THK RU85UUCC0P4 (XRU85UUCC0P4) Crossed Roller Bearing
The THK RU85UUCC0P4 (also designated as XRU85UUCC0P4) is a high-precision, face-mount crossed roller bearing with double-sided contact seals (UU suffix) belonging to THK's RU series (Integrated Inner/Outer Ring Type with Mounting Holes). This advanced bearing design features cylindrical rollers arranged perpendicular to each other in 90° V-grooves, separated by a precision spacer retainer, enabling it to simultaneously accommodate radial, axial, and moment loads from all directions.
The THK RU85UUCC0P4 (also designated as XRU85UUCC0P4) is a high-precision, face-mount crossed roller bearing with double-sided contact seals (UU suffix) belonging to THK's RU series (Integrated Inner/Outer Ring Type with Mounting Holes). This advanced bearing design features cylindrical rollers arranged perpendicular to each other in 90° V-grooves, separated by a precision spacer retainer, enabling it to simultaneously accommodate radial, axial, and moment loads from all directions while maintaining exceptional rotational accuracy and rigidity. The integrated inner and outer ring construction with pre-machined mounting holes on both rings eliminates the need for special flanges or housings, simplifying installation and ensuring stable performance. The UU sealing system provides effective protection against contamination and retains lubrication for extended service life under normal operating conditions.
Model Coding Explanation
| Code | Meaning |
|---|---|
| RU/XRU | Integrated Inner/Outer Ring Type Crossed Roller Bearing with Mounting Holes |
| 85 | Dimension code (Inner diameter 55 mm, Outer diameter 120 mm, Width 15 mm) |
| UU | Double-sided contact seals (factory-lubricated for life under normal conditions) |
| CC0 | Radial clearance group (negative clearance/preload, Starting torque: 0.1-0.5 N•m) |
| P4 | Precision class (ABEC-4 equivalent, meeting strict THK accuracy standards for rotational precision - radial runout ≤ 4 μm, axial runout ≤ 4 μm) |
Key Specifications
| Parameter | Value |
|---|---|
| Model Number | RU85UUCC0P4 / XRU85UUCC0P4 |
| Inner Diameter (d) | 55 mm |
| Outer Diameter (D) | 120 mm |
| Width (B) | 15 mm |
| Roller Pitch Circle Diameter (dp) | 85 mm (THK official dimension data) |
| Mounting Holes - Inner Ring | 8 holes, PCD 65 mm, M5 threaded holes (THK official mounting specification) |
| Mounting Holes - Outer Ring | 8 holes, PCD 105 mm, φ5.5 through holes with φ9.5 counterbores (depth 5.4 mm) (THK official mounting specification) |
| Basic Dynamic Load Rating (Cr) | 20.3 kN (20300 N) (THK official load rating data) |
| Basic Static Load Rating (Cor) | 29.5 kN (29500 N) (THK official load rating data) |
| Mass | 1 kg (THK official weight specification) |
| Precision Class | P4 (Rotational accuracy: Radial runout - ≤ 4 μm, Axial runout - ≤ 4 μm) |
| Radial Clearance | CC0 group (negative clearance/preload) |
| Starting Torque | 0.1-0.5 N•m (CC0 group) |
| Material | High carbon chromium bearing steel (SUJ2, JIS G 4805) |
| Sealing System | Double-sided contact seals (UU) - factory-lubricated with lithium soap-based grease |
| Operating Temperature Range | -20°C to +110°C (THK official operating temperature specification) |
| Rotation Capability | Suitable for both inner-ring rotation and outer-ring rotation applications |
| Width Tolerance | 0 to -75 μm (THK official tolerance specification) |
| Shoulder Dimensions | d1=3.1 mm, rmin=0.6 mm, ds(min)=77 mm, Dh=93 mm (THK official shoulder dimension data) |
Structural Features
- Integrated Inner/Outer Ring Design: Both rings are one-piece construction, eliminating the need for special flanges or housings, providing exceptional rigidity and stability compared to split-ring designs. This structure ensures minimal deformation under load and maintains consistent rotational accuracy.
- Face-Mount Configuration: Pre-machined mounting holes on both rings allow direct bolting to equipment, simplifying installation and reducing assembly time. Mounting has virtually no effect on performance, ensuring stable, accurate rotation and torque.
- Crossed Roller Arrangement: Ensures uniform load distribution across all rollers, maximizing load capacity while minimizing overall bearing size. This design provides 3-4 times higher rigidity than traditional ball bearing arrangements.
- Spacer Retainer Technology: Prevents roller contact and cage locking, improving reliability, reducing friction, and extending service life compared to traditional steel plate retainers. The retainer also ensures proper roller alignment for smooth, precise rotation.
- Dual-Direction Load Capacity: Capable of handling radial, axial, and moment loads simultaneously from any direction, making it ideal for complex motion applications.
- Double-Sided Contact Seals (UU): Factory-installed seals provide excellent protection against dust, dirt, and moisture ingress while retaining lubrication. This eliminates the need for frequent re-lubrication and extends maintenance intervals under normal operating conditions.
Applications
The RU85UUCC0P4 is ideally suited for applications requiring compact dimensions, high rigidity, precise rotation control, and enhanced contamination protection:
- Industrial robot joints and rotary components operating in moderately dirty environments
- Precision rotary tables for machine tools and metrology equipment requiring sealed protection
- Medical devices (e.g., diagnostic scanners, surgical robots, imaging systems) needing contamination-free operation
- Semiconductor and IC manufacturing equipment with strict cleanliness requirements
- Measuring instruments and optical devices requiring long-term lubrication retention
- Medium-sized precision automation systems and manipulators in general industrial environments
- Compact rotary indexing tables and positioning mechanisms requiring P4 class accuracy with reduced maintenance needs
Installation & Maintenance Guidelines
- Mounting: Secure directly to equipment using appropriate M5 bolts for the inner ring and matching bolts for the outer ring without special housing or presser flanges. Ensure mounting surfaces are flat, parallel, and clean to maintain bearing accuracy.
- Preload: Factory-set CC0 radial clearance (negative clearance/preload) provides optimal performance for most applications; additional preload can be applied if required by specific operating conditions following THK's technical guidelines.
- Lubrication: UU sealed version is factory-lubricated for life with lithium soap-based grease under normal operating conditions. Avoid washing or relubricating unless specified by THK technical support.
- Operating Limits: Avoid shock loads and excessive speeds beyond rated capacity to ensure maximum service life and maintain precision performance.
- Accuracy Assurance: Mounting surfaces should have a flatness tolerance of ≤ 2 μm and parallelism tolerance of ≤ 3 μm to maintain the bearing's P4 class rotational accuracy (radial runout ≤ 4 μm, axial runout ≤ 4 μm).
- Seal Care: Do not damage the seal lips during installation. If seals become damaged, replace the bearing or consult THK for repair options.
