RKB Multi-Row Roller Bearing Mounting and Maintenance

Product catalog summary

General Information
Multi-row tapered and cylindrical roller bearings are used in rolling mill stands for their ability to handle high radial and axial loads. Made from durable materials, these bearings are compact yet have a high load capacity, suitable for restricted spaces.

Mounting of Multi-Row Roller Bearings
Mounting involves preparing chocks and shafts. For four-row tapered roller bearings, the entire bearing is mounted into the chock before placement onto the roll neck, unlike cylindrical roller bearings where inner rings are fitted first. Proper lubrication and fitting are crucial.

Lubrication
Lubrication is vital for bearing performance and lifespan. Grease is preferred for its cleanliness and cost-effectiveness, while sealed bearings help retain grease and protect against contaminants.

Maintenance
Regular maintenance includes checking axial internal clearance (Bench End Play) and ensuring proper storage. A balanced maintenance program extends bearing life and performance.

Conclusion
RKB's multi-row roller bearings are designed for high performance and cost efficiency. Proper handling, mounting, and maintenance are essential for maximizing service life.

Tapered Roller Bearings Configurations
The document outlines configurations like TQO, TQO/G, TQO/EG, each designed for specific applications with variations in components such as cones, cups, spacers, and seals.

Multi-Row Roller Bearing Mounting and Maintenance
Proper mounting and maintenance are emphasized for optimal performance. Procedures include preparing chocks and shafts, cleaning, checking dimensional accuracy, and applying lubricants.

Multi-Row Cylindrical Roller Bearings
These bearings are suitable for extreme radial loads and varying speeds. Different designs like A2D, C2C, D2C are described, each with specific features.

Mounting Procedures
Detailed instructions emphasize cleanliness and correct sequence for mounting multi-row roller bearings, including preliminary operations for chock and shaft preparation.

Sealing and Lubrication
Sealed bearings simplify design, reduce maintenance, and extend service life. Various seal designs and materials like fluoroelastomer (FKM) enhance performance in harsh environments.

Safety Guidelines for Handling Bearings with Fluoroelastomer Seals
Safety protocols include using protective gear and storing residual seal fragments in marked containers. Immediate medical consultation is advised in case of inhalation or contact.

Mounting and Maintenance of Multi-Row Roller Bearings
Mounting procedures for RKB TQO bearings involve aligning parts and ensuring proper seating with feeler gauges. Procedures vary based on bearing size and design.

Mounting of Unsealed TQO Bearing with Pressed Steel Cage
Steps include fastening the roll-side cover, aligning the chock with the shaft, and adjusting gasket thickness for proper fit.

Mounting of Sealed TQO Bearing
Steps include fastening the roll-side cover, assembling the bearing set, and ensuring proper alignment and seating.

Mounting of Four-Row Cylindrical Roller Bearings
Steps include preparing bearing parts, coating components with lubricant, and using appropriate tools for mounting.

Dismounting Procedures
Dismount bearings in reverse order of mounting, using appropriate tools to avoid damage.

Lubrication
Proper lubrication prevents premature bearing failures, which can account for up to 40% of such incidents.

Introduction to Lubrication in Bearings
Lubrication prevents metal-to-metal contact, protects against corrosion and wear, dissipates heat, and removes contaminants.

Elastohydrodynamic Lubrication
This regime occurs under high pressure, where a thin lubricant film supports the load.

Grease Lubrication
Grease selection should consider consistency, temperature range, and rust-inhibiting properties.

Temperature and Grease Properties
Greases with EP additives are recommended for heavily loaded bearings.

Grease Selection Criteria
Factors include bearing load and speed, operating conditions, and replenishment intervals.

Oil Lubrication
Mineral oils are used when grease lubrication is unsuitable.

Introduction
Mineral oils are cost-effective and manage heat and contaminants well.

Specifications of Grease
Grease consists of base oil with a viscosity of 320–460 mm²/s at 40°C and includes extreme pressure additives.

Advantages and Disadvantages of Mineral Oils
Mineral oils are versatile but have drawbacks like rapid oxidation.

Viscosity and Viscosity Index
Viscosity is a critical characteristic, measured at 40°C.

Lubricating Oil Selection
Selecting oil involves considering operating temperature, speed, and bearing geometry.

Additives in Lubricating Oils
Lubricating oils contain additives to enhance performance.

Oil Lubrication Methods
Methods include oil bath and circulating oil lubrication.

Conclusion
Lubricant selection should be based on specific application requirements.

Oil Lubrication Systems
Oil lubrication systems maintain bearing efficiency and longevity, especially in high-speed applications.

Maintenance of Multi-Row Roller Bearings
Proper maintenance includes monitoring lubricant quality and bearing wear.

Typical Maintenance Activities
Activities include registering bearing positions, cleaning, inspecting for wear, and adjusting axial internal clearance.

Checking and Readjustment of Axial Internal Clearance
Annual checks of axial internal clearance are necessary to evaluate wear.

Specifications and Procedures
Procedures for measuring and adjusting axial internal clearance are detailed.

Tables and Calculations
Tables illustrate equations and examples for determining axial internal clearance.

Storage Recommendations
Bearings should be stored in original cases at 18-20 ºC with humidity below 60%.

Maintenance Program
A balanced maintenance program is emphasized, highlighting the benefits of preventive, predictive, and proactive maintenance.

Disclaimer
Procedures are guidelines and should be followed along with other directives available on the RKB website.