Basic design bearings, BTW series
Bearings in the BTW series (fig. 1) consist of two single row angular contact thrust ball bearings with a 60° contact angle, arranged back-to-back. This configuration, combined with the large number of balls, enables these bearings to accommodate high axial loads in both directions and provides a high degree of system rigidity. Bearings in the BTW series are separable. When the shaft washers are pressed together, preload within a predetermined range will result.
On request, bearings in the BTW series can be provided with an annular groove and three lubrication holes in the housing washer (designation suffix W33, table 1). They can also be supplied with a larger bore diameter so that they can be mounted immediately adjacent to the large diameter side of a cylindrical roller bearing with a tapered bore (e.g. BTW 60 CATN9/SP).