Barrel roller bearings

Barrel roller bearings are suitable:

• for compensating angular misalignments where there is skewing between the outer and inner ring ➤ section
• where high radial shock type loads occur, as a result of the line contact ➤ section
• where angular misalignments and high radial loads occur, but speed is not a priority ➤ Figure

Barrel roller bearing: speed comparison with self-aligning ball bearing, compensation of misalignments Fr = radial load Cr = radial basic dynamic load rating

Bearing design

Design variants

Barrel roller bearings are available as:

• bearings of basic design ➤ Figure
• bearings with adapter sleeve ➤ Figure

Bearings of basic design

The outer ring has a curved raceway

Barrel roller bearings are single row, self-retaining radial roller bearings, which are part of the group of self-aligning bearings. The outer ring has a concave raceway. As a result, the bearings permit the compensation of static and dynamic angular misalignments (skewing between the inner and outer ring) within certain limits ➤ section. The inner ring has a formed raceway for the rolling elements and two rigid ribs. The rollers are barrel-shaped and are guided between the inner ring ribs. Their outside surface line closely follows the raceway profile of the outer and inner ring. Solid cages made from polyamide PA66 or brass are used ➤ Table.

The bore is cylindrical or tapered

Barrel roller bearings of basic design are available with a cylindrical or tapered bore, as a function of the bore diameter d ➤ Figure.

Bearings with a tapered bore have a bore taper of 1:12 and the suffix K ➤ Table.

Barrel roller bearings of basic design Fr = radial load Fa = axial load Barrel roller bearing with cylindrical bore Barrel roller bearing with tapered bore, bore taper 1:12

Bearings with adapter sleeve

Ready-to-fit bearing mounting kits facilitate the ordering and mounting of barrel roller bearings

Complete bearing mounting kits comprising the bearing of basic design, slotted adapter sleeve, tab washer and locknut, are also available for use in the location of barrel roller bearings with a tapered bore on a cylindrical shaft journal (series 202..-K + H, 203..-K + H) ➤ Figure. Adapter sleeves allow bearings to be located on smooth and stepped shafts. The adapter sleeves must also be stated when placing the order. Ordering example ➤ Figure.

Barrel roller bearing with adapter sleeve Fr = radial load Fa = axial load Barrel roller bearing with tapered bore Adapter sleeve Locknut Tab washer

Load carrying capacity

Suitable for high radial loads

The balls are in line contact with the raceways. As a result, barrel roller bearings have a very high radial load carrying capacity ➤ Figure. In contrast, they have only a low axial load carrying capacity.

Axial load carrying capacity of bearings with adapter sleeve

Where bearings with adapter sleeves are located on a smooth shaft without a fixed stop (e. g. rigid shoulder), their axial load carrying capacity is dependent on the friction between the shaft and the sleeve.

If there is any uncertainty regarding the axial load carrying capacity of the adapter sleeve location method, please consult Schaeffler.

Compensation of angular misalignments

Barrel roller bearings compensate dynamic and static angular misalignments

Due to the concave rolling element raceway in the outer ring, barrel roller bearings are capable of angular adjustment ➤ section. As a result, they permit skewing between the outer and inner ring within certain limits, without causing damage to the bearings, and can thus compensate misalignments, shaft deflections and housing deformations.

Permissible adjustment angle

With a rotating inner ring, barrel roller bearings can swivel up to 4° from their central position

The magnitude of alignment and angular defects may only be so large when the bearings are mounted that the contact surfaces of the rolling elements under load still lie within the width of the raceway. Under normal operating conditions and with a rotating inner ring, barrel roller bearings can swivel by up to 4° from their central position. The extent to which this value can be used for skewing between the inner and outer ring is, however, essentially dependent on the design of the bearing arrangement.

If the outer ring rotates or the inner ring undergoes tumbling motion, the angular adjustment facility is smaller. In such cases, please consult Schaeffler.

Lubrication

Oil or grease lubrication

The bearings are not greased. They must be lubricated with oil or grease and can be lubricated from the end faces.

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.

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

The bearings are open; providing additional seals in the adjacent construction

Barrel roller bearings are supplied without seals. As a result, sealing of the bearing position must be carried out in the adjacent construction. The sealing system should reliably prevent:

• moisture and contaminants from entering the bearing
• the egress of lubricant from the bearing position

Speeds

The product tables give the limiting speed n_G. This 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.

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 rings and rolling elements
• the cage
• the lubricant

Possible operating temperatures of barrel roller bearings ➤ Table.

Permissible temperature ranges

Operating temperature	Barrel roller bearings
	with brass cage	with polyamide cage PA66
	–30 °C to +150 °C, for D ＞ 120 mm up to +200 °C	–30 °C to +120 °C

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

Cages

Standard cages for barrel roller bearings ➤ Table.

Cage, cage suffix, bore code

Bearing series	Solid cage made from polyamide PA66	Solid brass cage
	TVP	MB
	Bore code
202	up to 16	from 17
203	up to 12	from 13

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.

Internal clearance

Radial internal clearance – bearings with cylindrical bore

The standard is CN

Barrel roller bearings with cylindrical bore are manufactured as standard with radial internal clearance CN (normal) ➤ Table. CN is not stated in the designation.

Certain sizes are also available by agreement with the smaller internal clearance C2 and with the larger internal clearance C3 and C4.

Values for radial internal clearance ➤ Table. These are valid for bearings which are free from load and measurement forces (without elastic deformation).

Radial internal clearance of barrel roller bearings with cylindrical bore

Nominal bore diameter		Radial internal clearance
d		C2		CN		C3		C4
mm		μm		μm		μm		μm
over	incl.	min.	max.	min.	max.	min.	max.	min.	max.
–	30	2	9	9	17	17	28	28	40
30	40	3	10	10	20	20	30	30	45
40	50	3	13	13	23	23	35	35	50
50	65	4	15	15	27	27	40	40	55
65	80	5	20	20	35	35	55	55	75
80	100	7	25	25	45	45	65	65	90
continued ▼

Radial internal clearance of barrel roller bearings with cylindrical bore

Nominal bore diameter		Radial internal clearance
d		C2 (Group 2)		CN (Group N)		C3 (Group 3)		C4 (Group 4)
mm		μm		μm		μm		μm
over	incl.	min.	max.	min.	max.	min.	max.	min.	max.
100	120	10	30	30	50	50	70	70	95
120	140	15	35	35	55	55	80	80	110
140	160	20	40	40	65	65	95	95	125
160	180	25	45	45	70	70	100	100	130
180	225	30	50	50	75	75	105	105	135
225	250	35	55	55	80	80	110	110	140
250	280	40	60	60	85	85	115	115	145
continued ▲

Radial internal clearance – bearings with tapered bore

C3 is normally used

Barrel roller bearings with tapered bore are normally manufactured with the larger radial internal clearance C3 ➤ Table.

Certain sizes are also available by agreement with the smaller internal clearance C2, with internal clearance CN (normal) and with the larger internal clearance C4.

Values for radial internal clearance ➤ Table. These are valid for bearings which are free from load and measurement forces (without elastic deformation).

Radial internal clearance of barrel roller bearings with tapered bore

Nominal bore diameter		Radial internal clearance
d		C2		CN		C3		C4
mm		μm		μm		μm		μm
over	incl.	min.	max.	min.	max.	min.	max.	min.	max.
–	30	9	17	17	28	28	40	40	55
30	40	10	20	20	30	30	45	45	60
40	50	13	23	23	35	35	50	50	65
50	65	15	27	27	40	40	55	55	75
65	80	20	35	35	55	55	75	75	95
80	100	25	45	45	65	65	90	90	120
100	120	30	50	50	70	70	95	95	125
120	140	35	55	55	80	80	110	110	140
140	160	40	65	65	95	95	125	125	155
160	180	45	70	70	100	100	130	130	160
180	225	50	75	75	105	105	135	135	165
225	250	55	80	80	110	110	140	140	170
250	280	60	85	85	115	115	145	145	175

Dimensions, tolerances

Dimension standards

The main dimensions of barrel roller bearings correspond to DIN 635‑1:2010. Nominal dimensions of barrel roller bearings ➤ link.

Chamfer dimensions

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

Tolerances

The tolerances for the dimensional and running accuracy of barrel roller bearings correspond to tolerance class Normal in accordance with ISO 492:2014. Tolerance values in accordance with ISO 492 ➤ link.

Suffixes

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

Suffixes and corresponding descriptions

Suffix	Description of suffix
C2	Radial internal clearance C2 (smaller than normal)	Special design, available by agreement
C3	Radial internal clearance C3 (larger than normal)	Normally used for bearings with tapered bore, available by agreement for bearings with cylindrical bore
C4	Radial internal clearance C4 (larger than C3)	Special design, available by agreement
CN	Radial internal clearance CN (normal)	Normally used for bearings with cylindrical bore, available by agreement for bearings with tapered bore
K	Tapered bore, taper 1:12	Standard
MB	Solid brass cage, guided on inner ring	Standard, cage material dependent on bore code
TVP	Solid cage made from glass fibre reinforced polyamide PA66	Standard, cage material dependent on bore code

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 designations is subject to DIN 623‑1➤ Figure.

Barrel roller bearing with cylindrical bore: designation structure

Barrel roller bearing with tapered bore and adapter sleeve: designation structure

Dimensioning

Equivalent dynamic bearing load

P = F_r under purely radial load of constant magnitude and direction

The basic rating life equation L = (C_r/P)^p used in the dimensioning of bearings under dynamic load assumes a load of constant magnitude and direction. In radial bearings, this is a purely radial load F_r. If this condition is met, the bearing load F_r is used in the rating life equation for P (P = F_r).

P is a substitute force for combined load and various load cases

If this condition is not met, a constant radial force must first be determined for the rating life calculation that (in relation to the rating life) represents an equivalent load. This force is known as the equivalent dynamic bearing load P.

To calculate P for barrel roller bearings under dynamic load ➤ Equation.

Equivalent dynamic load

Legend

P	N	Equivalent dynamic bearing load
Fr	N	Radial load
Fa	N	Axial load

Equivalent static bearing load

For barrel roller bearings subjected to static load ➤ Equation.

Equivalent static load

Legend

P0	N	Equivalent static bearing load
F0r, F0a	N	Largest radial or 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

In order to prevent damage due to slippage, a minimum radial load of P ＞ C_0r/60 is required

In order that no slippage occurs between the contact partners, the barrel roller bearings must be constantly subjected to a sufficiently high load. Based on experience, a minimum radial load of the order of P ＞ C_0r/60 is thus necessary. In most cases, however, the radial load is already higher than the requisite minimum load due to the weight of the supported parts and the external forces.

If the minimum radial load 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 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 over their entire circumference and over the entire width of the raceway. Support can be provided by means of a cylindrical or tapered seating surface ➤ Figure to ➤ Figure. The seating and contact surfaces should not be interrupted by grooves, holes or other recesses. The accuracy of mating parts must meet specific requirements ➤ Table to ➤ Table.

Radial location – fit recommendations for bearings with cylindrical bore

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 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.

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) ➤ link
• shaft fits ➤ link
• tolerance classes for bearing seats in housings (radial bearings) ➤ link
• housing fits ➤ link
• shaft tolerances for adapter sleeves and withdrawal sleeves ➤ link

Axial location – fit recommendations for bearings with cylindrical bore

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 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 shoulders, housing covers, nuts, spacer rings, retaining rings, adapter and withdrawal sleeves etc. are generally suitable.

Location of bearings with tapered bore

Location by means of locknut and tab washer

If a bearing with a tapered bore is mounted directly on a tapered journal the bearing can be axially located with ease using an axial locknut and tab washer ➤ Figure.

Barrel roller bearing with tapered bore, mounted directly on the tapered shaft jounal Tapered journal with fixing thread Locknut Tab washer

Location of bearings by means of adapter sleeve

Mounting can be carried out quickly and reliably by means of wrench sets from Schaeffler

Barrel roller bearings with a tapered bore can be located easily and reliably on smooth or stepped shafts by means of an adapter sleeve ➤ Figure. The adapter sleeves do not need to be secured on the shaft by any additional means. The bearings can be positioned at any point on smooth shafts. Axial load carrying capacity of bearing arrangements by means of adapter sleeve connection ➤ section.

Barrel roller bearing with adapter sleeve, located on smooth shaft Adapter sleeve Locknut Tab washer

Location by means of adapter sleeve, axial support by means of a support ring

If very high axial forces are present, a support ring can also be used to provide axial support ➤ Figure. In this instance, the mounting dimensions of the support ring B_a and d_b in the product tables must be observed ➤ link.

Stepped shaft, axial support by means of a support ring Adapter sleeve Locknut Tab washer Support ring Shaft shoulder

Dimensional, geometrical and running accuracy of cylindrical bearing seats

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

The accuracy of the cylindrical bearing seat on the shaft and in the housing should correspond to the accuracy of the bearing used. For barrel roller bearings with the tolerance class Normal, the shaft seat should correspond to a minimum of standard tolerance grade IT6 and the housing seat to a minimum of IT7. Guide values for the geometrical and positional tolerances of bearing seating surfaces ➤ Table, tolerances t₁ to t₃ in accordance with ➤ Figure. Numerical values for IT grades ➤ Table.

Guide values for the geometrical and positional tolerances 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 shoulders
				t1	t2	t3
Normal	PN (P0)	Shaft	IT6 (IT5)	Circumferential load IT4/2	Circumferential load IT4/2	IT4
		Shaft	IT6 (IT5)	Point load IT5/2	Point load IT5/2	IT4
		Housing	IT7 (IT6)	Circumferential load IT5/2	Circumferential load IT5/2	IT5
		Housing	IT7 (IT6)	Point load IT6/2	Point load IT6/2	IT5

Numerical values for ISO standard tolerances (IT grades) to ISO 286-1:2010

IT grade	Nominal dimension in mm
	over	18	30	50	80	120	180	250
	incl.	30	50	80	120	180	250	315
	Values in μm
IT4		6	7	8	10	12	14	16
IT5		9	11	13	15	18	20	23
IT6		13	16	19	22	25	29	32
IT7		21	25	30	35	40	46	52

Roughness of cylindrical bearing seating surfaces

Ra must not be too high

The roughness of the bearing seats must be matched to the tolerance class of the bearings. The mean roughness 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 ➤ Table.

Roughness values for cylindrical bearing seating surfaces – guide values

Nominal diameter of the bearing seat d (D)		Recommended mean roughness 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

Tolerances for tapered bearing seats

Specifications for tapered bearing seats

For bearings located directly on a tapered shaft journal, ➤ Figure, the data are in accordance with ➤ Figure.

Mounting dimensions for the contact surfaces of bearing rings

The contact surfaces for the rings must be of sufficient height

The mounting dimensions of the shaft and housing shoulders, and spacer rings etc., must ensure that the contact surfaces 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 for the radii and diameters of the abutment shoulders are indicated in the product tables. These dimensions are limiting dimensions (maximum or minimum dimensions); the actual values should not be higher or lower than specified.

Suitable bearing housings for barrel roller bearings

A large range of housings is available

For economical, operationally reliable and easily interchangeable bearing arrangement units, the barrel roller bearings can also be combined with Schaeffler bearing housings ➤ Figure. These easy-to-fit units fulfil all of the requirements for modern machine and plant designs with favourable maintenance-related characteristics.

Due to the large number of application areas, an extensive range of split plummer block housings and flanged housings is available for bearings with cylindrical and tapered bores. Detailed information on bearing housings can be found in publication GK 1 http://www.schaeffler.de/std/1B63. This book can be ordered from Schaeffler.

Split plummer block housing with a barrel roller bearing Split plummer block housing SNV Barrel roller bearing

Mounting and dismounting

The mounting and dismounting options for barrel 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

Barrel roller bearings are not separable. In the mounting of non-separable bearings, the mounting forces must always be applied to the bearing ring with a tight fit.

Bearings with tapered bore – methods for achieving a sufficiently tight fit

Suitable methods: measuring the reduction in radial internal clearance or axial displacement

Bearings with a tapered bore are mounted with a tight fit on the shaft or adapter and withdrawal sleeve. The tight fit can be checked:

• by measuring the reduction in radial internal clearance or
• by measuring the axial displacement of the inner ring on the tapered bearing seat

The malfunction-free operation of barrel roller bearings presupposes that these have been mounted correctly. An insufficient operating clearance or inadequately tight fit on the shaft generally leads to bearing damage.

If there is any uncertainty regarding the practical application of both methods, Schaeffler must always be consulted.

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