Things You Need to Know About Crossed Roller Bearings
A crossed roller bearing is a high-precision bearing engineered to support radial, axial, and moment loads simultaneously. Instead of the conventional ball or roller arrangement, it employs cylindrical rollers positioned at right angles (90°) to each other between the inner and outer rings. This distinctive design provides exceptional rigidity and accuracy while keeping the overall structure compact.
Key Features of Crossed Roller Bearings
- Orthogonal Roller Arrangement
Cylindrical rollers are alternately aligned in perpendicular directions, allowing forces to be evenly distributed and balanced across all load directions. - High Load-Carrying Capacity
Unlike ball bearings that rely on point contact, crossed roller bearings use line contact, enabling them to handle significantly higher loads. - Compact and Rigid Structure:
Despite their slim configuration, these bearings deliver outstanding rigidity and rotational precision, making them ideal for applications where space is limited. - Smooth and Stable Rotation
Optimized roller guidance and cage design reduce friction, ensuring consistent, vibration-free performance even under demanding precision requirements. - Versatility:
A single crossed roller bearing can simultaneously manage radial, axial, and moment loads, reducing the need for multiple bearing components.
Main Types of Crossed Roller Bearings
Crossed roller bearings can be classified based on their structural design and application requirements. The main categories include:
RA Series (Split Outer Ring, Integrated Inner Ring, Utral-thin type)
- Compared with other crossed roller series, RA bearings are ultra-thin profile, lightweight, space-saving design.
RB Series (Split Outer Ring, Integrated Inner Ring)
- The inner ring is one-piece, while the outer ring is split into two halves.
- Ideal for applications requiring high rigidity of the inner ring, such as rotating shafts.
CRB Series (Split Outer ring, integrated inner ring)
- Compared with RA series, CRB bearings are easy mounting, stronger structure, high rigidity.
SX Series (Split Outer Ring, inner ring rotating type)
- The SX series is similar to the RB type, featuring a split outer ring composed of two segments secured by three fastening rings, while the inner ring is a single-piece design. This structure provides high rigidity and stable performance, making the SX type especially suitable for applications that demand high rotational accuracy of the inner ring.
XSU Series (Integrated Inner/Outer Ring Type)
- There are 2 types of dimension series, XSU08 series inner diameter range is Φ130~Φ360mm, XSU14 series inner diameter range is Φ344~Φ1024mm.
RU Series (Integrated Inner/Outer Ring Type)
- The inner and outer rings are designed as one-piece structures.
- Easy to mount directly without complex adjustments.
- High rigidity and rotational accuracy.
- Suitable for applications such as rotary tables, indexing mechanisms, and precision positioning.
CRBH series (integrated inner and outer ring, thin section)
- The CRBH crossed roller bearing is a compact type of crossed roller bearing designed with both the inner and outer rings made as one-piece structures. The rollers are arranged orthogonally in a crossed pattern and separated by spacers, allowing the bearing to handle radial, axial, and moment loads simultaneously with high rigidity.
RE Series (Split inner ring, Integrated Outer Ring)
- The outer ring is one-piece, while the inner ring is split.
- Easier to assemble rollers and cages inside the bearing.
- Suitable when high rigidity of the outer ring is required.
XR Series (crossed tapered roller bearing)
- Features a large cone angle and optimized geometry for maximum span and compact design.
- It delivers high rotational accuracy, strong tilting moment resistance, and high-speed performance, ideal for rotary tables in vertical machining centers, boring mills, and grinding machines.
Crossed Roller Bearing Product Parameters
Model RA/RB/CRB/SX
(Separable Outer Ring, Type for Inner Ring Rotation)
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| Model / Type | RA | RB | CRB | SX |
| Features |
Ultral-thin Type Equivalent Model: CRBS type |
Basic Model, Equivalent Model: CRB type, NRXT Type | Equivalent Model: RB type | Smaller sections than RB series |
| Inner Diameter Range (ID) | Φ50-Φ200mm | Φ20-Φ1250mm | Φ30-Φ800mm | Φ70-Φ500mm |
| Outer Diameter Range (OD) | Φ66-Φ226mm | Φ36-Φ1500mm | Φ55-Φ1030mm | Φ90-Φ620mm |
| Width (H) | 8mm/13mm |
8mm-110mm |
10mm-100mm | 10mm-56mm |
| Seals | Open type / Sealed (UU optional) | Open type / Sealed (UU optional) | Open type / Sealed (UU optional) | Open type |
| Precision Grade | P5,P4,P2 | P5,P4,P2 | P5,P4,P2 | P5,P4,P2 |
| Material | GCr15/100Cr6 | GCr15/100Cr6 | GCr15/100Cr6 | GCr15/100Cr6 |
| Radial Clearance | CC0,C0, | CC0,C0, | CC0,C0, | CC0,C0, |
| Surface Treatment | Anti-Corrosion Coating: Black oxide treatment, phosphate treatment | Anti-Corrosion Coating: Black oxide treatment, phosphate treatment | Anti-Corrosion Coating: Black oxide treatment, phosphate treatment | Anti-Corrosion Coating: Black oxide treatment, phosphate treatment |
| Working Temperature | -20℃-80℃ | -20℃-80℃ | -20℃-80℃ | -20℃-80℃ |
Crossed Roller Bearing Product Parameters
Model RU/XSU/CRBH/XU
(Integrated Inner/Outer Ring Type, both for inner-ring rotation and outer-ring rotation)
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| Model / Type | RU | XSU | CRBH | XU |
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With mounting Holes Equivalent Type: CRBF Type |
XSU08 series, XSU14 Series, with mounting holes | Compact type of RU series | With mounting holes |
| Inner Diameter Range (ID) | Φ20-Φ350mm |
XSU08: Φ130~Φ360mm; XSU14: Φ344~Φ874mm |
Φ20-Φ250mm | Φ40-Φ382mm |
| Outer Diameter Range (OD) | Φ70-Φ540mm |
XSU08: Φ205~Φ435mm; XSU14: Φ415~Φ945mm |
Φ36-Φ310mm | Φ112-Φ646mm |
| Width (H) | 12-45mm |
XSU08: 25.4mm; XSU14: 56mm |
8-25mm | 22-86mm |
| Seals | UU-NBR Seals on Both sides | UU-NBR Seals on Both sides | Open type/ UU sealing type | UU-NBR Seals on Both sides |
| Precision Grade | P5,P4,P2 | P5,P4,P2 | P5,P4,P2 | P5,P4,P2 |
| Material | GCr15/100Cr6 | GCr15/100Cr6 | GCr15/100Cr6 | GCr15/100Cr6 |
| Radial Clearance | CC0,C0, | CC0,C0, | CC0,C0, | CC0,C0, |
| Surface Treatment | Anti-Corrosion Coating: Black oxide treatment, phosphate treatment | Anti-Corrosion Coating: Black oxide treatment, phosphate treatment | Anti-Corrosion Coating: Black oxide treatment, phosphate treatment | Anti-Corrosion Coating: Black oxide treatment, phosphate treatment |
| Working Temperature | -20℃-80℃ | -20℃-80℃ | -20℃-80℃ | -20℃-80℃ |
Crossed Roller Bearing Product Parameters
Model RE series (Separate inner ring, with outer ring rotating)
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| Features | RE |
| Inner Diameter Range (ID) | Φ40-Φ600mm |
| Outer Diameter Range (OD) | Φ65-Φ700mm |
| Width (H) | 10-40mm |
| Seals | UU-NBR Seals on Both sides |
| Precision Grade | P5,P4,P2 |
| Material | GCr15/100Cr6 |
| Radial Clearance | CC0,C0, |
| Surface Treatment |
Anti-Corrosion Coating:Black oxide treatment, phosphate treatment |
| Working Temperature | -20℃-80℃ |
Industries Served by Crossed Roller Bearings
Crossed roller bearings feature a compact structure capable of supporting radial, axial, and moment loads simultaneously. Their high rigidity, precision, and space-saving design make them indispensable across a wide range of industries.
1. Machine Tools
In CNC machining centers, rotary tables, indexing machines, and spindle heads, crossed roller bearings deliver smooth rotation, excellent positioning accuracy, and extended service life.
2. Robotics & Automation
Robot joints, arms, and precision positioning systems benefit from their high load capacity and compact design, ensuring stability and efficiency in automated production environments.
3. Medical Equipment
From CT scanners to surgical robots and imaging systems, these bearings guarantee precise rotation and reliability, which are critical for patient safety and medical accuracy.
4. Aerospace & Defense
Radar antennas, satellite communication systems, flight simulators, and weapon turrets demand bearings with outstanding rigidity and precision, making crossed roller bearings the preferred choice.
5. Semiconductor & Electronics
Wafer handling equipment, LCD/LED production machinery, and measuring instruments rely on their smooth motion and high accuracy to meet the requirements of micro-scale operations.
6. Precision Measurement Instruments
Coordinate measuring machines (CMM), optical devices, and high-precision turntables use crossed roller bearings for their superior accuracy and rigidity in sensitive testing applications.
7. Energy & Transportation
Wind turbine yaw and pitch drives, railway bogies, and marine navigation systems depend on the durability and load-bearing strength of crossed roller bearings to ensure long-term performance.
Crossed roller bearings application scenarios
Crossed roller bearings are widely used in industries that require high precision, compact design, and strong load capacity.
Why Crossed Roller Bearings Are Ideal for CNC Rotary Tables?
Crossed roller bearings are a key component in CNC rotary tables and other precision machine tools, designed to deliver rigidity, high accuracy, and long service life in compact form.
1. Key Advantages
- High Accuracy & Rigidity – The orthogonal roller design minimizes runout, enabling micron-level positioning accuracy.
- Compact Structure – A slim cross-section provides high load capacity while saving valuable installation space.
- Moment Load Resistance – Excellent performance under heavy tilting moments, ideal for vertical lathes and grinding machines.
- Smooth High-Speed Rotation – Optimized geometry ensures stability and accuracy at high spindle speeds.
2. Technical Highlights
- Preload Options – light, medium, or heavy preload to balance stiffness and motion control.
- Clearance Choices – zero or negative clearance for precise rotary positioning.
- Lubrication Systems – long-life grease or oil lubrication reduces maintenance downtime.
- Sealing Protection – effective against dust, coolant, and cutting fluids in harsh machining environments.
3. Value-Added Features
- Surface Treatments – black oxide and other coatings improve anti-rust and wear resistance.
- Material Options – stainless steel or hybrid ceramic rollers for demanding or high-speed applications.
- Custom Solutions – engineered bearings for large rotary tables, compact indexing units, or special automation equipment.
Advantages of crossed roller bearings
Crossed roller bearings are precision-engineered bearings designed to handle radial, axial, and moment loads simultaneously in a compact design.
High Load Capacity
Supports heavy multi-directional loads with uniform distribution.
Compact & Space-Saving
Replaces multiple bearings, reducing system size and weight.
High Rotational Accuracy
Ensures precise movement for robotics, rotary tables, and medical equipment.
Excellent Rigidity
Resists deformation under heavy loads, ideal for machine tools and automation.
Smooth, Low-Friction Operation
Reduces wear and energy consumption, extending service life.
Versatile Applications
Suitable for aerospace, robotics, precision instruments, and industrial machinery.
Easy Assembly
Simplifies installation and minimizes alignment errors.
Easy to choose right type and size
Standard structures and dimensions, make clients easy to choose the right type and right size for their machines.
What are the well-known manufacturers of crossed roller bearings?
TEDIN Bearing is renowned for its excellent quality and reliable after-sales service, earning widespread recognition worldwide and standing out among both domestic and international enterprises.
What Industry Problems Do Crossed Roller Bearings Solve?
Modern industries demand ever higher levels of precision, reliability, and compact design in their equipment. Crossed roller bearings are engineered to address these challenges across a wide range of applications.
Space Constraints in Compact Machinery
Robotic arms, medical devices, and precision instruments often operate within very limited space. Crossed roller bearings deliver high load capacity and rigidity in a slim profile, making them the ideal solution where every millimeter counts.
Handling Multi-Directional Loads
Rotary tables, aerospace systems, and heavy industrial machines are exposed to combined radial, axial, and moment loads. Crossed roller bearings can support all of these simultaneously, eliminating the need for multiple bearing types and simplifying system design.
Maintaining Accuracy Under Stress
In industries such as semiconductors, optics, and metrology, even small vibrations or shocks can compromise accuracy. The rigid structure of crossed roller bearings minimizes deflection and runout, ensuring consistent precision and smooth motion.
Reducing Maintenance and Downtime
Continuous operation is critical in industrial environments. With their durable construction and long service life under demanding loads, crossed roller bearings reduce the risk of unexpected failures, lowering maintenance costs and downtime.
Ensuring Stability in Harsh Conditions
Applications like wind turbines, marine navigation systems, and construction machinery require components that can withstand shocks, tilting forces, and vibration. Crossed roller bearings provide the necessary stability and reliability in these challenging conditions.
Simplified Assembly
Many crossed roller bearing types feature mounting holes directly on the inner and outer rings. This design allows for quick, secure installation, improving efficiency in equipment assembly and maintenance.
How to Choose the Clearance of Crossed Roller Bearings?
The clearance of a crossed roller bearing plays a critical role in its performance, directly affecting accuracy, rigidity, and service life. Clearance is typically measured with a dial gauge and is generally divided into two main categories:
- Negative clearance (preload)
- Positive clearance, which can be further classified as small or large clearance
Lack of Unified Standards
Unlike some other bearing types, there is currently no global standard for defining clearance in crossed roller bearings. Instead, manufacturers use their own classification systems, particularly for radial and axial clearance.
- THK (RU, RB, RE series): Clearance is specified in three levels - CC0 / C0 / C1, with CC0 representing negative clearance.
- IKO (CRBF, CRB, CRBH series): Clearance is divided into T1 / C1 / C2, with T1 corresponding to negative clearance.
Importance of Proper Clearance Selection
Selecting the correct clearance depends on the application requirements:
- Negative clearance (preload): Used when high rigidity and positioning accuracy are required, such as in CNC rotary tables or measuring equipment.
- Small positive clearance: Suitable for applications requiring smooth motion at moderate loads.
- Large positive clearance: Applied where thermal expansion or heavy loading must be accommodated.
Regular Inspection and Adjustment
During operation, clearance should be inspected at regular intervals. If the clearance becomes too large, accuracy may decline and vibration may increase. If it is too tight, friction and heat generation can lead to premature failure. Timely adjustment helps maintain performance, prevents machine malfunction, and reduces the risk of equipment damage.
Factors Causing Clearance Changes in Crossed Roller Bearings
Manufacturing Precision
Small production errors in rings or rollers can affect clearance.
Operating Temperature
Heat from rotation causes thermal expansion, reducing clearance.
Installation Fit
Tight fits on the shaft or housing can compress rings, altering clearance.
Applied Load
Loads during rotation cause elastic deformation, changing internal clearance.
Temperature Gradient
Uneven temperatures among bearing components can affect clearance.
Material Expansion Differences
Different thermal expansion rates of shaft, housing, and bearing materials can increase or decrease clearance.
How Bearing Materials Affect Crossed Roller Bearing Performance?
The performance of a crossed roller bearing is closely linked to the materials used in its construction. Material selection determines critical properties such as hardness, wear resistance, toughness, corrosion protection, and dimensional stability. These factors directly influence service life, accuracy, and reliability in demanding applications.
1. Hardness and Wear Resistance
- Chrome Bearing Steel: The most common material, offering excellent hardness and wear resistance for applications with high load and speed.
- High-Carbon Chrome Steel: Delivers even higher hardness and durability, making it suitable for heavy-duty and high-speed bearings.
- Carburized Steel: Creates a hardened surface layer with good wear resistance and impact strength, ideal for bearings exposed to shock loads.
- Ceramic: Lightweight, extremely hard, and with very low friction, ceramics are preferred in high-speed and low-friction applications.
2. Elastic Limit and Toughness
- Elastic Limit: A higher elastic limit prevents permanent deformation of raceways and rollers under heavy contact stress.
- Toughness: Ensures the bearing can resist impact and shock loads without cracking or breaking during operation.
3. Corrosion Resistance and Anti-Rust Properties
- Stainless Steel: Offers superior corrosion resistance, making it ideal for use in food processing, medical equipment, and chemical industries.
- Anti-Rust Protection: Essential for storage and use in humid or corrosive environments to maintain performance and extend service life.
4. Other Critical Material Properties
- Dimensional Stability: Ensures consistent precision and accurate rotation, even under temperature fluctuations.
- Mechanical Strength: Bearing cages must maintain strength and rigidity to support rollers under dynamic forces.
- Machinability: Materials must allow precise cutting, grinding, and heat treatment to achieve the required tolerances.
Summary
Selecting the right material is essential for achieving long-lasting, high-precision performance in crossed roller bearings. The correct choice enhances durability, reduces maintenance, and ensures stability in applications such as gearboxes, CNC rotary tables, high-speed machinery, and industrial automation systems.
Who we are?
TEDIN is a trusted manufacturer and supplier of precision bearings, specializing in crossed roller bearings, thin-section bearings, and tapered roller bearings. We provide high-precision, durable bearing solutions for industries including machine tools, robotics, aerospace, and industrial automation.
With a focus on quality, innovation, and reliability, our team combines advanced manufacturing technology with decades of experience to deliver products that meet the highest standards of accuracy, performance, and longevity.