RU85 Cross Roller Bearing RU Series Thin Section Slewing Ring Bearings

RU Series Slewing Ring Bearing – The Ultimate High-Rigidity, Compact Rotary Solution for Precision Machinery

When your application demands exceptional rotational accuracy, outstanding rigidity, and the ability to handle complex combined loads in a compact footprint, the RU Series Slewing Ring Bearing stands as the industry benchmark.

Key Features:

• Simple installation
  The most distinctive feature of the RU series is the integration of precisely spaced mounting holes on both the inner and outer rings. Because these holes are already machined, you do not need a separate presser flange or support housing – simply bolt the bearing directly to your machine’s base plate and rotary table. This design reduces part count, lowers machining costs, shortens assembly time, and eliminates potential alignment errors introduced by intermediate components.
• Unmatched Rigidity
  Cylindrical rollers arranged at alternating 90° angles create a line-contact bearing surface between the rollers and raceways. Line contact distributes load over a larger area than point contact (ball bearings), resulting in rigidity approximately 3 to 4 times higher than conventional ball bearings of the same size. This exceptional stiffness is critical for applications where even minute deflection would compromise positioning accuracy.

• Low Friction, Stable Torque
  Unlike full-complement crossed roller designs where rollers contact each other, the RU series uses spacer retainers (typically nylon) between adjacent rollers. These separators prevent roller-to-roller friction, eliminate the risk of roller skewing or jamming, and ensure low, consistent rotational torque throughout the bearing’s service life.

• Thin-Section Profile
  Despite its high load capacity and rigidity, the RU series features an ultra-thin cross-section – the outer ring diameter is only slightly larger than the inner ring diameter. This compact “thin-section” design minimizes the bearing’s footprint, allowing machine designers to reduce overall equipment size, lower weight, and create more streamlined mechanical assemblies without sacrificing performance.

• Long Life, Low Maintenance
  RU series bearings are pre-filled with high-quality lithium grease and feature integrated grease nipples for relubrication. The optional double-lip rubber seal (UU configuration) effectively blocks dust, debris, and moisture from entering the bearing cavity, extending service life even in harsh environments. Under normal operating conditions, the bearing runs maintenance-free for thousands of hours.

Applications

• Industrial & Collaborative Robots
  Robot joints (waist, shoulder, elbow, wrist) require bearings that combine high rigidity, compact size, and the ability to handle complex moment loads. RU series bearings are widely used in articulated robot arms, SCARA robots, and cobots, providing smooth, precise rotation that enables accurate path following and repeatable positioning.

• CNC Machine Tools & Rotary Tables
  Machining centers, 4th/5th axis rotary tables, indexing heads, and grinding spindles all benefit from the RU series’ high rigidity and accuracy. The bearing’s ability to resist tilting moments under cutting forces ensures that machined parts meet tight tolerances, even during heavy milling or turning operations.

• Medical Imaging Equipment
  CT scanners, MRI gantries, and X-ray C-arms require bearings that rotate smoothly and quietly while supporting heavy, off-center loads. The RU series delivers the necessary stability and low vibration, ensuring clear images and patient comfort.

• Semiconductor Manufacturing
  Wafer handling robots, precision stages for lithography equipment, and IC testing machines demand sub-micron positioning accuracy and extremely low particle generation. The RU series’ clean operation, high rigidity, and optional seals make it suitable for cleanroom environments.
• Precision Measuring Instruments
  Coordinate measuring machines (CMMs), optical inspection turntables, gear testers, and metrology stages rely on the RU series’ consistent rotational accuracy and low torque variation to produce reliable measurement data.
• Aerospace & Defense
  Radar antenna positioning systems, optical gimbals for surveillance equipment, missile guidance platforms, and satellite deployment mechanisms all utilize RU series bearings for their combination of light weight, high stiffness, and reliability under demanding conditions.