Schaeffler Product catalogue - medias
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Tapered roller bearings
 

Tapered roller bearings are particularly suitable where:

 
 
  • high radial loads occur ➤ section and ➤ section
  • high axial loads act on one side ➤ section
  • combined loads must be supported (radial and axial forces acting simultaneously) ➤ section
  • precise axial guidance of the shaft is required (locating bearing function)
  • the bearing arrangement
    Arrangement of bearings, for example locating/locating, semi-locating/semi-locating, non-locating/non-locating, or semi-locating bearings in tandem, O or X arrangement
    must have very high axial rigidity
  • the bearing position is operated clearance-free or under preload
    Force due to negative operating clearance or negative bearing clearance in rolling bearings
    (single bearings are adjusted against each other) ➤ section
  • high running accuracy
    Measured in terms of radial runout and axial runout, due to the dimensional and geometrical tolerances of the bearing in motion, defined according to DIN
    is required
  • the load
    Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

    See Contact surface
    carrying capacity of angular contact ball bearings is no longer sufficient and the higher speed suitability of angular contact ball bearings is not required ➤ Figure 1
  • the bearings are not required to compensate misalignments
  • the design objective comprises compact, rigid and economical bearing arrangements with a high load
    Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

    See Contact surface
    carrying capacity.
 
   

Figure 1
Load carrying capacity and speed comparison – single row tapered roller bearings/single row angular contact ball bearings

Fr =  radial load
Cr =  basic dynamic load
The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
rating
nG =  limiting speed

 

imageref_21939220235_All.gif

 
 

Bearing design

 
 

Tapered roller bearings are available in an extensive range of single row and multi-row designs. X-life is the new performance standard for tapered roller bearings and stands for eXtended life ➤ link . The key designs based on single row tapered roller bearings are:

 
 
  • single row tapered roller bearings
  • matched tapered roller bearings
  • integral tapered roller bearings.
 
imageref_18348417035_All.gif   Tapered roller bearings are also available in many other designs and sizes, as well as for specific applications, by agreement. For general availability, please contact Schaeffler. An upgrade to X-life performance is available. X-life bearings ➤ TPI 241. Matched tapered roller bearings ➤ TPI 245. Integral tapered roller bearings ➤ TPI 151. Larger catalogue bearings and other bearing designs ➤ GL 1.  

Available in metric and inch sizes

 

Tapered roller bearings are produced in metric and inch sizes.

 
 

Classification and designation – bearings in metric and inch sizes

 

Bearings in metric sizes:

 
 
  • DIN 720:2008 
  • ISO 355:2007
  • ANSI/ABMA 19.1:2011 (prefix KJ).
 
 

Bearings in inch sizes:

 
 
  • ANSI/ABMA 19.2:2013 (prefix K).
 
 

Tapered roller bearings of basic design

Fundamental design features

 

Tapered roller bearings are part of the group of radial roller bearings. In contrast to the ball, the roller has a larger contact area perpendicular to the roller axis. As a result, it can transmit higher forces, has greater rigidity
Resistance to displacement under load in the elastic deformation area, dependent on bearing clearance and bearing type

See Deflection
and allows smaller rolling element
Point or rotationally symmetrical bodies for transmitting loads between raceways.
diameters under the same load. The single row and multi-row bearings comprise a ribless outer ring, an inner ring with two ribs of different heights and a cage ➤ Figure 2, ➤ Figure 5. The cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
contains truncated conical rollers. The roller and cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
assembly together with the inner ring forms a unit. The low rib retains, in conjunction with the cage, the rollers
Barrel-shaped, tapered or cylindrical rolling elements
on the inner ring raceway; the high rib supports the axial force component arising from the tapered form of the rollers. While the tapered rollers
Barrel-shaped, tapered or cylindrical rolling elements
roll on the raceways, they slide on the higher rib of the inner ring. The projected lines of contact of the tapered rollers
Barrel-shaped, tapered or cylindrical rolling elements
intersect the projected raceways of the inner and outer ring at a point on the bearing axis ➤ Figure 2. As a result of this geometrical characteristic, tapered roller bearings are highly suitable for supporting combined loads. This also prevents any kinematic forced slippage at the rolling contact.

 

The high dimensional and geometrical accuracy
Deviation of the actual dimension from the nominal dimension as described by tolerances. For monorail systems, the parallel deviation of the reference surfaces within given tolerances.

See
Running accuracy
Dimensional accuracy
of the rollers
Barrel-shaped, tapered or cylindrical rolling elements
reduces running noise and vibrations

 

Due to the dimensional and geometrical accuracy
Deviation of the actual dimension from the nominal dimension as described by tolerances. For monorail systems, the parallel deviation of the reference surfaces within given tolerances.

See
Running accuracy
Dimensional accuracy
of the tapered rollers, the rolling elements in a roller set are subjected to virtually the same proportion of load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
in the load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
range. In operation, this leads to low-noise and low-vibration running, as well as a high adjustment accuracy.

 
   

Figure 2
Single row tapered roller bearing: the apex points of the tapered surfaces
The effective surface is the surface which separates the object from its surrounding medium.The actual surface is the approximate image from measuring technology of the ideal geometric surface. Note: various measuring processes or measuring conditions (e.g. stylus radius) can give different actual surfaces.The geometric surface is an ideal surface whose nominal form is defined by a drawing or other technical documentation. See DIN 4760 for further details.

See
Surface protection
Surface tension
meet at a point on the bearing axis

Fr =  radial load
Fa =  axial load
R =  roller cone apex
α =  nominal contact angle

 

imageref_21605642123_All.gif

 
 

X-life premium quality

imageref_19964530187_All.gif   Single row tapered roller bearings are available in numerous series and dimensions as X-life bearings. These bearings exhibit considerably higher performance than comparable tapered roller bearings without X-life characteristics ➤ Figure 3. This is achieved, in part, by superior ring materials and optimised contact geometry between roller and raceway, as well as between roller and rib. In combination with an increased surface quality, this leads to improved lubricant film
Layer separating the sliding or rolling partners
formation.
 
 

Advantages

 

These technical enhancements offer a range of advantages, such as:

 
 
  • up to 20 % higher basic dynamic load
    The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
    ratings Cr ➤ Figure 3
  • a higher running accuracy
    Measured in terms of radial runout and axial runout, due to the dimensional and geometrical tolerances of the bearing in motion, defined according to DIN
    and smooth running
  • running with reduced friction
    The resistance to relative movement of two bodies in contact with each other; subdivided into friction terms, friction types and friction conditions
    and greater energy efficiency (reduction in friction
    The resistance to relative movement of two bodies in contact with each other; subdivided into friction terms, friction types and friction conditions
    up to 50 %, in the case of tapered roller bearings with a steep taper, up to 75 %)
  • lower heat generation in the bearing
  • higher limiting speeds
  • lower lubricant
    Gaseous, fluid, consistent, plastic or solid material for reduction of friction and wear between two friction elements.
    consumption and therefore longer maintenance
    Inspection, maintenance and repair of equipment and machines.
    intervals if relubrication is carried out
  • a measurably longer operating life
    See Life, rating
    of the bearings ➤ Figure 4
  • high reliability and operational security
  • lower overall operating costs
  • compact, environmentally-friendly bearing arrangements.
 

Lower operating costs, higher machine availability

 

In conclusion, these advantages improve the overall cost-efficiency of the bearing position significantly and thus bring about a sustainable increase in the efficiency of the machine and equipment.

 

Suffix XL

 

X-life tapered roller bearings include the suffix XL in the designation ➤ section .

 
   

Figure 3
Comparison of basic dynamic load
The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
rating Cr of X-life tapered roller bearings with bearings without X-life performance

Cr =  basic dynamic load
The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
rating

 

imageref_21634074635_All.gif

 
   

Figure 4
Fatigue running time in Weibull diagram – comparison of X-life tapered roller bearings with bearings without X-life performance

Symbole/00016410_mei_in_0k_0k.gif  Probability of failure
Symbole/00016411_mei_in_0k_0k.gif  Running time in hours

 

imageref_21610121483_All.gif

 
 

Areas of application

Areas of application

 

Due to their special technical features, X-life tapered roller bearings are highly suitable for bearing arrangements in:

 
 
  • mobile hydraulics (axial piston and orbital motors)
  • tractors (wheel bearings and gearboxes)
  • vertical mills (grinding rolls)
  • hot and cold rolling mills (work rolls in roll stands)
  • applications for oil
    Fluid lubricant with a mineral oil and/or synthetic oil base, usually with active ingredients or additives.
    and gas extraction
  • offshore and onshore wind turbines (gearboxes)
  • construction machinery (road rollers, drill head bearings).
 
imageref_17757210635_All.gif   X-life indicates a high product performance density
Mass ratio of a lubricant with respect to its volume to DIN 51 757.

Usual units for solid materials (apparent density):
- gramms per cubic centimeter g/cm3

fluids:
- gramms per millilitre g/ml

gases:
- kilogrammes per cubic meter kg/cm3

Other permissible units are kg/dm3, kg/cm3, kg/l
and thus a particularly significant benefit to the customer. Further information on X-life   ➤ link and ➤ TPI 241.
 
 

Single row tapered roller bearings

Optimised product characteristics give a sustainable improvement in operating behaviour

 

Tapered roller bearings are individual, single row bearings of open design which, for technical reasons, are always adjusted against a second tapered roller bearing
See Rolling bearing
in a mirror image arrangement ➤ Figure 5. The bearings are designed such that they reliably cover
Device for protecting guidance elements against contaminants, swarf, coolant lubricants and mechanical damage.
the extensive demands in relation to generally common requirements. For example, in order to improve the lubricant film
Layer separating the sliding or rolling partners
formation and running characteristics, the sliding surfaces
The effective surface is the surface which separates the object from its surrounding medium.The actual surface is the approximate image from measuring technology of the ideal geometric surface. Note: various measuring processes or measuring conditions (e.g. stylus radius) can give different actual surfaces.The geometric surface is an ideal surface whose nominal form is defined by a drawing or other technical documentation. See DIN 4760 for further details.

See
Surface protection
Surface tension
on the guidance rib of the inner ring, as well as the end faces and contact profile of the rollers, have been optimised ➤ link . In addition, the high production accuracy
Deviation of the actual dimension from the nominal dimension as described by tolerances. For monorail systems, the parallel deviation of the reference surfaces within given tolerances.

See
Running accuracy
Dimensional accuracy
allows the bearings to be adjusted against each other with high functional security. This in turn leads to improved operating characteristics and thus to a higher operational reliability. Tapered roller bearings are not self-retaining. As a result, the inner ring with the roller and cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
assembly can be mounted separately from the outer ring. This gives simplified mounting of the bearings.

 
   

Figure 5
Single row tapered roller bearing

Fr =  radial load
Fa =  axial load
α =  nominal contact angle

 

imageref_21605644043_All.gif

 
 

Matched tapered roller bearings

 

If the load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
carrying capacity of a bearing is not sufficient or the shaft is to be guided in both directions with a specific axial clearance, then ready-to‑fit, matched bearing sets are available. Matched tapered roller bearings are essentially available in three arrangements comprising an X, O and tandem arrangement.

 
   

Figure 6
Matched tapered rolling bearing
Ready-to-fit machine element, often defined in standards, for transmitting movements, loads and tilting moments with a high level of efficiency; rolling bearings consist of rolling elements, cages and raceways on rings, guideways or carriages as well as lubricant and, if necessary, seals and accessories
pairs in tandem, X and O arrangement, load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
directions, contact lines

Fr =  radial load
Fa =  axial load
Symbole/00016410_mei_in_0k_0k.gif  X arrangement
Symbole/00016411_mei_in_0k_0k.gif  O arrangement
Symbole/00016412_mei_in_0k_0k.gif  Tandem arrangement
Symbole/00016413_mei_in_0k_0k.gif  Fit ring

 

imageref_21610117643_All.gif

 

X arrangement

 

For bearing sets in an X arrangement, the contact lines converge relative to the bearing axis ➤ Figure 6. Axial forces occur from both directions, but are always only supported by one bearing. The X arrangement is of simple design and the most frequently used arrangement of matched tapered roller bearings fitted in pairs.

 

O arrangement

 

For bearing sets in an O arrangement, the contact lines diverge relative to the bearing axis ➤ Figure 6. Axial forces occur from both directions, but are always only supported by one bearing. The support base is at its largest in the O arrangement, which is beneficial if the component with small bearing spacing must be guided with the smallest possible tilting
Deviation from the normal position due to load or geometrical influence

See Misalignment error
clearance, or tilting
Deviation from the normal position due to load or geometrical influence

See Misalignment error
forces must be supported. Bearing arrangements in an O arrangement are relatively rigid and can also support loads resulting from tilting
Deviation from the normal position due to load or geometrical influence

See Misalignment error
moments.

 

Tandem arrangement

 

For bearing sets in a tandem arrangement, the contact lines run parallel to each other. In contrast to an X and O arrangement, the tandem arrangement can only support axial force in one direction. This bearing pair is usually adjusted against another tapered roller bearing, which supports axial forces in the opposite direction.

 
imageref_18348417035_All.gif   The product tables ➤ dimension table contain only a few examples of matched tapered roller bearing
See Rolling bearing
sets in an X arrangement for reference purposes. Other matched tapered roller bearing
See Rolling bearing
sets are available in an X arrange­ment by agreement. Further information on “Matched tapered roller bearings” ➤ TPI 245.
 
 

Matched bearing pairs in an O or X arrangement provide an economical solution to various bearing arrangement
Arrangement of bearings, for example locating/locating, semi-locating/semi-locating, non-locating/non-locating, or semi-locating bearings in tandem, O or X arrangement
problems due, for example, to:

 
   
 

Ordering and designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
system

Ordering and designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
system

 

In order to simplify the ordering process, the ordering designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
has been modified for matched tapered roller bearings fitted in pairs:

 
 
  • The first module letter D = 2 (duplex) represents the number of bearings
  • The second module letter represents the bearing arrangement:
    • B = O arrangement – Back to Back
    • F = X arrangement – Face to Face
    • T = tandem arrangement
  • Where necessary (special design), a third module letter is added as a continuous counter for describing a variant. Example: A, B, … = different set width, variant of intermediate ring design
  • The axial internal clearance is indicated explicitly in the designation. For example, A80-120 means that the axial internal clearance of the unmounted bearing pair (delivered condition) is between 80 μm and 120 μm. Ordering example ➤ Figure 15.
 
imageref_17757187211_All.gif   The number of bearing pairs must be stated when ordering matched tapered roller bearings.  
 

Integral tapered roller bearings (JK0S) – fitted in pairs

The bearings are predominantly fitted in pairs

 

Integral tapered roller bearings are ready-to-fit bearing units, which are greased, sealed on one side and predominantly mounted in pairs in an O arrangement ➤ Figure 7. The bearings are not separable.

 

There is no need to set the axial internal clearance

 

The precise axial internal clearance is not achieved by adjusting the bearings, but is set automatically when the recommended bearing seat tolerances
See
Running accuracy
Dimensional accuracy
are observed. As a result, there is no need to adjust the bearings against each other in the manner normally required. When integral tapered roller bearings are mounted in pairs, a slot is formed on the outer ring for the retaining ring (snap ring BR). Schaeffler integral tapered roller bearings are interchangeable with each other.

 
 

When ordering, please always state the number of single bearings and not the number of bearing pairs. The snap ring must be ordered separately, for example:

 
 
  • 2 tapered roller bearings JK0S080-A ➤ dimension table
  • 1 snap ring BR125.
 
 

   

Figure 7
Paired integral tapered roller bearing, load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
directions

Fr =  radial load
Fa =  axial load
Symbole/00016410_mei_in_0k_0k.gif  Integral tapered roller bearings (JK0S), fitted in pairs in an O arrangement, sealed, clearance preset

 

imageref_21610119563_All.gif

 
 

Load carrying capacity

 
 

Bearings of basic design

Capable of supporting axial loads in one direction and radial loads

 

Single row tapered roller bearings can support axial loads in one direction and high radial loads ➤ Figure 2 and ➤ Figure 5. However, they must always be axially adjusted against a second bearing fitted in a mirror image arrangement. This bearing combination is then fitted in an O or X arrangement.

 

The larger the contact angle, the higher the axial load
Force acting in the direction of the shaft.
carrying capacity

 

The axial load
Force acting in the direction of the shaft.
carrying capacity of the bearings is dependent on the nominal contact angle α ➤ Figure 2. The greater this angle, the higher the axial load
Force acting in the direction of the shaft.
to which the bearing can be subjected. The size of the contact angle – and thus the load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
carrying capacity of the bearing – is indicated by the value e in the product tables ➤ dimension table. The nominal contact angle α in most bearing series is between 10° and 20°. In special series, α is approximately 28° to 30°. Bearings of series 313, 323..-B, T5ED and T7FC have a very high axial load
Force acting in the direction of the shaft.
carrying capacity due to their particularly large contact angle.

 
 

Basic load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
rating and
fatigue limit load
for bearing pairs comprising single bearings

Basic load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
rating and
fatigue limit load
for bearing pairs comprising single bearings

 

If two bearings of the same size and design are fitted immediately adjacent to each other in an O or X arrangement, the basic dynamic load
The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
rating Cr
, the basic static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
rating C0r
and the fatigue
Structural changes, apparent as surface delamination, caused by a large number of overrolling movements under load
limit load Cur of the bearing pair are as follows:

 
 
  • Cr = 1,715 · Cr single bearing
  • C0r = 2 · C0r single bearing
  • Cur = 2 · Cur single bearing.
 
 

Values for single bearings in the product tables ➤ dimension table, ➤ dimension table.

 
 

Matched bearings

Capable of supporting radial loads, axial loads in both directions and moment loads

 

Matched tapered roller bearings support higher radial forces than single row tapered roller bearings. In X and O arrangements, axial forces and moment loads are supported in both directions. The tandem arrangement can only support axial forces in one direction.

 
 

Basic load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
rating and fatigue
Structural changes, apparent as surface delamination, caused by a large number of overrolling movements under load
limit load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
for matched bearings

 

For matched bearing pairs of design DF, the basic load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
ratings and fatigue
Structural changes, apparent as surface delamination, caused by a large number of overrolling movements under load
limit loads are given in the dimension tables ➤ dimension table.

 
 

Integral tapered roller bearings – fitted in pairs

Capable of supporting axial loads in both directions and radial loads

 

Single row integral tapered roller bearings fitted in pairs in an O arrangement support high axial loads in both directions and high radial loads ➤ Figure 7.

 
 

Compensation of angular misalignments

 

Compensation of angular misalignments possible

 

The modified line contact between the tapered rollers
Barrel-shaped, tapered or cylindrical rolling elements
and the raceways ensures optimum stress
Mechanical, mechanical-thermal, mechanical-chemical or tribological influences acting individually or jointly on a component
distribution at the contact points and prevents stress
Mechanical, mechanical-thermal, mechanical-chemical or tribological influences acting individually or jointly on a component
increases at the edges. As a result, the bearings can tolerate certain angular misalignments and give better support of moment loads ➤ Figure 8.

 
   

Figure 8
Uniform load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
distribution due to optimised roller and raceway profile

F =  load on the roller
Symbole/00016410_mei_in_0k_0k.gif  Straight profile
Symbole/00016411_mei_in_0k_0k.gif  Logarithmic profile

 

imageref_22767956235_All.gif

 
 

Permissible angular misalignment

imageref_17757187211_All.gif   If the load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
ratio P/C0r ≦ 0,2, the tilting
Deviation from the normal position due to load or geometrical influence

See Misalignment error
of the bearing rings relative to each other must not exceed 4 angular minutes. This is, however, subject to the position of the shaft and housing
See Mounting dimenstions
axis remaining constant (no dynamic movements).
 
imageref_18348417035_All.gif   If larger loads/misalignments or dynamic angular defects are present, please consult Schaeffler.  
 

Lubrication

 
 

Single row and matched tapered roller bearings

Oil or grease
See
Lubricant
Grease cartridge
Fatty acids
lubrication
Feed of fresh lubricant to friction points. Fresh lubricant mixes with used lubricant at the friction point. Lubricant feed is by means of lubrication equipment. The time period for relubrication is shorter than that for the lubricant change interval.

See
Lubrication method
Lubrication condition
Recirculating lubrication
Lubrication technology
One-off lubrication
Hydrodynamic lubrication
Lubricant change intervall
Lubricant change
Lubricant
Lubricant paste
Oil
Grease
Lubrication film
Lubrication system
is possible

 

Single row and matched tapered roller bearings are not greased. These bearings must be lubricated with oil
Fluid lubricant with a mineral oil and/or synthetic oil base, usually with active ingredients or additives.
or grease.

 

Compatibility with plastic cages

 

When using bearings with plastic cages, compatibility between the lubricant
Gaseous, fluid, consistent, plastic or solid material for reduction of friction and wear between two friction elements.
and the cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
material must be ensured if synthetic oils, lubricating greases
Consistent grease with a mineral oil and/or synthetic oil base with thickener as well as active ingredients or additives. See DIN 51 825 part 1 for demands on greases, grease type K, operating temperature range -20 to 140°C or DIN 51 825 part 2, for grease type KT.
with a synthetic oil
Fluid lubricant with a mineral oil and/or synthetic oil base, usually with active ingredients or additives.
base or lubricants containing a high proportion of EP additives are used.

 

Observe oil change
See Lubricant change
intervals

 

Aged oil
Fluid lubricant with a mineral oil and/or synthetic oil base, usually with active ingredients or additives.
and additives
Lubricant additive to improve viscosity-temperature behaviour or pour point, prevent corrosion, oxidation or ageing or reduce wear or foaming
in the oil
Fluid lubricant with a mineral oil and/or synthetic oil base, usually with active ingredients or additives.
can impair the operating life
See Life, rating
of plastics at high temperatures. As a result, stipulated oil change
See Lubricant change
intervals must be strictly observed.

 
 

Integral tapered roller bearings

Usually maintenance-free due to initial greasing

 

Integral tapered roller bearings are supplied already greased with a quality
See DIN 55 350 part 11 and ISO 8402 for terminology and definitions.
grease
See
Lubricant
Grease cartridge
Fatty acids
to DIN 51825. The grease
See
Lubricant
Grease cartridge
Fatty acids
filling is measured such that these bearings are maintenance-free during their operating lives in most applications.

 
 

Sealing

 
 

Single row and matched tapered roller bearings

 

Single row and matched tapered roller bearings are not sealed, i.e. sealing
See Seals
of the bearing position must be carried out in the adjacent construction. This must reliably prevent:

 
 
  • moisture and contaminants from entering the bearing
  • the egress of lubricant
    Gaseous, fluid, consistent, plastic or solid material for reduction of friction and wear between two friction elements.
    from the bearing position.
 
 

Integral tapered roller bearings

 

Integral tapered roller bearings are sealed on one side with a contact seal
See Seal
(lip seal).

 
 

Speeds

 
 

The product tables give two speeds for most bearings ➤ dimension table:

 
 
  • the kinematic limiting speed nG
  • the thermal speed rating nϑr.
 
 

Limiting speeds

imageref_17757187211_All.gif   The limiting speed nG is the kinematically permissible speed of the bearing. Even under favourable mounting and operating conditions, this value should not be exceeded without prior consultation with Schaeffler    ➤ link.  
 

Reference speeds

nϑr is used to calculate nϑ

 

The thermal speed rating nϑr is not an application-oriented speed limit, but is a calculated ancillary value for determining the thermally safe operating speed nϑ    ➤ link.

 

Bearings with contact seals

 

For bearings with contact seals, no reference speeds are defined in accordance with DIN ISO 15312:2004. As a result, only the limiting speed nG is given in the product tables for these bearings.

 
 

Speeds for matched bearings fitted in pairs

Observing the thermal balance

 

For matched bearing pairs, the limiting speeds nG given in the product tables are permissible if the less favourable thermal balance of the bearing pair is taken into consideration in the operating conditions.

 
 

Noise

 
 

The Schaeffler Noise Index (SGI) has been developed as a new feature for comparing the noise level of different bearing types and series. As a result, a noise evaluation of rolling bearings can now be carried out for the first time.

 
 

Schaeffler Noise Index

 

The SGI value is based on the maximum permissible noise level of a bearing in accordance with internal standards, which is calculated on the basis of ISO 15242. In order that different bearing types and series can be compared, the SGI value is plotted against the basic static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
rating C0.

 
 

This permits direct comparisons between bearings with the same load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
carrying capacity. The upper limit value is given in each of the diagrams. This means that the average noise level of the bearings is lower than illustrated in the diagram.

 
imageref_17757187211_All.gif   The Schaeffler Noise Index is an additional performance characteristic in the selection of bearings for noise-sensitive applications. The specific suitability of a bearing for an application in terms of installation space, load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
carrying capacity or speed limit for example, must be checked independently of this.
 
 

   

Figure 9
Schaeffler Noise Index for tapered roller bearings

SGI =  Schaeffler Noise Index
C0 =  basic static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
rating

 

imageref_23602437643_All.gif

 
 

Temperature range

 
 

The operating temperature
A measured relubrication interval can be achieved within given limits. The lubricant should be sufficiently thermally stable at the upper operating temperature and should not be too thick at the lower operating temperature.
of the bearings is limited by:

 
 
  • the dimensional stability of the bearing rings and tapered rollers
  • the cage
  • the lubricant
  • the seals.
 
 

 

Possible operating temperatures of tapered roller bearings ➤ Table 1

 
   
Table 1
Permissible temperature ranges
 

Operating temperature
Open tapered roller bearings
Sealed tapered
roller bearings
imageref_19988082955_All.gif
   
D ≦ 220 mm,
–30 °C to +120 °C
D > 220 mm,
–30 °C to +200 °C
–30 °C to +110 °C,
limited by the lubricating grease
See
Lubricant
Grease cartridge
Fatty acids
and seal
Elements such as axial face seal, labyrinth seal, rotary shaft seal or gap seal which prevent the ingress of gaseous, liquid and solid materials through the gaps between combined components during movement or whilst stationary
material

 
imageref_18348417035_All.gif   In the event of anticipated temperatures which lie outside the stated values, please contact Schaeffler.  
 

Cages

 

Sheet steel cages are used as standard

 

Open tapered roller bearings have sheet steel cages. Plastic cages are available by agreement.

 

Cages for JK0S

 

Integral tapered roller bearings have cages made from glass fibre reinforced polyamide PA66.

 
imageref_18348417035_All.gif   For high continuous temperatures and applications with difficult operating conditions, bearings with sheet steel cages should be used. If there is any uncertainty regarding cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
suitability, please consult Schaeffler.
 
 

Internal clearance

 
 

For tapered roller bearings, the axial internal clearance sa is a character­istic value. This is the result of mounting the bearing against a second tapered roller bearing ➤ Figure 10.

 
   

Figure 10
Axial internal clearance

sa =  axial internal clearance

 

imageref_22516887435_All.gif

 

Indicating the axial internal clearance

 

The axial internal clearance is indicated explicitly in the designation. Ordering example ➤ Figure 15.

 
 

Matched tapered roller bearing
See Rolling bearing
sets

Matched tapered roller bearing
See Rolling bearing
sets

 

Simple mounting of the bearing sets in the mounting position is achieved by precise matching of the intermediate ring to the required geometric axial internal clearance. As a result, ready-to-fit, matched bearing sets are made available by Schaeffler. This offers high economical and technical advantages such as:

 
   
 

Dimensions, tolerances

 
 

Dimension standards – bearings in metric sizes

imageref_17757201419_All.gif   The main dimensions of bearings in metric sizes correspond to ISO 355:2007 and DIN 720:2008. Bearings in metric sizes with the prefix KJ correspond to ANSI/ABMA 19.1:2011.  
 

Chamfer dimensions

 

Tapered roller bearings in metric sizes

 

The limiting dimensions for the chamfer dimensions of metric tapered roller bearings to DIN/ISO correspond to ISO 582:1995. Overview and limiting values for metric tapered roller bearings to DIN/ISO ➤ Table .

 
 

Minimum chamfer dimensions for metric tapered roller bearings to ANSI/ABMA with the prefix KJ correspond to ANSI/ABMA 19.1:2011. The values are given in the product tables.

 
 

Bearings in inch sizes to ANSI/ABMA

imageref_17757201419_All.gif   Minimum chamfer dimensions rmin for bearings in inch sizes correspond to ANSI/ABMA 19.2:2013. The values are given in the product tables ➤ dimension table.  
 

Tolerances

imageref_17757201419_All.gif   All tapered roller bearings to DIN 720, ISO 355 and integral tapered roller bearings have the tolerance class Normal to ISO 492:2014. In contrast to the standard, X-life bearings achieve improved radial runout values tKia and tKea, in addition to dedicated axial runout values tSia ➤ Figure 11. Inner ring tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 2, outer ring tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 3, width tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 4. This excludes bearings of series 320, 329, 330, 331, 332 for d ≦ 200 mm: these have the tolerance class 6X ➤ link . The width tolerances tΔTs of the T7FC series with the suffix XL correspond to the tolerance class 6X in accordance with ISO 492:2014 ➤ Table 5.
 
   
Table 2
Inner ring tolerances, tolerance class Normal
 

Nominal
bore diameter
Bore deviation
Variation
Radial runout
Axial runout
ISO 492
X-life
X-life
d
tΔdmp
tVdsp
tVdmp
tKia
tKia
tSia
mm
μm
μm
μm
μm
μm
μm
over
incl.
U
L
max.
max.
max.
max.
max.
10
18
0
–12
12
9
15
7
10
18
30
0
–12
12
9
18
8
13
30
50
0
–12
12
9
20
9
13
50
80
0
–15
15
11
25
10
15
80
120
0
–20
20
15
30
13
18
120
180
0
–25
25
19
35
19
20
180
250
0
–30
30
23
50
24
25
250
315
0
–35
35
26
60
28
28
315
400
0
–40
40
30
70
33
35

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
tSia =  axial runout to Schaeffler standard ➤ Figure 11
 
   
Table 3
Outer ring tolerances, tolerance class Normal
 

Nominal
outside diameter
Deviation
of outside diameter
Variation
Radial runout
ISO 492
X-life
D
tΔDmp
tVDsp
tVDmp
tKea
tKea
mm
μm
μm
μm
μm
μm
over
incl.
U
L
max.
max.
max.
max.
18
30
0
–12
12
9
18
9
30
50
0
–14
14
11
20
10
50
80
0
–16
16
12
25
13
80
120
0
–18
18
14
35
16
120
150
0
–20
20
15
40
19
150
180
0
–25
25
19
45
21
180
250
0
–30
30
23
50
25
250
315
0
–35
35
26
60
30
315
400
0
–40
40
30
70
34
400
500
0
–45
45
34
80
40
500
630
0
–50
60
38
100
46

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
 
   
Table 4
Width tolerances, tolerance class Normal
 

Nominal
bore diameter
Deviation
of inner ring width
Deviation
of outer ring width
Width deviation
d
tΔBs
tΔCs
tΔTs
tΔT1s
tΔT2s
mm
μm
μm
μm
μm
μm
over
incl.
U
L
U
L
U
L
U
L
U
L
10
18
0
–120
0
–120
+200
0
+100
0
+100
0
18
30
0
–120
0
–120
+200
0
+100
0
+100
0
30
50
0
–120
0
–120
+200
0
+100
0
+100
0
50
80
0
–150
0
–150
+200
0
+100
0
+100
0
80
120
0
–200
0
–200
+200
–200
+100
–100
+100
–100
120
180
0
–250
0
–250
+350
–250
+150
–150
+200
–100
180
250
0
–300
0
–300
+350
–250
+150
–150
+200
–100
250
315
0
–350
0
–350
+350
–250
+150
–150
+200
–100
315
400
0
–400
0
–400
+400
–400
+200
–200
+200
–200

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
 
   

Figure 11
Axial and radial runout on the drawing

D =  outside diameter
d =  bearing bore

 

imageref_22512669579_All.gif

 
 

Series 320, 329, 330, 331, 332 for d ≦ 200 mm and bearings with the prefix KJ

 

Bearings 320, 329, 330, 331, 332 for d ≦ 200 mm and bearings with the prefix KJ have dimensional and running tolerances
See
Running accuracy
Dimensional accuracy
to the tolerance class Normal, but have restricted width tolerances
See
Running accuracy
Dimensional accuracy
to tolerance class 6X in accordance with ISO 492:2014 ➤ Table 5; inner ring tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 2, outer ring tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 3.

 
   
Table 5
Width tolerances, tolerance class 6X
 

Nominal
bore diameter
Deviation
of inner ring width
Deviation
of outer ring width
Width deviation
d
tΔBs
tΔCs
tΔTs
tΔT1s
tΔT2s
mm
μm
μm
μm
μm
μm
over
incl.
U
L
U
L
U
L
U
L
U
L
10
18
0
–50
0
–100
+100
0
+50
0
+50
0
18
30
0
–50
0
–100
+100
0
+50
0
+50
0
30
50
0
–50
0
–100
+100
0
+50
0
+50
0
50
80
0
–50
0
–100
+100
0
+50
0
+50
0
80
120
0
–50
0
–100
+100
0
+50
0
+50
0
120
180
0
–50
0
–100
+150
0
+50
0
+100
0
180
200
0
–50
0
–100
+150
0
+50
0
+100
0

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
 
 

Restricted tolerances
See
Running accuracy
Dimensional accuracy
to tolerance class 5

imageref_18348417035_All.gif   Tapered roller bearings are also available by agreement with restricted tolerances
See
Running accuracy
Dimensional accuracy
to tolerance class 5 in accordance with ISO 492:2014; inner ring tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 6, outer ring tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 7, width tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 8.
 
   
Table 6
Restricted inner ring tolerances, tolerance class 5
 

Nominal
bore diameter
Bore deviation
Variation
Radial runout
Axial runout of lateral face
d
tΔdmp
tVdsp
tVdmp
tKia
tSd
mm
μm
μm
μm
μm
μm
over
incl.
U
L
max.
max.
max.
max.
10
18
0
–7
5
5
5
7
18
30
0
–8
6
5
5
8
30
50
0
–10
8
5
6
8
50
80
0
–12
9
6
7
8
80
120
0
–15
11
8
8
9
120
180
0
–18
14
9
11
10
180
250
0
–22
17
11
13
11
250
315
0
–25
19
13
13
13
315
400
0
–30
23
15
15
15

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
 
   
Table 7
Restricted outer ring tolerances, tolerance class 5
 

Nominal
outside diameter
Deviation
of outside diameter
Variation
Radial runout
Axial runout of lateral face
D
tΔDmp
tVDsp
tVDmp
tKea
tSi
mm
μm
μm
μm
μm
μm
over
incl.
U
L
max.
max.
max.
max.
18
30
0
–8
6
5
6
4
30
50
0
–9
7
5
7
4
50
80
0
–11
8
6
8
4
80
120
0
–13
10
7
10
4,5
120
150
0
–15
11
8
11
5
150
180
0
–18
14
9
13
5
180
250
0
–20
15
10
15
5,5
250
315
0
–25
19
13
18
6,5
315
400
0
–28
22
14
20
6,5
400
500
0
–33
26
17
24
8,5
500
630
0
–38
30
20
30
10

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
 
   
Table 8
Width tolerances, tolerance class 5
 

Nominal
bore diameter
Deviation
of inner ring width
Deviation
of outer ring width
Width deviation
d
tΔBs
tΔCs
tΔTs
tΔT1s
tΔT2s
mm
μm
μm
μm
μm
μm
over
incl.
U
L
U
L
U
L
U
L
U
L
10
18
0
–200
0
–200
+200
–200
+100
–100
+100
–100
18
30
0
–200
0
–200
+200
–200
+100
–100
+100
–100
30
50
0
–240
0
–240
+200
–200
+100
–100
+100
–100
50
80
0
–300
0
–300
+200
–200
+100
–100
+100
–100
80
120
0
–400
0
–400
+200
–200
+100
–100
+100
–100
120
180
0
–500
0
–500
+350
–250
+150
–150
+200
–100
180
250
0
–600
0
–600
+350
–250
+150
–150
+200
–100
250
315
0
–700
0
–700
+350
–250
+150
–150
+200
–100
315
400
0
–800
0
–800
+400
–400
+200
–200
+200
–200

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
 
 

Total width tolerance of matched bearings

imageref_17757201419_All.gif   The tolerance for the total width 2T of matched bearing sets of design DF is determined from the axial internal clearance and the deviations of the width tΔTs of the single bearings. The tolerance for the total width 2B is determined from the deviations of the inner ring width tΔBs of the single bearings ➤ Table 4.  
 

Bearings in inch sizes to ANSI/ABMA

imageref_17757201419_All.gif   Tapered roller bearings with the prefix K are manufactured as standard to the following tables. The values in the tables meet the requirements for normal tolerances
See
Running accuracy
Dimensional accuracy
in accordance with ANSI/ABMA 19.2:2013 and, in some cases, exceed these by a considerable margin. Exception: bearings with the prefix KJ correspond to ISO 492:2014. The bore and outside diameters of bearings in inch sizes have plus tolerances; inner ring tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 9, outer ring tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 10, width tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 11.
 
   
Table 9
Inner ring tolerances, bearings in inch sizes
 

Nominal
bore diameter
Bore deviation
Radial runout
Axial runout
According
to standard
X-life
X-life
d
tΔdmp
tKia
tKia
tSia
mm
μm
μm
μm
μm
over
incl.
U
L
max.
max.
max.
10
18
+12
0
15
7
10
18
30
+12
0
18
8
13
30
50
+12
0
20
9
13
50
80
+12
0
25
10
15
80
120
+25
0
30
13
18
120
180
+25
0
35
19
20
180
250
+25
0
50
24
25
250
304,8
+25
0
50
28
28
304,8
315
+50
0
50
28
28
315
400
+50
0
50
33
35
400
500
+50
0
50
39
38
500
609,6
+50
0
50
45
43
609,6
800
+75
0
75
54
-

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
tSia =  axial runout to Schaeffler standard ➤ Figure 11
 
   
Table 10
Outer ring tolerances, bearings in inch sizes
 

Nominal
outside diameter
Bore deviation
Radial runout
According
to standard
X-life
D
tΔDmp
tKea
tKea
mm
μm
μm
μm
over
incl.
U
L
max.
max.
18
30
+25
0
18
9
30
50
+25
0
20
10
50
80
+25
0
25
13
80
120
+25
0
35
16
120
150
+25
0
40
19
150
180
+25
0
45
21
180
250
+25
0
50
25
250
304,8
+25
0
50
29
304,8
609,6
+50
0
50
45
609,6
800
+75
0
75
54

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
 
   
Table 11
Width tolerances, bearings in inch sizes
 

Nominal
bore diameter
Deviation
of inner ring width
Deviation
of outer ring width
Width deviation
d
tΔBs
tΔCs
tΔTs
mm
μm
μm
μm
over
incl.
U
L
U
L
U
L
10
50
0
–120
0
–120
+200
0
50
80
0
–150
0
–150
+200
0
80
101,6
0
–200
0
–200
+200
0
101,6
120
0
–200
0
–200
+350
–250
120
180
0
–250
0
–250
+350
–250
180
304,8
0
–250
0
–250
+350
–250
304,8
800
0
–250
0
–250
+375
–375

 
 
______
Tolerance symbols ➤ Table
U =  upper limit deviation
L =  lower limit deviation
 
 

Suffixes

 
 

For a description of the suffixes used in this chapter ➤ Table 12 and medias interchange http://www.schaeffler.de/std/1D52.

 
   
Table 12
Suffixes and corresponding descriptions
 

Suffix
Description of suffix
A
Modified internal construction (excluding bearings to ANSI/ABMA)
B
Increased contact angle
See
Operating contact angle
Nominal contact angle
(for bearings to DIN)
DF-A..-..
Two tapered roller bearings matched in an X arrangement,
with an intermediate ring between the outer rings. Axial internal clearance between .. and .. in μm
X
External dimensions matched to international standards
(for bearings to DIN)
XL
X-life

 
 

Tapered roller bearings for special applications

imageref_18348417035_All.gif   Special tapered roller bearings are available for applications where tapered roller bearing
See Rolling bearing
arrangements are used under very difficult operating conditions, for example at high operating temperatures or with heavily contaminated lubricating oil. In such cases, please consult Schaeffler. Suffixes for special designs ➤ Table 13.
 
   
Table 13
Special designs, available by agreement
 

Suffix
Description of suffix
DB-A..-..
Two tapered roller bearings matched in an O arrangement,
with an intermediate ring between the outer rings and the inner rings, axial internal clearance between .. and .. in μm
DT
Two tapered roller bearings matched in a tandem arrangement,
with an intermediate ring between the outer rings
P5
Bearing in tolerance class 5

 
 

Other special designs with suffixes are available by agreement, such as for:

 
 
  • dimensional stabilisation
  • special heat treatment
  • special materials
  • tapered roller bearings with reduced friction
  • tolerance classes
  • restricted width tolerances.
 
 

Structure of bearing designation

 

Examples of composition of bearing designation

 

The designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
of bearings follows a set model. Examples ➤ Figure 12 to ➤ Figure 16. The composition of designations is subject to DIN 623-1:1993    ➤ Figure, DIN 720:2008    ➤ Figure, ISO 10317:2008, ISO 355:2007    ➤ Figure, ANSI/ABMA 19.1:2011 and ANSI/ABMA 19.2:2013.

 
 

   

Figure 12
Single row tapered roller bearing, metric, to DIN 623-1:1993, DIN 720:2008: designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
structure


 

imageref_21610124555_en.gif

 
   

Figure 13
Single row tapered roller bearing, metric, to ISO 10317:2008, ISO 355:2007: designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
structure


 

imageref_22523984395_en.gif

 
   

Figure 14
Single row tapered roller bearing, metric, to ANSI/ABMA 19.1:2011; inch sizes, to ANSI/ABMA 19.2:2013: designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
structure


 

imageref_22524054923_en.gif

 
   

Figure 15
Matched tapered roller bearing
See Rolling bearing
pair: designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
structure


 

imageref_21610142731_en.gif

 
   

Figure 16
Integral tapered roller bearing: designation
Identification of a bearing by letters and numbers, indicating, for example, the series, dimensional series or size code, bore diameter, bearing design and information such as Corrotect plating or length of guideways
structure


 

imageref_21610148363_en.gif

 
 

Dimensioning

 
 

Equivalent dynamic bearing load

P = Fr under purely radial load
A force which acts at an angle of b = 0°.
of constant magnitude and direction

 

The basic rating life
The basic rating life is the life reached or exceeded by 90% of a sufficiently large group of apparently identical bearings before the first evidence of material fatigue develops
equation L = (Cr/P)p used in the dimensioning of radial bearings under dynamic load
The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
assumes a radial load P of constant magnitude. If the bearing is subjected to purely radial load, the radial load Fr is used directly in the rating life
The basic rating life is the life reached or exceeded by 90% of a sufficiently large group of apparently identical bearings before the first evidence of material fatigue develops
equation for P (P = Fr).

 

P is a substitute force for combined load
Indication of a force acting in a non-perpendicular direction on the bearing.
Load angle b not equal to 0° or 90°.

 

If this condition is not met, a constant radial force must first be determined for the rating life
The basic rating life is the life reached or exceeded by 90% of a sufficiently large group of apparently identical bearings before the first evidence of material fatigue develops
calculation that (in relation to the rating life) represents an equivalent load. This force is known as the equivalent dynamic bearing load P.

 

Fa/Fr ≦ e or Fa/Fr > e

 

The calculation of P is dependent on the load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
ratio Fa/Fr and the factor e.

 

Single bearings and JK0S bearings

 

For single bearings under dynamic load
The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
and integral tapered roller bearings ➤ Equation 1 and ➤ Equation 2

 

Equation 1
Equivalent dynamic load
 
imageref_19670284299_All.gif


Equation 2
Equivalent dynamic load
 
imageref_19993724683_All.gif

Legend

 
P
 N
Equivalent dynamic bearing load
Fr
 N
Radial load
Fa
 N
Resulting axial force ➤ Table 14. The information in the section “Calculation of internal resulting axial force Fa for single bearings” must be taken into consideration when calculating Fa ➤ link
e, Y
Factors ➤ dimension table.
 

Bearing pairs in O or X arrangement

 

For bearing pairs under dynamic load
The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
in an O or X arrangement comprising single bearings ➤ Equation 3 and ➤ Equation 4

 

Equation 3
Equivalent dynamic load
 
imageref_19994309899_All.gif


Equation 4
Equivalent dynamic load
 
imageref_19994973835_All.gif

Legend

 
P
 N
Equivalent dynamic bearing load
Fr
 N
Radial load
Fa
 N
Resulting axial force ➤ Table 14. The information in the section “Calculation of internal resulting axial force Fa for single bearings” must be taken into consideration when calculating Fa ➤ link
e, Y
Factors ➤ dimension table.
 

Matched bearing pairs

 

For matched bearing pairs under dynamic load 313 (320, 322, 329)..-DF-A ➤ Equation 5 and ➤ Equation 6.

 

Equation 5
Equivalent dynamic load
 
imageref_17794274443_All.gif


Equation 6
Equivalent dynamic load
 
imageref_21316669963_All.gif

Legend

 
P
 N
Equivalent dynamic bearing load
Fr
 N
Radial load
Fa
 N
Resulting axial force. The information in the section “Calculation of internal resulting axial force Fa for single bearings” must be taken into consideration when calculating Fa ➤ link
e, Y1, Y2
Factors ➤ dimension table.
 
 

Calculation of internal resulting axial force Fa for single bearings and for bearing pairs in an X and O arrangement

Reasons why the internal resulting axial force Fa must be taken into consideration

 

Single row tapered roller bearings transmit radial forces from one raceway to the other oblique to the bearing axis. In the case of a shaft supported by two single row tapered roller bearings of identical or different size, the radial load
A force which acts at an angle of b = 0°.
on bearing A leads, due to the inclination
See Angular misalignment
of the raceways 0 ≠ 0°), to an axial load
Force acting in the direction of the shaft.
on bearing B. The radial load
A force which acts at an angle of b = 0°.
on bearing B also has the effect of an axial load
Force acting in the direction of the shaft.
on bearing A; external forces in bearing systems of this type ➤ Figure 17 and ➤ Figure 18. This internal resulting axial force Fa must be taken into consideration in the calculation of the equivalent dynamic bearing load P.

 

Equations for calculation

 

Equations for calculation of resulting axial force Fa➤ Table 14.

 

Preconditions for calculation

 

Bearing A is subjected to a radial load FrA, bearing B to a radial load FrB ➤ Figure 17 and ➤ Figure 18. FrA and FrB act at the central pressure points of the bearings and are always regarded as positive. The bearings are clearance-free, but without preload.

 
imageref_17757187211_All.gif   The stated equations for determining the axial load
Force acting in the direction of the shaft.
correspond to an approximation carried out under the assumption of a load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
zone of 180° in bearings under radial load. For a more precise calculation, the use of BEARINX or BEARINX is recommended.
 
   
Table 14
Equations for calculation of the internal resulting axial force Fa
 

Case
Load ratio
External axial force
1
imageref_10902688267_All.gif
   
Ka ≧ 0
2
imageref_10903176715_All.gif
   
imageref_21564562187_All.gif
   
3
imageref_21564597259_All.gif
   
continued ▼

 
 
______
Parameters ➤ Equation 6, ➤ Figure 17 and ➤ Figure 18
 
 
YA = YB ➤ dimension table
 
   
Table 15
Equations for calculation of the internal resulting axial force Fa
 

Case
Load ratio
Resulting axial force Fa
Bearing A
Bearing B
1
imageref_10902688267_All.gif
   
imageref_21564456203_All.gif
   
Fa is not taken into con­sideration in the calculation
2
imageref_10903176715_All.gif
   
imageref_21564456203_All.gif
   
Fa is not taken into con­sideration in the calculation
3
Fa is not taken into con­sideration in the calculation
imageref_19998704267_All.gif
   
continued ▲

 
 
______
Parameters ➤ Equation 6, ➤ Figure 17 and ➤ Figure 18
 
 
YA = YB ➤ dimension table
 
   

Figure 17
Adjusted bearing arrangement
Arrangement of bearings, for example locating/locating, semi-locating/semi-locating, non-locating/non-locating, or semi-locating bearings in tandem, O or X arrangement
with two single row tapered roller bearings in O arrangement, external forces

Ka =  external axial force acting on the shaft
FrA =  radial load, bearing A
FrB =  radial load, bearing B

 

imageref_21610166795_All.gif

 
   

Figure 18
Adjusted bearing arrangement
Arrangement of bearings, for example locating/locating, semi-locating/semi-locating, non-locating/non-locating, or semi-locating bearings in tandem, O or X arrangement
with two single row tapered roller bearings in X arrangement, external forces

Ka =  external axial force acting on the shaft
FrA =  radial load, bearing A
FrB =  radial load, bearing B

 

imageref_21610988683_All.gif

 
 

Example of calculation of internal resulting axial force Fa

Bearing arrangement for pinion shaft

 

Two single row tapered roller bearings are used for the bearing arrangement
Arrangement of bearings, for example locating/locating, semi-locating/semi-locating, non-locating/non-locating, or semi-locating bearings in tandem, O or X arrangement
of a pinion shaft ➤ Figure 19. The bearing arrangement
Arrangement of bearings, for example locating/locating, semi-locating/semi-locating, non-locating/non-locating, or semi-locating bearings in tandem, O or X arrangement
should be adjusted and in an O arrangement. In order to calculate the basic rating life
The basic rating life is the life reached or exceeded by 90% of a sufficiently large group of apparently identical bearings before the first evidence of material fatigue develops
of bearing A, the equivalent dynamic bearing load PA must be determined.

 
   

Figure 19
BEARINX calculation model: load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
on bearing A and B

Ka =  external axial force = 6,52 kN
Kr =  external radial force
Kt =  tangential force
FrA =  radial load, bearing A (resultant of reaction forces FyA and FzA)
FrB =  radial load, bearing B (resultant of reaction forces FyB and FzB)
l1 =  spacing between pinion and contact cone apex of bearing A
l2 =  spacing between contact cone apexes of bearing A and bearing B

 

imageref_23085245451_All.gif

 
 

The resulting radial forces FrA and FrB on the bearings must be determined from the external radial force Kr and the tangential force Kt by the solution of the equilibrium of moments and forces on the shaft. Result:

 
 
  • FrA = 7,3 kN
  • FrB = 2,2 kN.
 

In a bearing arrangement
Arrangement of bearings, for example locating/locating, semi-locating/semi-locating, non-locating/non-locating, or semi-locating bearings in tandem, O or X arrangement
with two single bearings, the resulting axial force Fa must be taken into consideration

 

Since this is an adjusted bearing arrangement
Semi-locating bearing arrangement in X or O arrangement with adjusted clearance or preload.
with two single bearings, the internal resulting axial force Fa in the bearing system must be taken into consideration in the bearing calculation in accordance with ➤ Table 14. For both tapered roller bearings YA = YB = 1,6. Loads ➤ Figure 19.Tapered roller bearing 32206-XL is envisaged for bearing A.

 
 

Step 1

 

Calculate the load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
ratio using ➤ Equation 7.

 

Equation 7
Load ratio
 
imageref_23086686859_All.gif


Equation 8
 
imageref_23086691723_All.gif


Equation 9
 
imageref_23425555211_All.gif

 

Step 2

 

Compare the result with possible cases ➤ Table 14. Case 2 or case 3 can be considered ➤ Table 16.

 
   
Table 16
Equations for calculation of the internal resulting axial force Fa
 

Case
Load ratio
External axial force
Resulting axial force Fa
Bearing A
Bearing B
2
imageref_10903176715_All.gif
   
imageref_21564562187_All.gif
   
imageref_21564456203_All.gif
   
-
3
imageref_21564597259_All.gif
   
- imageref_19998704267_All.gif
   

 
 
______
Parameters ➤ Equation 6
 
 
YA = YB = 1,6
 
 

Step 3

 

Using ➤ Equation 10, check whether case 2 applies ➤ Table 16.

 

Equation 10
External axial force in relation to Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.See Contact surface ratio
 
imageref_21602763915_All.gif


Equation 11
 
imageref_21324076811_All.gif

 

If case 2 applies ➤ Table 16. This means that bearing A supports the external axial force Ka.

 
 

Step 4

Calculating Fa

 

Using ➤ Equation 12, calculate the internal resulting axial force Fa for bearing A. The calculations are in accordance with ➤ Table 16, case 2.

 

Equation 12
Internal resulting axial force for bearing A
 
imageref_21602783115_All.gif


Equation 13
 
imageref_21324087179_All.gif

 

Example of calculation of P

Using value Fa in the calculation of P

 

Using ➤ Equation 14, calculate the ratio between the axial force Fa and radial force Fr of bearing A and compare this with the limit value e in accordance with the product table (in this instance e = 0,37).

 

Equation 14
Load ratio, bearing A
 
imageref_23327599627_All.gif


Equation 15
 
imageref_23086984459_All.gif

  This gives:

Equation 16
 
imageref_23326036619_All.gif

 

As a result, the axial force Fa of bearing A (FaA) must be taken into consider­ation within the equivalent bearing load PA of bearing A ➤ Equation 2 and thus ➤ Equation 17 apply.

 

Equation 17
P for Fa/Fr > e
 
imageref_23327571851_All.gif


Equation 18
 
imageref_23086989579_All.gif

 

The equivalent dynamic bearing load PA of bearing A is then used to calculate the basic rating life
The basic rating life is the life reached or exceeded by 90% of a sufficiently large group of apparently identical bearings before the first evidence of material fatigue develops
of bearing A.

 
 

Equivalent static bearing load

Single bearings and JK0S bearings

 

For single bearings under static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
and integral tapered roller bearings ➤ Equation 19 and ➤ Equation 20.

 
 


Equation 19
Equivalent static load
 
imageref_20000460427_All.gif


Equation 20
Equivalent static load
 
imageref_20000467211_All.gif

Legend

 
P0
 N
Equivalent static bearing load
F0r, F0a
 N
Largest radial or axial load
Force acting in the direction of the shaft.
present (maximum load)
Y0
Axial load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
factor.
 
 

For bearing pairs under static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
in an O or X arrangement ➤ Equation 21

 

Equation 21
Equivalent static load
 
imageref_20000502027_All.gif

Legend

 
P0
 N
Equivalent static bearing load
F0r, F0a
 N
Largest radial or axial load
Force acting in the direction of the shaft.
present (maximum load)
Y0
Axial load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
factor.
 
 

For matched bearing pairs under static load 313 (320, 322, 329)..-DF-A.. ➤ Equation 22

 

Equation 22
Equivalent static load
 
imageref_20000537483_All.gif

Legend

 
P0
 N
Equivalent static bearing load
F0r, F0a
 N
Largest radial or axial load
Force acting in the direction of the shaft.
present (maximum load)
Y0
Axial load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
factor.
 
 

Static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
safety factor

S0 = C0/P0

 

In addition to the basic rating life L (L10h), it is also always necessary to check the static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
safety factor S0
 ➤ Equation 23.

 

Equation 23
Static Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.See Contact surface safety factor
 
imageref_27021597814984331_All.gif

Legend

 
S0
Static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
safety factor
C0
 N
Basic static load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
rating
P0
 N
Equivalent static bearing load.
 
 

Minimum load

 

In order to prevent damage
Loss of essential or required characteristics in equipment, machinery or plant or their component parts.
due to slippage, a minimum radial load
A force which acts at an angle of b = 0°.
of P > C0r/60 is required

 

In order that no slippage occurs between the contact partners, the tapered roller bearings must be constantly subjected to a sufficiently high load. Based on experience, a minimum radial load
A force which acts at an angle of b = 0°.
of the order of P > C0r/60 is thus necessary. In most cases, however, the radial load
A force which acts at an angle of b = 0°.
is already higher than the requisite minimum load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
due to the weight of the supported parts and the external forces.

 
imageref_18348417035_All.gif   If the minimum radial load
A force which acts at an angle of b = 0°.
is lower than indicated above, please consult Schaeffler.
 
 

Design of bearing arrangements

 
 

Radial location of bearings

For secure radial location, tight fits are necessary

 

In addition to supporting the rings adequately, the bearings must also be securely located in a radial direction, to prevent creep of the bearing rings on the mating parts under load. This is generally achieved by means of tight fits between the bearing rings and the mating parts. If the rings are not secured adequately or correctly, this can cause severe damage
Loss of essential or required characteristics in equipment, machinery or plant or their component parts.
to the bearings and adjacent machine parts. Influencing factors, such as the conditions of rotation, magnitude of the load, internal clearance, temperature conditions, design of the mating parts and the mounting and dismounting options must be taken into consideration in the selection of fits.

 
imageref_17757187211_All.gif   If shock type loads occur, tight fits (transition fit or interference fit) are required to prevent the rings from coming loose at any point. Clearance, transition or interference fits ➤ Table and ➤ Table .  
 

The following information provided in Technical principles must be taken into consideration in the design of bearing arrangements:

 
 
  • conditions of rotation    ➤ link
  • tolerance classes for cylindrical shaft seats (radial bearings) ➤ Table , excluding tapered roller bearings to ANSI/ABMA 19.2:2013 or with special tolerances
  • shaft fits ➤ Table
  • tolerance classes for bearing seats in housings (radial bearings) ➤ Table , excluding tapered roller bearings to ANSI/ABMA 19.2:2013 or with special tolerances
  • housing fits ➤ Table .
 
 

Shaft and housing
See Mounting dimenstions
fits for bearings in inch sizes

imageref_17757187211_All.gif   For bearings with a different tolerance accuracy, such as ANSI/ABMA 19.2:2013 for example, the tolerance class must be shifted in accordance with the fit.  
 

Shaft and housing
See Mounting dimenstions
fits for integral tapered roller bearings

 

Recommended shaft and housing
See Mounting dimenstions
tolerances
See
Running accuracy
Dimensional accuracy
for integral tapered roller bearings ➤ Table 17

 
   
Table 17
Tolerances for integral tapered roller bearings
 

Circumferential load
Tolerance class
Shaft
Housing
on inner ring
m6
H7
on outer ring
g6
M7

 
 

Axial location of bearings

The bearings must also be securely located in an axial direction

 

As a tight fit alone is not normally sufficient to also locate the bearing rings securely on the shaft and in the housing
See Mounting dimenstions
bore in an axial direction, this must usually be achieved by means of an additional axial location or retention method. The axial location of the bearing rings must be matched to the type of bearing arrangement. Shaft and housing
See Mounting dimenstions
shoulders, housing
See Mounting dimenstions
covers, nuts, spacer rings and retaining rings etc., are fundamentally suitable ➤ Figure 20.

 
 

Dimensional, geometrical and running accuracy
Measured in terms of radial runout and axial runout, due to the dimensional and geometrical tolerances of the bearing in motion, defined according to DIN
of the bearing seats

A minimum of IT6 should be provided for the shaft seat and a minimum of IT7 for the housing
See Mounting dimenstions
seat

 

The accuracy
Deviation of the actual dimension from the nominal dimension as described by tolerances. For monorail systems, the parallel deviation of the reference surfaces within given tolerances.

See
Running accuracy
Dimensional accuracy
of the cylindrical bearing seat on the shaft and in the housing
See Mounting dimenstions
should correspond to the accuracy
Deviation of the actual dimension from the nominal dimension as described by tolerances. For monorail systems, the parallel deviation of the reference surfaces within given tolerances.

See
Running accuracy
Dimensional accuracy
of the bearing used. For single row tapered roller bearings with the tolerance class Normal or 6X, the shaft seat should correspond to a minimum of standard tolerance grade IT6 and the housing
See Mounting dimenstions
seat to a minimum of IT7; with tolerance class 5, the shaft seat should correspond to a minimum of IT5 and the housing
See Mounting dimenstions
seat to a minimum of IT6. Guide values for the geometrical and positional tolerances
See
Running accuracy
Dimensional accuracy
of bearing seating surfaces
The effective surface is the surface which separates the object from its surrounding medium.The actual surface is the approximate image from measuring technology of the ideal geometric surface. Note: various measuring processes or measuring conditions (e.g. stylus radius) can give different actual surfaces.The geometric surface is an ideal surface whose nominal form is defined by a drawing or other technical documentation. See DIN 4760 for further details.

See
Surface protection
Surface tension
➤ Table 18, tolerances t1 to t3 in accordance with   ➤ Figure. Numerical values for IT grades ➤ Table 19.

 
   
Table 18
Guide values for the geometrical and positional tolerances
See
Running accuracy
Dimensional accuracy
of bearing seating surfaces
 

Bearing
tolerance class
Bearing seating surface
Standard tolerance grades to ISO 286-1
(IT grades)
to ISO 492
to DIN 620
Diameter tolerance
Roundness tolerance
Parallelism tolerance
Total axial runout tolerance of abutment shoulder
t1
t2
t3
Normal 6X
PN (P0) P6X
Shaft
IT6 (IT5)
Circumferential load
IT4/2
Circumferential load
IT4/2
IT4
Point load
IT5/2
Point load
IT5/2
Housing
IT7 (IT6)
Circumferential load
IT5/2
Circumferential load
IT5/2
IT5
Point load
IT6/2
Point load
IT6/2
5
P5
Shaft
IT5
Circumferential load
IT2/2
Circumferential load
IT2/2
IT2
Point load
IT3/2
Point load
IT3/2
Housing
IT6
Circumferential load
IT3/2
Circumferential load
IT3/2
IT3
Point load
IT4/2
Point load
IT4/2


 
   
Table 19
Numerical values for ISO standard tolerances
See
Running accuracy
Dimensional accuracy
(IT grades) to ISO 286-1:2010
 

IT grade
Nominal dimension in mm
over
10
18
30
50
80
120
180
250
315
400
500
630
incl.
18
30
50
80
120
180
250
315
400
500
630
800
Values in μm
IT2
  2
2,5
2,5
3
4
5
7
8
9
10
11
13
IT3
  3
4
4
5
6
8
10
12
13
15
16
18
IT4
  5
6
7
8
10
12
14
16
18
20
22
25
IT5
  8
9
11
13
15
18
20
23
25
27
32
36
IT6
  11
13
16
19
22
25
29
32
36
40
44
50
IT7
  18
21
25
30
35
40
46
52
57
63
70
80

 
 

Roughness of cylindrical bearing seats

Ra must not be too high

 

The roughness
Regular or irregular repeat deviation from an ideal geometric profile.
of the bearing seats must be matched to the tolerance class of the bearings. The mean roughness
Regular or irregular repeat deviation from an ideal geometric profile.
value Ra must not be too high, in order to maintain the interference loss within limits. The shafts must be ground, while the bores must be precision turned. Guide values as a function of the IT grade of bearing seating surfaces
The effective surface is the surface which separates the object from its surrounding medium.The actual surface is the approximate image from measuring technology of the ideal geometric surface. Note: various measuring processes or measuring conditions (e.g. stylus radius) can give different actual surfaces.The geometric surface is an ideal surface whose nominal form is defined by a drawing or other technical documentation. See DIN 4760 for further details.

See
Surface protection
Surface tension
➤ Table 20.

 
   
Table 20
Roughness values for cylindrical bearing seating surfaces
The effective surface is the surface which separates the object from its surrounding medium.The actual surface is the approximate image from measuring technology of the ideal geometric surface. Note: various measuring processes or measuring conditions (e.g. stylus radius) can give different actual surfaces.The geometric surface is an ideal surface whose nominal form is defined by a drawing or other technical documentation. See DIN 4760 for further details.

See
Surface protection
Surface tension
– guide values
 

Nominal diameter
of the bearing seat
d (D)
Recommended mean roughness
Regular or irregular repeat deviation from an ideal geometric profile.
value
for ground bearing seats
Ramax
mm
μm
Diameter tolerance (IT grade)
over
incl.
IT7
IT6
IT5
IT4
- 80
1,6
0,8
0,4
0,2
80
500
1,6
1,6
0,8
0,4
500
1 250
3,21)
1,6
1,6
0,8

 
 
______
 1    For the mounting of bearings using the hydraulic method, a value Ra = 1,6 μm must not be exceeded.
 
 

Mounting dimensions for the contact surfaces
The effective surface is the surface which separates the object from its surrounding medium.The actual surface is the approximate image from measuring technology of the ideal geometric surface. Note: various measuring processes or measuring conditions (e.g. stylus radius) can give different actual surfaces.The geometric surface is an ideal surface whose nominal form is defined by a drawing or other technical documentation. See DIN 4760 for further details.

See
Surface protection
Surface tension
of bearing rings

The contact surfaces
The effective surface is the surface which separates the object from its surrounding medium.The actual surface is the approximate image from measuring technology of the ideal geometric surface. Note: various measuring processes or measuring conditions (e.g. stylus radius) can give different actual surfaces.The geometric surface is an ideal surface whose nominal form is defined by a drawing or other technical documentation. See DIN 4760 for further details.

See
Surface protection
Surface tension
for the rings must be of sufficient height

 

The mounting dimensions
Dimensions such as shaft diameter or hole distances, for example of bearings and guideways, which influence fitting for correct functioning
of the shaft and housing
See Mounting dimenstions
shoulders, and spacer rings etc., must ensure that the contact surfaces
The effective surface is the surface which separates the object from its surrounding medium.The actual surface is the approximate image from measuring technology of the ideal geometric surface. Note: various measuring processes or measuring conditions (e.g. stylus radius) can give different actual surfaces.The geometric surface is an ideal surface whose nominal form is defined by a drawing or other technical documentation. See DIN 4760 for further details.

See
Surface protection
Surface tension
for the bearing rings are of sufficient height. However, they must also reliably prevent rotating parts of the bearing from grazing stationary parts. Proven mounting dimensions
Dimensions such as shaft diameter or hole distances, for example of bearings and guideways, which influence fitting for correct functioning
for the radii and diameters of the abutment shoulders are defined in accordance with DIN 5418➤ dimension table. These dimensions are limiting dimensions (maximum or minimum dimensions); the actual values should not be higher or lower than specified.

 
imageref_18348417035_All.gif   If single row tapered roller bearings are mounted in a tandem arrangement, it must be ensured that the end faces of the outer rings in contact with each other have sufficient overlap. In case of doubt, please consult Schaeffler.  
 

Cage projection

imageref_17757187211_All.gif   In the open bearings, the cages project laterally to a certain extent. In order to prevent the cages from grazing the adjacent construction, the lateral minimum distances Ca and Cb in the product tables must be taken into consideration in the design of the adjacent construction ➤ dimension table.  
 

Adjustment of bearings

Always adjust single bearings against a second bearing

 

Due to their internal construction, single row tapered roller bearings cannot be mounted alone, but must always be used together with a second bearing or as a bearing set ➤ Figure 20. In bearing arrangements with two individual single row bearings, these must be adjusted against each other until the requisite preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
or desired clearance is achieved ➤ Figure 20. The preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
is only achieved once the bearings have been fitted and is dependent on the adjustment against the second bearing.

 

Select the adjustment such that full function and operational reliability of the bearings is ensured

 

The correct adjustment of the bearings has a considerable influence on the function and operational reliability of the bearing arrangement. If the clearance is too large, the load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
carrying capacity of the bearings will not be fully utilised; if the preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
is too high, the increased friction
The resistance to relative movement of two bodies in contact with each other; subdivided into friction terms, friction types and friction conditions
losses will give rise to higher operating temperatures, which will, in turn, have a negative effect on the rating life
The basic rating life is the life reached or exceeded by 90% of a sufficiently large group of apparently identical bearings before the first evidence of material fatigue develops
of the bearings.

 
imageref_17757187211_All.gif   In order that the rollers
Barrel-shaped, tapered or cylindrical rolling elements
can be positioned correctly, the shaft or housing
See Mounting dimenstions
must be rotated several times in both directions when adjusting the bearings.
 
   

Figure 20
Adjusted bearing arrangement
Arrangement of bearings, for example locating/locating, semi-locating/semi-locating, non-locating/non-locating, or semi-locating bearings in tandem, O or X arrangement
with two single row tapered roller bearings

H =  support spacing
Symbole/00016410_mei_in_0k_0k.gif  Tapered roller bearings mounted in an O arrangement and adjusted against each other
Symbole/00016411_mei_in_0k_0k.gif  Fixing nut

 

imageref_21603362699_All.gif

 
 

Matched bearings

Adjustment not required for matched bearing sets

 

Matched tapered roller bearings do not need to be adjusted ➤ section . The desired operating clearance
The amount by which the bearing rings in a fitted bearing can be moved in the radial or axial direction from one extreme position to the other.
or required preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
is already set at the manufacturing plant.

 
 

Mounting and dismounting

 
imageref_17757187211_All.gif   The mounting and dismounting options for tapered roller bearings, by thermal, hydraulic or mechanical methods, must be taken into consideration in the design of the bearing position.  

Ensure that the bearings are not damaged during mounting

 

Integral tapered roller bearings are not separable. In the mounting of such bearings, the mounting forces must always be applied to the bearing ring with a tight fit.

 
 

Schaeffler Mounting Handbook

Rolling bearings must be handled with great care

 

Rolling bearings are well-proven precision machine elements for the design of economical and reliable bearing arrangements, which offer high operational security. In order that these products can function correctly and achieve the envisaged operating life
See Life, rating
without detrimental effect, they must be handled with care.

 
imageref_21602891659_en.gif   The Schaeffler Mounting Handbook MH 1 gives comprehensive infor­mation about the correct storage, mounting, dismounting and mainten­ance of rotary rolling bearings http://www.schaeffler.de/std/1D53. It also provides information which should be observed by the designer, in relation to the mounting, dismounting and maintenance
Inspection, maintenance and repair of equipment and machines.
of bearings, in the original design of the bearing position. This book is available from Schaeffler on request.
 
 

Legal notice regarding data freshness

 

The further development of products may also result in technical changes to catalogue products

 

Of central interest to Schaeffler is the further development and opti­misation of its products and the satisfaction of its customers. In order that you, as the customer, can keep yourself optimally informed about the progress that is being made here and with regard to the current technical status of the products, we publish any product changes which differ from the printed version in our electronic product catalogue.

 
imageref_18350433803_All.gif   We therefore reserve the right to make changes to the data and illus­trations in this catalogue. This catalogue reflects the status at the time of printing. More recent publications released by us (as printed or digital media) will automatically precede this catalogue if they involve the same subject. Therefore, please always use our electronic product catalogue to check whether more up-to-date information or modification notices exist for your desired product.  
 

Further information

 

In addition to the data in this chapter, the following chapters in Technical principles must also be observed in the design of bearing arrangements:

 
   
   
  
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