RKB Taper roller thrust bearings
RKB taper roller thrust bearings have the following separable parts: shaft washer, housing washer and rolling element assembly. RKB manufacturing program includes the single direction type, the double direction type and the screwdown special type. RKB single direction taper roller thrust bearings are manufactured in two constructive versions, with tapered raceway on both washers or on only one. The rollers are radially guided by the rib of one washer. They have controlled contour to redistribute end stress concentration and provide more uniform distribution of the applied loads (suffix ZB). These bearings can also be produced in the version without the cage to obtain the maximum axial load carrying capacity (suffix V). The most common series are T type, TK type and 351 type. Bearings made of case hardened carburizing alloy steels can be produced for particular applications where required. RKB double direction taper roller thrust bearings are normally used in the rolling mill applications associated with a multi row cylindrical roller bearing. RKB produces this type of bearing in two constructive versions, either with central plane shaft washer and taper raceways in both housing washers or with both plane housing washers and taper raceways in the central shaft washer. A special sleeve is arranged between the two housing washers, so that, when mounting, no special adjustment of the bearing is required. As the double direction taper roller bearings are usually mounted with loose fit on the roll neck, the shaft washer is normally provided with one or two locating slots that, engaged with key-way or similar devices, prevent the shaft washer from rotating on the seating. If the load carrying capacity is not adequate to the expected life, TDIS type can be used in alternative. The most common series are 350 type, 351 type, 353 type and TTK type.
RKB screw-down bearings are a special design of the single direction taper roller thrust bearings used for rolling mill arrangements. They are generally produced with case hardened carburizing alloy steels and with full complement of long rollers of large diameter to accommodate very heavy axial loads and shocks. In order to accept the angular movements of the screw spindle with respect to the support without detrimental effects on bearing performance, the bearings have one sphered washer that could be either the shaft or the housing washer. An additional concave sphered pressure plate can be supplied with the bearing. Usually screw-down bearings are custom-made to meet the specific requirements of different applications. The dimensions of taper roller thrust bearings are not standardized. The main boundary dimensions are produced with normal tolerances according to ISO 199:1979.