RKB Deep Groove ball Bearings
Non-separable, for operations at high speeds, of simple design and little maintenance, RKB deep groove ball
bearings are the most versatile and popular bearings in rolling applications.
The internal designs are the Conrad assembly (the majority of the production) and the filling slot assembly (for
special applications with cage or with full ball complement).
The single row deep groove ball bearings can take radial and double direction axial loads.
They have limited abilities to compensate for errors of misalignment. Because of the values, in order to avoid
inadmissible high additional loads and noise increase as a result of complex relationships among several influencing
factors, the permissible misalignments are considered those between 2 to 10 minutes of arc depending on the
The basic design of RKB deep groove ball bearings is open type either with boundary metric dimensions in
accordance with ISO 15:1988 or with inch dimensions as per American AFBMA specifications.
The version with a snap ring groove on the outer ring (suffix N) for the easy axial location in the housing is in
accordance with ISO 464.
When required by the application, these ball bearings are also produced in the sealed and shielded versions
that have the seal recesses in the outer rings (suffix 2RS and ZZ). In case of bearings with shields, there is a small
interstice between the shield and the rib of the inner ring; in case of bearings with seals, the oil resistant elastic
rubber lip runs on the groove on the side of the inner ring or directly on the outside surface of the inner ring.
Bearings sealed and shielded on both sides manufactured in series are delivered filled with normal lithium base
grease of consistency NLGI 2 or with special grease suitable for specific applications.
Bearings with shields have been designed first of all for those cases where the inner ring rotates.
RKB single row deep groove ball bearings are produced as standard to normal tolerances P0. Higher precision
bearings in accordance with ISO 492:2002 can be considered.
The radial clearance, according to ISO 5753, can be normal or in different classes as per international specifications.
The axial clearance is generally not standardized and depends on the values of the radial clearance, ball size and raceway radius. The cage depends on the bearing series and size; RKB single row deep groove ball bearings are supplied with one of the following designs: ribbon type cage of steel or brass sheet, riveted type of steel or brass sheet and machined brass type centered on balls, inner ring or outer ring. Large size bearings are also available in special executions such as lubrication grooves in the guiding surfaces of machined brass cage (suffix MAS or MBS) and/or one notch in the outer ring side face to prevent ring from rotating (suffix N1). Non ISO standard dimensions (including special part numbers) can be manufactured on request.