Axial cylindrical roller bearings

Single and double row axial cylindrical roller bearings are particularly suitable where:

high axial and shock loads occur in one direction but no radial loads are present ➤ Figure and ➤ section
the load carrying capacity of the corresponding axial deep groove ball bearings is no longer adequate (in this case, bearings of series 811 and 812 are especially suitable)➤ Figure
the bearing arrangement must have very high axial rigidity
the axial space available is very small ➤ Figure and ➤ dimension table
the bearing arrangement can be configured, where the axial space is very small, as a direct bearing arrangement ➤ section
the bearing parts can or must be mounted separately
the bearing arrangement is not configured in itself but, for cost reasons, ready-to-fit standard bearings are to be used

Axial cylindrical roller bearing and axial ball bearing – comparison of load carrying capacity and design envelope

F_a = axial load

C_a = basic dynamic load rating

D_w = roller diameter

T = axial section height of axial deep groove ball bearing

Bearing design

Design variants

Axial cylindrical roller bearings are available as:

single and double row bearings

Larger catalogue bearings and other bearing designs GL 1.

Axial cylindrical roller bearings

Designed for bearing arrangements with very small axial space

Axial cylindrical roller bearings are part of the group of axial 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 and allows smaller rolling element diameters under the same load. The single and double row bearings comprise flat, ribless washers (housing and shaft locating washers) between which axial cylindrical roller and cage assemblies are arranged ➤ Figure and ➤ Figure. Their axial section height T corresponds only to the diameter of the rollers plus the thickness of the washers. Due to this design, the bearings are particularly small in axial height ➤ dimension table. The axial cages are made from brass or plastic and are fitted with one or two rows of cylindrical rollers. Since sliding occurs towards the ends of the rollers during rolling of the rolling elements and this increases with the length of the roller, bearings with a wide cross-section have several short rollers arranged adjacent to each other, e. g. double row designs ➤ Figure.

Rollers with profiled ends increase the operating life of the bearings

The cylindrical rollers have profiled ends, i. e. they have a slight lateral curvature towards the ends. This modified line contact between the rollers and raceways prevents damaging edge stresses ➤ Figure. This in turn has a positive effect on the operating life of the bearings.

The use of complete axial cylindrical roller bearings (shaft locating washer, axial cylindrical roller and cage assembly and housing locating washer) is then advisable if, for example, high speeds occur and the bearing washers must therefore be centred precisely.

Roller and cage assembly and bearing washers are also available individually

The bearing parts for axial cylindrical roller bearings are also available individually ➤ Figure and ➤ Figure. Axial cylindrical roller and cage assemblies (without shaft and housing locating washers) are suitable, for example, for bearing arrangements with very small axial design space.

Cylindrical roller bearings 811 and 812 are of a single row design and correspond to DIN 722:2005 and ISO 104:2015. The bearings 893 and 894 are of a double row design and are configured in accordance with DIN 616:2000 and ISO 104:2015.

Axial cylindrical roller bearings

F_a = axial load

Single row bearing

Double row bearing

Shaft locating washer

Housing locating washer

Axial cylindrical roller and cage assembly

Roller profile and stress distribution

Cylindrical roller profile (high stress peaks)

Roller with profiled ends (no stress peak)

Cylindrical outside surface region

Region of logarithmic tapering

Rounding of edge

Axial cylindrical roller and cage assemblies

Very high axial load carrying capacity with low section height

The cage assemblies comprise axial cages and one or two rows of cylindrical rollers ➤ Figure. They have a particularly small axial section height and high axial load carrying capacity. The cages are made from polyamide or brass and are guided on the shaft.

For direct bearing arrangements, running surfaces must be produced as a rolling bearing raceway

Axial cylindrical roller and cage assemblies are generally combined with one housing locating washer and one shaft locating washer. If they are to be used directly – i. e. without axial bearing washers – in the adjacent construction, the raceway for the rollers must be produced as a rolling bearing raceway ➤ section. It is also possible to use two shaft locating washers or two housing locating washers in combination with one axial cylindrical roller and cage assembly.

The diameter series 1, 2, 3, 4 of the axial cylindrical roller and cage assemblies correspond to DIN 616:2000 and ISO 104:2015.

Axial cylindrical roller and cage assemblies

F_a = axial load

Single row

Double row

Axial bearing washers

Housing and shaft locating washers

Housing locating washers are externally centred, shaft locating washers are internally centred ➤ Figure and ➤ section. They must be used if the adjacent construction cannot be used as a raceway for the rolling elements. The washers are made from through-hardening rolling bearing steel. The bore and outside diameter are precision machined, the raceways are ground to high accuracy.

The diameter series 1, 2, 3, 4 of the axial bearing washers correspond to DIN 616:2000 and ISO 104:2015.

Bearing washers

Bearing washers are suitable for use as a housing or shaft locating washer. They are used in applications that do not require precise centring of the axial bearing washers. The raceway of the bearing washers is hardened and ground. The bearing washers are suitable for axial cylindrical roller and cage assemblies K811 and axial needle roller and cage assemblies AXK.

Axial bearing washers

Housing locating washer, externally centred

Shaft locating washer, internally centred

Bearing washer

Raceway

Load carrying capacity

For very high axial loads acting in one direction

Single and double row axial cylindrical roller bearings can support high axial loads as well as axial shock loads in one direction, but must not be subjected to radial load ➤ section. If radial loads do occur, these forces must be supported by an additional bearing (e. g. by a needle roller and cage assembly) ➤ Figure.

Axial and radial loads

F_r = radial load

F_a = axial load

Needle roller and cage assembly as radial bearing (direct bearing arrangement)

Axial cylindrical roller and cage assembly as axial bearing (direct bearing arrangement)

Compensation of angular misalignments

The bearings do not permit any skewing between the shaft and the housing. If angular misalignments occur between the locating surfaces on the shaft and in the housing, this will cause damage to the bearing and considerably reduce its operating life.

Lubrication

Oil or grease lubrication is possible

Axial cylindrical roller bearings are not greased. The bearings must be lubricated with oil or grease.

Compatibility with plastic cages

When using bearings with plastic cages, compatibility between the lubricant and the cage material must be ensured if synthetic oils, lubricating greases with a synthetic oil base or lubricants containing a high proportion of EP additives are used.

If there is any uncertainty regarding the suitability of the selected lubricant for the application, please consult Schaeffler or the lubricant manufacturer.

Observe oil change intervals

Aged oil and additives in the oil can impair the operating life of plastics at high temperatures. As a result, stipulated oil change intervals must be strictly observed.

Sealing

Provide seals in the adjacent construction

The bearings are not sealed; i. e. sealing 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 from the bearing position

Speeds

Limiting speeds and reference speeds in the product tables

Two speeds are generally indicated in the product tables ➤ dimension table:

the kinematic limiting speed n_G
the thermal speed rating n_ϑr

Limiting speed

The limiting speed n_G is the kinematically permissible speed of a bearing. Even under favourable mounting and operating conditions, this value should not be exceeded without prior consultation with Schaeffler ➤ link. The values in the product tables are valid for oil lubrication.

Values for grease lubrication

For grease lubrication, 25% of the value stated in the product tables is permissible in each case.

Reference speeds

n_ϑr is used to calculate n_ϑ

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

Noise

Schaeffler Noise Index

The Schaeffler Noise Index (SGI) is not yet available for this bearing type ➤ link. The data for these bearing series will be introduced and updated in stages.

Temperature range

Limiting values

The operating temperature of the bearings is limited by:

the dimensional stability of the bearing washers and cylindrical rollers
the cage
the lubricant

Possible operating temperatures of axial cylindrical roller bearings ➤ Table.

Permissible temperature range

Operating temperature	Axial cylindrical roller bearings with brass or polyamide cage PA66
	–20 °C to +120 °C

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

Cages

Solid cages made from brass and polyamide PA66 are used as standard

Standard cages ➤ Table . The cage design is dependent on the bearing series and the bearing size. Other cage designs are available by agreement. With such cages, however, suitability for high speeds and temperatures as well as the basic load ratings may differ from the values for the bearings with standard cages.

For high continuous temperatures and applications with difficult operating conditions, bearings with brass cages should be used. If there is any uncertainty regarding cage suitability, please consult Schaeffler.

Cage, cage suffix, bore code

Bearing series	Solid cage made from polyamide PA66	Solid brass cage
	TV	M
	standard	standard
	Bore code
811, K811	up to 34	from 36
812, K812	06 to 26	from 28
893, K893	06 to 16	17 to 30
894, K894	12 to 14	from 15

Internal clearance

Axial clearance and preload are determined by the application

In the case of axial cylindrical roller bearings, the internal clearance (axial clearance) is only achieved when the bearings are mounted. The requisite axial clearance of the bearing arrangement is dependent on the application and must take account of the conditions in the bearing arrangement while warm from operation and subjected to load. If axial cylindrical roller bearings are subjected to vibrations while under predominantly static load, for example, they must be lightly preloaded. Preload can be applied, for example, using calibrated sheets (shims) ➤ Figure. Other suitable means include shaft nuts, disc springs, etc. ➤ section. It must always be ensured that no slippage occurs in operation between the rolling elements and raceways ➤ section. It must also be ensured that the preload does not exceed the optimum value, otherwise there will be an increase in friction and therefore in heat generation in the bearing. These will both have a negative effect on the operating life of the bearings.

If there is any uncertainty regarding correct setting, please consult Schaeffler.

Setting of the axial clearance by means of shims

Calibrated sheet (shim)

Dimensions, tolerances

Dimension standards

The main dimensions of axial cylindrical roller bearings correspond to ISO 104:2015.

Chamfer dimensions

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

Tolerances

The dimensional and running tolerances of axial bearing washers GS and WS correspond to the tolerance class Normal in accordance with ISO 199:2014 ➤ Table to ➤ Table.

Tolerances of the bore and outside diameter as well as of the width of the bearing parts ➤ Table and ➤ Figure.

Dimensions and tolerances of bearing parts

Bearing component	Dimension	Tolerance
Axial cylindrical roller and cage assembly K	D_c1	E11
	D_c	a13
	D_w	to DIN 5402-1
Housing locating washer GS	D₁	‒
	D	to ISO 199
	B	h11
Shaft locating washer WS	d	to ISO 199
	d₁	‒
	B	h11
Bearing washer LS	d	E12
	D	a12
	B	h11

Deviation of the bore diameter Δ_dmp and deviation of the outside diameter Δ_Dmp ➤ link.

Bearing parts – axial cylindrical roller and cage assemblies and bearing washers

Suffixes

For a description of the suffixes used in this chapter ➤ Table and medias interchange http://www.schaeffler.de/std/1B69.

Suffixes and corresponding descriptions

Suffix	Description of suffix
M	Solid brass cage	Standard, dependent on bore code
TV	Solid cage made from glass fibre reinforced polyamide PA66	Standard, dependent on bore code
P5	High dimensional, geometrical and running accuracy	Special design for axial bearing washers GS, WS; available by agreement

Structure of bearing designation

Examples of composition of bearing designation

The designation of bearings follows a set model. Examples ➤ Figure and ➤ Figure. The composition of the designation is subject to DIN 623-1 ➤ Figure.

Single row axial cylindrical roller bearing, comprising axial roller and cage assembly, shaft locating washer and housing locating washer: designation structure

Double row axial cylindrical roller bearing, comprising axial roller and cage assembly, shaft locating washer and housing locating washer: designation structure

Dimensioning

Equivalent dynamic bearing load

Axial cylindrical roller bearings can only support axial forces ➤ section. In the rating life equation, P is therefore substituted by the value for F_a ➤ Equation.

Equivalent dynamic load

Legend

P	N	Equivalent dynamic bearing load
F_a	N	Axial load.

Equivalent static bearing load

Combined loads are not possible

In relation to the direction of load, the same conditions apply as for the equivalent dynamic bearing load, i. e. combined loads are not permissible. In the rating life equation, P₀ is therefore substituted by the value for F_0a ➤ Equation.

Equivalent static load

Legend

P₀	N	Equivalent static bearing load
F_0a	N	Largest axial load present (maximum load).

Static load safety factor

S₀ = C₀/P₀

In addition to the basic rating life L (L_10h), it is also always necessary to check the static load safety factor S₀ ➤ Equation.

Static load safety factor

Legend

S₀		Static load safety factor
C₀	N	Basic static load rating
P₀	N	Equivalent static bearing load.

Minimum load

Rolling bearings under low loads are particularly prone to slippage

In order to prevent slippage damage, the bearing must be subjected to a minimum axial load F_{a min} ➤ Equation and ➤ Table. In vertical bearing arrangements in particular, the requisite minimum axial load F_{a min} is normally achieved, however, simply by the weight of the bearing parts and the external forces. If this is not the case, the bearing arrangement must be preloaded, for example by means of springs or a housing nut.

Minimum axial load

Legend

F_{a min}	N	Minimum axial load
C_0a	N	Basic static load rating ➤ dimension table
k_a		Factor for determining the minimum axial load ➤ Table
n	min–1	Speed.

Factor k_a for calculating the minimum axial load

Series	Factor k_a
K811	1,4
K812	0,9
K893	0,7
K894	0,5

Design of bearing arrangements

Design of adjacent parts

Axial cylindrical roller bearings cannot tolerate angular misalignments ➤ section. The locating surfaces for the bearing parts on the shaft and in the housing must therefore be vertical to the shaft axis, while the adjacent parts must be rigid and flat. They must be configured such that the bearing washers are supported as far as possible over the whole circumference and over the whole raceway width; values ➤ dimension table. The radial cage guidance surfaces must be precision machined and wear-resistant (Ramax 0,8(Rzmax 4)).

Mounting diameter on the shaft and in the housing

For the mounting dimensions, the following values apply ➤ dimension table:

mounting diameter on the shaft ≧ d_a
mounting diameter in the housing ≦ D_a

Tolerances for shaft and housing bore

Proven tolerances are given in ➤ Table . If the data are observed, this will give correct radial guidance of the bearing elements.

Tolerances for shafts and housing bores

Bearing component		Tolerance class for
Bearing component		Shaft	Bore
Axial cylindrical roller bearings	Shaft guided	h8	‒
Housing locating washers	‒	‒	H9
Shaft locating washers	‒	h8	‒
Bearing washers	Externally centred as housing locating washer	Shaft released	H9
Bearing washers	Internally centred as shaft locating washer	h8	Bore released

The envelope requirement Ⓔ applies.

Guidance of bearing parts

Release of shaft and housing locating washers, as a function of centring

If the bearing washers are centred on the shaft, they must have radial clearance in the housing bore while, if they are centred in the housing, there must be radial clearance between the washer bore and the shaft ➤ Figure.

Guidance and release of shaft and housing locating washers

Housing locating washer (guidance in the housing), radial clearance on the shaft

Shaft locating washer (guidance on the shaft), radial clearance in the housing

Guidance of axial roller and cage assemblies

In order to give the lowest possible sliding speeds on the guidance surfaces, the axial cylindrical roller and cage assemblies are in general guided on the shaft. This is particularly important in the case of high speeds.

For a direct bearing arrangement of roller and cage assemblies: harden and grind the raceways for the rollers

If the axial design space is particularly small, axial cylindrical roller and cage assemblies can also run directly (without axial bearing washers) on the adjacent construction. In this case – and if the load carrying capacity of the axial cylindrical roller and cage assemblies is to be fully utilised – the raceways on the shaft and in the housing must be produced as a rolling bearing raceway or must correspond to the quality and hardness of axial bearing washers. The surface hardness of the raceway must be 670 HV to 840 HV, the hardening depth CHD or SHD must be sufficiently large ➤ link. The surface roughness Ra must be ≦ 0,2 μm. At a mean roughness value of Ra ＞ 0,2 μm, it is no longer possible to utilise the full load carrying capacity of the bearings. When designing the raceway on the shaft and in the housing, the raceway dimensions E_a and E_b must be observed ➤ dimension table. If the values are observed, this will ensure that the raceways for the cylindrical rollers – taking account of any possible axial offset of the roller and cage assembly – are adequately dimensioned.

Mounting and dismounting

The mounting and dismounting options for the bearings must be taken into consideration in the design of the bearing position.

As the bearings are not self-retaining, they are easy to mount

Axial cylindrical roller bearings are not self-retaining. As a result, it is possible to mount the bearing parts (shaft locating washer, housing locating washer and axial cylindrical roller and cage assembly) separately from each other. This gives simplified mounting of the bearings.

Mounting position of the bearing washers

The correct mounting position has a considerable influence on the function of the bearing arrangement. Axial bearing washers must always be mounted with the raceway side facing the rolling elements.

Shaft locating washers

On shaft locating washers, the raceway side is indicated by the smaller chamfer on the bore diameter of the washer.

Housing locating washers

On housing locating washers, the raceway side is indicated by the smaller chamfer on the outside diameter of the washer.

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 without detrimental effect, they must be handled with care.

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/1B68. It also provides information which should be observed by the designer, in relation to the mounting, dismounting and maintenance 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.

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:

Determining the bearing size ➤ link
Rigidity ➤ link
Friction and increases in temperature ➤ link
Speeds ➤ link
Bearing data ➤ link
Lubrication ➤ link
Sealing ➤ link
Design of bearing arrangements ➤ link
Mounting and dismounting ➤ link