king buchas du
DESCRIPTION
Buchas auto lubrificantes de 2" até 300 mm. ou em polegadas.Buchas DU,DP4,DX,DB,buchas sinterizadas de bronze.TRANSCRIPT
I
QualityAll the products described in this handbook are manufactured under DIN ISO 9001/2 or QS 9000 approved qualitymanagement systems.
Technical approvals:Tested and approved by MPA Stuttgart (for DUTM-B) for structural bearings for civil engineering applications.Civil aviation authority (United Kingdom): CAA release for material, finished components and test methods.Quality control committee of the United Kingdom Ministry of Defence under the heading of: MOD DCL No.14 VGO4 AQAP4 forbearings, bushes, washers in metal and non-metal specifications.French defence authority: RAO-2/6-86-155.NATO authority: F21 07-AQAP4.
II
Formula Symbols and Designations
FormulaSymbol Unit Designation
A mm2 Surface Area of DU bearing
AM mm2 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 length
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
Dγ 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 (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/mm² Specific load
plim N/mm² Specific load limit
psta,max N/mm² Maximum static load
pdyn,max N/mm² Maximum dynamic load
Q - Permissible number of cycles
Ra mm Surface roughness (DIN 4768, ISO/DIN 4287/1)
ROB Ω 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 mm Maximum usable strip width
ZT - Total number of cycles
α1 1/106K Coefficient of linear thermal expansion parallel to surface
α2 1/106K Coefficient of linear thermal expansion normal to surface
σc N/mm² Compressive Yield strength
λ W/mK Thermal conductivity
ϕ ° Angular displacement
η Ns/mm² Dynamic Viscosity
FormulaSymbol Unit Designation
III
HistoricalThe development of a polytetrafluoroethylene (PTFE) lined composite dry bearing material was first begun by the Gla-cier Metal 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 ofPTFE with the mechanical properties of conventional metallic bearings, and has a wider range of performance andgreater number of applications than probably any other bearing material.
Content
3
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
Content
4
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 DU-B Cylindrical Bushes . . . . 428.6 DU-B Flanged Bushes . . . . . . . 448.7 DU Cylindrical Bushes -
Inch sizes . . . . . . . . . . . . . . . . . 458.8 DU Thrust Washers -
Inch sizes . . . . . . . . . . . . . . . . . 48
8.9 DU Strip . . . . . . . . . . . . . . . . . . 498.10 DU-B Strip . . . . . . . . . . . . . . . . 498.11 DU Strip - Inch sizes . . . . . . . . 49
9 Test Methods . . . . . . . . . 509.1 Measurement of
Wrapped Bushes . . . . . . . . . . . 50Test A of ISO 3547 Part 2 . . . . . 50Test B (alternatively to Test A) . 50Test C . . . . . . . . . . . . . . . . . . . . 50Measurement of Wall Thickness(alternatively to Test C) . . . . . . . 50Test D . . . . . . . . . . . . . . . . . . . . 50
1Introduction
5
1 IntroductionThe purpose of this handbook is to providecomprehensive technical information onthe characteristics of DUTM 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 conside-
rations• 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 tole-
rant 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
1 Introduction
6
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 DU-B
Material Backing Bearing LiningOperating Temperature [°C]
Maximum Load p lim [N/mm2]Minimum Maximum
DU Steel PTFE+Lead -200 +280 250
DU-B Bronze PTFE+Lead -200 +280 140
2Material
7
2 Material2.1 StructureDU and DU-B 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.DU-B 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 high corro-sion resistance, anti magnetic propertiesand good thermal conductivity.
DU
Fig. 3: DU Microsection
DU-B
Fig. 4: DU-B 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
2 Material
8
During 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
Following 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
After 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.
2Material
9
2.3 Physical, Mechanical and Electrical Properties
Table 2: Properties of DU and DU-B
Characteristic SymbolValue
Unit CommentsDU DU-B
Physical Properties
Thermal Conductivity λ 40 60 W/mK after running in.
Coefficient of linear thermal expansion : measured on strip 1.9 mm thick.
parallel to surface α1 11 18 1/106K
normal to surface α2 30 36 1/106K
Maximum Operating Temperature
Tmax +280 +280 °C
Minimum Operating Temperature
Tmin –200 –200 °C
Mechanical Properties Compressive Yield Strength sc 350 300 N/mm2
measured on disc 25 mm diameter x 2.44 mm thick.
Maximum Load
Static psta,max 250 140 N/mm2
Dynamic pdyn,max 140 140 N/mm2
Electrical Properties Surface Resistance ROB 1 – 10 1 – 12 Ω depends on applied pressure
and contact area
Nuclear Radiation Resistance
Maximum Thermal Neutron dose
DNth 2 x 1015 2 x 1015 nvt nvt = thermal neutron flux
Maximum gamma ray dose Dg 106 106 Gy = J/kg 1 Gray = 1 J/kg
2 Material
10
2.4 Chemical PropertiesThe following table provides an indicationof the chemical resistance of DU and DU-Bto 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 DU-B
Electrochemical CorrosionDU-B 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/mm2]
• The sliding speed U [m/s]
• The roughness of the mating runningsurface Ra [µm]
• 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 DU-B
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.
2Material
11
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 tem-perature 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/mm²Sliding speedU = 0.003 m/sFriction coefficientf = 0.14
Sliding speed U [m/s]
Specific load p [N/mm2]
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/mm²TemperatureT= 40 °CFriction coefficientf = 0.125
Specific load p [N/mm2]
Friction coefficient f
Temperatur 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
3 Performance
12
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. hou-sing 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 bea-ring 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/mm2.
Cylindrical Bush
Thrust Washer
Flanged Bush (Axial Loading)
Slideway
Permanent deformation of the DU bearinglining may occur at specific loads above140 N/mm2 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/mm2]
[N/mm2]
p 4Fπ Do
2 Di2
–( )⋅---------------------------------=
(3.2.2)
p F0 04, Dfl
2 Di2
–( )⋅-------------------------------------------=
(3.2.3) [N/mm2]
•
p FL W⋅-------------=
(3.2.4) [N/mm2]
3Performance
13
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
BD
i
Projected Area
A = Di x B
Type of loading plim [N/mm2]
steady load, rotating movement 140
steady load, oscillating movementplim 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 movementplim 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
UDi π N⋅ ⋅
60 103⋅----------------------=
(3.4.1) [m/s]
U
Do Di+
2------------------- π N⋅ ⋅
60 103⋅------------------------------------=
(3.4.2) [m/s]
UDi π⋅
60 103⋅--------------------
4ϕ Nosz⋅360
------------------------⋅=
(3.4.3) [m/s]
U
Do Di+
2------------------- π⋅
60 103⋅---------------------------
4ϕ Nosz⋅360
------------------------⋅=
(3.4.4) [m/s]
3 Performance
14
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/mm² x m/s]
3.6 Application FactorsThe following factors influence the bearingperformance of DU and must be concide-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 Unitp 140 N/mm²
U 2.5 m/s
pU continuous 1.8 N/mm² x m/s
pU intermittent 3.6 N/mm² x m/s
pU p U⋅=
(3.5.1) [N/mm2 x m/s]
Mode of Operation Nature of housingTemperature of bearing environment Tamb [°C]
and Temperature application factor aT
25 60 100 150 200 280Dry 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 - -
3Performance
15
Mating SurfaceThe effect of the mating surface materialtype on the operating life of DU bearings isindicated by the mating surface factor aM
and 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 µm Ra • A ground surface is preferred to fine tur-
ned• Surfaces should be cleaned of abrasive
particles after polishing
• Cast iron surfaces should be ground to<0.3 µm Ra
• The grinding cut should be in the samedirection as the bearing motion relativeto the shaft
Bearing SizeThe running clearance of a DU bearingincreases with bearing diameter resultingin a proportionally smaller contact areabetween the shaft and bearing. This reduc-tion in contact area has the effect of increa-sing the actual unit load and hence pU
factor. The bearing size factor (Fig. 13) isused in the design calculations to allow forthis effect. The bearing size factor is alsoapplicable to thrust washers, where forother reasons, bearing diameter has aneffect on performance.
Fig. 12: Contact area between bearing and shaft.
Material aM aL
Steel and Cast IronCarbon Steel 1 200
Carbon Manganese Steel 1 200
Alloy Steel 1 200
Case Hardened Steel 1 200
Nitrided Steel 1 200
Salt bath nitrocarburised 1 200
Stainless Steel(7-10 % Ni, 17-20 % Cr) 2 200
Sprayed Stainless Steel 1 200
Cast Iron(0.3 µm Ra) 1 200
Plated Steel with minimum thickness of pla-ting 0.013 mmCadmium 0.2 600
Hard Chrome 2.0 600
Lead 1.5 600
Nickel 0.2 600
Phosphated 0.2 300
Tin Nickel 1.2 600
Titanium Nitride 1.0 600
Tungsten Carbide Flame Plated 3.0 600
Zinc 0.2 600
Non ferrous metalsAluminium Alloys 0.4 200
Bronze and Copper Base Alloys
0.1-0.4 200
Hard Anodised Aluminium (0.025 mm thick) 3.0 600
Material aM aL
3 Performance
16
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
Bear
ing
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
aC
Burnishing: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
3Performance
17
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
BF N LH aL+( )⋅ ⋅
1 25 107 aT aM aB⋅⋅ ⋅ ⋅,------------------------------------------------------------- F
plim Di⋅--------------------+=
(3.7.1) [mm]
•
BF N LH aL+( )⋅ ⋅
2 5 107 aT aM aB⋅⋅ ⋅ ⋅,---------------------------------------------------------- F
plim Di⋅--------------------+=
(3.7.2) [mm]
•
Do Di–F N LH aL+( )⋅ ⋅
1 25, 107 aT aM aB⋅⋅ ⋅ ⋅------------------------------------------------------------- Di
2 1 3F,plim-------------++= Di–
(3.7.3) [mm]
•
•
A2 38 F U LH aL+( )⋅ ⋅,
103 aT aM⋅ ⋅------------------------------------------------------
L LS+( )L
--------------------- Fplim----------+⋅=
(3.7.4) [mm2]•
L
LS
W
DU/DU-B Strip
Mating Surface
3 Performance
18
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 ϕ
p FDi B⋅--------------=
(3.8.1) [N/mm2]
p F0 04, Dfl
2 Di2
–( )⋅-------------------------------------------=
(3.8.2) [N/mm2]
•
p 4Fp Do
2 Di2
–( )⋅---------------------------------=
(3.8.3) [N/mm2]
aEplim p–
plim-----------------=
(3.8.4) [–]
plim see Table 4, Page 13
pU 5 25 10 5–⋅, F N⋅aE B aT aM aB⋅⋅ ⋅ ⋅-------------------------------------------------=
(3.8.5) [N/mm2 x m/s]
•
pU 6 5 10 4–⋅, F N⋅aE Dfl Di–( ) aT aM aB⋅⋅ ⋅ ⋅---------------------------------------------------------------------=
(3.8.6) [N/mm2 x m/s]
•
pU 3 34 10 5–⋅, F N⋅aE Do Di–( ) aT aM aB⋅⋅ ⋅ ⋅---------------------------------------------------------------------=
(3.8.7) [N/mm2 x m/s]
•
N4ϕ Nosz⋅
360------------------------=
(3.8.8) [1/min]ϕ ϕ
123 4
3Performance
19
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 (Table8, 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
Note: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 wear after ZTcyclesIf 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 A Fplim----------–=
(3.8.14) [–]
aE2420 aT aM⋅ ⋅
F U⋅---------------------------------=
(3.8.15) [–]
aE3A
AM--------=
(3.8.16) [–]
LH aE1 aE2 aE3 aL–⋅ ⋅=
(3.8.17) [h]
3 Performance
20
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/mm² (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/mm²]
(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/mm² x m/s]
(3.8.5), Page 18
LifeLH [h]
(3.8.9), Page 19
p FDi B⋅------------- 5000
40 30⋅----------------- 4 17,= = = •
U Di π N⋅ ⋅
60 103⋅---------------------- 40 3 14, 50⋅ ⋅
60 103⋅----------------------------------- 0 105,= = = •
•
pU p U⋅ 4 17 0 105 0 438,=,⋅,= = • • •
aEplim p–
plim---------------- 140 4 17,–
140-------------------------- 0 97,= = = •
•
pU 5 25 10 5–⋅, F N⋅aE B aT aM aB⋅⋅ ⋅ ⋅----------------------------------------------- 0 53,= = •
•
LH615pU---------- aL– 615
0 53,-------------= 200 960=–=
•
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/minLoad frequency
Calculation Constants and Application FactorsSpecific Load Limit plim 60 N/mm² (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/mm²]
(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/mm² 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/mm² = bearing will fatigue after 105 cy-cles (= 28 h)
p FDi B⋅------------- 25000
30 30⋅----------------- 27 78,= = = •
U Di π N⋅ ⋅
60 103⋅---------------------- 30 3 14, 15⋅ ⋅
60 103⋅----------------------------------- 0 024,= = =•
•
pU p U⋅ 27 87 0 024 0 669,=,⋅,= = • • •
aEplim p–
plim---------------- 60 27 87,–
60-------------------------- 0 54,= = =•
•
pU 5 25 10 5–⋅, F N⋅aE B aT aM aB⋅⋅ ⋅ ⋅----------------------------------------------- 1 23,= =•
•
LH615pU---------- aL– 615
1 23,-------------= 200 350=–=
•
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/mm² (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/mm²]
(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/mm² x m/s]
(3.8.5), Page 18
LifeLH [h]
(3.8.9), Page 19
p FDi B⋅------------- 10000
50 50⋅----------------- 4 0,= = = •
U Di π N⋅ ⋅
60 103⋅---------------------- 50 3 14, 50⋅ ⋅
60 103⋅----------------------------------- 0 131,= = =•
•
pU p U⋅ 4 0 0 131 0 524,=,⋅,= = •• •
aEplim p–
plim---------------- 60 4 0,–
60-------------------- 0 93,= = =•
•
pU 5 25 10 5–⋅, F N⋅aE B aT aM aB⋅⋅ ⋅ ⋅----------------------------------------------- 1 20,= =•
•
LH1230pU------------- aL– 1230
1 2,-------------= 200 825=–=
•
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 ϕ 20 °
Calculation Constants and Application FactorsSpecific Load Limit plim 140 N/mm² (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/mm²]
(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/mm² 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/mm² = 108 bearing o.k.!
p FDi B⋅------------- 40000
45 40⋅----------------- 22 22,= = = •
U 45 3 14, 33 33,⋅ ⋅60 103⋅
--------------------------------------------- 0 078,= =••
•
N 4ϕ Nosz⋅360
----------------------- 4 20 150⋅ ⋅360
----------------------------- 33 33,= = = •
pU p U⋅ 22 22 0 078 1 733,=,⋅,= = • • •
aEplim p–
plim---------------- 140 22 22,–
140------------------------------ 0 84,= = =•
•
pU 5 25 10 5–⋅, F N⋅aE B aT aM aB⋅⋅ ⋅ ⋅----------------------------------------------- 1 29,= = •
•
LH615pU---------- aL– 615
1 29,-------------= 200 277=–=
•
ZT 277 150 60⋅ ⋅ 2 5, 106⋅= = •
3Performance
21
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/mm² (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/mm²]
(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/mm² x m/s]
(3.8.7), Page 18
Life LH [h]
(3.8.12), Page 19
p 4 6500⋅3 14, 622 382–( )⋅-------------------------------------------- 3 45,= =
•
•
U
62 38+( )2
------------------------ 3 14, 60⋅ ⋅
60 1000⋅----------------------------------------------------- 0 157,= =
•
•
pU p U⋅ 3 45 0 157 0 541,=,⋅,= = • • •
aE140 3 45,–
140-------------------------- 0 98,= =•
•
pU 3 34, 10 5–⋅ 6500 60⋅0 87, 62 38–( ) 1 1 0 85,⋅⋅ ⋅ ⋅-------------------------------------------------------------------------- 0 65,= =
•
•
••
LH4100 65,------------- 200 431=–=
•
Flanged BushGiven:Load Details Axial Load Flange outside Diameter
Dfl
23 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/mm² (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/mm²]
(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/mm² x m/s]
(3.8.6), Page 18
Life LH [h]
(3.8.11), Page 19
p 2500 04, 232 152–( )⋅-------------------------------------------- 20 55,= =
•
•
U
23 15+( )2
------------------------ 3 14, 25⋅ ⋅
60 1000⋅----------------------------------------------------- 0 025,= =
•
•
pU p U⋅ 20 55 0 025 0 513,=,⋅,= = • • •
aE140 20 55,–
140------------------------------ 0 85,= =•
•
pU 6 5, 10 5– 250⋅ 50⋅0 85, 23 15–( ) 1 1 1⋅⋅ ⋅ ⋅----------------------------------------------------------------- 0 59,= =•
••
LH4100 59,------------- 200 495=–=
•
4 Data Sheet
22
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 ϕ [°]
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 transfer pro-perties
Material
Mating surface
Surface finish Ra [µm]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 η
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
BD
i (D
i,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:
5Lubrication
23
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 stai-ning
• 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 bea-
ring 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 η⋅7 5,------------ B
Di-----⋅≤
(5.2.1) [N/mm2]
.
5 Lubrication
24
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 supportdeveloped.
• 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 contact bet-ween 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 operating under boundary or mixed film conditions DU shows excellent wear resistance and low friction.
• Start up and shut down under load With insufficient speed to generate a hydrodynamic film the bearing will ope-rate under boundary or mixed film condi-tions. DU minimises wear and requires less start up torque than conventional metallic bearings.
• Sparse lubrication Many applications require the bearing to operate with less than the ideal lubricant
supply, typically with splash or mist lubri-cation only. DU provides excellent self lubricating properties.
• Non lubricating fluids DU operates satisfactorily in low visco-sity and non lubricating fluids such as water and some process fluids.Note the following however:If a DU bearing is required to run dry after running in water under non hydro-dynamic conditions then the wear resi-stance will be substantially reduced due to an 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 cen-
tipoise, of the lubricant.If the operating temperature of the fluid isunknown, a provisional temperature of25 °C above ambient can be used.
5Lubrication
25
Area 1The bearing will operate with boundarylubrication and pU factor will be the majordeterminant of bearing life. DU bearingperformance can be calculated using the
method given in Section 3, although theresult will probably underestimate the bea-ring life
Area 2The bearing will operate with mixed filmlubrication and pU factor is no longer asignificant parameter in determining the
bearing life. DU bearing performance willdepend upon the nature of the fluid and theactual service conditions.
Area 3The bearing will operate with hydrodyna-mic lubrication. Bearing wear will be deter-mined 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 .Bearing performance may be improved bythe addition of one or more grooves to thebearing and a shaft surface finish<0,05 µmRa.
Fig. 21: Design guide for lubricated application
Table 9: Viscosity data
Spec
ific
bear
ing
load
p [N
/mm
²]
Journal surface speed U [m/s]
0.1
1.0
10
0.01 0.1 1.0 10
Increased clearances may be necessary
Detail bearing design may be necessary - consult the company
Area 1Effectively dry rubbing
Area 2Mixed film lubrication
Area 3Full hydrodynamic lubrication
Area 4
Visc
osity
η [c
P]
Conditions:
- Steady unidirectional loading- Continuous, non reversing shaft rotation- Sufficient clearance between shaft and bearing- Sufficient lubricant flow
Viscosity cP
Temperature [°C] 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
LubricantISO VG 32 310 146 77 44 27 18 13 9.3 7.0 5.5 4.4 3.6 3.0 2.5 2.2
ISO VG 46 570 247 121 67 40 25 17 12 9.0 6.9 5.4 4.4 3.6 3.0 2.6
ISO VG 68 940 395 190 102 59 37 24 17 12 9.3 7.2 5.8 4.7 3.9 3.3
ISO VG 100 2110 780 335 164 89 52 33 22 15 11.3 8.6 6.7 5.3 4.3 3.6
ISO VG 150 3600 1290 540 255 134 77 48 31 21 15 11 8.8 7.0 5.6 4.6
Diesel oil 4.6 4.0 3.4 3.0 2.6 2.3 2.0 1.7 1.4 1.1 0.95
Petrol 0.6 0.56 0.52 0.48 0.44 0.40 0.36 0.33 0.31
Kerosene 2.0 1.7 1.5 1.3 1.1 0.95 0.85 0.75 0.65 0.60 0.55
Water 1.79 1.30 1.0 0.84 0.69 0.55 0.48 0.41 0.34 0.32 0.28
5 Lubrication
26
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 µm Boundary lubrication• Ra = 0.1-0.2 µm Mixed film or hydrody-
namic conditions
• Ra ≤ 0.05 µm 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 following must be avoided:• Dynamic loads - which can result in ero-
sion of the PTFE/lead bearing surface.• Greases with EP additives or fillers such
as graphite or MoS2 which can causerapid wear of DU.
gap
20°-60°0°-45°
0.25-0.40
10-15 % of inside diameter of bearing0°-45°
Groove Detail Z
Z
F
6Bearing Assembly
27
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/mm2) 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. 24 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 rise
Reduction 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 DJ
<25 mm -0.019-0.029
>25 mm < 50 mm -0.021-0.035
Di CD
10 mm 0.005 - 0.078
50 mm 0.005 - 0.130
6 Bearing Assembly
28
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 60±2) and polished (RZ ≈1µm).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°
6±2
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
6Bearing Assembly
29
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 >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
DH
DH
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
6 Bearing Assembly
30
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
6Bearing Assembly
31
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 gui-
dance 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
7 Modification
32
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 DU-B 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 5µm 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.
8Standard Products
33
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
Bush Walls3
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass. Inside-∅
Di,a
ClearanceCD
Di Domax.min.
max.min.
max.min.
max.min.
max.min.
max.min.
0203DU2 3.5 0.745
0.725
3.252.75 2.000
1.9943.5083.500
2.0582.010
0.0640.010
0205DU 5.254.75
0303DU
3 4.5
0.7500.730
3.252.75
3.0002.994
4.5084.500
3.0483.000
0.0540.0000305DU 5.25
4.75
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
4.9904.978
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
0710DU 7 9 10.259.75
6.9876.972
9.0159.000
7.0556.990
0.0830.003
0806DU
8 10
6.255.75
7.9877.972
10.01510.000
8.0557.9900808DU 8.25
7.75
0810DU 10.259.75
ID and OD chamferss3 Co Ci
0.75 0.5 ± 0.3 –0.1 to –0.4
1 0.6 ± 0.4 –0.1 to –0.5
1.5 0.6 ± 0.4 –0.1 to –0.7
s3 Co Ci2 1.2 ± 0.4 –0.1 to –0.7
2.5 1.6 ± 0.8 –0.2 to –1.0
8 Standard Products
34
0812DU 8 10
1.0050.980
12.2511.75
7.9877.972
10.01510.000
8.0557.990
0.0830.003
1008DU
10 12
8.257.75
9.9879.972
12.01812.000
10.0589.990
0.0860.003
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
13.05812.990
1320DU 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 20.2519.75
16.98416.966
19.02119.000
17.06116.990
0.0950.006
1810DU
18 20 1.0050.980
10.259.75
17.98417.966
20.02120.000
18.06117.990
0.0950.006
1815DU 15.2514.75
1820DU 20.2519.75
1825DU 25.2524.75
Part No.
Nominal Diameter
Bush Walls3
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass. Inside-∅
Di,a
ClearanceCD
Di Domax.min.
max.min.
max.min.
max.min.
max.min.
max.min.
8Standard Products
35
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 30.25
29.75
3240DU 40.2539.75
Part No.
Nominal Diameter
Bush Walls3
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass. Inside-∅
Di,a
ClearanceCD
Di Domax.min.
max.min.
max.min.
max.min.
max.min.
max.min.
8 Standard Products
36
3520DU
35 39
2.0051.970
20.2519.75
34.97534.950
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 20.2519.75
36.97536.950
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
Bush Walls3
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass. Inside-∅
Di,a
ClearanceCD
Di Domax.min.
max.min.
max.min.
max.min.
max.min.
max.min.
8Standard Products
37
6530DU
65 70
2.5052.460
30.2529.75
64.97064.940
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 50.25
49.75
7070DU 70.2569.75
7560DU75 80
60.2559.75 74.970
74.94080.03080.000
75.11074.990
7580DU 80.2579.75
8060DU80 85
2.4902.440
60.5059.50 80.000
79.95485.03585.000
80.15580.020
0.2010.020
80100DU 100.5099.50
8530DU
85 90
30.5029.50
85.00084.946
90.03590.000
85.15585.020
0.2090.020
8560DU 60.5059.50
85100DU 100.5099.50
9060DU90 95
60.5059.50 90.000
89.94695.03595.000
90.15590.020
90100DU 100.5099.50
9560DU95 100
60.5059.50 95.000
94.946100.035100.000
95.15595.020
95100DU 100.5099.50
10050DU
100 105
50.5049.50
100.00099.946
105.035105.000
100.155100.02010060DU 60.50
59.50
100115DU 115.50114.50
10560DU105 110
60.5059.50 105.000
104.946110.035110.000
105.155105.020
105115DU 115.50114.50
11060DU110 115
60.5059.50 110.000
109.946115.035115.000
110.155110.020
110115DU 115.50114.50
11550DU115 120
50.5049.50 115.000
114.946120.035120.000
115.155115.020
11570DU 70.5069.50
12050DU
120 125
2.4652.415
50.5049.50
120.000119.946
125.040125.000
120.210120.070
0.2640.07012060DU 60.50
59.50120100DU
100.5099.50125100DU 125 130 125.000
124.937130.040130.000
125.210125.070
0.2730.07013060DU
130 135
60.5059.50 130.000
129.937135.040135.000
130.210130.070130100DU 100.50
99.50
Part No.
Nominal Diameter
Bush Walls3
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass. Inside-∅
Di,a
ClearanceCD
Di Domax.min.
max.min.
max.min.
max.min.
max.min.
max.min.
8 Standard Products
38
8.2 DU Flanged Bushes
All dimensions in mm
13560DU135 140
2.4652.415
60.5059.50 135.000
134.937140.040140.000
135.210135.070
0.2730.070
13580DU 80.5079.50
14060DU140 145
60.5059.50 140.000
139.937145.040145.000
140.210140.070
140100DU 100.5099.50
15060DU
150 155
60.5059.50
150.000149.937
155.040155.000
150.210150.07015080DU 80.50
79.50
150100DU 100.5099.50
16080DU160 165
80.5079.50 160.000
159.937165.040165.000
160.210160.070160100DU
100.5099.50
180100DU 180 185 180.000179.937
185.046185.000
180.216180.070
0.2790.070
200100DU 200 205 200.000199.928
205.046205.000
200.216200.070
0.2880.070210100DU 210 215 210.000
209.928215.046215.000
210.216210.070
220100DU 220 225 220.000219.928
225.046225.000
220.216220.070
250100DU 250 255 250.000249.928
255.052255.000
250.222250.070
0.2940.070
300100DU 300 305 300.000299.919
305.052305.000
300.222300.070
0.3030.070
Part No.
Nominal Diameter
Bush Walls3
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass. Inside-∅
Di,a
ClearanceCD
Di Domax.min.
max.min.
max.min.
max.min.
max.min.
max.min.
s 3D
i (D
i,a)
Do
r
0.3
min
.
Dfl
Co
Ci
B
20˚ ±8˚
Z
sfl
Detail Z
Split
s3 1,0 1,5 2,0 2,5r 1 -0,5 1 ±0,5 1,4 ±0,5 2 ±0,5Dimensions and Tolerances according to ISO 3547 and GSP-Specifications
Part No.
Nominal Diameter
Bush Wall s3
Flange Wallsfl
Flange-∅ Dfl
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass.Inside-
∅Di,a
Clearance CD
Di Domaxmin.
max.min.
max.min.
max.min.
max.min.
max.min.
max.min.
max. min.
BB0304DU 3 4.50.7500.730
0.8000.700
7.5006.500 4.25
3.75
3.0002.994
4.5084.500
3.0483.000
0.0540.000
BB0404DU 4 5.5 9.5008.500
4.0003.992
5.5084.500
4.0484.000
0.0560.000
BB0505DU 5 7
1.0050.980
1.0500.950
10.5009.500
5.254.75
4.9904.978
7.0157.000
5.0554.990
0.0770.000BB0604DU
6 8 12.511.5
4.253.75 5.990
5.9788.0158.000
6.0555.990BB0608DU 8.25
7.75
8Standard Products
39
BB0806DU
8 10
1.0050.980
1.0500.950
15.514.5
5.755.25
7.9877.972
10.01510.000
8.0557.990
0.0830.003BB0808DU 7.75
7.25
BB0810DU 9.759.25
BB1007DU
10 12 18.517.5
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 20.519.5
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 22.5
21.5
12.2511.75 13.984
13.96616.01816.000
14.05813.990
BB1417DU 17.2516.75
BB1509DU
15 17 23.522.5
9.258.75
14.98414.966
17.01817.000
15.05814.990BB1512DU 12.25
11.75
BB1517DU 17.2516.75
BB1612DU16 18 24.5
23.5
12.2511.75 15.984
15.96618.01818.000
16.05815.990
BB1617DU 17.2516.75
BB1812DU
18 20 1.0050.980
1.0500.950
26.525.5
12.2511.75
17.98417.966
20.02120.000
18.06117.990
0.0950.006BB1817DU 17.25
16.75
BB1822DU 22.2521.75
BB2012DU
20 23
1.5051.475
1.6001.400
30.529.5
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 35.534.5
11.7511.25
24.98024.959
28.02128.000
25.07124.990BB2517DU 16.75
16.25
BB2522DU 21.7521.25
BB3016DU30 34
2.0051.970
2.1001.900
42.541.5
16.2515.75 29.980
29.95934.02534.000
30.08529.990
0.1260.010
BB3026DU 26.2525.75
BB3516DU35 39 47.5
46.5
16.2515.75 34.975
34.95039.02539.000
35.08534.990
0.1350.015
BB3526DU 26.2525.75
BB4016DU40 44 53.5
52.5
16.2515.75 39.975
39.95044.02544.000
40.08539.990
BB4026DU 26.2525.75
Part No.
Nominal Diameter
Bush Wall s3
Flange Wallsfl
Flange-∅ Dfl
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass.Inside-
∅Di,a
Clearance CD
Di Domaxmin.
max.min.
max.min.
max.min.
max.min.
max.min.
max.min.
max. min.
8 Standard Products
40
8.3 DU Flanged Washers
All dimensions in mm
BB4516DU45 50 2.505
2.4602.6002.400
58.557.5
16.2515.75 44.975
44.95050.02550.000
45.10544.990
0.1550.015
BB4526DU 26.2525.75
Part No.
Nominal Diameter
Bush Wall s3
Flange Wallsfl
Flange-∅ Dfl
LengthB
Shaft-∅DJ
Hou-sing-∅
DH
Ass.Inside-
∅Di,a
Clearance CD
Di Domaxmin.
max.min.
max.min.
max.min.
max.min.
max.min.
max.min.
max. min.
r 1.25
Do
d p
2 ±0,02
4,8 -0,6
Di
Dfl
1.5 x 45˚
r 1.25
8±1
5 ±0,1
30˚
Part No.
Inside-∅Di
Body-∅Do
Outside-∅Dfl
Location-∅dP
max.min.
max.min.
max.min.
max.min.
BS 40 DU 40.740.2
44.00043.900
75.074.5
65.064.5
BS 50 DU 51.551.0
55.00054.880
85.084.5
75.074.5
BS 60 DU 61.561.0
65.00064.880
95.094.5
85.084.5
BS 70 DU 71.571.0
75.00074.880
110.0109.5
100.099.5
BS 80 DU 81.581.0
85.00084.860
120.0119.5
110.0109.5
BS 90 DU 91.591.0
95.00094.860
130.0129.5
120.0119.5
BS 100 DU 101.5101.0
105.000104.860
140.0139.5
130.0129.5
8Standard Products
41
8.4 DU Thrust Washer
All dimensions in mm
dP
Di
Do
sT
Ha
Hd
[D10
]
d p
dD
Part No.
Inside-∅Di
Outside-∅Do
Wall thickness
sT
Dowel hole-∅dD
Dowel hole PCD-∅ dP
Recess Depth Ha
min. max. max.min.
max.min.
max.min.
max.min.
max.min.
WC 08 DU 10.00 10.25 20.0019.75
1.501.45
No Hole No Hole
1.200.95
WC 10 DU 12.00 12.25 24.0023.75
1.8751.625
18.1217.88
WC 12 DU 14.00 14.25 26.0025.75
2.3752.125
20.1219.88
WC 14 DU 16.00 16.25 30.0029.75
22.1221.88
WC 16 DU 18.00 18.25 32.0031.75
25.1224.88
WC 18 DU 20.00 20.25 36.0035.75
3.3753.125
28.1227.88
WC 20 DU 22.00 22.25 38.0037.75
30.1229.88
WC 22 DU 24.00 24.25 42.0041.75
33.1232.88
WC 24 DU 26.00 26.25 44.0043.75
35.1234.88
WC 25 DU 28.00 28.25 48.0047.75
4.3754.125
38.1237.88
WC 30 DU 32.00 32.25 54.0053.75
43.1242.88
WC 35 DU 38.00 38.25 62.0061.75
50.1249.88
WC 40 DU 42.00 42.25 66.0065.75
54.1253.88
WC 45 DU 48.00 48.25 74.0073.75
2.001.95
61.1260.88
1.701.45WC 50 DU 52.00 52.25 78.00
77.7565.1264.88
WC 60 DU 62.00 62.25 90.0089.75
76.1275.88
8 Standard Products
42
8.5 DU-B 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
LengthB
Shaft-∅DJ
Housing-∅
DH
Ass. Inside-∅
Di,a
Clearance CD
Di Domax.min.
max.min.
max.min.
max.min.
max.min. max.
0203 DU-B2 3.5
0.7500.730
3.252.75 2.000
1.9943.5083.500
2.0482.000 0.054
0.0000205 DU-B 5.254.75
0306 DU-B 3 4.56.255.75
3.0002.994
4.5084.500
3.0483.000
0406 DU-B 4 5.5 4.0003.992
5.5085.500
4.0484.000
0.0560.000
0505 DU-B5 7
1.0050.980
5.254.75 4.990
4.9787.0157.000
5.0554.990
0.0770.000
0510 DU-B 10.259.75
0606 DU-B
6 8
6.255.75
5.9905.978
8.0158.000
6.0555.9900608 DU-B 8.25
7.75
0610 DU-B 10.259.75
0808 DU-B8 10
8.257.75 7.987
7.97210.01510.000
8.0557.990
0.0830.003
0812 DU-B 12.2511.75
1010 DU-B10 12
10.259.75 9.987
9.97212.01812.000
10.0589.990
0.0860.003
1015 DU-B 15.2514.75
1208 DU-B
12 14
8.257.75
11.98411.966
14.01814.000
12.05811.990
0.0920.006
1210 DU-B 10.259.75
1212 DU-B 12.2511.75
1215 DU-B15.2514.751415 DU-B
14 16 13.98413.966
16.01816.000
14.05813.9901420 DU-B 20.25
19.75
1515 DU-B15 17
15.2514.75 14.984
14.96617.01817.000
15.05814.990
1525 DU-B 25.2524.75
ID and OD chamferss3 Co Ci
0.75 0.5 ± 0.3 –0.1 to –0.4
1 0.6 ± 0.4 –0.1 to –0.5
1.5 0.6 ± 0.4 –0.1 to –0.7
s3 Co Ci2 1.2 ± 0.4 –0.1 to –0.7
2.5 1.6 ± 0.8 –0.2 to –1.0
8Standard Products
43
1615 DU-B16 18
1.0050.980
15.2514.75 15.984
15.96618.01818.000
16.05815.990
0.0920.006
1625 DU-B 25.2524.75
1820 DU-B18 20
20.2519.75 17.984
17.96620.02120.000
18.06117.990
0.0950.006
1825 DU-B 25.2524.75
2015 DU-B
20 23
1.5051.475
15.2514.75
19.98019.959
23.02123.000
20.07119.990
0.1120.0102020 DU-B 20.25
19.75
2030 DU-B 30.2529.75
2215 DU-B
22 25
15.2514.75
21.98021.959
25.02125.000
22.07121.990 0.112
0.0102220 DU-B 20.25
19.752225 DU-B
25.2524.752525 DU-B 25 28 24.980
24.95928.02128.000
25.07124.990
2830 DU-B 28 32
2.0051.970
30.2529.75
27.98027.959
32.02532.000
28.08527.990
0.1260.010
3020 DU-B
30 34
20.2519.75
29.98029.959
34.02534.000
30.08529.9903030 DU-B 30.25
29.75
3040 DU-B 40.2539.75
3520 DU-B35 39
20.2519.75 34.975
34.95039.02539.000
35.08534.990
0.1350.015
3530 DU-B30.2529.754030 DU-B
40 44 39.97539.950
44.02544.000
40.08539.9904050 DU-B 50.25
49.75
4530 DU-B45 50
2.5052.460
30.2529.75 44.975
44.95050.02550.000
45.10544.990
0.1550.0154550 DU-B 50.25
49.75
5040 DU-B50 55
40.2539.75 49.975
49.95055.03055.000
50.11049.990
0.1600.0155060 DU-B 60.25
59.75
5540 DU-B 55 60 40.2539.75
54.97054.940
60.03060.000
55.11054.990
0.1700.020
6040 DU-B60 65
59.97059.940 65.030
65.00060.11059.9906070 DU-B 70.25
69.75
7050 DU-B70 75
50.2549.75 69.970
69.94075.03075.000
70.11069.9907070 DU-B 70.25
69.75
8060 DU-B80 85
2.4902.440
60.5059.50 80.000
79.95485.03585.000
80.15580.020
0.2010.02080100 DU-B 100.50
99.50
9060 DU-B90 95
60.5059.50 90.000
89.94695.03595.000
90.15590.020
0.2090.020
90100 DU-B 100.5099.50
10060 DU-B100 105
60.5059.50 100.000
99.946105.035105.000
100.155100.020100115 DU-B 115.50
114.50
Part No.
Nominal Diameter
Wall thickness
s3
LengthB
Shaft-∅DJ
Housing-∅
DH
Ass. Inside-∅
Di,a
Clearance CD
Di Domax.min.
max.min.
max.min.
max.min.
max.min. max.
8 Standard Products
44
8.6 DU-B Flanged Bushes
All dimensions in mm
s 3D
i (D
i,a)
Do
r
0.3
min
.
Dfl
Co
Ci
B
20˚ ±8˚
Z
sfl
Detail Z
Split
s3 1,0 1,5 2,0 2,5r 1 -0,5 1 ±0,5 1,4 ±0,5 2 ±0,5Dimensions and Tolerances according to ISO 3547 and GSP-Specifications
Part No.
Nominal Diameter
Bush Wall s3
Flange Wall sfl
Flange-∅ Dfl
Length B
Shaft-∅DJ
Hou-sing-∅
DH
Ass. Inside-∅ Di,a
Clear-ance CD
Di Domaxmin.
max.min.
max.min.
max.min.
max.min.
max.min.
max.min.
max. min.
BB0304DU-B 3 4.50.7500.730
0.8000.700
7.5006.500 4.25
3.75
3.0002.994
4.5084.500
3.0483.000
0.0540.000
BB0404DU-B 4 5.5 9.5008.500
4.0003.992
5.5084.500
4.0484.000
0.0560.000
BB0505DU-B 5 7
1.0050.980
1.0500.950
10.5009.500
5.254.75
4.9904.978
7.0157.000
5.0554.990 0.077
0.000BB0604DU-B 6 8 12.511.5
4.253.75
5.9905.978
8.0158.000
6.0555.990
BB0806DU-B8 10 15.5
14.5
5.755.25
7.9877.972 10.015
10.0008.0557.990
0.0830.000BB0810DU-B 9.75
9.257.9877.972
BB1007DU-B10 12 18.5
17.5
7.256.75
9.9879.972 12.018
12.00010.0589.990
0.0860.003BB1012DU-B 12.25
11.759.9879.972
BB1207DU-B
12 14 20.519.5
7.256.75
11.98411.966
14.01814.000
12.05811.990
0.0920.006
BB1209DU-B 9.258.75
11.98411.966
BB1212DU-B 12.2511.75
11.98411.966
BB1417DU-B 14 16 22.5 21.5
17.2516.75
13.98413.966
16.01816.000
14.0513.990
BB1512DU-B15 17 23.5
22.5
12.2511.75 14.984
14.96617.01817.000
15.05814.990BB1517DU-B 17.25
16.75
BB1612DU-B16 18 24.5
23.5
12.2511.75 15.984
15.96618.01818.000
16.05815.990
BB1617DU-B 17.2516.75
BB1822DU-B 18 20 26.525.5
22.2521.75
17.98417.966
20.02120.000
18.06117.990
0.0950.006
BB2012DU-B20 23
1.5051.475
1.6001.400
30.529.5
11.7511.25 19.980
19.95923.02123.000
20.07119.990 0.112
0.010BB2017DU-B 16.7516.25
BB2522DU-B 25 28 35.534.5
21.7521.25
24.98024.959
28.02128.000
25.07124.990
BB3016DU-B30 34
2.0051.970
2.1001.900
42.541.5
16.2515.75
29.98029.959
34.02534.000 30.085
29.9900.1260.010
BB3026DU-B26.2525.75
29.98029.959
34.02534.000
BB3526DU-B 35 39 47.546.5
34.97534.950
39.02539.000
35.08534.990
0.1350.015
BB4026DU-B 40 44 2.0051.970
2.1001.900
53.552.5 26.25
25.75
39.97539.950
44.02544.000
40.08539.990
0.1350.015
BB4526DU-B 45 50 2.5052.460
2.6002.400
58.557.5
44.97544.950
50.02550.000
45.10544.990
0.1550.015
8Standard Products
45
8.7 DU Cylindrical Bushes - Inch sizes
All dimensions in inch
Ci
Co
.012
min
.
α
β
Di
Do
(Di,a
)s 3
B
ZDetail Z
Split
Part No.Nominal Diameter
Bush Walls3
LengthB
Shaft-∅DJ
Housing-∅ DH
Ass. Inside-∅
Di,a
Clearance CD
Di Do B max.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
0.00320.0000
02DU03 3/160.19750.1775
025DU0255/32
7/32
5/320.166250.14265 0.1554
0.1547
0.21910.2186 0.1581
0.15560.00340.0002
025DU04 1/40.26000.2400
03DU03
3/161/4
3/160.19750.1775
0.18650.1858
0.25030.2497
0.18930.1867
0.00350.000203DU04 1/4
0.26000.2400
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 3/8 0.38500.365005DU06
5/163/8
3/8 0.31150.3106
0.37530.3747
0.31430.311705DU08 1/2
0.51000.4900
06DU06
3/8 15/32
3/8
0.04710.0461
0.38500.3650
0.37400.3731
0.46910.4684
0.37690.3742
0.00380.000206DU08 1/2
0.51000.4900
06DU12 3/40.76000.7400
07DU087/16
17/32
1/20.51000.4900 0.4365
0.43550.53160.5309
0.43940.4367
0.00390.000207DU12 3/4
0.76000.7400
08DU06
1/2 19/32
3/8
0.04710.0461
0.38500.3650
0.49900.4980
0.59410.5934
0.50190.4992
0.00390.0002
08DU08 1/20.51000.4900
08DU10 5/80.63500.6150
08DU14 7/80.88500.8650
09DU089/16
21/32
1/20.51000.4900 0.5615
0.56050.65660.6559
0.56440.5617
09DU12 3/40.76000.7400
ID and OD chamfersDi Co α Ci β
1/8" - 5/16" 0.008" - 0.024" 30°-45° 0.004" - 0.012" 30°-45°3/8" - 11/16" 0.020" - 0.040" 20°-30° 0.005" - 0.025" 40°-55°
3/4" - 7" 0.020" - 0.040" 15°-25° 0.005" - 0.025" 40°-50°
8 Standard Products
46
10DU08
5/8 23/32
1/2
0.04710.0461
0.51000.4900
0.62400.6230
0.71920.7184
0.62700.6242 0.0040
0.0002
10DU10 5/80.63500.6150
10DU12 3/40.76000.7400
10DU147/8
0.88500.865011DU14 11/16
25/320.68650.6855
0.78170.7809
0.68950.6867
12DU08
3/4 7/8
1/2
0.06270.0615
0.51000.4900
0.74910.7479
0.87550.8747
0.75250.7493
0.00460.0002
12DU12 3/40.76000.7400
12DU16 1 1.01000.9900
14DU12
7/8 1
3/40.76000.7400
0.87410.8729
1.00050.9997
0.87750.874314DU14 7/8
0.88500.8650
14DU16 1 1.01000.9900
16DU12
1 11/8
3/40.76000.7400
0.99910.9979
1.12561.1246
1.00260.9992
0.00470.000116DU16 1 1.0100
0.9900
16DU24 11/21.51001.4900
18DU1211/8 19/32
3/4
0.07840.0770
0.76000.7400 1.1238
1.12261.28181.2808
1.12781.1240
0.00520.000218DU16 1 1.0100
0.9900
20DU12
11/4 113/32
3/40.76000.7400
1.24881.2472
1.40681.4058
1.25281.2490
0.00560.0002
20DU16 1 1.01000.9900
20DU20 11/41.26001.2400
20DU28 13/41.76001.7400
22DU16
13/8 117/32
1 1.01000.9900
1.37381.3722
1.53181.5308
1.37781.374022DU22 13/8
1.38501.3650
22DU28 13/41.76001.7400
24DU16
11/2 121/32
1 1.01000.9900
1.49881.4972
1.65681.6558
1.50281.4990
24DU20 11/41.26001.2400
24DU24 11/21.51001.4900
24DU32 2 2.01001.9900
26DU1615/8 125/32
1 1.01000.9900 1.6238
1.62221.78181.7808
1.62781.6240
0.00560.0002
26DU24 11/21.51001.4900
28DU16
13/4 115/16
1
0.09410.0923
1.01000.9900
1.74871.7471
1.93811.9371
1.75351.7489
0.00640.0002
28DU24 11/21.51001.4900
28DU28 13/41.76001.7400
28DU32 2 2.01001.9900
Part No.Nominal Diameter
Bush Walls3
LengthB
Shaft-∅DJ
Housing-∅ DH
Ass. Inside-∅
Di,a
Clearance CD
Di Do B max.min.
max.min.
max.min.
max.min.
max.min.
max.min.
8Standard Products
47
30DU16
17/8 21/16
1
0.09410.0923
1.01000.9900
1.87371.8721
2.06332.0621
1.87871.8739
0.00660.000230DU30 17/8
1.88501.8650
30DU36 21/42.26002.2400
32DU16
2 23/16
1 1.01000.9900
1.99871.9969
2.18832.1871
2.00371.9989
0.00680.0002
32DU24 11/21.51001.4900
32DU32 2 2.01001.9900
32DU40 21/22.51002.4900
36DU32
21/4 27/16
2
0.09280.0902
2.01001.4900
2.25072.2489
2.43772.4365
2.25732.2509
0.00840.0002
36DU36 21/42.26002.2400
36DU40 21/22.51002.4900
36DU48 3 3.01002.9900
40DU32
21/2 211/16
2 2.01001.9900
2.50112.4993
2.68812.6869
2.50772.5013
40DU40 21/22.51002.4900
40DU48 3 3.01002.9900
40DU56 31/23.51003.4900
44DU32
23/4 215/16
2 2.01001.9900
2.75002.7482
2.93702.9358
2.75662.7502
44DU40 21/22.51002.4900
44DU48 3 3.01002.9900
44DU56 31/23.51003.4900
48DU32
3 33/16
21/22.51002.4900
3.00002.9982
3.18723.1858
3.00683.0002
0.00860.000248DU48 3 3.0100
2.9900
48DU60 33/43.76003.7400
56DU40
31/2 311/16
21/22.51002.4900
3.50003.4978
3.68723.6858
3.50683.5002
0.00900.000256DU48 3 3.0100
2.9900
56DU60 33/43.76003.7400
64DU48
4 43/16
3
0.09280.0902
3.01002.9900
4.00003.9978
4.18724.1858
4.00684.0002
0.00900.000264DU60 33/4
3.76003.7400
64DU76 43/44.76004.7400
80DU485 53/16
3 3.01002.9900 4.9986
4.99615.18605.1844
5.00564.9988
0.00950.0002
80DU60 33/43.76003.7400
96DU486 63/16
3 3.01002.9900 6.0000
5.99756.18746.1858
6.00706.000296DU60 33/4 3.7600
3.7400112DU60 7 73/16 33/46.99546.9929
7.18307.1812
7.00266.9956
0.00970.0002
Part No.Nominal Diameter
Bush Walls3
LengthB
Shaft-∅DJ
Housing-∅ DH
Ass. Inside-∅
Di,a
Clearance CD
Di Do B max.min.
max.min.
max.min.
max.min.
max.min.
max.min.
8 Standard Products
48
8.8 DU Thrust Washers - Inch sizes
All dimensions in inch
dP ±0.005
Di
Do -0.010
sT
Ha
Do
d p
+0.010
dD ±0.005
Hd
[D10
]
DJ
Part No.
Inside-∅Di
Outside-∅Do
Wall thickness sT
Dowel hole-∅dD
Dowel holePCD-∅
dP
Recess Depth
Ha
max. min. max.min.
max.min.
max.min.
max.min.
max.min.
DU06 0.510 0.500 0.8750.865
0.0630.061
0.0770.067
0.6920.682
0.0500.040
DU07 0.572 0.562 1.0000.990
0.7860.776
DU08 0.635 0.625 1.1251.115
0.1090.099
0.8800.870
DU09 0.697 0.687 1.1871.177
0.9420.932
DU10 0.760 0.750 1.2501.240
1.0050.995
DU11 0.822 0.812 1.3751.365
1.0991.089
DU12 0.885 0.875 1.5001.490 0.140
0.130
1.1921.182
DU14 1.010 1.000 1.7501.740
1.3801.370
DU16 1.135 1.125 2.0001.990
0.1710.161
1.5671.557
DU18 1.260 1.250 2.1252.115
1.6921.682
DU20 1.385 1.375 2.2502.240
1.8171.807
DU22 1.510 1.500 2.5002.490
0.2020.192
2.0051.995
DU24 1.635 1.625 2.6252.615
2.1302.120
DU26 1.760 1.750 2.7502.740
2.2552.245
DU28 2.010 2.000 3.0002.990
0.0930.091
2.5052.495
0.0800.070DU30 2.135 2.125 3.125
3.1152.6302.620
DU32 2.260 2.250 3.2503.240
2.7552.745
8Standard Products
49
8.9 DU Strip
All dimensions in mm
8.10DU-B StripAll dimensions in mm
8.11DU Strip - Inch sizesAll dimensions in inch
ss
Wu
L+3
W
Inch sizes: L +.031 Inch sizes: sS ±.006
Part No. Length L Total Width W Useable Width WUThickness sS
max.min.
S 07150 DU
500
160 150 0.7440.704
S 10200 DU 225 215 0.9900.950
S 15240 DU
254 245
1.5101.470
S 20240 DU 2.0001.960
S 25240 DU 2.5002.460
S 30240 DU 3.0603.020
Part No. Length L Total Width W Useable Width WUThickness sS
max.min.
S 10180 DU-B
500 193 180
0.9900.950
S 15180 DU-B 1.5001.470
S 20180 DU-B 2.0001.960
S 25180 DU-B 2.5002.460
Part No. Length L Total Width W Thickness sSGroup 0
18
2.75 0.0277-0.0293Group 1
4.00
0.0431-0.0447Group 2 0.0586-0.0602Group 3 0.0740-0.0756Group 4 0.0897-0.0913Group 5 0.1190-0.1210
9 Test Methods
50
9 Test Methods9.1 Measurement of Wrapped BushesIt is not possible to accurately measure theexternal and internal diameters of a wrap-ped bush in the free condition. In its freestate a wrapped bush will not be perfectlycylindrical and the butt joint may be open.When correctly installed in a housing thebutt joint will be tightly closed and the bushwill conform to the housing.
For this reason the external diameter andinternal diameter of a wrapped bush canonly be chekked with special gauges andtest equipment.The checking methods are defined inISO 3547 Part 1 and 2 and ISO 12306respectively.
Test A of ISO 3547 Part 2Checking the external diameter in a testmachine with checking blocks and adju-sting mandrel.
Fig. 34: Test A, Data for drawingTable 14: Test A of ISO 3547 Part 2
Test B (alternatively to Test A)Check external diameter with GO andNOGO ring gauges.
Test CChecking the internal diameter of a bushpressed into a ring gauge, which nominaldiameter corresponds to the dimensionspecified in table 5 of ISO 3547 Part 1. Fig. 35: Example Di = 20 mm
Fig. 35: Test C, Data for drawing
Measurement of Wall Thickness (alternatively to Test C)The wall thickness is measured at one, twoor three positions axially according to thebearing dimensions.
Fig. 36: Measurement positionTable 15: Measurement position
Test DCheck external diameter by precisionmeasuring tape.
Checking block
gap
dch,1
Fch Test A of ISO 3547 Part 2 on 20DU15Test housing and mandrel dch,1
23.062 mm
Test load Fch 4500 NLimits for ∆z 0 and -0.065 mmBush outside diameter Do
23.035 to 23.075 mm
20.06120.001
Bush inserted in ring gauge ∅ 23.011 mm
A
A
∅ 0.050
X X measurement position
B
B [mm] X [mm] measurement position
≤15 B/2 1>15 ≤50 4 2>50 ≤90 6 and B/2 3
>90 8 and B/2 3
©2003 GGB. All rights reserved
GGB warrants that products described in this brochure are free from defects in workmanship and material but unless expressly agreed in writing GGB gives no warranty that these products are suitable for any particular purpose of for use under any specific conditions notwithstan-ding that such purpose would appear to be covered by this publication. GGB accepts no liability for any loss, damage, or expense whatsoever arising directly or indirectly from use of its products. All business under-taken by GGB is subject to its standard Conditions of Sale, copies of which are available upon request. GGB products are subject to conti-nual development and GGB reserves the right to make changes in the specification and design of its products without prior notice.
GLACIERTM is a trademark of GGB.
DUTM is a trademark of GGB.
DUTM-B is a trademark of GGB.
Health Hazard - WarningThere are two separate aspects of health hazard which could arise from certain usage of DU materials.FabricationAt temperatures up to 250 °C the polytetrafluroethylene (PTFE) pre-sent in the lining material is completely inert so that even on the rare occasions in which DU bushes are drilled, or sized, after assembly there is no danger in boring or burnishing. At higher temperatures however, small quantities of toxic fumes can be produced and the direct inhalation of these can cause an influenza type of illness which may not appear for some hours but which subsi-des without after-effects in 24-48 hours. Such fumes can arise from PTFE particles picked up on the end of a cigarette. Therefore smoking should be prohibited where DU is being machined.Lead contamination of food, drink and other edible products
DU contains a small quantity of metallic lead (0.25 kg/m² of total bea-ring surface) and the designer should ensure that this does not conta-minate any edible product being processed to the extent that it might cause a health hazard. The majority of the lead is retained in the bearing, and that which escapes does so over a long period of time. The highest rate of release occurs during the bedding-in period which normally lasts for 1-2% of the life of the bearing. As a guide a MB2525DU bush with unidirectio-nal load will emit 0.05g of lead in the bedding-in wear debris with a fur-ther 0.1g during the remaining 98% of the bearing life. 0.05g is sufficient, if evenly distributed, to contaminate 100 kg of food product to 0.5 ppm or 1000 litres of liquid to 0.05 ppm. If the rate of food proces-sing is comparable to or less than these quantities per 1% of the bea-ring life, it should be sealed so as to prevent wear debris contaminating the product. These quantities are proportional to the surface area of the bearing and should be factored for other sizes, and increased by a factor of 3 if there is a rotating load. Where lead emission rates approach the critical level, and sealing is not effective, adequate prototype testing should be carried out to deter-mine the bearing's operating life. Adverse conditions (extraneous material in the bearing, overloading etc) can decrease the life of the bearing and therefore increase the lead emission rates.
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