as the rapid development of China high-precision processing equipment, and the Chinese technology become more sophisticated, more and more CNC rotary table, vertical machining centers, vertical lathes, grinders and other high-precision CNC machining equipment are to abandon traditional design,and are to adopt  better performance cross-roller bearings.
Cross roller bearings, the rolling element is generally cylindrical roller or tapered roller, the rollers are arranged so that they cross between the inner ring and the outer ring., and is maintained between the isolation blocks. The bearing has high rotational accuracy, larger carry capacity, smaller size and higher speed of rotation and higher rigid, with the absolute advantages and more widely applications compared with other bearings.
the criss-cross arrangement of the roller structure makes individual bearing can carry axial load, radial load and overturning moment in all directions. Compared with the traditional structure, the bearing rigidity is 3-4 times of that of traditional bearings. and the size of the bearing is close to the limit of ultra-thin of the structure, and has high rigidity. It is well apply to the joints or rotating parts of industrial robots, the rotation of the machining center, robot rotation parts, precision rotary table, medical equipment and other applications.
Crossed tapered roller bearings with large cone angle and cone geometric design enables the bearing overall effective span to be bigger, while also saving space, saving material costs. Therefore, the cross-tapered roller bearings have a higher overturning moment capacity, higher rotation accuracy and higher limit speed, is the ideal choice for high-speed vertical lathe, vertical boring machine, and vertical grinder.
Structure of crossed roller bearings
Crossed roller bearings have the structure of outer ring division type with inner rotating, inner ring division type with outer rotating, inner Ring Rotation / Outer Ring Rotation. the rolling element is cylindrical roller, cylindrical rollers are arrange crosswise with each roller perpendicular to the adjacent roller in 90V groove, separated from each other by spacer retainer. The criss-cross arrangement of the roller structure makes individual bearing can carry axial load, radial load and overturning moment in all directions. and the size of the bearing is close to the limit of ultra-thin of the structure, and the bearing has high rigidity, higher rotation accuracy and larger carry capacity.  so it is well apply to the joints or rotating parts of industrial robots, the rotation of the machining center, robot rotation parts, precision rotary table, medical equipment and other applications.

RB series(outer ring division type with inner rotating), this type is the basic type of crossed roller bearings. the outer rings have two parts, and the inner ring is one integer. the type is well apply to the situation which need high rotation accuracy on inner ring. for example,it is suitable for the rotary part of the indexing table of the tools machine.