Angular contact thrust ball bearings

Double direction angular contact thrust ball bearings / Double direction axial angular contact ball bearings

Double direction axial angular contact ball bearings can support axial forces in both directions. Bearings of series 2344 and 2347 with metric dimensions are used as high precision bearings in machine tool spindles. The axial angular contact ball bearing is arranged against a double row cylindrical roller bearing of series NN30 that supports the radial forces. The parts of the axial bearing can be mounted separately. For rotary tables in drilling rigs, double direction axial angular contact ball bearings with inch size main dimensions and non-standardised designations (Z-5..ASKLZ) were developed. These special bearings comprise an upper bearing capable of supporting loads and a smaller bearing that fulfils the counterstay function. These bearings can support not only axial loads but also radial and moment loads. The bearing parts can be mounted separately.

Product overview 

Super precision bearings for machine tools	Bearings for rotary tables

Features 

Double direction axial angular contact ball bearings are availableas super precision bearings for machine tools as well as rotary table 

bearings for drilling rigs.

Super precision bearings 

Double direction axial angular contact ball bearings of series 2344 and 2347 are super precision bearings with restricted tolerances 

corresponding to class SP. They comprise solid shaft locating washers, a spacer ring, a housing locating washer and ball and cage assemblies with solid brass 

cages. The bearing parts are matched to each other and can be mounted separately, but must not be interchanged with parts from bearings of the same size. The contact angle is 60°. As a result,these highly rigid axial angular contact ball bearings can support high axial forces in both directions.

The double direction precision bearings are therefore particularly suitable for precision spindle bearing arrangements in machine tools. In this case, the axial angular contact ball bearing is combined with a double row cylindrical roller bearing with a tapered bore, 

which supports the radial forces. Axial angular contact ball bearings in a super precision design of series 2344 can be mounted on the small diameter of the shaft taper, while those of series 2347 can be mounted on the large diameter of the shaft taper.

These series have the same nominal outside diameter as cylindrical roller bearings NN30..-AS-K. However, the outside diameter tolerance is designed to give a loose fit when the seats of the axial angular contact ball bearing and the cylindrical roller bearing are machined together.

Sealing 

The super precision bearings are not sealed.

Lubrication 

They can be lubricated using oil or grease. Higher speeds can be achieved with oil lubrication. In order to allow oil to flow between the two rows of balls, the housing locating washer has a lubrication groove and lubrication holes.

At high speeds, overlubrication of the radial bearing can be prevented if the installation space is separated from that of the axial angular contact ball bearing.