Tapered Roller Bearings
Double-Row Taper Roller Bearings: Bearing Selection
MAC offers double-row taper roller bearing in two different arrangements:
Face-to-face (TDI)
Back-to-back (TDO)
In the TDI configuration the load lines are converging as the axis of rotation is approached. This arrangement doesn’t increase the stiffness of the assembly and the bearing cannot support overturning moments. Reversely, in the TDO configuration, the contact angle is diverging as the axis of rotation is approached, increasing the stiffness of the assembly. This type of arrangement is suitable to resist overturning moments
TDO Configuration
TDO configuration consists of a double-row taper roller bearing composed of two single cones, one double cup, two pressed steel cages, two rows of back-to-back rollers and one cone spacer (plain or with annular groove and lubrication holes). The width of the cone spacer permits to obtain the correct B.E.P. The TDO bearings with a blind hole in the double cup are particularly suitable to be mounted with a loose fit in the housing, due to the hole counter bored that allows the insertion of a pin to avoid sliding between the double cup and the housing.
TDI Configuration
TDI configuration consists of a double-row taper roller bearing composed of two single cups, one double cone, two pressed steel cages, two rows of face-to-face rollers and one cup spacer. The width of the cup spacer permits to obtain the correct B.E.P.
TDONAZ Configuration
TDONAZ configuration consists of a double-row taper roller bearing composed of two single cones, one double cup, two pressed steel cages, two rows of back-to-back rollers and two pressed steel shields. There are no spacers and the bearing is supplied with the correct B.E.P.
TQO Configuration
TQO configuration is a four-row taper roller bearing composed of two double cones, one double cup, two single cups, four pressed steel cages, four rows of rollers, one cone spacer (also available with lubrication grooves) and two cup spacers (with annular groove and lubrication holes). The paired rollers are in face-to-face configuration.
B TQO/G Configuration
B TQO/G configuration is a four-row taper roller bearing composed of two double cones with helical groove in bore, one double cup, two single cups, four pressed steel cages, four rows of rollers, one cone spacer (also available with lubrication grooves) and two cup spacers (with annular groove and lubrication holes). The paired rollers are in face-to-face configuration. When the bearing is mounted on the shaft with a loose fit, RKB performs the helical groove in bearing bore to reduce the wear between the two parts. The wear reduction is obtained by interposing oil in the contact zone between the shaft and the two double cones.
TQO/EG configuration
TQO/EG configuration is a four-row taper roller bearing composed of two double cones with helical groove in bore, two central single cups, two single cups, four pressed steel cages and four rows of rollers. This type of configuration differs from the other types of TQO by the absence of spacers. The B.E.P. is obtained adjusting the dimensions of the cones and the cups. The paired rollers are in face-to-face configuration.
All of the multi-row taper roller bearings offered by MAC are supplied correctly assembled, with the axial internal clearance (B.E.P. – Bench End Play) required. Usually the correct B.E.P. range is obtained by adjusting the width of the spacers between cones and cups, but in some designs, with no spacers between cones and cups, the B.E.P. is pre–adjusted. When the bearing is mounted on the shaft and in the housing with interference fit, the axial internal clearance is reduced. The remaining axial internal clearance after mounting is called M.E.P. (Mounted End Play).