RKB Single angular contact ball bearings
RKB single row angular contact ball bearings are designed to accommodate combined loads acting in radial and axial direction. They can take axial loads in one direction only. When radially loaded, in the bearing occurs an axially acting load which has to be compensated. For this reason one bearing or paired bearings are mounted on each shaft end. These bearings are not separable and their use at relatively high speed is allowed. Manufactured in various constructive versions, they can be with different contact angles, depending on the application (suffix AC, A and B). RKB produces two types of single row angular contact ball bearings: those of normal design and those intended for paired mounting (used respectively for tandem arrangement, DB and DF arrangements when axial loads have to be taken in both directions). In the case of single row angular contact ball bearings the efforts between rings and rolling elements are transmitted at an angle to a plane perpendicular to the bearing axis. The value of this angle depends on the magnitude of the raceway radius, ball diameter and radial clearance in the bearing when the curvature centers of the raceway are in the same plane. The main dimensions are in accordance with ISO/R 15. The values for the tolerance of the normal, P6 and P5 classes conform to ISO 492. Internal axial clearance or preload is obtained only when the bearings are mounted in the assembly and depends on the location of the second bearing which assures the shaft axial guiding. RKB single row angular contact ball bearings are fitted with a cage type depending on series and size: pressed steel sheet cage, machined brass cage guided on balls or on the inner ring and machined steel cage. Large size paired 718 and 719 series bearings in DF and DB configuration for power transmission equipment are included in RKB production program.
FOUR-POINT ANGULAR CONTACT BALL BEARINGS RKB four-point angular contact ball bearings are single row bearings where the raceway is designed to accommodate significant axial loads in both directions. Generally they have contact angle of either 35° or 45°. They need less axial space than double row or paired angular contact ball bearings. The four-point contact ball bearings have a split two-part inner (bearing designation QJ) or outer (bearing designation Q) ring, allowing a large number of balls to be incorporated, thus providing a high load carrying capacity. The bearings are of separable design of the parts. To prevent rotation of the outer ring (when split inner ring) all the bearings with outside diameter over 160 mm are provided with locating slots (suffix N). The main boundary dimensions are in accordance to ISO 15. The tolerances have values conform to ISO 492 and the normal class is for RKB standard production. The fitted cage is machined brass centered on outer ring for the standard common type QJ with split inner ring. RKB produces these bearings with normal axial internal clearance measured before mounting under zero measuring loads, but most sizes can also be supplied with greater or smaller clearance to special order.