Crossed Roller Bearings: Key Features and Series Overview from BY Bearings

What Are Crossed Roller Bearings?

Crossed roller bearings are high-precision rolling bearings characterized by cylindrical rollers arranged at 90-degree alternating angles within a single V-shaped raceway. Unlike traditional ball bearings that rely on point contact, crossed roller bearings achieve line contact between rollers and raceways. This fundamental difference in contact geometry yields significant performance advantages in precision, rigidity, and load capacity.

In a crossed roller bearing, each roller is precisely separated from the adjacent roller by a durable spacer retainer. This specialized design prevents the rollers from skewing and minimizes friction as they alternate their rolling contact surfaces along the ground raceway. The orthogonal arrangement enables a single bearing to simultaneously support radial loads, axial loads from both directions, and overturning moments—all within a compact cross-section.

Due to their exceptional rigidity, compact design, and high precision, crossed roller bearings are widely used in industrial robot joints, CNC rotary tables, medical imaging equipment, semiconductor manufacturing machines, precision measuring instruments, and machine tool swiveling units. These applications demand reliable rotational accuracy and multi-directional load support, making crossed roller bearings the preferred solution.

Key Features of Crossed Roller Bearings

Structure Features

With the Cross Roller bearing, cylindrical rollers are arranged crosswise, with each roller perpendicular to the adjacent roller, in a 90° V-groove, separated from each other by a spacer retainer. This design allows just one bearing to receive loads in all directions including radial, axial and moment loads. Since the Cross-Roller Ring achieves high rigidity and the precision can reach up to P5, P4, P2, despite the minimum possible dimensions of the inner and outer rings, it is optimal for applications such as joints and swiveling units of industrial robots, swiveling tables of machining centers, precision rotary tables, medical equipment, measuring instruments and IC manufacturing machines.

Rotation Accuracy

The spacer retainer fitting among cross-arrayed rollers prevents rollers from skewing and the rotation torque from increasing due to friction between rollers. Unlike conventional types using steel sheet retainers, the Cross Roller Bearing does not cause displacement or locking of rollers and provides a stable rotation torque. Since the inner and outer rings are designed to be separable, the bearing clearance can be adjusted. In addition, highly accurate rotary motion is ensured through adjusting the bearing clearance to provide a preload.

Usage Characteristics

The inner and outer rings, which are separable, are secured to the Cross Roller Bearing body after the rollers and spacer retainers are installed. This procedure prevents the rings from separating from each other. Thus, it is easy to handle the rings when installing the Cross Roller Bearing. The spacer retainer keeps rollers in their proper position, thereby preventing them from skewing. This eliminates friction between rollers, and therefore secures a stable rotation torque. The cross array of rollers allows a single Cross Roller Bearing unit to receive loads in all directions, increasing the rigidity to three to four times greater than the conventional type.

Classification of Crossed Roller Bearings from BY Bearings

BRB Series Bearings

Model BRB (Separable Outer Ring, Type for Inner Ring Rotation)
This series is the basic model of the Cross-Roller Ring. Despite the minimum possible dimensions of the inner and outer rings, its outer ring is separable while the inner ring is integrated with the main body. This model is used in locations where the rotation accuracy of the inner ring is required.

BRE Series Bearings

Model BRE (Separable Inner Ring, Type for Outer Ring Rotation)
This new model is based on the design principle of the BRB, having the same major dimensions as model BRB. Its inner ring is separable while the outer ring is integrated with the main body. This model is used in locations where the rotation accuracy of the outer ring is required.

BRU, BSU, BXU Series Bearings

Model BRU, BSU, BXU (Integrated Inner/Outer Ring Type)
Since the mounting holes are provided, this model does not require a presser flange or housing. In addition, because it has an integrated inner/outer ring structure and it's equipped with washers, its performance is minimally affected by the mounting procedure, ensuring stable rotation accuracy and torque. This model can be used for both inner-ring rotation and outer-ring rotation.

BX Series Bearings

Model BX (Separable Outer Ring, Type for Inner Ring Rotation)
Its structure is similar to BRB series, the outer ring is separable and connected with three sealing rings. While the inner ring is integrated with the main body. This model is used in locations where the rotation accuracy of the outer ring is required.

BBH Series Bearings

Model BBH (Integrated Inner/Outer Ring Type)
This model is with an integrated inner/outer ring structure, can be used for both inner-ring rotation and outer-ring rotation.

BRA Series Bearings

Model BRA (Separable Outer Ring, Type for Inner Ring Rotation)
Based on model BRB, this model is a light and compact type with the thinnest possible inner and outer rings. It is optimal for locations where weight reduction and downsizing are required, such as the hand swiveling unit of robots and manipulators.

BBS Series Bearings

Model BBS (Integrated Inner/Outer Ring Type)
This series has the same size specifications as the BRA series, and both the inner and outer rings have high rotational accuracy.

BY Bearings Crossed Roller Series Comparison and Selection Guide

Series	Ring Structure	Primary Rotation	Key Feature	Typical Application
BRB	Separable outer ring, integrated inner ring	Inner ring rotation	Basic model, high inner-ring accuracy	CNC index tables, manipulator joints
BRE	Separable inner ring, integrated outer ring	Outer ring rotation	High outer-ring rotation accuracy	Rotary platforms, direct drive motor rotors
BRU / BSU / BXU	Integrated rings with mounting holes	Both inner and outer ring	Easy installation, no housing required	Robotic bases, industrial turntables
BX	Separable outer ring, connected by sealing rings	Inner ring rotation	Similar to BRB with enhanced sealing	Precision measuring instruments
BBH	Integrated inner and outer rings	Both inner and outer ring	High rigidity, simple structure	Automation equipment, medical devices
BRA	Separable outer ring, ultra-thin	Inner ring rotation	Lightweight, compact design	Robot hand swiveling, compact joints
BBS	Integrated inner and outer rings	Both inner and outer ring	Same size as BRA, high accuracy	Space-constrained precision applications

BY Bearings: Precision Crossed Roller Bearing Manufacturer

BY Bearings (Luoyang Boying Bearing Co., Ltd.) specializes in the manufacturing of high-precision crossed roller bearings and rotary table bearings for CNC machine tools, robotics, and industrial automation systems. With over 16 years of industry experience, the company has established itself as a reliable partner for precision motion control applications.

BY Bearings offers a comprehensive portfolio of crossed roller bearings across all series—BRB, BRE, BRU, BSU, BXU, BX, BBH, BRA, and BBS—available in precision grades up to P2. Every bearing undergoes 100% inspection on runout, dimensional accuracy, and rotational torque consistency before shipment.

The company also provides custom dimension tailoring, specialized preload options, sealing configurations, and lubrication solutions based on application requirements. With exports to over 100 countries, BY Bearings delivers reliable solutions for robotics, CNC machining, medical equipment, and precision instrumentation worldwide.

Need precision crossed roller bearings for your application? Contact BY Bearings today for technical consultation and find the optimal bearing solution for your specific requirements.

Frequently Asked Questions

Q1: What are the main advantages of crossed roller bearings over ball bearings?
Crossed roller bearings offer approximately three times the rigidity of ball bearings of equivalent size due to line contact between rollers and raceways. They also handle radial, axial, and moment loads within a single unit, providing compact design and zero-backlash performance.

Q2: What is the difference between BRB and BRE series bearings?
BRB series has a separable outer ring with an integrated inner ring, optimized for inner ring rotation. BRE series has a separable inner ring with an integrated outer ring, optimized for outer ring rotation.

Q3: Which series is easiest to install?
The BRU, BSU, and BXU series are easiest to install because they feature integrated rings with pre-drilled mounting holes, eliminating the need for a presser flange or housing.

Q4: What precision grades are available for crossed roller bearings?
BY Bearings offers crossed roller bearings in P5, P4, and P2 precision grades, with P2 offering the highest level of accuracy.

Q5: Can BY Bearings provide customized crossed roller bearing solutions?
Yes. BY Bearings offers custom dimension tailoring, specialized preload options, sealing configurations, and lubrication solutions based on equipment structure, load requirements, and installation space.