XRUI Series

What is XRUI series crossed roller slewing bearing?

XRUI series crossed roller slewing bearing is a specially designed precision bearing. Its main feature is that the internal rollers are arranged in a 90-degree cross, and each roller is in contact with the V-type raceway surface. This unique structure enables it to simultaneously withstand loads from all directions, including radial, axial and tilting moments, which are critical in many applications.

Core Benefits of the XRUI Series: Why Choose Us?
In order to satisfy users' in-depth understanding of product performance, application scenarios and technical specifications, we have summarized the core advantages of the XRUI series for you:

High Accuracy and Rigidity: The XRUI series utilizes a precision roller and raceway design to ensure extremely high rotational accuracy and rigidity. This is critical for machine tools, industrial robots, medical equipment and other applications that require precise positioning and motion control.

Compact, space-saving design: The XRUI series has a very compact design with small cross-section dimensions that provide significant space savings for installation, especially for applications where equipment size is critical.

Outstanding load carrying capacity: With the unique arrangement of crossed rollers, XRUI series crossed roller slewing bearings are able to withstand huge radial, axial and tilting loads, which effectively improves the safety and stability of the equipment.

Wide range of applications: XRUI series is widely used in industrial robot joints, CNC rotary tables, precision measuring instruments, radar antennas, medical equipment and other high-end fields due to its excellent performance. If you are looking for industrial robot joint bearings or CNC rotary table bearings, XRUI series will provide you with reliable solutions.

RUI Series Cross Roller Slewing Bearings Installation Guide

Pre-installation preparation: making sure nothing goes wrong 

Adequate preparation is vital before formal installation. This not only improves mounting efficiency, but also avoids potential mounting errors.

Cleaning and inspection: Carefully inspect and clean the mounting surfaces, including the bearing mounts and brackets. Ensure that these surfaces are flat, free of burrs, welding slag or foreign matter. Any minor impurities may affect the smooth operation of the bearing. Also, inspect the XRUI series crossed roller slewing bearings themselves to ensure that they have not been damaged during transportation.

Soft Belt Location: Many slewing bearings have an unhardened area on the raceway, often referred to as the “soft belt” (marked with an “S” or plugged hole). To maximize bearing life, this soft zone should be placed in the unstressed or least loaded areas. For example, in lifting or excavating machinery, the soft belt should be placed at an angle of 90° to the direction of the boom.

Lubrication: XRUI series crossed roller slewing bearings are usually pre-filled with grease when shipped from the factory, but before mounting, it is recommended to reapply an appropriate amount of grease on the raceway and gear section to ensure good lubrication during initial operation.

XRUI series bearing installation steps: step by step

Following the steps below can ensure the correct installation of XRUI series slewing bearings:

Seating and Positioning: Use lifting bolts (eyebolts) or a suitable lifting tool to lift the bearing smoothly onto the support base. Ensure that the bearing fits snugly into the mounting surface. Check the clearance between the bearing flats and the support housing using a plug gauge. If there is a gap, level it with shims to prevent the bearing from distorting after the bolts are tightened.

Pre-tighten: Install all mounting bolts, but do not fully tighten them yet. Use high-strength bolts and select the appropriate strength level according to the shaft load.

Tightening of bolts: The bolts should be tightened in a symmetrical and continuous manner, usually in a 180° direction. Starting with one bolt, tighten gradually and symmetrically until all bolts reach the specified preload. Never tighten all bolts at once, as this may cause deformation of the bearing. Use a torque wrench to ensure consistent preload on all bolts.

Backlash adjustment (if toothed): For XRUI series crossed roller slewing bearings with toothed teeth, it is necessary to adjust the backlash of the gears before tightening the bolts. This is usually accomplished by measuring the highest point of radial runout of the gear (usually marked). Once the adjustment is complete, recheck the side play of all the gear rings to ensure uniformity.

FINAL INSPECTION AND LUBRICATION: After installation is complete, remove all dirt and dust from the bearings. Spray exposed parts with anti-rust paint and reapply grease to raceways and gear sections. Fill the grease nipple of the bearing with grease until some grease squeezes out from the seal.

Mounting precautions: details determine success

No impact: During mounting, it is strictly prohibited to use hammers and other tools for violent impact, which may cause irreversible damage to the raceways and rollers.

Use flat washers: When installing bolts, use tempered flat washers, and strictly prohibit the use of spring washers.

Keep clean: The whole mounting process should be carried out in a clean and dust-free environment to prevent contaminants from entering the bearings.

Correct installation of XRUI series crossed roller slewing bearings is the cornerstone of ensuring stable operation and prolonging the service life of the equipment. If you have any questions during the installation process, we recommend that you consult the product manual or contact our technical support team for more professional guidance.