What is the difference between XRBT crossed roller bearings and standard crossed roller bearings?

The XRBT series features a thinner bearing cross-section, specifically designed to meet requirements for miniaturization, weight reduction, and compact installation space. It utilizes an internal structure of crossed cylindrical rollers, allowing it to support loads from multiple directions simultaneously.

For what types of precision equipment is the XRBT series suitable?

The XRBT series is suitable for small-scale robots, medical instruments, optical equipment, precision inspection devices, and automated rotating mechanisms that align with its specific dimensions, load capacities, and rotational accuracy requirements.

What is the minimum bearing width for the XRBT series?

For the XRBT205, XRBT305, XRBT405, and XRBT505 models, the width is 5 mm. For other specifications, the actual width should be verified according to the parameters of the specific model.

Are XRBT crossed roller bearings suitable for high-speed rotation?

Suitability depends on the bearing model, internal design, preload status, lubrication conditions, and operating loads. For applications involving higher rotational speeds or continuous rotation, an evaluation should be conducted based on the permissible speed and thermal performance requirements of the specific model.

Can XRBT bearings serve as replacements for thin-walled crossed roller bearings from other brands?

PRS provides documentation offering guidance on replacing certain CRBT-series bearings with XRBT models. When considering a replacement, it is essential to verify each parameter—including inner diameter, outer diameter, width, load ratings, mounting dimensions, accuracy, and preload requirements—rather than assuming interchangeability based solely on similar model designations.

Is the XRBT series suitable for lightweight robot designs?

With its thin cross-section and low weight, the XRBT series is a viable option for rotating mechanisms in small, lightweight robots. Specific applicability depends on joint loads, installation space, and stiffness requirements.

No Image

Ultra Thin XRBT Crossed Roller Bearings

Q: Can the XRBT series support both radial and axial loads?

Yes. Through the use of cylindrical rollers arranged in a 90° crossed configuration, the XRBT series can simultaneously accommodate radial loads, bidirectional axial loads, and overturning moments. However, the specific load-carrying capacity must be determined based on the individual model.

Ultra-thin Section · Lightweight · Precision Rotation

The PRS XRBT series of ultra-light and ultra-thin crossed roller bearings are precision bearing products specifically designed for compact, lightweight, and high-precision rotating mechanisms. Featuring an ultra-thin-walled structure and cylindrical rollers arranged in a 90° crossed configuration, this series is capable of simultaneously supporting radial loads, bidirectional axial loads, and overturning moments within limited radial and axial installation space.

Send E-mail Request A Quote

Ultra Thin XRBT Crossed Roller Bearings Introduction

Building upon the foundation of traditional thin-section crossed roller bearings, the XRBT series features further reduced cross-sectional dimensions for both the inner and outer rings. This design enables their use in precision mechanical systems where space is limited and there are strict requirements regarding equipment size and weight.

Compared to standard-section crossed roller bearings, the XRBT series places a greater emphasis on a compact design. By utilizing crossed cylindrical rollers in conjunction with precision raceways within a minimal installation footprint, these bearings deliver the necessary structural rigidity and rotational accuracy required for their respective models.

This series is well-suited for applications such as precision instruments, medical equipment, compact rotating mechanisms in robotics, optical devices, and miniature automation systems—particularly in rotating support assemblies where the overall structural thickness and equipment weight must be strictly controlled.

In current technical documentation from PRS, the XRBT series is classified as "ultra-light, ultra-thin-section crossed cylindrical roller bearings." Available models include the XRBT205, XRBT305, XRBT405, and XRBT505, which can serve as potential alternatives to certain bearings in the CRBT series.

Available Models & Specifications

Click on any part number to view detailed CAD drawings and download PDF specifications.

Part Number	Bore (d)	Outer (D)	Width (B)
XRBT1005	100 mm	111 mm	5 mm
XRBT105	10 mm	21 mm	5 mm
XRBT155	15 mm	26 mm	5 mm
XRBT205	20 mm	31 mm	5 mm
XRBT255	25 mm	36 mm	5 mm

Product Structure and Operating Principle

Ultra-light, ultra-thin-section structure

The XRBT series achieves a compact, thin-walled design by reducing the cross-sectional dimensions of the bearing rings. This allows the bearings to provide independent, precision rotational support for equipment, even when installation space is highly restricted.

Given the thin cross-section, the rigidity of the surrounding mounting structure, the precision of the fits, and the control of applied forces during the assembly process are of critical importance.

90° crossed cylindrical roller configuration

The XRBT series employs a design in which cylindrical rollers are arranged in a crossed pattern along the circumference, with the axes of adjacent rollers oriented at a 90° angle to one another.

Through line contact between the rollers and the raceways, the bearing can accommodate loads from multiple directions, allowing a single unit to simultaneously support radial loads, axial loads, and overturning moments.

Precision raceway and roller interface

The rotational accuracy of the bearing is closely linked to the geometric precision of the raceways, the dimensional consistency of the rollers, the internal clearance, and the conditions under which the bearing is assembled. Through precision raceway machining and an optimized arrangement of rolling elements, stable rotational motion can be achieved within a compact bearing structure.

Compact Support Configuration

Unlike support schemes that require multiple bearings, the XRBT series can accommodate combined loads using a single bearing, thereby reducing the axial installation space required for the equipment.

However, due to the ultra-thin-walled design of this series, the risk of bearing ring deformation must be carefully considered during installation. Appropriate clamping and support structures—as specified in the product drawings—must be employed.

Friction and Rotational Performance

The crossed cylindrical roller configuration provides a precision rolling support. Actual rotational resistance and frictional torque are influenced by factors such as bearing preload, lubrication, applied loads, and assembly precision.

The ultra-thin structure of the XRBT series does not imply that all models are suitable for unrestricted high-speed rotation; the permissible rotational speed should be determined based on specific bearing parameters and operating conditions.

Core Product Features and Advantages

STEP 1

Ultra-light and Ultra-thin Design

The XRBT series features an ultra-thin cross-sectional structure. While meeting specific precision support requirements, it helps reduce the overall size and weight of the equipment, making it ideal for compact rotating mechanisms.

STEP 2

Multi-directional Combined Loading

Utilizing a 90° crossed cylindrical roller configuration, a single bearing can simultaneously accommodate radial loads, bi-directional axial loads, and overturning moments, thereby simplifying the bearing arrangement for precision rotating mechanisms.

STEP 3

High-precision Rotational Support

Through the precise fit of raceways and rolling elements, the series provides stable rotational motion for small-scale precision equipment—perfect for applications requiring high rotational accuracy and repeatable positioning performance.

STEP 4

Compact Installation Space

The XRBT series is particularly well-suited for equipment with restricted bearing width or limited radial cross-sectional space, facilitating the development of thinner, more compact mechanical structures.

STEP 5

Facilitates Equipment Lightweighting

The reduced cross-section and compact dimensions lower the mass of the bearing itself, making it an excellent choice for precision mechanisms that are sensitive to the weight of moving components.

STEP 6

Ideal for Precision Equipment Design

The XRBT series is suitable for precision rotating components in medical devices, optical instruments, robotics, and small-scale automation equipment, offering a broader range of bearing options for compact mechanical designs.