XR855053 Preloaded Cross Tapered Roller Bearing for High Tilting Moment

Product Features and Advantages

Exceptional Rigidity and High Resistance to Overturning Moments: The steep conical geometry of the tapered rollers provides an effective load-bearing span that can extend well beyond the bearing’s own width, enabling it to withstand substantial overturning moments. The effective support span and double-row roller arrangement significantly improve operational stability and reduce deformation under heavy loads.

High-Speed Capability and Reduced Friction Losses: Compared with crossed cylindrical roller bearings, tapered rollers offer favorable rolling characteristics and support higher limiting speeds. The bearing also features lower friction torque and starting torque. While maintaining high load-carrying capacity, it can accommodate operating conditions involving relatively higher rotational speeds.

Compact Cross-Section and Lower Rotary Center of Gravity: The compact cross-sectional design helps reduce the center of gravity of the rotating assembly while maintaining high rigidity. This makes the bearing suitable for large precision rotary tables with limited installation space and provides an effective support solution for heavy-duty precision rotary equipment.

Factory Preload for Easy Installation and Long-Term Precision: XR series bearings are preloaded at the factory, eliminating the need for on-site clearance adjustment. The preload helps accommodate, to some extent, the effects of shaft thermal expansion, supporting long-term positioning accuracy in machine tools and rotary equipment.

Applications

With its combination of large-size construction, heavy-load capacity, and high precision, the XR855053 is suitable for a wide range of large, heavy-duty precision rotary mechanisms.

Large Machine Tool Rotary Tables: Suitable for rotary worktables in vertical lathes, vertical boring machines, and vertical grinding machines, as well as high-precision CNC indexing rotary tables. Its high rigidity and resistance to overturning moments help maintain table stability during heavy cutting operations.

Radar and Military Equipment: Used in radar antenna pedestals and rotary support systems for military turrets, where the bearing must withstand combined loads caused by wind forces, vibration, and the weight of the rotating assembly.

Heavy-Duty Construction Equipment: Suitable for rotary assemblies in large construction machinery, including tunnel boring machines.

Other Applications: Applicable to large rotary worktables, heavy-duty precision measuring equipment, and other rotary shaft systems where installation space is limited and high rigidity is essential.

Installation and Operating Precautions

1. Thorough Cleaning Before Installation

Tapered roller bearings are sensitive to contamination. Before installation, thoroughly clean the bearing housing, shaft, and all mating components. Ensure that all parts are free from burrs, sharp edges, dirt, and other contaminants.

2. Ensure Adequate Rigidity of Mating Components

A critical requirement for crossed tapered roller bearings is sufficient rigidity of both the bearing housing and the shaft. If either component lacks adequate stiffness, high-torque operating conditions may cause stress concentrations at the contact areas between the rollers and raceways, directly compromising bearing performance. Verify the rigidity of the bearing housing and the strength of the mounting bolts. Particular attention should be paid to structural verification in applications involving substantial overturning moments.

3. Simplified Installation with Factory-Set Preload

XR preloaded series bearings only require the mounting flanges (6 and 7) to be secured to the base with bolts, as the preload is preset at the factory and does not require on-site adjustment.

The standard assembly sequence is as follows: position the bearing and flange assembly (components 1 and 4), secure component 6 first, then secure the assembly consisting of components 2 and 5, install component 8, and finally secure components 3 and 7.

4. Rotation Testing and Lubrication Maintenance After Installation

After assembly, perform a rotation test to verify smooth operation and check for any abnormal resistance or noise. The standard configuration uses grease lubrication and includes built-in lubrication ports. Ensure that lubrication is adequate and correctly applied, and regularly inspect the lubrication system to confirm that it remains in proper working condition.

5. Avoid Overloading and Impact Loads

Do not operate the bearing beyond its rated parameters. Minimize exposure to impact loads to prevent damage to the raceways and rollers and help extend the bearing’s service life.