RA Series

RA Series Crossed Roller Bearing (Small Type)

The RA Series is an ultra-compact, thin-section crossed roller bearing designed for applications where space is limited and weight reduction is critical. Developed as a lightweight evolution of the RB Series, the RA Series reduces the wall thickness of both inner and outer rings to the practical limit while maintaining high rigidity and load-carrying capacity. This design makes it an ideal solution for precision rotational motion in compact machinery.

Applications

Robotics: Joints and swivel units of industrial robots and manipulators, especially for end-effector (hand) rotation where space constraints are critical.
Medical Equipment: Robotic surgical instruments and diagnostic devices requiring high-precision rotational positioning with minimal installation space.
Automation: Rotary tables, turntables, and indexing equipment in automated manufacturing systems.
CNC Machinery: Precision rotary axes and positioning systems

Whatsapp Send Inquiry

Inquiry	Type	Brand	Shaft Diameter	Inner Diameter	Outer Diameter	Roller Pitch Circle Diameter	Width	Greasing Hole		Rmin	Shoulder Dimensions		Basicloadrating(radial)		Mass
Inquiry	Type	Brand	Shaft Diameter	Inner Diameter	Outer Diameter	Roller Pitch Circle Diameter	Width	a	b	Rmin	ds	Dh	C kN	C0 kN	Mass

The RA Series features a split outer ring (two semi-rings) and a one-piece integrated inner ring. The outer ring halves are factory-fastened with bolts or rivets to prevent separation during handling and installation.

The bearing incorporates cylindrical rollers arranged with their axes alternately crossed at 90° within V-shaped raceways. This crossed-roller configuration enables the bearing to simultaneously accommodate radial, axial, and moment loads in all directions using just a single bearing set.

The RA Series crossed roller bearing combines ultra-thin section design with exceptional rigidity and precision, making it the optimal choice for applications where weight reduction, space savings, and high load capacity must be achieved simultaneously. Its robust crossed-roller configuration ensures reliable performance under multi-directional loading, while the split outer ring design facilitates precise preload adjustment for demanding motion control applications.