THK’s RB SERIES Cross Roller Bearing for Inner Ring Rotation represents a specialized linear motion component engineered for applications requiring high rigidity, precision rotation, and compact design. This standard model features a unique crossed roller arrangement where cylindrical rollers are positioned at right angles to each other between the inner and outer rings, alternating contact directions to handle complex load combinations efficiently. The bearing’s construction allows the inner ring to rotate while the outer ring remains stationary, making it ideal for situations where rotational movement needs to be confined to the shaft or internal components.
Key technical features include a compact cross-sectional profile that minimizes space requirements while maximizing load capacity. The rollers are precision-ground to ensure uniform stress distribution and are separated by an integrated spacer or cage to prevent skewing and reduce friction-induced heat generation. RB SERIES bearings are available in various sizes and configurations, with options for standard accuracy or high-precision grades to suit different application demands. They typically incorporate sealing mechanisms to protect against contaminants and retain lubrication, enhancing service life in harsh environments. Mounting is simplified through bolt holes on the outer ring, facilitating secure installation without additional complex fixtures.
Performance advantages stem from the crossed roller design, which provides simultaneous support for radial, axial, and moment loads. This multi-directional load capacity eliminates the need for multiple bearing assemblies, reducing system complexity and potential points of failure. The RB SERIES offers high rotational accuracy with minimal runout, ensuring smooth and precise motion critical for automated processes. Its rigid structure minimizes elastic deformation under load, maintaining positioning accuracy even during high-speed operations or under heavy loads. Low friction characteristics contribute to energy efficiency and reduced heat buildup, while the optimized lubrication system extends maintenance intervals and operational longevity.
Typical applications span industrial machinery, automotive systems, and precision equipment where reliable rotational guidance is paramount. In industrial automation, these bearings are integral to rotary tables, indexing mechanisms, and robotic arm joints, providing the stability needed for repetitive positioning tasks. The automotive industry utilizes them in steering systems, transmission components, and testing equipment rotators, where durability and precision under dynamic loads are essential. For precision instruments, such as medical imaging devices, semiconductor manufacturing tools, and optical alignment systems, the RB SERIES ensures vibration-free rotation and sub-micron level accuracy. Its versatility also extends to packaging machinery, CNC rotary attachments, and measuring device pivots, where compactness and high load-bearing capacity optimize performance in space-constrained designs.
| Model No. | Main dimensions | Basic load rating (Radial) |
|||
| Inner diameter d |
Outer diameter D |
Width B B1 |
Dynamic rating C |
Static rating C0 |
|
| mm | mm | mm | kN | kN | |
1250 |
1500 |
110 |
1350 |
3970 |
|
1000 |
1250 |
110 |
1220 |
3220 |
|
900 |
1050 |
70 |
494 |
1490 |
|
350 |
400 |
20 |
54.1 |
143 |
|
200 |
280 |
30 |
114 |
200 |
|
200 |
295 |
35 |
151 |
252 |
|
220 |
280 |
25 |
92.3 |
171 |
|
240 |
300 |
25 |
68.3 |
145 |
|
250 |
310 |
25 |
69.3 |
150 |
|
250 |
330 |
30 |
126 |
244 |
|
250 |
355 |
40 |
195 |
348 |
|
300 |
360 |
25 |
76.3 |
178 |
|
300 |
395 |
35 |
183 |
367 |
|
300 |
405 |
40 |
212 |
409 |
|
400 |
480 |
35 |
156 |
370 |
|
400 |
510 |
40 |
241 |
531 |
|
450 |
500 |
25 |
61.7 |
182 |
|
500 |
550 |
25 |
65.5 |
201 |
|
500 |
600 |
40 |
239 |
607 |
|
500 |
625 |
50 |
267 |
653 |
|
600 |
700 |
40 |
264 |
721 |
|
700 |
815 |
45 |
281 |
836 |
|
800 |
950 |
70 |
468 |
1330 |
|
170 |
220 |
20 |
29 |
62.1 |
|