Schaeffler Product catalogue - medias
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Single row angular contact ball bearings
 

Single row angular contact ball bearings are particularly suitable where:

 
 
  • bearing arrangements must support combined loads, i.e. radial and axial loads acting simultaneously  ➤ Figure 2
  • moderate to high axial loads are present on one side
  • rigid axial guidance is required
  • 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 be axially clearance-free or preloaded
  • high speeds are required under higher radial and axial loads
  • 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
    is to run quietly in addition to meeting the requirements stated above.
 
   

Figure 1
Angular contact ball bearings: speed comparison with tapered roller bearings

nG =  limiting speed

 

imageref_20000688395_All.gif

 
 

Bearing design

 
 

The standard product range comprises bearings of series 718..-B, 70..‑B(‑2RS), 72..-B(-2RS), 73..-B(-2RS) and 74..-B. These bearings are also available for various applications as:

 
   
imageref_18348417035_All.gif   Single row angular contact ball bearings are also available in other dimension series, designs and sizes. Information on these bearings is available from Schaeffler on request. Larger catalogue bearings ➤ GL 1.  
 

Bearings of basic design for bearing arrangements with single bearings

The forces are transmitted oblique to the radial plane

 

Single row angular contact ball bearings are part of the group of radial ball bearings. These self-retaining units have solid outer and inner rings. The rolling elements are guided by cages made from polyamide, sheet steel, or brass. The bearing rings are designed with one high shoulder and one low shoulder ➤ Figure 2. As a result of the different shoulder heights, the mounting method differs from that of deep groove ball bearings. The possible number of balls for angular contact ball bearings with identical dimensions is higher than for deep groove ball bearings. In contrast to deep groove ball bearings, the raceways on the inner and outer rings are arranged obliquely to each other in the direction of the bearing axis. As a result, the forces are transmitted from one raceway to the other at a defined contact angle
See
Operating contact angle
Nominal contact angle
(oblique to the radial plane) ➤ Figure 7.

 

For bearing positions with only one bearing each

 

These angular contact ball bearings can be considered when only one bearing is used per bearing position. As the bearings have standard bearing ring tolerances
See
Running accuracy
Dimensional accuracy
(they are manufactured to tolerance class Normal), they are not suitable for mounting directly adjacent to each other. In such cases, universal bearings should be used.

 
 

   

Figure 2
Single row angular contact ball bearing of basic design

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

 

imageref_19846822155_All.gif

 
 

Universal bearings for mounting in sets

Bearings can be mounted in pairs in any arrangement required

 

Single row angular contact ball bearings, which are intended for mounting in pairs (in sets) directly adjacent to each other, are manufactured in the so-called universal design ➤ Figure 3, ➤ Figure 4, ➤ Figure 5. These bearings can be used in pairs in any arrangement without shims. Depending on the design selected, the mounted bearing pair has the required axial clearance, freedom from clearance or preload. This gives easier design of 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
and mounting of the bearings.

 
imageref_17757187211_All.gif   When ordering, please state the number of bearings, not the number of bearing pairs.  
 

Bearings of a universal design are indicated by the suffix UA, UB, UO, UL, UM or UH ➤ Table 6. If bearings of the universal design are arranged in sets, this gives a defined axial clearance
The amount by which the bearing rings in a fitted bearing can be moved in an axial direction from one end position to the other without axial loading.
or an axial preload:

 
 
  • UA = bearing set with small axial internal clearance
  • UB = bearing set with smaller axial internal clearance than UA
  • UO = bearing set clearance-free in O or X arrangement
  • UL = bearing set with light preload
  • UM = bearing set with moderate preload
  • UH = bearing set with high preload.
 
 

Single row angular contact ball bearings are mounted in sets 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 one bearing is not sufficient (bearing set in a tandem arrangement)
  • combined or axial loads occur in both directions and 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 a defined axial clearance
    The amount by which the bearing rings in a fitted bearing can be moved in an axial direction from one end position to the other without axial loading.
    (bearing set in O or X arrangement).
 
 

The following arrangements are possible for mounting in sets:

 
   
 

Bearing sets in tandem arrangement

Tandem arrangement

 

In a tandem arrangement, the contact lines run parallel to each other ➤ Figure 3. Axial forces are distributed equally over both bearings, but can only be supported by the bearing set from one direction. In order to support axial forces from the opposing direction, as well as combined loads, the bearing set is always adjusted against a further bearing.

 
   

Figure 3
Universal bearings, mounted in set in a tandem arrangement

Bearing set in tandem arrangement

 

imageref_19846824075_All.gif

 
 

Bearing sets in O arrangement

O arrangement

 

In an O arrangement, the apexes of the cones formed by the contact lines point outwards, i.e. they diverge relative to the bearing axis ➤ Figure 4. Bearing sets in an O arrangement support axial forces from both directions, but only ever with one bearing. Due to the large support spacing (i.e. the spacing between the contact cone apexes), these give relatively rigid bearing arrangements (small tilting
Deviation from the normal position due to load or geometrical influence

See Misalignment error
clearance) and are also suitable for supporting tilting
Deviation from the normal position due to load or geometrical influence

See Misalignment error
moments.

 
   

Figure 4
Universal bearings, mounted in set in an O arrangement

Bearing set in O arrangement
S =  contact cone apex
H =  support spacing

 

imageref_19846825995_All.gif

 
 

Bearing sets in X arrangement

X arrangement

 

In an X arrangement, the apexes of the cones formed by the contact lines point inwards, i.e. they converge relative to the bearing axis ➤ Figure 5. Once again, bearing sets of this type support axial forces from both directions, but also only ever with one bearing. The support base is, however, smaller than in an O arrangement. As a result, the sets are not as rigid as in an O arrangement. Furthermore, they are less suitable for supporting tilting
Deviation from the normal position due to load or geometrical influence

See Misalignment error
moments.

 
   

Figure 5
Universal bearings, mounted in set in an X arrangement

Bearing set in X arrangement
H =  support spacing

 

imageref_19846827915_All.gif

 
 

X-life premium quality

imageref_19964530187_All.gif   Many sizes in series 70..-B, 72..-B, 73..-B and 74..-B are available as X-life bearings ➤ dimension table. These bearings exhibit considerably higher perform­ance than standard single row angular contact ball bearings ➤ Figure 6. This is achieved, for example, through the modified internal construction, higher surface quality
See DIN 55 350 part 11 and ISO 8402 for terminology and definitions.
of 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
and optimised cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
design, as well as through the improved quality
See DIN 55 350 part 11 and ISO 8402 for terminology and definitions.
of the steel and rolling elements.
 
 

Advantages

 

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

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

    See Contact surface
    distribution in the bearing and thus a higher dynamic load
    The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
    carrying capacity of the bearings ➤ Figure 6
  • quieter 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
  • lower heat generation in the bearing
  • higher possible speeds
  • lower lubricant
    Gaseous, fluid, consistent, plastic or solid material for reduction of friction and wear between two friction elements.
    consumption and, consequently, longer maintenance
    Inspection, maintenance and repair of equipment and machines.
    intervals
  • a measurably longer operating life
    See Life, rating
    of the bearings
  • high operational security
  • 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

 

Single row X-life angular contact ball bearings include the suffix XL in the designation ➤ Figure 9, ➤ Figure 10 and ➤ dimension table.

 
 

   

Figure 6
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 – bearing series 73..‑B‑XL, bore code 05 to 26, with a bearing which is not of X-life quality
See DIN 55 350 part 11 and ISO 8402 for terminology and definitions.
(73..-B)

Cr =  basic dynamic load
The term dynamic indicates that the operating condition is with the bearing rotating. This is not a variable load.
rating
Symbole/00016410_mei_in_0k_0k.gif  Bore code

 

imageref_19988503435_All.gif

 
 

Areas of application

 

Due to their special technical features, single row X-life angular contact ball bearings are highly suitable for bearing arrangements in:

 
 
  • compressors
  • fluid and hydraulic pumps
  • automotive chassis and gearboxes
  • industrial gearboxes
  • electric motors
  • industrial ventilators
  • machine tools
  • textile machinery.
 
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.
 
 

Load carrying capacity

 

Radial load

 

Single row angular contact ball bearings can support high radial forces. Pure radial loads are also possible, if the bearings are adjusted.

 

Axial loading
Point at which a load acts within the co-ordinate system
is only possible on one side

 

Due to the geometry and position of the raceway shoulders, axial loads are only transmitted from one direction ➤ Figure 2. If these angular contact ball bearings are required to support axial forces from both directions, they are adjusted against a second bearing in a mirror image arrangement ➤ Figure 11 and ➤ Figure 12.

 

The axial load
Force acting in the direction of the shaft.
carrying capacity of the bearings increases with the size of the contact angle

 

The contact angle
See
Operating contact angle
Nominal contact angle
α is the angle encompassed by the contact line and the radial plane, under which the load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
is transmitted from one raceway to the other ➤ Figure 7. The axial load
Force acting in the direction of the shaft.
carrying capacity of the bearing increases with the value of α, i.e. the greater the angle, the higher the axial load
Force acting in the direction of the shaft.
to which the bearing can be subjected. As a result, angular contact ball bearings are more suitable than deep groove ball bearings for supporting higher axial forces. Due to the nominal contact angle
Angle enclosed by the contact line between the bearing and the radial plane; applies to unloaded bearings, in which the rolling elements are in stress-free contact with the raceways
of α = 40°, single row angular contact ball bearings can support high axial loads on one side.

 
imageref_18348417035_All.gif   For information on angular contact ball bearings available with contact angles other than α = 40°, please consult Schaeffler.  
 

   

Figure 7
Contact angle and force flow

α =  contact angle
Symbole/00016410_mei_in_0k_0k.gif  Contact line
Symbole/00016411_mei_in_0k_0k.gif  Force flow

 

imageref_18344218123_All.gif

 
 

Load carrying capacity of bearing sets

 

The basic dynamic and static load ratings Cr and C0r in the product tables always refer to the single bearing. If two bearings of the same size and design are arranged immediately adjacent to each other in an O or X arrangement, the following will apply to the bearing pairs:

 
 
  • Cr = 1,625 · Cr single bearing
  • C0r = 2 · C0r single bearing.
 
 

Compensation of angular misalignments

 

The angular adjustment facility of the bearings is very limited

 

Single row angular contact ball bearings are not suitable for the compensation of angular misalignments. In addition, misalignments induce internal forces in the bearing, which not only lead to higher temperatures, but also to a reduction in the bearing rating life.

 
 

Angular contact ball bearings arranged in sets

imageref_17757187211_All.gif   Misalignments in angular contact ball bearings mounted in sets lead – particularly with a small internal clearance and an O arrangement – to increased loads on the balls and cage, as the angular misalignments are supported under constraint between the balls and raceways. This can, in turn, have a negative effect on the operating life
See Life, rating
of the bearings. In addition, it should be noted that running noise is increased by a misalignment
Deviation of an actual line from a theoretical ideal line, for example a bearing axis from the shaft axis; may be due to machining, flexing of shaft or deformation of housing.
of the bearing rings.
 
 

Lubrication

 

Greased bearings are maintenance-free

 

Angular contact ball bearings sealed on both sides are greased with a high quality
See DIN 55 350 part 11 and ISO 8402 for terminology and definitions.
grease
See
Lubricant
Grease cartridge
Fatty acids
and do not require relubrication.

 

Ungreased bearings must be lubricated

 

Open bearings and bearings with seals
Elements intended to prevent the ingress of gaseous, fluid and solid materials through the gaps formed by adjacent components whilst stationary or moving.

See
Seal
Operating life
Friction
on one side 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.

 
 

Sealing

 

Sealing with contact seals 2RS

 

Bearings with the suffix 2RS have lip seals
Elements intended to prevent the ingress of gaseous, fluid and solid materials through the gaps formed by adjacent components whilst stationary or moving.

See
Seal
Operating life
Friction
on both sides ➤ Table 6. Due to their good sealing
See Seals
action, they are suitable for use in dusty, contaminated or damp environments.

 
 

In the case of unsealed bearings, sealing
See Seals
of the bearing position must be carried out by the adjacent construction. The sealing
See Seals
system should 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.
 
 

Speeds

 
 

Two speeds are generally indicated in the product tables ➤ 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.  
  The values given in the product tables are valid for oil
Fluid lubricant with a mineral oil and/or synthetic oil base, usually with active ingredients or additives.
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
in the case of bearings without seals
Elements intended to prevent the ingress of gaseous, fluid and solid materials through the gaps formed by adjacent components whilst stationary or moving.

See
Seal
Operating life
Friction
or shields and for 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
where bearings are supplied greased and with seals
Elements intended to prevent the ingress of gaseous, fluid and solid materials through the gaps formed by adjacent components whilst stationary or moving.

See
Seal
Operating life
Friction
or shields.
 

Values for grease
See
Lubricant
Grease cartridge
Fatty acids
lubrication

 

For grease
See
Lubricant
Grease cartridge
Fatty acids
lubrication, 75% of the value stated in the product tables is permissible in each case.

 
 

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.

 
 

Bearing sets of universal design

Bearing pairs usually operate at lower speeds than single bearings

 

Angular contact ball bearings of universal design can be used in an X, O or tandem arrangement ➤ Figure 3 to ➤ Figure 5. The thermally safe operating speed of the bearing pair is then approximately 20% below the calculated permissible operating speed of the single bearing.

 
 

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 8
Schaeffler Noise Index for single row angular contact ball 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_23598375179_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 rolling elements
  • the cage
  • the lubricant
  • the seals.
 
 

 

Possible operating temperatures of single row angular contact ball bearings ➤ Table 1.

 
   
Table 1
Permissible temperature ranges
 

Operating temperature
Single row angular contact ball bearings, open
Single row angular contact ball bearings, sealed
with sheet steel or brass cage
with polyamide cage PA66
imageref_19988082955_All.gif
   
–30 °C to +150 °C,
for D > 240 mm
up to +200 °C
–30 °C to +120 °C
–30 °C to +110 °C, limited by the lubricant
Gaseous, fluid, consistent, plastic or solid material for reduction of friction and wear between two friction elements.
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

 

Solid cages made from brass and PA66, as well as sheet steel cages, are used as standard

 

Standard cages and additional cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
designs for single row angular contact ball bearings are made from brass, polyamide or steel ➤ Table 2. Other cages are available by agreement. With such cages, however, suitability for high speeds and temperatures as well as 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 may differ from the values for the bearings with standard cages.

 
imageref_18348417035_All.gif   For high continuous temperatures and applications with difficult operating conditions, bearings with brass or 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.
 
 

   
Table 2
Cage, cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
suffix, bore code
 

Bearing series
Solid cage
made from polyamide PA66
Solid brass cage
Sheet steel cage
TVH, TVP
MP
JP
standard
also
available for
standard
also
available for
also
available for
Bore code
718
06 to 16
- - - -
70
04 to 08
- - - -
72
up to 20,
22 to 26
- 21,
from 28
00, 03,
from 05
up to 20, 22
73
up to 20,
22 to 26
- 21,
from 28
from 04
up to 20, 22
74
- 07 to 15
05 to 16
- 07 to 15

 
 

Internal clearance

 
 

Axial internal clearance, preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
and preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
force of bearing sets with universal bearings in O or X arrangement

Valid for bearing sets in O or X arrangement

 

Values for axial internal clearance, preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
and preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
force of bearings of universal design ➤ Table 3. The values for axial internal clearance are valid for unmounted bearing sets in an O or X arrangement, which are free from load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
and measurement forces (without elastic deformation).

 
imageref_18348417035_All.gif   The angular contact ball bearings can also be supplied with a different internal clearance. Please consult Schaeffler in this case.  
   
Table 3
Axial internal clearance, preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
and preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
force of bearing sets with universal bearings in O or X arrangement for tolerance classes Normal, 6, 5
 

Bore code
Axial internal clearance or preload
of bearing pair
Nominal dimension
Preload force

 FV max
μm
N
UA
UB
UO
UL
UL
Bearing series
70..-B, 72..-B, 73..-B, 74..-B
70..-B
72..-B
73..-B
74..-B
70..-B
72..-B
73..-B
74..-B
00
22
14
0
- –3
- - - 38
- -
01
24
15
0
- –4
–5
- - 53
82
-
02
24
15
0
- –4
–5
- - 62
99
-
03
24
15
0
- –4
–6
- - 77
123
-
04
28
16
0
–4
–5
–6
–8
103
103
146
258
05
34
19
0
–4
–4
–6
–8
115
112
200
300
06
34
19
0
–5
–5
–7
–8
141
157
250
365
07
40
22
0
–5
–6
–7
–9
172
208
300
462
08
40
22
0
–5
–6
–8
–10
200
246
385
535
09
44
24
0
- –6
–9
–10
- 277
462
600
10
44
24
0
- –6
–10
–10
- 288
535
692
11
46
25
0
- –7
–10
–11
- 358
600
785
12
46
25
0
- –7
–10
–11
- 431
692
877
13
46
25
0
- –8
–11
–12
- 492
785
977
14
50
27
0
- –8
–11
–12
- 535
877
1 154
15
50
27
0
- –8
–12
–13
- 523
977
1 154
16
50
27
0
- –8
–12
–16
- 615
1 077
1 385
17
54
31
0
- –8
–13
- - 692
1 154
-
18
54
31
0
- –9
–13
- - 815
1 231
-
19
54
31
0
- –10
–14
- - 892
1 331
-
20
54
31
0
- –11
–14
- - 992
1 485
-
21
58
34
0
- –11
–14
- - 1 100
1 538
-
22
58
34
0
- –12
–15
- - 1 177
1 723
-
24
58
34
0
- –12
–16
- - 1 277
1 923
-
26
60
34
0
- –12
–17
- - 1 431
2 115
-
28
60
34
0
- –12
–17
- - 1 508
2 308
-
30
60
34
0
- –13
–18
- - 1 723
2 500
-
32
60
34
0
- –13
–18
- - 1 815
2 769
-
34
70
40
0
- –14
–19
- - 2 038
3 115
-

 
 
______
UA =  bearing with small axial internal clearance
UB =  bearing with smaller axial internal clearance than UA
UO =  bearing clearance-free in O or X arrangement
UL =  bearing with light preload
 

Tolerances for axial internal clearance and preload

 

Tolerances for axial internal clearance and preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
of bearing sets with universal bearings in O and X arrangement ➤ Table 4

 
   
Table 4
Tolerances for axial internal clearance and preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
of bearing sets with universal bearings in O or X arrangement
 

Bore code
Tolerances
μm
Bearing series
70..-B, 72..-B
73..-B
74..-B
Tolerance class
Normal, 6
5
Normal, 6
5
Normal, 6
5
00 to 07
+8
0
+6
0
+8
0
+6
0
+8
0
+6
0
08 to 09
+8
0
+6
0
+8
0
+6
0
+12
0
+10
0
10 to 11
+8
0
+6
0
+12
0
+10
0
+12
0
+10
0
12 to 34
+12
0
+10
0
+12
0
+10
0
+12
0
+10
0

 
 

Dimensions, tolerances

 
 

Dimension standards

imageref_17757201419_All.gif   The main dimensions of angular contact ball bearings of the basic design correspond to DIN 628-1:2008 and ISO 12044:2014. Nominal dimensions of angular contact ball bearings ➤ dimension table.  
 

Chamfer dimensions

imageref_17757201419_All.gif   The limiting dimensions for chamfer dimensions correspond to DIN 620‑6:2004. Overview and limiting values   ➤ section. Nominal value of chamfer dimension ➤ dimension table.  
 

Tolerances

imageref_17757201419_All.gif   The tolerances
See
Running accuracy
Dimensional accuracy
for the dimensional 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 single row angular contact ball bearings correspond to tolerance class Normal in accordance with ISO 492:2014. Tolerance values in accordance with ISO 492 ➤ Table .
 
 

Tolerances for bearings of universal design

 

In addition to the tolerance class Normal (no tolerance suffix), angular contact ball bearings of universal designs UA, UB, UO and UL are also available by agreement in tolerance class 5 and, in some cases, in tolerance class 6. Tolerance values in accordance with ISO 492 ➤ Table to ➤ Table . The tolerance suffix
Addition to the designation, consisting of letters and/or numbers, for example, it may indicate variants of a series
for bearings of universal design in tolerance class 5 is then:

 
 
  • P5-UA, P5-UB, P5-UO, P5-UL.
 
imageref_17757187211_All.gif   The bores of bearings of universal design for all tolerance classes are uniformly toleranced to tolerance class 5 (no special suffix). The bearing width for universal bearings is toleranced to ISO 492:2014. For width tolerances
See
Running accuracy
Dimensional accuracy
➤ Table 5.
 
 

   
Table 5
Tolerance for ring width in bearings of universal design
 

Nominal bore diameter
Width deviation
d
tΔBs
mm
μm
Bearings in tolerance class
Normal, 6
5
over
incl.
U
L
U
L
- 50
0
–250
0
–250
50
80
0
–380
0
–250
80
120
0
–380
0
–380
120
180
0
–500
0
–380
180
315
0
–500
0
–500

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

Suffixes

 
 

For a description of the suffixes used in this chapter ➤ Table 6 and medias interchange http://www.schaeffler.de/std/1D52.

 
   
Table 6
Suffixes and corresponding descriptions
 

Suffix
Description of suffix
B
Modified internal construction,
nominal contact angle α = 40°
Standard
JP
Sheet steel cage
Standard, dependent
on bore code
MP
Solid brass cage
TVH, TVP
Solid cage
The part of a rolling bearing which separates, retains and, where necessary, guides the rolling elements
made from glass fibre reinforced polyamide PA66
P5
Bearing in tolerance class 5
Special design, available
by agreement
2RS
Contact 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
on both sides (lip seal)
Standard
UA
Universal design for fitting in pairs,
bearing pair has a small axial internal clearance
in O and X arrangement
UB
Universal design for fitting in pairs,
bearing pair has a smaller axial internal clearance
in O and X arrangement than in UA
UH
Universal design for fitting in pairs,
bearing pair has a high preload
in O and X arrangement
Available
by agreement
UL
Universal design for fitting in pairs,
bearing pair has a light preload
in O and X arrangement
Standard
UM
Universal design for fitting in pairs,
bearing pair has a moderate preload
in O and X arrangement
Available
by agreement
UO
Universal design for fitting in pairs,
bearing pair is clearance-free
in O and X arrangement
Standard
XL
X-life bearing, dependent on bore code and
bearing type
Standard

 
 

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 9 and ➤ Figure 10. The composition of designations is subject to DIN 623‑1    ➤ Figure.

 
 

   

Figure 9
Single row angular contact ball bearing of basic design: 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_18345229323_en.gif

 
   

Figure 10
Single row angular contact ball bearing of universal design: 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_19846829835_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 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 load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
of constant magnitude and direction. In radial bearings, this is a purely radial load Fr. If this condition is met, the bearing 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°.
and various load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
cases

 

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 ≦ 1,14 or Fa/Fr > 1,14

 

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 1,14.

 

Tandem arrangement

 

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 bearing pairs in a tandem arrangement ➤ Equation 1 and ➤ Equation 2.

 

Equation 1
Equivalent dynamic load
 
imageref_18144016139_All.gif


Equation 2
Equivalent dynamic load
 
imageref_18144054283_All.gif

Legend

 
P
 N
Equivalent dynamic bearing load
Fr
 N
Radial load
Fa
 N
Resulting axial force ➤ Table 7. The information in the section “Calculation of internal resulting axial force Fa for single bearings and for bearings in a tandem arrangement” must be taken into consideration when calculating Fa ➤ link .
 

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 O or X arrangement ➤ Equation 3 and ➤ Equation 4.

 

Equation 3
Equivalent dynamic load
 
imageref_18144058635_All.gif


Equation 4
Equivalent dynamic load
 
imageref_18144060811_All.gif

Legend

 
P
 N
Equivalent dynamic bearing load
Fr
 N
Radial load
Fa
 N
Resulting axial force ➤ Equation 2 and ➤ Table 7.
 
 

Calculation of internal resulting axial force Fa for single bearings and for bearings in a tandem arrangement

Equations for calculation of internal resulting axial force Fa

 

Single row angular contact ball 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 angular contact ball bearings of identical or different size, the radial load
A force which acts at an angle of b = 0°.
on bearing A therefore leads, due to the inclination
See Angular misalignment
of the raceways (α ≠ 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 11 and ➤ Figure 12. This internal resulting axial force Fa must be taken into consideration in the calculation of the equivalent dynamic bearing load P. Equations for calculation of resulting axial force Fa➤ Table 7. The table shows the magnitude of the resulting axial force – that is the sum of or the difference between the internal and external axial force – for bearing arrangements in accordance with ➤ Figure 11 and ➤ Figure 12. The following applies to the table: the bearing aligned to the external axial force Ka is marked A and the opposing bearing is marked B.

 

Preconditions for calculation

 

Bearing A is subjected to a radial load FrA, bearing B to a radial load FrB ➤ Figure 11 and ➤ Figure 12. FrA and FrB act at the central pressure points of the bearings (dimension a in the product tables) and are always regarded as positive. The bearings are clearance-free, but without preload.

 
   
Table 7
Calculation of internal resulting axial force Fa
 

Case
Load ratio
External axial force
Resulting axial force Fa
Bearing A
Bearing B
1
imageref_10902688267_All.gif
   
Ka ≧ 0
imageref_10902693643_All.gif
   
Fa is not taken
into consideration in the calculation
2
imageref_10903176715_All.gif
   
imageref_10903180939_All.gif
   
imageref_10902693643_All.gif
   
Fa is not taken
into consideration in the calculation
3
imageref_10903176715_All.gif
   
imageref_10903202955_All.gif
   
Fa is not taken
into consideration in the calculation
imageref_10903239819_All.gif
   

 
 
______
Fa =  internal resulting axial force, which must be used in the calculation of the equivalent dynamic bearing load P.
YA = YB = 0,57
 
   

Figure 11
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 angular contact ball bearings in O arrangement, external forces

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

 

imageref_14201941131_All.gif

 
   

Figure 12
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 angular contact ball bearings in X arrangement, external forces

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

 

imageref_14201943307_All.gif

 
 

Example of calculation of internal resulting axial force Fa

Bearing arrangement for pinion shaft

 

Single row angular contact ball 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 13. 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 equivalent dynamic bearing load P must be determined.

 
   

Figure 13
Load scheme for pinion shaft

Ka =  external axial force = 6,52 kN
Kr =  external radial force = 0,82 kN
Kt =  tangential force = 5,88 kN
Resulting radial forces Fr
Bearing A, FrA = 7,30 kN
Bearing B, FrB = 2,20 kN

 

imageref_19988529547_All.gif

 

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

 

Bearing A supports the external axial force Ka. 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 7. For both angular contact ball bearings YA = YB = 0,57. Loads ➤ Figure 13.

 
 

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 5.

 

Equation 5
Load ratio
 
imageref_19293152011_All.gif


Equation 6
 
imageref_19293155083_All.gif

 

Step 2

 

Compare the result with possible cases ➤ Table 7. Case 2 or case 3 can be considered ➤ Table 8.

 
   
Table 8
Calculation of 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_10903180939_All.gif
   
imageref_9007210157434635_All.gif
   
-
3
imageref_10903202955_All.gif
   
- imageref_9007210157980811_All.gif
   

 
 
______
Parameters ➤ Equation 2
YA = YB = 0,57
 
 

Step 3

 

Using ➤ Equation 7, check whether case 2 applies ➤ Table 8.

 

Equation 7
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_19293278731_All.gif


Equation 8
 
imageref_19293300747_All.gif

 

If case 2 applies ➤ Table 8.

 
 

Step 4

Calculating Fa

 

Using ➤ Equation 9, calculate the internal resulting axial force Fa for bearing A. The calculations are in accordance with ➤ Table 8, case 2.

 

Equation 9
Internal resulting axial force
 
imageref_19293363339_All.gif


Equation 10
 
imageref_19293373323_All.gif

Using value Fa in the calculation of P

 

For calculation of the equivalent dynamic bearing load P, the calculated value for Fa in ➤ Equation 2 is then used for bearing A, since Fa/FrA > 1,14 (8,45 kN/7,30 kN > 1,14).

 
 

Equivalent static bearing load

Tandem arrangement

 

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 bearing pairs in a tandem arrangement ➤ Equation 11 and ➤ Equation 12

 

Equation 11
Equivalent static load
 
imageref_18144169611_All.gif


Equation 12
Equivalent static load
 
imageref_18144171787_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).
 
 

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 13.

 

Equation 13
Equivalent static load
 
imageref_19700806155_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).
 
 

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 14.

 

Equation 14
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/100 is required

 

In order that no slippage occurs between the contact partners, the angular contact ball 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/100 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

 

Support bearing rings over their entire circumference and width

 

In order to allow full utilisation of 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 and thus also achieve the requisite rating life, the bearing rings must be rigidly and uniformly supported by means of 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
over their entire circumference and over the entire width of the raceway. Support can be provided by means of a cylindrical seating surface. The seating and 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
should not be interrupted by grooves, holes or other recesses. 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 mating parts must meet specific requirements ➤ Table 9 to ➤ Table 11.

 
 

Radial location of bearings – fit recommendations

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
  • shaft fits    ➤ link
  • tolerance classes for bearing seats in housings (radial bearings) ➤ Table
  • housing fits    ➤ link
 
 

Axial location of bearings – location methods

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 11 and ➤ Figure 12.

 
 

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 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 angular contact ball bearings with the tolerance class Normal, 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 6, the shaft seat should correspond to a minimum of IT5 and the housing
See Mounting dimenstions
seat to 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 9, tolerances t1 to t3 in accordance with   ➤ Figure. Numerical values for IT grades ➤ Table 10.

 
   
Table 9
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
PN (P0)
Shaft
IT6 (IT5)
Circumferential load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
IT4/2
Circumferential load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
IT4/2
IT4
Point load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
IT5/2
Point load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
IT5/2
Housing
IT7 (IT6)
Circumferential load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
IT5/2
Circumferential load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
IT5/2
IT5
Point load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
IT6/2
Point load
Load which, for example, is to be supported at a friction point. Also strain from pressure and/or heat.

See Contact surface
IT6/2
6
P6
Shaft
IT5
Circumferential load
IT3/2
Circumferential load
IT3/2
IT3
Point load
IT4/2
Point load
IT4/2
Housing
IT6
Circumferential load
IT4/2
Circumferential load
IT4/2
IT4
Point load
IT5/2
Point load
IT5/2

 
   
Table 10
Numerical values for ISO
Abbreviation for International Organisation for Standardization.
standard tolerances
See
Running accuracy
Dimensional accuracy
(IT grades) to ISO 286-1:2010
 

IT grade
Nominal dimension in mm
over
3
6
10
18
30
50
80
120
incl.
6
10
18
30
50
80
120
180
Values in μm
IT3
  2,5
2,5
3
4
4
5
6
8
IT4
  4
4
5
6
7
8
10
12
IT5
  5
6
8
9
11
13
15
18
IT6
  8
9
11
13
16
19
22
25
IT7
  12
15
18
21
25
30
35
40

 
 

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 11.

 
   
Table 11
Roughness values for cylindrical bearing seating surfaces – 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

 
 

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 abutment shoulders ➤ 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 angular contact 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.  
 

Adjustment of bearings

Always adjust single bearings against a second bearing

 

Single row angular contact ball bearings must always be used with a second bearing or as a bearing set ➤ Figure 14. If two individual single row angular contact ball bearings are used, 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.

 

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.

 
 

   

Figure 14
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 angular contact ball bearings

Symbole/00016410_mei_in_0k_0k.gif  Angular contact ball bearings mounted in X arrangement

 

imageref_18239993739_All.gif

 

Adjustment not required for bearing sets

 

Universal bearings arranged immediately adjacent to each other, or matched bearings, do not need to be adjusted. In such cases, 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 achieved by selecting the internal clearance or preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
class in conjunction with the suitable shaft and housing
See Mounting dimenstions
fits. As a result, particular attention must be paid to the correct selection of internal clearance or preload
Force due to negative operating clearance or negative bearing clearance in rolling bearings
for these bearing sets.

 
 

Mounting and dismounting

 
imageref_17757187211_All.gif   The mounting and dismounting options for angular contact ball 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

 

Single row angular contact ball 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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