Crossed roller bearings are a special type of bearing featuring a segmented inner ring and a rotating outer ring. As the segmented inner or outer ring, after being fitted with the rollers and spacer retainer, is fixed together with the crossed roller outer ring to prevent separation, installation of the crossed roller outer ring is straightforward. The crossed arrangement of the rollers enables a single set of crossed roller bearings to withstand loads in all directions, offering 3 to 4 times greater rigidity compared to conventional types.

Furthermore, the split construction of the inner or outer ring allows for bearing clearance adjustment. This enables high-precision rotational motion even under preload conditions. Owing to their unique structure, these bearings are commonly employed as joint bearings in industrial robots.

Their rollers are arranged in a staggered, perpendicular pattern between the inner and outer rings. They can simultaneously withstand loads from all directions (such as axial, thrust, or moment loads). As the rollers make line contact with the raceway surfaces, the possibility of elastic deformation under load is minimal. This bearing type is widely employed in applications requiring high rigidity, compactness, and precision under high-speed conditions, such as industrial robotic arms, machine tools, and medical equipment.

Within a crossed roller bearing, cylindrical rollers are arranged perpendicular to each other via an spacer cage. Consequently, a single crossed roller bearing can withstand loads from all directions, including radial, axial, and moment loads. The dimensions of the inner and outer rings are minimised to the greatest extent possible. The ultra-thin type, in particular, achieves near-limit compact dimensions while maintaining high rigidity. Consequently, it is ideally suited for applications such as the joints or rotating sections of industrial robots, rotary tables in machining centres, manipulator rotary sections, precision rotary tables, medical equipment, measuring instruments, and IC manufacturing apparatus.