The RB2008 cross roller bearing is a compact precision bearing with a 20 mm bore, 36 mm outer diameter and 8 mm width. It uses an integrated inner ring and split outer ring, making it primarily suitable for applications requiring accurate inner-ring rotation.
Cylindrical rollers arranged alternately at 90 degrees allow one bearing to support radial loads, axial loads in both directions, and overturning moments. Its compact dimensions and high rigidity make RB2008 suitable for small robot joints, measuring instruments, optical equipment and precision positioning mechanisms.
LYDL Bearing manufactures RB2008 cross roller bearings in standard, P5, P4, P2 and application-specific customized accuracy configurations. Clearance, preload, seals, lubricant, marking and inspection requirements can also be specified according to the application.
RB2008 Key Facts
- Dimensions: 20 × 36 × 8 mm
- Structure: Integrated inner ring and split outer ring
- Recommended rotation: Inner-ring rotation
- Supported loads: Radial, axial and overturning moment loads
- Available accuracy: Standard, P5, P4, P2 and customized
- Available configurations: Open or double-sealed
- Main advantage: High rigidity in a compact installation space
- Typical applications: Robotics, measuring, optical and positioning equipment
RB2008 Technical Specifications
| Specification | RB2008 |
|---|---|
| Bearing type | Cross roller bearing |
| Series | RB series |
| Inner diameter | 20 mm |
| Outer diameter | 36 mm |
| Width | 8 mm |
| Inner ring | Integrated, one-piece structure |
| Outer ring | Split structure |
| Rolling elements | Precision cylindrical rollers |
| Roller arrangement | Alternately crossed at 90 degrees |
| Supported loads | Radial, axial and overturning moment loads |
| Recommended rotation | Inner-ring rotation |
| Accuracy options | Standard, P5, P4, P2 or customized |
| Internal setting | Controlled clearance or preload |
| Sealing options | Open or double-sealed |
| Lubrication | Standard or application-specific grease |
| Typical applications | Robotics, measuring and precision positioning |
The model number identifies the basic series and principal dimensions, but it does not specify every production requirement. Accuracy, clearance, preload, seals, lubricant and rotational torque should be confirmed before ordering.
How Does the RB2008 Cross Roller Bearing Work?
Inside the RB2008, cylindrical rollers are arranged alternately at right angles in V-shaped raceways. Spacer retainers separate adjacent rollers and help reduce direct roller-to-roller friction.
Because adjacent rollers face different directions, one compact bearing can support radial forces, axial forces and tilting moments. This can simplify mechanisms that would otherwise require separate radial and thrust bearings.
Cross roller bearings use line contact between the cylindrical rollers and raceways. This provides high rigidity within a small bearing envelope and helps limit elastic deformation under load.
Spacer retainers also support stable roller guidance and controlled rotational torque. These characteristics are valuable in servo-driven systems, measuring equipment and precision rotary mechanisms.
Final system accuracy still depends on the shaft, housing, retaining flange, mounting fit, preload and assembly quality.
Why Choose RB2008 for Precision Applications?
Compact Installation
RB2008 measures only 20 × 36 × 8 mm. It can fit into mechanisms where a conventional combination of radial and thrust bearings would require more space.
A properly selected RB2008 may reduce the number of surrounding components while supporting loads from several directions. Any replacement of a multi-bearing arrangement should still be verified through load, rigidity, speed and service-life calculations.
High Rigidity
Line contact between the cylindrical rollers and raceways helps reduce elastic deformation. This supports angular stability, positioning repeatability and resistance to tilting under moment loads.
Preload can further increase rigidity and reduce internal movement. Excessive preload may increase torque and heat, so the correct setting must be selected according to the load, speed, temperature and mounting conditions.
P2 and Customized Accuracy
High-precision equipment may require tighter dimensional tolerances and rotational accuracy than standard bearings can provide.
LYDL can manufacture P2 RB2008 cross roller bearings and customized configurations according to approved drawings or inspection agreements. Available requirements may include:
- Customized radial runout
- Customized axial runout
- Controlled rotational torque
- Specified clearance or preload
- Special grease
- Customer-specified laser marking
- Individual inspection records
- Customized anti-rust and protective packaging
The achievable values should be confirmed according to the selected configuration and mounting requirements.
Typical RB2008 Applications
| Application | Why RB2008 May Be Suitable |
|---|---|
| Small robot joints | Compact dimensions and moment-load support |
| Measuring instruments | Stable low-speed precision rotation |
| Optical inspection equipment | Controlled clearance and angular rigidity |
| Small rotary stages | Combined-load support in limited space |
| Precision positioning devices | High rigidity and accurate inner-ring rotation |
| Semiconductor automation | Compact rotary support with customized cleaning and lubrication |
Standard RB2008 bearings are not automatically suitable for vacuum or semiconductor clean-room conditions. Special grease, cleaning, assembly and packaging requirements must be specified separately.
RB2008 vs. RE2008 and RU-Series Bearings
Bearings with similar dimensions are not necessarily interchangeable. Ring structure and rotation mode must also be considered.
| Selection factor | RB2008 | RE2008 | RU-series bearing |
|---|---|---|---|
| Integrated ring | Inner ring | Outer ring | Inner and outer rings |
| Split ring | Outer ring | Inner ring | Normally none |
| Preferred rotation | Inner ring | Outer ring | Either ring |
| Mounting holes | Normally not provided | Normally not provided | Usually provided |
| External housing | Required | Required | May be simplified |
| Main advantage | Compact inner-ring rotation | Suitable for outer-ring rotation | Convenient direct mounting |
If the inner ring rotates, RB2008 is normally the first structure to evaluate. For outer-ring rotation, RE2008 may be more appropriate. When direct mounting holes are required, an RU-series or another integrated-ring bearing may simplify the installation.
The final selection should be based on the complete mounting drawing rather than dimensions alone.
When RB2008 May Not Be the Best Choice
An alternative bearing should be evaluated when:
- Continuous high-speed rotation is required
- The outer ring is the primary rotating component
- Direct mounting holes are required
- The housing cannot provide sufficient accuracy or rigidity
- The mechanism is exposed to severe impact loads
- Operating temperature exceeds the range of standard grease or seals
- Vacuum or special clean-room compatibility is required
- The calculated load or service life exceeds the capability of RB2008
For high-speed applications, angular contact ball bearings may provide lower friction and better thermal performance. For outer-ring rotation or direct mounting, an RE- or RU-type structure may be more suitable.
How to Specify the Correct RB2008
For an accurate quotation and technical evaluation, customers should confirm the following requirements.
Accuracy
LYDL can provide standard, P5, P4, P2, and customized accuracy. The appropriate grade should be selected according to allowable runout, positioning error and equipment performance.
The highest available grade is not always necessary. A suitable grade can reduce cost while still meeting the application requirements.
Clearance or Preload
Internal clearance affects rigidity, rotational torque and stability. Available requirements can include:
- Controlled positive clearance
- Near-zero clearance
- Light preload
- Application-specific preload
The correct setting depends on the load, speed, housing rigidity, fit and working temperature.
Seals and Lubrication
Open construction may be suitable for clean mechanisms with external protection. Double seals can help retain grease and reduce the entry of dust.
Grease should be selected according to operating speed, temperature, starting torque and environment. Low-torque, low-temperature, high-temperature or customer-specified grease can be evaluated when required.
Operating Conditions
Please provide:
- Required quantity
- Radial and axial loads
- Overturning moment
- Operating and maximum speed
- Rotating ring
- Required runout
- Accuracy grade
- Clearance or preload
- Working temperature
- Lubrication requirements
- Installation drawing
Need help confirming the RB2008 configuration? Contact LYDL with your mounting drawing and operating conditions. Our team can evaluate the suitable accuracy, preload, sealing and lubrication requirements before quotation.
How LYDL Manufactures and Inspects RB2008
Luoyang Deeplink Technology Co., Ltd. manufactures precision cross roller bearings for robotics, measuring equipment, rotary tables, optical systems and automation machinery.
The RB2008 manufacturing and inspection process can include:
- Bearing steel and forging inspection
- Precision turning of the rings
- Controlled heat treatment and dimensional stabilization
- Precision raceway grinding
- Raceway superfinishing
- Roller inspection and micro-sorting
- Deep cleaning and demagnetization
- Clearance or preload matching
- Rotational torque verification
- Dimensional and runout inspection
- Laser marking and traceability identification
- Anti-rust and protective packaging
For P2 or customized bearings, additional inspection items can be agreed before production.
| LYDL Inspection Item | Inspection Basis |
|---|---|
| Bore, outside diameter and width | Approved drawing |
| Radial runout | Selected accuracy or customer requirement |
| Axial runout | Selected accuracy or customer requirement |
| Rotational torque | Recorded when specified |
| Clearance or preload | Confirmed order requirement |
| Surface and marking | Visual and traceability inspection |
| Packaging | Standard or customized requirement |
Inspection values are determined by the ordered accuracy, internal configuration and technical agreement.
RB2008 Installation Recommendations
Inspect the shaft, housing, shoulder and retaining flange before installation. Remove burrs, rust, contamination and surface damage. Roundness, perpendicularity and flange contact should meet the approved mounting requirements.
Keep the bearing in its original packaging until installation. Prevent metal chips, abrasive dust and lint from entering the bearing.
Although the outer ring is split, it should normally remain assembled during handling. Do not remove its temporary fixing components unless required by the manufacturer’s instructions.
Tighten the retaining-flange bolts gradually in a diagonal sequence. Uneven flange pressure can deform the split outer ring and cause excessive torque, localized preload or runout.
After installation, rotate the mechanism slowly through a complete revolution and check for uneven resistance or abnormal noise.
Frequently Asked Questions
What are the RB2008 dimensions?
RB2008 has a 20 mm bore, 36 mm outer diameter and 8 mm width. Chamfers, tolerances, seals and internal settings should be confirmed before finalizing the mounting components.
Can RB2008 support radial and axial loads simultaneously?
Yes. Its crossed roller arrangement allows one bearing to support radial loads, axial loads in both directions and overturning moments.
Can LYDL manufacture P2 RB2008 bearings?
Yes. LYDL can manufacture P2 and customized RB2008 bearings. Required runout, preload, torque, lubricant, marking and inspection records should be confirmed before production.
Is RB2008 suitable for outer-ring rotation?
RB2008 is primarily designed for inner-ring rotation. For outer-ring rotation, RE2008 or another suitable bearing structure should be evaluated.
Is LYDL RB2008 interchangeable with other RB2008 bearings?
LYDL RB2008 uses the commonly adopted 20 × 36 × 8 mm RB-series envelope. However, interchangeability should not be confirmed from dimensions alone. Accuracy, clearance, preload, seals, chamfers and mounting tolerances must be compared with the original drawing.
Request an RB2008 Quotation or Technical Drawing
The LYDL RB2008 cross roller bearing provides compact multidirectional load support for applications requiring high rigidity and accurate inner-ring rotation.
LYDL can supply standard, P5, P4, P2 and customized configurations with controlled clearance or preload, different grease options, laser marking, inspection records and protective packaging.
To request a quotation or drawing, send us your quantity, accuracy, preload, seal configuration, required runout and operating conditions.
Explore LYDL RB Series Cross Roller Bearings
Luoyang Deeplink Technology Co., Ltd.
Brand: LYDL
Website: https://lydl-bearing.com/
Email: sales@luoyangdeeplink.com
Phone / WhatsApp / WeChat: +86 180 3700 3779
References and Sources
- THK Co., Ltd. “Cross-Roller Ring—Structure and Features.” General reference for crossed cylindrical roller arrangement and multidirectional load support.
Source: https://www.thk.com/eu/en/products/cross_roller_ring/cross_roller_ring/ - THK Co., Ltd. “Cross-Roller Ring Series—Model RB.” General reference for the integrated inner-ring and split outer-ring structure of RB-series bearings.
Source: https://pdf.directindustry.com/pdf/thk/cross-roller-ring-series/328-256191.html - International Organization for Standardization. ISO 492, “Rolling bearings—Radial bearings—Geometrical product specifications and tolerance values.”
Source: https://www.iso.org/ - Harris, T. A., and Kotzalas, M. N. Essential Concepts of Bearing Technology. CRC Press. General reference for rolling-bearing load, contact and rigidity principles.
- RB2008 dimensions, P2 and customized manufacturing capabilities, inspection options and LYDL supplier information are provided by Luoyang Deeplink Technology Co., Ltd.
Source: https://lydl-bearing.com/
Manufacturer’s Note: LYDL recommends confirming RB2008 selection from the mounting drawing and operating conditions rather than dimensions alone. Bearings with the same 20 × 36 × 8 mm envelope may differ in accuracy, clearance, preload, seals, and rotational torque.
Written by: LYDL Technical Content Team
Technical review: LYDL Bearing Engineering Department
This original technical article was prepared for Luoyang Deeplink Technology Co., Ltd. External materials are cited as general engineering references. Final dimensions, tolerances, load ratings, accuracy, preload and availability must be confirmed in the applicable LYDL drawing and sales agreement.
