THK RB2508UUCC0P5 Cross Roller Ring
RB2508UUCC0P5 Cross-Roller Ring is specifically designed for applications requiring compact size, high rigidity, and exceptional rotational accuracy.
Basic Information
Product Name: THK Cross-Roller Ring RB2508UUCC0P5Model Type: Separable Outer Ring Type for Inner Ring RotationBrand: THK (Tokyo Hatsudoki Kogyo Co., Ltd.)
Model Number Explanation
| Code | Meaning |
|---|---|
| RB | Cross-Roller Ring basic type with separable outer ring and integrated inner ring |
| 25 | Inner diameter (d) = 25 mm |
| 08 | Width (B/B1) = 8 mm |
| UU | Double-sided contact seals for dust protection |
| CC0 | No preload (clearance setting) |
| P5 | Precision grade P5 (high rotational accuracy) |
Structural Features
- Innovative Crossed Roller Design: Cylindrical rollers are arranged perpendicular to each other in a 90° V-groove raceway, separated by a precision spacer retainer
- Single Bearing, Multiple Load Capabilities: Capable of handling radial loads, axial loads (both directions), and moment loads simultaneously with just one bearing
- Separable Outer Ring: Outer ring is split into two parts and secured with screws to prevent separation during handling/installation, ensuring easy mounting
- Integrated Inner Ring: One-piece inner ring design provides superior rotational accuracy, ideal for applications requiring precise inner ring rotation
- Line Contact Technology: Rollers make line contact with raceway surfaces, minimizing elastic deformation under load and delivering exceptional rigidity
- Double-Sided Seals (UU): Protects internal components from dust, dirt, and contaminants while retaining lubricant for extended service life
- Precision Grade P5: Ensures ultra-high rotational accuracy and minimal runout for demanding precision applications
- Lubrication Hole: Equipped with a standard lubrication hole for easy maintenance and re-greasing
Technical Specifications
| Parameter | Value | Unit |
|---|---|---|
| Inner Diameter (d) | 25 | mm |
| Outer Diameter (D) | 41 | mm |
| Roller Pitch Circle Diameter (dp) | 32 | mm |
| Width (B/B1) | 8 | mm |
| Lubrication Hole Diameter (a) | 2 | mm |
| Lubrication Hole Depth (b) | 0.8 | mm |
| Minimum Chamfer (rmin) | 0.5 | mm |
| Maximum Shoulder Height for Inner Ring (ds(max)) | 28.5 | mm |
| Minimum Shoulder Height for Outer Ring (Dh(min)) | 35.5 | mm |
| Basic Dynamic Load Rating (C) | 3.63 | kN |
| Basic Static Load Rating (Co) | 3.83 | kN |
| Weight | 0.05 | kg |
| Preload | CC0 (No Preload) | - |
| Sealing Type | UU (Double-sided contact seals) | - |
| Precision Grade | P5 | - |
| Lubrication | Grease lubrication (standard) | - |
Applications
RB2508UUCC0P5 Cross-Roller Ring is specifically designed for applications requiring compact size, high rigidity, and exceptional rotational accuracy:
- Joints and swiveling units of industrial robots
- Swiveling tables of machining centers
- Rotary units of manipulators
- Precision rotary tables in semiconductor manufacturing equipment
- Medical diagnostic and treatment equipment
- High-precision measuring instruments
- Index tables of machine tools
- IC manufacturing machines and inspection equipment
Installation & Handling Notes
- Mounting Surface Preparation: Ensure housing and shaft mounting surfaces are clean, flat, and free from burrs or scratches
- Seat Fit Recommendations: Use recommended fits for inner and outer rings to maintain precision and rigidity
- Bolt Tightening: When mounting, use uniform bolt tightening torque to prevent distortion
- Lubrication: Apply appropriate THK grease before operation (re-grease periodically based on operating conditions)
- Handling Care: Avoid dropping or subjecting the bearing to impact loads that could damage raceways or rollers
- Outer Ring Separation: The separable outer ring is factory-secured with screws - do not remove these screws during installation unless necessary for special mounting procedures