamic operation cannotbe maintained, for example:

    High load conditionsIn highly loaded applications operatingunder boundary or mixed film conditionsDU shows excellent wear resistance andlow friction.

    Start up and shut down under load With insufficient speed to generate ahydrodynamic film the bearing will oper-ate under boundary or mixed film condi-tions. DU minimises wear and requiresless start up torque than conventionalmetallic bearings.

    Sparse lubrication Many applications require the bearing tooperate with less than the ideal lubricantsupply, typically with splash or mist lubri-cation only. DU provides excellent selflubricating properties.

    Dry operation after running in waterIf a DU bearing is required to run dryafter running in water under non hydro-dynamic conditions then the wear resist-ance will be substantially reduced due toan increased amount of bedding in wear.

    5.4 Design Guidance for Lubricated ApplicationsFig. 21 shows the three lubrication regimesdiscussed above. In order to use Fig. 21,using the formula on page 12 and page 13: Calculate the specific load p, Calculate the shaft surface speed U.

    Using the viscosity temperature relati-onships presented in Table 9. Determine the lubricant viscosity in

    centipoise, of the lubricant.If the operating temperature of the fluid isunknown, a provisional temperature of25 C above ambient can be used.

  • 25

    5Lubrication

    Area 1The bearing will operate with boundarylubrication and pU factor will be the majordeterminant of bearing life. The DU bea-ring performance can be calculated using

    the method given in Section 3, althoughthe result will probably underestimate thebearing life

    Area 2The bearing will operate with mixed filmlubrication and the pU factor is no longer asignificant parameter in determining the

    bearing life. The DU bearing performancewill depend upon the nature of the fluid andthe actual service conditions.

    Area 3The bearing will operate with hydrodyna-mic lubrication. The bearing wear will bedetermined only by the cleanliness of the

    lubricant and the frequency of start up andshut down.

    Area 4These are the most demanding operatingconditions. The bearing is operated undereither high speed or high bearing load toviscosity ratio, or a combination of both. These conditions may cause:

    excessive operating temperature and/or high wear rate.The bearing performance may be impro-ved by adding one or more grooves to thebearing and a shaft surface finish

  • 26

    5 Lubrication

    5.5 Clearances for lubricated operationThe recommended shaft and housing dia-meters given for standard DU bushes willprovide sufficient clearance for applicati-ons operating with boundary lubrication.For bearings operating with mixed film orhydrodynamic lubrication it may be neces-

    sary to improve the fluid flow through thebearing by reducing the recommendedshaft diameter by approximately 0.1 %,particularly when the shaft surface speedexceeds 2.5 m/s.

    5.6 Mating Surface Finish for lubricated operation Ra 0.4 m Boundary lubrication Ra = 0.1-0.2 m Mixed film or hydrody-

    namic conditions

    Ra 0.05 m for the most demandingoperating conditions

    5.7 Grooving for lubricated operationIn demanding applications an axial oilgroove will improve the performance ofDU. Fig. 22 shows the recommended formand location of a single groove with

    respect to the applied load and the bearingsplit. GGB can manufacture special DUbearings with embossed or milled grooveson request.

    Fig. 22: Location of oil holes and grooves

    5.8 Grease LubricationDU is not generally recommended for usewith grease lubrication. In particular the fol-lowing must be avoided: Dynamic loads - which can result in ero-

    sion of the PTFE/lead bearing surface.

    Greases with EP additives or fillers suchas graphite or MoS2 which can causerapid wear of DU.

    gap

    20 -600 -45

    0.25-0.40

    10-15 % of inside diameter of bearing0-45

    Groove Detail Z

    Z

    F

  • 27

    6Bearing Assembly

    6 Bearing AssemblyDimensions and TolerancesDU bushes are prefinished in the bore, andexcept in very exceptional circumstances,must not be burnished, broached or other-wise modified. It is essential that the cor-rect running clearance is used and thatboth the diameter of the shaft and the boreof the housing are finished to the limitsgiven in the tables. Under dry running con-ditions any increase in the clearancesgiven will result in a proportional reductionin performance.If the bearing housing is unusually flexiblethe bush will not close in by the calculated

    amount and the running clearance will bemore than the optimum. In these circum-stances the housing should be boredslightly undersize or the journal diameterincreased, the correct size being determi-ned by experiment.Where free running is essential, or wherelight loads (less than 0.1 N/mm) prevailand the available torque is low, increasedclearance is required and it is recommen-ded that the shaft size quoted in the tablebe reduced by 0.025 mm.

    6.1 Allowance for Thermal ExpansionFor operation in high temperature environ-ments the clearance should be increasedby the amounts indicated by Fig. 23 to

    compensate for the inward thermal expan-sion of the bearing lining.

    Fig. 23: Increase in diametral clearanceIf the housing is non-ferrous then the boreshould be reduced by the amounts given inTable 10, in order to give an increased

    interference fit to the bush, with a similarreduction in the journal diameter additionalto that indicated by Fig. 23.

    Table 10: Allowance for high temperature

    6.2 Tolerances for minimum clearanceWhere it is required to keep the variation ofassembled clearance to a minimum, closertolerances can be specified towards theupper end of the journal tolerance and thelower end of the housing tolerance.

    If housings to H6 tolerance are used, thenthe journals should be finished to the follo-wing limits.The sizes in Table 11 give the followingnominal clearance range.

    Table 11: Shaft tolarances for use with H6 housings

    Table 12: Clearance vs bearing diameter

    Incr

    ease

    in m

    inim

    um

    diam

    etra

    l cle

    aran

    ce [m

    m]

    Environmental temperature Tamb [C]

    0.01

    0.02

    0 40 60 800

    20 100 120 140

    Housing material Reduction in housing diameter per 100 C riseReduction in shaft diameter

    per100 C rise

    Aluminium alloys 0.1 % 0.1 % + values from Fig. 23

    Copper base alloys 0.05 % 0.05 % + values from Fig. 23

    Steel and cast iron values from Fig. 23

    Zinc base alloys 0.15 % 0.15 % + values from Fig. 23

    Di DJ25 mm < 50 mm -0.021 to -0.035

    Di CD10 mm 0.005 to 0.078

    50 mm 0.005 to 0.130

  • 28

    6 Bearing Assembly

    Sizing

    Fig. 24: Burnishing toolThe burnishing or fine boring of the bore ofan assembled DU bush in order to achievea smaller clearance tolerance is only per-missible if a substantial reduction in perfor-mance is acceptable. Fig. 24 shows arecommended burnishing tool for thesizing of DU bushes.

    The coining section of the burnishing toolshould be case hardened (case depth 0.6-1.2 mm, HRC 602) and polished (RZ 1 m).Note: Ball burnishing of DU bushes is notrecommended.

    Table 13: Burnishing tool tolerances

    The values given in Table 13 indicate thedimensions of the burnishing tool requiredto give specific increases in the bearingbore diameter.Exact values must be determined by test.The reduction in bearing performance as aresult of burnishing is allowed for in thebearing life calculation by the applicationfactor aC (Table 8, Page 16).

    6.3 Counterface DesignThe suitability of mating surface materialsand recommendations of mating surfacefinish for use with DU are discussed indetail on page 15.DU is normally used in conjunction withferrous journals and thrust faces, but indamp or corrosive surroundings, particu-larly without the protection of oil or grease,stainless steel, hard chromium plated mildsteel, or hard anodised aluminium isrecommended. When plated mating sur-faces are specified the plating should pos-sess adequate strength and adhesion,particularly if the bearing is to operate withhigh fluctuating loads.The shaft or thrust collar used in con-junction with the DU bush or thrust washermust extend beyond the bearing surface inorder to avoid cutting into it. The matingsurface must also be free from grooves orflats, the end of the shaft should be given alead-in chamfer and all sharp edges orprojections which may damage the softoverlay of the DU must be removed. Fig. 25: Counterface Design

    0.5

    62

    Di

    B +1

    0B

    DC

    R 1.5

    Assembled bush

    Inside-

    Required bush

    Inside-

    Required burnishing

    tool diameter DC

    Di,a Di,a + 0.025 Di,a + 0.06

    Di,a Di,a + 0.038 Di,a + 0.08

    Di,a Di,a + 0.050 Di,a + 0.1

    incorrect correct

  • 29

    6Bearing Assembly

    6.4 Installation

    Fitting of cylindrical bushes

    Fig. 26: Fitting of cylindrical bushes

    Fitting of flanged bushes

    Fig. 27: Fitting of flanged bushes

    Insertion Forces

    Fig. 28: Maximum Insertion Force

    Do 55 mm Do >120 mm

    15 -30

    Mounting Ring

    Note:Lightly oil back of bush to assist assembly.

    for D

    H

    125

    = 0.

    8fo

    r DH

    > 1

    25 =

    2

    for D

    H

    125

    = 0.

    8fo

    r DH

    > 1

    25 =

    2Di

    Di

    DHDH

    cham

    fer m

    in =

    r m

    ax x

    45

    Z

    Z

    0.5

    x 15

    r max see pages 38/44

    Max

    imum

    inse

    rtion

    forc

    e [N

    /mm

    uni

    t len

    gth]

    Bush bore diameter Di [mm]

    200

    400

    1000

    0 30 40 50

    800

    0

    20 100

    600

    10

  • 30

    6 Bearing Assembly

    AlignmentAccurate alignment is an important consi-deration for all bearing assemblies, but isparticularly so for dry bearings becausethere is no lubricant to spread the load.

    With DU bearings misalignment over thelength of a bush (or pair of bushes), or overthe diameter of a thrust washer should notexceed 0.020 mm as illustrated in Fig. 29.

    Fig. 29: Alignment

    SealingWhile DU can tolerate the ingress of somecontaminant materials into the bearing wit-hout loss of performance, where there isthe possibility of highly abrasive material

    entering the bearing, a suitable sealingarrangement, as illustrated in Fig. 30should be provided.

    Fig. 30: Recommended sealing arrangements

    6.5 Axial LocationWhere axial location is necessary, it isadvisable to fit DU thrust washers in con-

    junction with DU bushes, even when theaxial loads are low.

    Fitting of Thrust WashersDU thrust washers should be located in arecess as shown in Fig. 31. The recessdiameter should be 0.125 mm larger thenthe washer diameter and the depth asgiven in the product tables.

    If a recess is not possible one of the follo-wing methods may be used: Two dowel pins Two screws Adhesive Soldering

  • 31

    6Bearing Assembly

    Important Note Ensure the washer ID does not touch the

    shaft after assembly Ensure that the washer is mounted with

    the steel backing to the housing Dowels pins should be recessed

    0.25 mm below the bearing surface Screws should be countersunk 0.25 mm

    below the bearing surface DU must not be heated above 320 C Contact adhesive manufacturers for

    guidance selection of suitable adhesives Protect the bearing surface to prevent

    contact with adhesive

    Fig. 31: Installation of Thrust-Washer

    Grooves for Wear Debris RemovalTests with thrust washers have demonstra-ted that for optimum dry wear performanceat specific loads in excess of 35 N/mm2,four wear debris removal grooves should

    be machined in the bearing surface asshown in Fig. 32. Grooves in bushes have not been found tobe beneficial in this respect.

    Fig. 32: Debris removal Grooves

    SlidewaysDU strip material for use as slideway bea-rings should be installed using one of thefollowing methods:

    Countersunk screws Adhesives Mechanical location as shown in Fig. 33

    Fig. 33: Mechanical location of DU slideplates

    0.1 x Di 0.4 deep

  • 32

    7 Modification

    7 Modification7.1 Cutting and MachiningThe modification of DU bearing compon-ents requires no special procedures. Ingeneral it is more satisfactory to performmachining or drilling operations from thePTFE side in order to avoid burrs. Whencutting is done from the steel side, the

    minimum cutting pressure should be usedand care taken to ensure that any steel orbronze particles protruding into the remai-ning bearing material, and all burrs, areremoved.

    Drilling Oil HolesBushes should be adequately supportedduring the drilling operation to ensure that

    no distortion is caused by the drilling pres-sure.

    Cutting Strip MaterialDU strip material may be cut to size by anyone of the following methods. Care must be taken to protect the bearingsurface from damage and to ensure thatno deformation of the strip occurs: Using side and face cutter, or slitting

    saw, with the strip held flat and securely

    on a horizontal milling machine. Cropping Guillotine

    (For widths less than 90 mm only) Water-jet cutting Laser cutting (see Health Warning)

    7.2 Electroplating

    DU ComponentsIn order to provide some protection inmildly corrosive environments the steelback and end faces of standard range DUbearings are tin flashed. If exposed to corrosive liquids further pro-tection should be provided and in very cor-rosive conditions DUB should beconsidered.DU can be electroplated with most of theconventional electroplating metals inclu-ding the following: zinc ISO 2081-2 cadmium ISO 2081-2 nickel ISO 1456-8 hard chromium ISO 1456-8

    For the harder materials if the specifiedplating thickness exceeds approximately 5m then the housing diameter should beincreased by twice the plating thickness inorder to maintain the correct assembledbearing bore size.With light deposits of materials such ascadmium, no special precautions arenecessary. Harder materials such as nickelhowever, may strike through the PTFE/lead surface layer of DU and it is advisableto use an appropriate method of maskingthe bearing surface.Where electrolytic attack is possible testsshould be conducted to ensure that all thematerials in the bearing environment aremutually compatible.

    Mating SurfacesDU can be used against some platedmaterials as indicated on page 15.

    Care should be taken to ensure that therecommended shaft sizes and surfacefinish are achieved after the plating pro-cess.

  • 33

    8Standard Products

    8 Standard Products8.1 DU Cylindrical Bushes

    All dimensions in mm

    0.3

    min

    .

    s 3D

    i(D

    i,a)

    Do

    Co

    Ci

    B

    Z

    20 8

    Detail Z

    Split

    Dimensions and Tolerances according to ISO 3547 and GSP-Specifications

    Part No.Nominal Diameter Wall thichnesss3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aAss. in H6/H7

    housing

    ClearanceCD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    0203DU2 3.5

    0.7500.730

    3.252.75

    h6

    2.0001.994

    H6

    3.5083.500

    2.0482.000

    0.0540.000

    0205DU 5.254.75

    0303DU

    3 4.5

    3.252.75

    3.0002.994

    4.5084.500

    3.0483.0000305DU

    5.254.75

    0306DU 6.255.75

    0403DU

    4 5.5

    3.252.75

    4.0003.992

    5.5085.500

    4.0484.000

    0.0560.000

    0404DU 4.253.75

    0406DU 6.255.75

    0410DU 10.259.75

    0505DU

    5 7

    1.0050.980

    5.254.75

    f7

    4.9904.978

    H7

    7.0157.000

    5.0554.990

    0.0770.000

    0508DU 8.257.75

    0510DU 10.259.75

    0604DU

    6 8

    4.253.75

    5.9905.978

    8.0158.000

    6.0555.990

    0606DU 6.255.75

    0608DU 8.257.75

    0610DU 10.259.75

    0705DU7 9

    5.254.75 6.987

    6.9729.0159.000

    7.0556.990

    0.0830.0030710DU 10.259.75

    Outside Co and Inside Ci chamfers

    a = Chamfer Co machined or rolled at the opinion of the manufacturer

    b = Ci can be a radius or a chamfer in accordance with ISO 13715

    Wall thickness s3

    Co (a) Ci (b)machined rolled

    0.75 0.5 0.3 0.5 0.3 -0.1 to -0.4 1 0.6 0.4 0.6 0.4 -0.1 to -0.5

    1.5 0.6 0.4 0.6 0.4 -0.1 to -0.7

    Wall thickness s3

    Co (a) Ci (b)machined rolled

    2 1.2 0.4 1.0 0.4 -0.1 to -0.72.5 1.8 0.6 1.2 0.4 -0.2 to -1.0

  • 34

    8 Standard Products

    0806DU

    8 10

    1.0050.980

    6.255.75

    f7

    7.9877.972

    H7

    10.01510.000

    8.0557.990

    0.0830.003

    0808DU 8.257.75

    0810DU 10.259.75

    0812DU 12.2511.75

    1006DU

    10 12

    6.255.75

    9.9879.972

    12.01812.000

    10.0589.990

    0.0860.003

    1008DU 8.257.75

    1010DU 10.259.75

    1012DU 12.2511.75

    1015DU 15.2514.75

    1020DU 20.2519.75

    1208DU

    12 14

    8.257.75

    11.98411.966

    14.01814.000

    12.05811.990

    0.0920.006

    1210DU 10.259.75

    1212DU 12.2511.75

    1215DU 15.2514.75

    1220DU 20.2519.75

    1225DU 25.2524.75

    1310DU13 15

    10.259.75 12.984

    12.96615.01815.000

    13.05812.9901320DU 20.2519.75

    1405DU

    14 16

    5.254.75

    13.98413.966

    16.01816.000

    14.05813.990

    1410DU 10.259.75

    1412DU 12.2511.75

    1415DU 15.2514.75

    1420DU 20.2519.75

    1425DU 25.2524.75

    1510DU

    15 17

    10.259.75

    14.98414.966

    17.01817.000

    15.05814.990

    1512DU 12.2511.75

    1515DU 15.2514.75

    1520DU 20.2519.75

    1525DU 25.2524.75

    1610DU

    16 18

    10.259.75

    15.98415.966

    18.01818.000

    16.05815.990

    1612DU 12.2511.75

    1615DU 15.2514.75

    1620DU 20.2519.75

    1625DU 25.2524.75

    1720DU 17 19 20.2519.7516.98416.966

    19.02119.000

    17.06116.990

    0.0950.006

    Part No.Nominal Diameter Wall thichnesss3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aAss. in H6/H7

    housing

    ClearanceCD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

  • 35

    8Standard Products

    1810DU

    18 20 1.0050.980

    10.259.75

    f7

    17.98417.966

    H7

    20.02120.000

    18.06117.990

    0.0950.006

    1815DU 15.2514.75

    1820DU 20.2519.75

    1825DU 25.2524.75

    2010DU

    20 23

    1.5051.475

    10.259.75

    19.98019.959

    23.02123.000

    20.07119.990

    0.1120.010

    2015DU 15.2514.75

    2020DU 20.2519.75

    2025DU 25.2524.75

    2030DU 30.2529.75

    2215DU

    22 25

    15.2514.75

    21.98021.959

    25.02125.000

    22.07121.990

    2220DU 20.2519.75

    2225DU 25.2524.75

    2230DU 30.2529.75

    2415DU

    24 27

    15.2514.75

    23.98023.959

    27.02127.000

    24.07123.990

    2420DU 20.2519.75

    2425DU 25.2524.75

    2430DU 30.2529.75

    2515DU

    25 28

    15.2514.75

    24.98024.959

    28.02128.000

    25.07124.990

    2520DU 20.2519.75

    2525DU 25.2524.75

    2530DU 30.2529.75

    2550DU 50.2549.75

    2815DU

    28 32

    2.0051.970

    15.2514.75

    27.98027.959

    32.02532.000

    28.08527.990

    0.1260.010

    2820DU 20.2519.75

    2825DU 25.2524.75

    2830DU 30.2529.75

    3010DU

    30 34

    10.259.75

    29.98029.959

    34.02534.000

    30.08529.990

    3015DU 15.2514.75

    3020DU 20.2519.75

    3025DU 25.2524.75

    3030DU 30.2529.75

    3040DU 40.2539.75

    3220DU

    32 36

    20.2519.75

    31.97531.950

    36.02536.000

    32.08531.990

    0.1350.0153230DU

    30.2529.75

    3240DU 40.2539.75

    Part No.Nominal Diameter Wall thichnesss3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aAss. in H6/H7

    housing

    ClearanceCD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

  • 36

    8 Standard Products

    3520DU

    35 39

    2.0051.970

    20.2519.75

    f7

    34.97534.950

    H7

    39.02539.000

    35.08534.990

    0.1350.015

    3530DU 30.2529.75

    3535DU 35.2534.75

    3540DU 40.2539.75

    3550DU 50.2549.75

    3720DU 37 41 20.2519.7536.97536.950

    41.02541.000

    37.08536.990

    4020DU

    40 44

    20.2519.75

    39.97539.950

    44.02544.000

    40.08539.990

    4030DU 30.2529.75

    4040DU 40.2539.75

    4050DU 50.2549.75

    4520DU

    45 50

    2.5052.460

    20.2519.75

    44.97544.950

    50.02550.000

    45.10544.990

    0.1550.015

    4530DU 30.2529.75

    4540DU 40.2539.75

    4545DU 45.2544.75

    4550DU 50.2549.75

    5020DU

    50 55

    20.2519.75

    49.97549.950

    55.03055.000

    50.11049.990

    0.1600.015

    5030DU 30.2529.75

    5040DU 40.2539.75

    5050DU 50.2549.75

    5060DU 60.2559.75

    5520DU

    55 60

    20.2519.75

    54.97054.940

    60.03060.000

    55.11054.990

    0.1700.020

    5525DU 25.2524.75

    5530DU 30.2529.75

    5540DU 40.2539.75

    5550DU 50.2549.75

    5555DU 55.2554.75

    5560DU 60.2559.75

    6020DU

    60 65 2.5052.460

    20.2519.75

    59.97059.940

    65.03065.000

    60.11059.990

    0.1700.020

    6030DU 30.2529.75

    6040DU 40.2539.75

    6050DU 50.2549.75

    6060DU 60.2559.75

    6070DU 70.2569.75

    Part No.Nominal Diameter Wall thichnesss3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aAss. in H6/H7

    housing

    ClearanceCD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

  • 37

    8Standard Products

    6530DU

    65 70

    2.5052.460

    30.2529.75

    f7

    64.97064.940

    H7

    70.03070.000

    65.11064.990

    0.1700.020

    6550DU 50.2549.75

    6570DU 70.2569.75

    7040DU

    70 75

    40.2539.75

    69.97069.940

    75.03075.000

    70.11069.9907050DU

    50.2549.75

    7070DU 70.2569.75

    7560DU75 80

    60.2559.75 74.970

    74.94080.03080.000

    75.11074.9907580DU 80.2579.75

    8040DU

    80 85

    2.4902.440

    40.5039.50

    h8

    80.00079.946

    85.03585.000

    80.15580.020

    0.2090.020

    8060DU 60.5059.50

    8080DU 80.5079.50

    80100DU 100.5099.50

    8530DU

    85 90

    30.5029.50

    85.00084.946

    90.03590.000

    85.15585.0208560DU

    60.5059.50

    85100DU 100.5099.50

    9060DU90 95

    60.5059.50 90.000

    89.94695.03595.000

    90.15590.02090100DU 100.5099.50

    9560DU95 100

    60.5059.50 95.000

    94.946100.035100.000

    95.15595.02095100DU 100.5099.50

    10050DU

    100 105

    50.5049.50

    100.00099.946

    105.035105.000

    100.155100.02010060DU

    60.5059.50

    100115DU 115.50114.50

    10560DU105 110

    60.5059.50 105.000

    104.946110.035110.000

    105.155105.020105115DU 115.50114.50

    11060DU110 115

    60.5059.50 110.000

    109.946115.035115.000

    110.155110.020110115DU 115.50114.50

    11550DU115 120

    50.5049.50 115.000

    114.946120.035120.000

    115.155115.02011570DU 70.5069.50

    12050DU

    120 125

    2.4652.415

    50.5049.50

    120.000119.946

    125.040125.000

    120.210120.070

    0.2640.07012060DU

    60.5059.50

    120100DU 100.5099.50

    125100DU 125 130 100.5099.50125.000124.937

    130.040130.000

    125.210125.070

    0.2730.07013060DU 130 135

    60.5059.50 130.000

    129.937135.040135.000

    130.210130.070130100DU 100.5099.50

    Part No.Nominal Diameter Wall thichnesss3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aAss. in H6/H7

    housing

    ClearanceCD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

  • 38

    8 Standard Products

    8.2 DU Flanged Bushes

    All dimensions in mm

    13560DU135 140

    2.4652.415

    60.5059.50

    h8

    135.000134.937

    H7

    140.040140.000

    135.210135.070

    0.2730.070

    13580DU 80.5079.50

    14060DU140 145

    60.5059.50 140.000

    139.937145.040145.000

    140.210140.070140100DU 100.5099.50

    15060DU

    150 155

    60.5059.50

    150.000149.937

    155.040155.000

    150.210150.07015080DU

    80.5079.50

    150100DU 100.5099.50

    16080DU160 165

    80.5079.50 160.000

    159.937165.040165.000

    160.210160.070160100DU 100.5099.50

    180100DU 180 185

    100.5099.50

    180.000179.937

    185.046185.000

    180.216180.070

    0.2790.070

    200100DU 200 205 200.000199.928205.046205.000

    200.216200.070

    0.2880.070210100DU 210 215

    210.000209.928

    215.046215.000

    210.216210.070

    220100DU 220 225 220.000219.928225.046225.000

    220.216220.070

    250100DU 250 255 250.000249.928255.052255.000

    250.222250.070

    0.2940.070

    300100DU 300 305 300.000299.919305.052305.000

    300.222300.070

    0.3030.070

    Part No.Nominal Diameter Wall thichnesss3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aAss. in H6/H7

    housing

    ClearanceCD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    D

    i(D

    i,a)

    Do

    rmax

    0.3

    min

    .

    Dfl

    Co

    Ci

    B

    20 8

    Z

    sfl

    Do - Di2

    s 3

    Detail Z

    Split

    Dimensions and Tolerances according to ISO 3547 and GSP-Specifications

    Part No.

    Nominal Diameter

    Wall thickness

    s3

    Flange thickness

    sfl

    Flange- Dfl

    WidthB

    Shaft-DJ [h6, f7]

    HousingDH [H6, H7]

    Bush- Di,aAss. in H6/H7

    housing

    Clearance CD

    Di Domaxmin.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max. min.

    BB0304DU 3 4.5 0.7500.730

    0.800.70

    7.506.50 4.25

    3.75 h6

    3.0002.994 H6

    4.5084.500

    3.0483.000

    0.0540.000

    BB0404DU 4 5.5 9.508.504.0003.992

    5.5084.500

    4.0484.000

    0.0560.000

    BB0505DU 5 7 1.0050.9801.050.80

    10.509.50

    5.254.75 f7

    4.9904.978 H7

    7.0157.000

    5.0554.990

    0.0770.000

    Outside Co and Inside Ci chamfers

    a = Chamfer Co machined or rolled at the opinion of the manufacturer

    b = Ci can be a radius or a chamfer in accordance with ISO 13715

    Wall thickness s3

    Co (a) Ci (b)machined rolled

    0.75 0.5 0.3 0.5 0.3 -0.1 to -0.4 1 0.6 0.4 0.6 0.4 -0.1 to -0.5

    1.5 0.6 0.4 0.6 0.4 -0.1 to -0.7

    Wall thickness s3

    Co (a) Ci (b)machined rolled

    2 1.2 0.4 1.0 0.4 -0.1 to -0.72.5 1.8 0.6 1.2 0.4 -0.2 to -1.0

  • 39

    8Standard Products

    BB0604DU6 8

    1.0050.980

    1.050.80

    12.5011.50

    4.253.75

    f7

    5.9905.978

    H7

    8.0158.000

    6.0555.990

    0.0770.000BB0608DU 8.257.75

    BB0806DU

    8 10 15.5014.50

    5.755.25

    7.9877.972

    10.01510.000

    8.0557.990

    0.0830.003BB0808DU

    7.757.25

    BB0810DU 9.759.25

    BB1007DU

    10 12 18.5017.50

    7.256.75

    9.9879.972

    12.01812.000

    10.0589.990

    0.0860.003

    BB1009DU 9.258.75

    BB1012DU 12.2511.75

    BB1017DU 17.2516.75

    BB1207DU

    12 14 20.5019.50

    7.256.75

    11.98411.966

    14.01814.000

    12.05811.990

    0.0920.006

    BB1209DU 9.258.75

    BB1212DU 12.2511.75

    BB1217DU 17.2516.75

    BB1412DU14 16 22.5021.50

    12.2511.75 13.984

    13.96616.01816.000

    14.05813.990BB1417DU 17.2516.75

    BB1509DU

    15 17 23.5022.50

    9.258.75

    14.98414.966

    17.01817.000

    15.05814.990BB1512DU

    12.2511.75

    BB1517DU 17.2516.75

    BB1612DU16 18 24.5023.50

    12.2511.75 15.984

    15.96618.01818.000

    16.05815.990BB1617DU 17.2516.75

    BB1812DU

    18 20 26.5025.50

    12.2511.75

    17.98417.966

    20.02120.000

    18.06117.990

    0.0950.006BB1817DU

    17.2516.75

    BB1822DU 22.2521.75

    BB2012DU

    20 23

    1.5051.475

    1.601.30

    30.5029.50

    11.7511.25

    19.98019.959

    23.02123.000

    20.07119.990

    0.1120.010

    BB2017DU 16.7516.25

    BB2022DU 21.7521.25

    BB2512DU

    25 28 35.5034.50

    11.7511.25

    24.98024.959

    28.02128.000

    25.07124.990BB2517DU

    16.7516.25

    BB2522DU 21.7521.25

    BB3016DU30 34

    2.0051.970

    2.101.80

    42.5041.50

    16.2515.75 29.980

    29.95934.02534.000

    30.08529.990

    0.1260.010BB3026DU 26.2525.75

    BB3516DU35 39 47.5046.50

    16.2515.75 34.975

    34.95039.02539.000

    35.08534.990

    0.1350.015

    BB3526DU 26.2525.75

    BB4016DU40 44 53.5052.50

    16.2515.75 39.975

    39.95044.02544.000

    40.08539.990BB4026DU 26.2525.75

    BB4516DU45 50 2.5052.460

    2.602.30

    58.5057.50

    16.2515.75 44.975

    44.95050.02550.000

    45.10544.990

    0.1550.015BB4526DU 26.2525.75

    Part No.

    Nominal Diameter

    Wall thickness

    s3

    Flange thickness

    sfl

    Flange- Dfl

    WidthB

    Shaft-DJ [h6, f7]

    HousingDH [H6, H7]

    Bush- Di,aAss. in H6/H7

    housing

    Clearance CD

    Di Domaxmin.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max. min.

  • 40

    8 Standard Products

    8.3 DU Flanged Washers

    All dimensions in mm

    Corrosion Protection: Washers will be supplied covered with a light coating of oil.Tab (Lug) Form: Washers are supplied with this feature in an unformed state (Flat). This feature may be supplied in the formedstate only when requested by the customer.

    r 1.25

    Do

    d p

    4.8 -0.6

    Di

    Dfl

    1.5 x 45

    r 1

    81

    5 0.1

    30

    2.00 +0/-0.05

    Part No.

    Inside-Di

    Outside-Do

    Flange-Dfl

    Location-dP

    max.min.

    max.min.

    max.min.

    max.min.

    BS40DU 40.740.275.074.5

    44.00043.900

    65.064.5

    BS50DU 51.551.085.084.5

    55.00054.880

    75.074.5

    BS60DU 61.561.095.094.5

    65.00064.880

    85.084.5

    BS70DU 71.571.0110.0109.5

    75.00074.880

    100.099.5

    BS80DU 81.581.0120.0119.5

    85.00084.860

    110.0109.5

    BS90DU 91.591.0130.0129.5

    95.00094.860

    120.0119.5

    BS100DU 101.5101.0140.0139.5

    105.000104.860

    130.0129.5

  • 41

    8Standard Products

    8.4 DU Thrust Washer

    All dimensions in mm

    dP

    Di

    Do

    sT

    Ha

    Do

    d p

    dD

    Hd

    [D10

    ]

    DJ

    Part No.

    Inside-Di

    Outside-Do

    Thickness sTDowel Hole Recess Depth

    Ha dD PCD- dPmin. max. max. min. max.min.

    max.min.

    max.min.

    max.min.

    WC08DU 10.00 10.25 20.00 19.75

    1.501.45

    No Hole No Hole

    1.200.95

    WC10DU 12.00 12.25 24.00 23.75 1.8751.62518.1217.88

    WC12DU 14.00 14.25 26.00 25.75

    2.3752.125

    20.1219.88

    WC14DU 16.00 16.25 30.00 29.75 22.1221.88

    WC16DU 18.00 18.25 32.00 31.75 25.1224.88

    WC18DU 20.00 20.25 36.00 35.75

    3.3753.125

    28.1227.88

    WC20DU 22.00 22.25 38.00 37.75 30.1229.88

    WC22DU 24.00 24.25 42.00 41.75 33.1232.88

    WC24DU 26.00 26.25 44.00 43.75 35.1234.88

    WC25DU 28.00 28.25 48.00 47.75

    4.3754.125

    38.1237.88

    WC30DU 32.00 32.25 54.00 53.75 43.1242.88

    WC35DU 38.00 38.25 62.00 61.75 50.1249.88

    WC40DU 42.00 42.25 66.00 65.75 54.1253.88

    WC45DU 48.00 48.25 74.00 73.75

    2.001.95

    61.1260.88

    1.701.45WC50DU 52.00 52.25 78.00 77.75

    65.1264.88

    WC60DU 62.00 62.25 90.00 89.75 76.1275.88

  • 42

    8 Standard Products

    8.5 DUB Cylindrical Bushes

    All dimensions in mm

    0.3

    min

    .

    s 3D

    i(D

    i,a)

    Do

    Co

    Ci

    B

    Z

    20 8

    Detail Z

    Split

    Dimensions and Tolerances according to ISO 3547 and GSP-Specifications

    Part No.

    Nominal Diameter

    Wall thickness s3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aass. in H6/H7

    housing

    Clearance CD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    0203DUB2 3.5

    0.7500.730

    3.252.75

    h6

    2.0001.994

    H6

    3.5083.500

    2.0482.000 0.054

    0.0000205DUB5.254.75

    0306DUB 3 4.5 6.255.753.0002.994

    4.5084.500

    3.0483.000

    0404DUB4 5.5

    4.253.75 4.000

    3.9925.5085.500

    4.0484.000

    0.0560.0000406DUB 6.255.75

    0505DUB5 7

    1.0050.980

    5.254.75

    f7

    4.9904.978

    H7

    7.0157.000

    5.0554.990

    0.0770.000

    0510DUB 10.259.75

    0606DUB

    6 8

    6.255.75

    5.9905.978

    8.0158.000

    6.0555.9900608DUB

    8.257.75

    0610DUB 10.259.75

    0808DUB

    8 10

    8.257.75

    7.9877.972

    10.01510.000

    8.0557.990

    0.0830.0030810DUB

    10.259.75

    0812DUB 12.2511.75

    1010DUB10 12

    10.259.75 9.987

    9.97212.01812.000

    10.0589.990

    0.0860.0031015DUB 15.2514.75

    1208DUB

    12 14

    8.257.75

    11.98411.966

    14.01814.000

    12.05811.990

    0.0920.006

    1210DUB 10.259.75

    1212DUB 12.2511.75

    1215DUB 15.2514.75

    Outside Co and Inside Ci chamfers

    a = Chamfer Co machined or rolled at the opinion of the manufacturer

    b = Ci can be a radius or a chamfer in accordance with ISO 13715

    Wall thickness s3

    Co (a) Ci (b)machined rolled

    0.75 0.5 0.3 0.5 0.3 -0.1 to -0.4 1 0.6 0.4 0.6 0.4 -0.1 to -0.5

    1.5 0.6 0.4 0.6 0.4 -0.1 to -0.7

    Wall thickness s3

    Co (a) Ci (b)machined rolled

    2 1.2 0.4 1.0 0.4 -0.1 to -0.72.5 1.8 0.6 1.2 0.4 -0.2 to -1.0

  • 43

    8Standard Products

    1410DUB

    14 16

    1.0050.980

    10.259.75

    f7

    13.98413.966

    H7

    16.01816.000

    14.05813.990

    0.0920.006

    1415DUB 15.2514.75

    1420DUB 20.2519.75

    1515DUB15 17

    15.2514.75 14.984

    14.96617.01817.000

    15.05814.9901525DUB 25.2524.75

    1615DUB16 18

    15.2514.75 15.984

    15.96618.01818.000

    16.05815.9901625DUB 25.2524.75

    1820DUB18 20

    20.2519.75 17.984

    17.96620.02120.000

    18.06117.990

    0.0950.0061825DUB 25.2524.75

    2015DUB

    20 23

    1.5051.475

    15.2514.75

    19.98019.959

    23.02123.000

    20.07119.990

    0.1120.010

    2020DUB 20.2519.75

    2025DUB 25.2524.75

    2030DUB 30.2529.75

    2215DUB

    22 25

    15.2514.75

    21.98021.959

    25.02125.000

    22.07121.9902220DUB

    20.2519.75

    2225DUB 25.2524.75

    2515DUB25 28

    15.2514.75 24.980

    24.95928.02128.000

    25.07124.9902525DUB 25.2524.75

    2830DUB 28 32

    2.0051.970

    30.2529.75

    27.98027.959

    32.02532.000

    28.08527.990

    0.1260.010

    3020DUB

    30 34

    20.2519.75

    29.98029.959

    34.02534.000

    30.08529.9903030DUB

    30.2529.75

    3040DUB 40.2539.75

    3520DUB35 39

    20.2519.75 34.975

    34.95039.02539.000

    35.08534.990

    0.1350.015

    3530DUB 30.2529.75

    4030DUB40 44

    30.2529.75 39.975

    39.95044.02544.000

    40.08539.9904050DUB 50.2549.75

    4530DUB45 50

    2.5052.460

    30.2529.75 44.975

    44.95050.02550.000

    45.10544.990

    0.1550.0154550DUB 50.2549.75

    5040DUB50 55

    40.2539.75 49.975

    49.95055.03055.000

    50.11049.990

    0.1600.0155060DUB 60.2559.75

    5540DUB 55 60 40.2539.7554.97054.940

    60.03060.000

    55.11054.990

    0.1700.020

    6040DUB

    60 65

    40.2539.75

    59.97059.940

    65.03065.000

    60.11059.990

    6050DUB 50.2549.75

    6060DUB 60.2559.75

    6070DUB 70.2569.75

    6570DUB 65 70 70.2569.7564.97064.940

    70.03070.000

    65.11064.990

    Part No.

    Nominal Diameter

    Wall thickness s3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aass. in H6/H7

    housing

    Clearance CD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

  • 44

    8 Standard Products

    8.6 DUB Flanged Bushes

    All dimensions in mm

    7050DUB70 75 2.505

    2.460

    50.2549.75

    f7

    69.97069.940

    H7

    75.03075.000

    70.11069.990 0.170

    0.0207070DUB70.2569.75

    7580DUB 75 80 80.2579.7574.97074.940

    80.03080.000

    75.11074.990

    8060DUB80 85

    2.4902.440

    60.5059.50

    h8

    80.00079.946

    85.03585.000

    80.15580.020

    0.2010.02080100DUB 100.5099.50

    85100DUB 85 90 100.5099.5085.00084.946

    90.03590.000

    85.15585.020

    0.2090.020

    9060DUB90 95

    60.5059.50 90.000

    89.94695.03595.000

    90.15590.02090100DUB 100.5099.50

    95100DUB 95 100 100.5099.5095.00094.946

    100.035100.000

    95.15595.020

    10060DUB100 105

    60.5059.50 100.000

    99.946105.035105.000

    100.155100.020100115DUB 115.50114.50

    105115DUB 105 110 115.50114.50105.000104.946

    110.035110.000

    105.155105.020

    110115DUB 110 115 115.50114.50110.000109.946

    115.035115.000

    115.155115.020

    Part No.

    Nominal Diameter

    Wall thickness s3

    WidthB

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,aass. in H6/H7

    housing

    Clearance CD

    Di Domax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    D

    i(D

    i,a)

    Do

    rmax

    0.3

    min

    .

    Dfl

    Co

    Ci

    B

    20 8

    Z

    sfl

    Do - Di2

    s 3

    Detail Z

    Split

    Dimensions and Tolerances according to ISO 3547 and GSP-Specifications

    Part No.

    Nominal Diameter

    Wall thickness

    s3

    Flange thickness

    sfl

    Flange- Dfl

    Width B

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,a Ass. in H6/H7 housing

    Clearance CD

    Di Domaxmin.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max. min.

    BB0304DUB 3 4.5 0.7500.730

    0.800.70

    7.506.50 4.25

    3.75 h6

    3.0002.994 H6

    4.5084.500

    3.0483.000

    0.0540.000

    BB0404DUB 4 5.5 9.508.504.0003.992

    5.5084.500

    4.0484.000

    0.0560.000

    BB0505DUB 5 7 1.0050.9801.050.80

    10.509.50

    5.254.75 f7

    4.9904.978 H7

    7.0157.000

    5.0554.990

    0.0770.000

    Outside Co and Inside Ci chamfers

    a = Chamfer Co machined or rolled at the opinion of the manufacturer

    b = Ci can be a radius or a chamfer in accordance with ISO 13715

    Wall thickness s3

    Co (a) Ci (b)machined rolled

    0.75 0.5 0.3 0.5 0.3 -0.1 to -0.4 1 0.6 0.4 0.6 0.4 -0.1 to -0.5

    1.5 0.6 0.4 0.6 0.4 -0.1 to -0.7

    Wall thickness s3

    Co (a) Ci (b)machined rolled

    2 1.2 0.4 1.0 0.4 -0.1 to -0.72.5 1.8 0.6 1.2 0.4 -0.2 to -1.0

  • 45

    8Standard Products

    BB0604DUB6 8

    1.0050.980

    1.050.80

    12.5011.50

    4.253.75

    f7

    5.9905.978

    H7

    8.0158.000

    6.0555.990

    0.0770.000BB0608DUB 8.257.75

    BB0806DUB8 10 15.5014.50

    5.755.25 7.987

    7.97210.01510.000

    8.0557.990

    0.0830.000BB0810DUB 9.759.25

    BB1007DUB10 12 18.5017.50

    7.256.75 9.987

    9.97212.01812.000

    10.0589.990

    0.0860.003BB1012DUB 12.2511.75

    BB1207DUB

    12 14 20.5019.50

    7.256.75

    11.98411.966

    14.01814.000

    12.05811.990

    0.0920.006

    BB1209DUB 9.258.75

    BB1212DUB 12.2511.75

    BB1417DUB 14 16 22.5021.5017.2516.75

    13.98413.966

    16.01816.000

    14.0513.990

    BB1512DUB15 17 23.5022.50

    12.2511.75 14.984

    14.96617.01817.000

    15.05814.990BB1517DUB 17.2516.75

    BB1612DUB16 18 24.5023.50

    12.2511.75 15.984

    15.96618.01818.000

    16.05815.990BB1617DUB 17.2516.75

    BB1812DUB18 20 26.5025.50

    12.2511.75 17.984

    17.96620.02120.000

    18.06117.990

    0.0950.006BB1822DUB 22.2521.75

    BB2012DUB20 23

    1.5051.475

    1.601.30

    30.5029.50

    11.7511.25 19.980

    19.95923.02123.000

    20.07119.990

    0.1120.010

    BB2017DUB 16.7516.25

    BB2512DUB25 28 35.5034.50

    11.7511.25 24.980

    24.95928.02128.000

    25.07124.990BB2522DUB 21.7521.25

    BB3016DUB30 34

    2.0051.970

    2.101.80

    42.5041.50

    16.2515.75 29.980

    29.95934.02534.000

    30.08529.990

    0.1260.010BB3026DUB 26.2525.75

    BB3526DUB 35 39 47.5046.5026.2525.75

    34.97534.950

    39.02539.000

    35.08534.990

    0.1350.015

    BB4026DUB 40 44 53.5052.5026.2525.75

    39.97539.950

    44.02544.000

    40.08539.990

    0.1350.015

    BB4526DUB 45 50 2.5052.4602.602.30

    58.5057.50

    26.2525.75

    44.97544.950

    50.02550.000

    45.10544.990

    0.1550.015

    Part No.

    Nominal Diameter

    Wall thickness

    s3

    Flange thickness

    sfl

    Flange- Dfl

    Width B

    Shaft-DJ [h6, f7, h8]

    HousingDH [H6, H7]

    Bush- Di,a Ass. in H6/H7 housing

    Clearance CD

    Di Domaxmin.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max. min.

  • 46

    8 Standard Products

    8.7 DU Cylindrical Bushes - Inch sizes

    All dimensions in inch

    Ci

    Co

    .012

    min

    .

    Di

    Do

    (Di,a

    )s 3

    B

    ZDetail Z

    Split

    Part No.Nominal Diameter Wall thicknesss3

    WidthB

    Shaft-DJ

    Housing-DH

    Bush- Di,aAss. in DH housing

    Clearance CD

    Di Do Bmax.min.

    max.min.

    max.min.

    max.min.

    max.min.

    max.min.

    02DU021/8 3/16

    1/8

    0.03150.0305

    0.13500.1150 0.1243

    0.12360.18780.1873

    0.12680.1243

    0.00320.000002DU03 3/16

    0.19750.1775

    025DU0255/32 7/32

    5/320.166250.14265 0.1554

    0.15470.21910.2186

    0.15810.1556

    0.00340.0002025DU04 1/4

    0.26000.2400

    03DU03

    3/16 1/4

    3/160.19750.1775

    0.18650.1858

    0.25030.2497

    0.18930.1867

    0.00350.000203DU04

    1/40.26000.2400

    03DU06 3/80.38500.3650

    04DU041/4 5/16

    1/40.26000.2400 0.2490

    0.24810.31280.3122

    0.25180.2492

    0.00370.0002

    04DU06 3/80.38500.3650

    05DU065/16 3/8

    3/80.38500.3650 0.3115

    0.31060.37530.3747

    0.31430.311705DU08 1/2

    0