As a core component of industrial and collaborative robot joints, the robot joint bearing directly determines the motion accuracy, load capacity and service life of robots. The RA Series Cross Roller Bearing is a dedicated robot joint bearing engineered to meet the rigorous demands of robot waist, elbow, wrist and ankle joints, outperforming conventional bearings in compact, high-frequency motion scenarios.
Robot joints require bearings to withstand composite loads—radial force from component weight, axial force from grabbing actions, and overturning moments during steering—while maintaining micron-level precision. The RA Series adopts 90° cross-arranged cylindrical rollers, forming line contact with raceways to deliver 3-5 times higher rigidity than standard ball bearings, ensuring stable operation even under heavy-load and high-speed (start-stop) cycles.
Lightweight and compact design is critical for robot joints, and the RA Series features an integrated non-separable inner and outer ring structure with widths of 8-13mm. This reduces joint volume by 43% and weight by 38% compared to traditional combined bearings, optimizing robot flexibility without compromising performance—ideal for collaborative and humanoid robot joints with space constraints.
Pre-lubricated with high-performance lithium grease and equipped with optional non-contact RS seals, this robot joint bearing achieves long-term maintenance-free operation, reducing downtime for automated production lines. Crafted from GCr15 bearing steel with TN plastic cages, it boasts a friction coefficient as low as 0.0012 and a service life of over 5000 hours, meeting the high-reliability needs of robot joints.
Available in inner diameters 20-250mm, the RA Series is a cost-effective alternative to IKO CRBS and THK RA-C robot joint bearings. Its P4/P2 grade rotation accuracy (repeat positioning error ≤±0.001mm) supports precision tasks like electronic component assembly and automotive welding, making it an indispensable part for advanced robot automation systems.