7...-B-M

Technical characteristics

Single row angular contact ball Bearings are non- separable,rigid radial bearings.

They consist of an inner ring and outer ring with a big and a small flange,so they can accommodate a large number of balls getting a relatively high load capacities.

Single row angular contact ball bearings are sui- table to support both axial and radial forces,in- cluding combined loads and tilting moments as well as being suitable for high speeds.As these

bearings only support axial loads in one direc- tion,they must be mounted in pairs against each other so each bearing will support the axial load in each direction.

Single row angular contact ball bearings transfer the loads acting on the bearing with an angle, called the contact angle (a)(Fig.1).

The capacity of single row angular contact ball Bearings for supporting axial loads depends on their contact angle.The wider the angle,the hig-  her the axial load capacity.

Usually the contact angle of these bearings is 40 degrees.This is indicated by the B suffix.

Their main dimensions are standardized in DIN 616 and DIN 628.

Standard design variants

VEO  single  row  angular  contact  ball  bearings  are available  in  a wide  range  of standardized  designs (see  Fig.2).

The  standard  range  includes  series  72..-B  and 73..-B,which  are  divided  into  two  designs,the basicone  anda  design  for  universal  matching.

The VEO single  row angular contact  ball  bearings with  basic  design,have  normal  tolerances  in  the flanges of the  rings  and  in the  bearing  width.This feature   does  not  allow  

matching  the  standard bearings  in  pairs  directly.

VEO  single  row  angular  contact  ball  bearings  for  universal  matching,have  different  suffixes   (see page 103  suffix  table)depending on the special needs,are arranged in    

tandem(DT),face  to face(DF)or  back  to  back  (DB).Due  to  their design,these  bearings  can  be  mounted  in  any arrangement  without  distinction.

These paired bearings are used in cases where the  load  capacity  of  a  single  bearing  does  not meet  the  requirements  of  the application.

It must be indicated the total number of  indivi- dual  bearings  when  ordering.

Arrangements

Tandem arrangement,suffix DT

This arrangement is used when the axial load ex- ceeds the axial load capacity of a single bearing. Thus,this load,as well as the radial load,are going to be divided equally between each of the

bearings.In case that there is an axial load in the opposite direction,these bearings should always be mounted with another bearing what supports the axial loads in the other direction.

Face to face arrangement,suffix DF

In this layout, the axial force is applied in both directions, and each direction is supported by a pairing bearing. The load line is collected towards the bearing axis. Because of its low rigidity, this

layout is not suitable for the loading torque. On the other hand, this layout does not require the middle and back to lay out as precise.

Back to back arrangement,suffix DB

In this arrangement,the axial forces are applied in both directions and each direction is suppor- ted by one of the paired bearings.Load lines diverge towards the bearing axis,which makes this

arrangement adequate for supporting tilting moments,being a relatively rigid arrangement. However,they are not valid to accommodate mi- salignments.

Misalignment

Due to their internal geometry,the  auto  align- ment capacity of single row angular contact ball bearings  is  reduced;therefore,the supports should be properly aligned.

Misalignment  errors  must  be  taken  in  mind,as these lead to an inappropriate ball rolling causing important  additional forces that shorten  life  and generate  higher  levels  of  noise

The  permissible angular  misalignment  between the inner and outer rings depend on:the size of  the  bearing,design,loads,bearing  radial  clea- rance,etc.Due  to  the  complex

relationship  bet- ween these factors and others,it cannot be given specific values.The  customer  must  take  special care when mounting the bearings.

It has been proven that in the face to face arran- gement with  preload  it  is  permissible  up  to two minutes of arc of misalignment from the  middle position  without   significantly  affecting

the per- formance  of  the bearings.

Tolerances

VEO single row angular contact ball bearings with basic design are made with normal tolerance class (PN)as standard.However,the bearings for universal matching are manufactured with tighter

tolerances than the normal class.

In applications where the precision is essential, VEO can supply,on request,single row angular  contact ball bearings with tighter tolerances (P6, P5,P4 and P2).

The tolerances for these bearings are according to IS0492:2002 and are shown inthe corresponding tables displayed in the Introduction chapter.

Cages

VEO single row angular contact ball bearings are fitted with different types of cage and materials depending on their size and series.

There are different models of cages with diffe- rent characteristics,both in material and shape, depending  on  the  application  of  the  bearing. Some of those cages and their characteristics are

described below:

·J:Pressed  window-type  steel  cage,ball  cen- tred

·M:machined   window-type   brass   cage,balls centred

·MB:Machined brass cage,inner ring centred

·TVP:Window-type glass fiber reinforced polya- mide cage,ball centred

Lubrication

VEO single row angular contact ball bearings with lip seals on both sides (suffix 2RS)are lubrica- ted forbearing life as standard with high quality grease.

VEO single row angular contact ball bearings in the designs opened and sealed only in oneside,can  be lubricated with grease or oil once assembled,  but they come as standard without

lubrication,  only with an anti-rust protective lubricant.

As in other type of bearings,for the optimum performance,it should be provided the correct lubricant in the correct quantity.Currently,VEO has in its standard production range different ty- pes

of lubricants that can meet the requirements in the different operating conditions,e.g.:

-Grease with lithium thickener NLGI 2:tempera- tures -50 to+140°C

-Grease with lithium thickener NLGI 2:tempera- tures -50 to +90°C

-Grease with polyurea thickener NLGI 2:tempe- ratures -30 to +150°C

-Grease with polyurea thickener NLGI 2:tempe- ratures -40 to +150°C

In case of doubt,please,contact the VEO Applica- tions Engineering department.

In addition,VEO sealed single row angularcontact ball bearings can also be supplied on request with any other grease that meets the conditions requi- red by the customer.

Axial clearance and/or preload

The axial clearance and preload of the VEO sin- gle row angular contact ball bearings matched in pairs is achieved during the assembly,setting each bearing against the other.These bearings,

when they are intended for fitting in pairs,are identified  with  the  suffixes  UA,UL,UO,which appear in sufix table of this chapter (table 3).

VEO single row angular contact ball bearings are manufactured as standard with three types of internal clearance and/or preload.These types and their values are shown in the following table

(table 1).Those values are applicable to bearings before  mounting  or without  applied  loads,and are valid for bearings matched face to face and back to back.

VEO single row angular contact ball bearings can be supplied on request in other tolerance groups.

Note:for rigid fits,the axial internal clearance is reduced and /or the preload increases