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Technical  characteristics

VEO double row angular contact ball bearings are similar intheir internal structure to them paired single row angular contact ball bearings in back to back arrangement,but they are rigidly mat-

ched and they take axially less space.

These double row bearings can withstand higher radial and axial loads in both directions.They are suitable for applications that require rigid arran- gements in order to support tilting moments.

Double row angular contact ball bearings,as well as single row angular contact ball bearings,trans- fer the loads acting on the bearing with anangle, called the contact angle (a)(see Fig.1).

The capacity of double 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.

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

Standard design variants

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

The VEO  standard  range  has  the following types of double  row  angular contact ball bearings:

Basic design bearings

Sealed suffixes  ,2RS or 2Z

Bearing  with two-pieces  inner  ring,DA suffix

Basic  design  (32  and  33  series)

This  bearing  design  is the  most  widely  used  wi- thin  this  type  of  bearings.They  do  not  have  fi- lling  slots,so  they  can  support  higher   radial   and axial   loads  in both directions,as  

well as their operation  is  more  silent.VEO  double  row  angu  - lar  contact   ball bearings  can  be  supplied,under  request,with different angles of contact,if the application  requires  it.

52 and 53 series:bearings  for  the  American  mar -ket;These   bearings   (also   sealed)have   the  same dimensions   and  characteristics  as  the  series 32 rings  that  incorporate 

special  grease  for  hightemperatures.

Sealed  bearings 

Double  row  angular  contact  ball  bearings  can  be supplied  with  seals   or  shields.Sealed  design  is lubricated with high quality grease and they are maintenance    free  (lubricated for

life).Bearings with  shields  are   supplied  with  sheet   steel   plates on  both  sides  of  the   bearing  and   like  the  previous type  are  greased  for  life.Grease  maybe  lost  from

sealed  bearings  under  extreme  operating  con- ditions   like  high   speeds   or   temperatures,hence their speed will be lower than the speed of the unsealed.

Bearings with two pieces inner ring,suffix DA

These bearingshave inner ring divided in two pie-  ces,which can be dismounted.They incorporate a larger number of larger balls and their contact angle is wider,thus,their axial loadcarrying ca-

pacity is higher in both directions,but specially in the axial direction.

Misalignment

Due to their internal geometry,the auto align- ment capacity of double row angular contact ball bearings is not allowed.

Misalignment errors must betaken into account, as these  lead  into  an  inappropriate  rolling  of balls,causing  significant  additional  loads  that shorten life and generate higher noise levels.

Tolerances

VEO double row angular contact ball bearings with basic design are made with normal tolerance class (PN)as standard.

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

Cages

VEO double row angular contact ball bearings are fitted with different types of cages made with different materials depending on their size and series

Internal clearance

VEO double row angular contact ball bearings are manufactured with normalaxial internal clearan- ce.

VEO can supply on request with C3 clearance, greater than the normal clearance,or with C2  clearance,lower than the normal clearance.

The clearance values are shown in table 1.These values are relative to bearings before mounting and without loads.

Internal axial clearance groups of VEO double row angular contact ball bearings in

Minimum  load

For the correct performance of VEO double row  angular contact ball bearings,it is needed a mi- nimum radial load.This minimum load will be es- sential in applications where speed is high,if

the- re will be sudden changes in acceleration,or if there is rapid changes in the direction of loads.

The minimum radial loadfor bearings with basic design,sealed or with two-pieces innerring must be at least 1%of the dynamic load C.