Cylindrical Roller Bearings for Backup Rolls of Multi-High Rolling Mills

Specifications

How to choose Cylindrical Roller Bearings

Points to check when selecting, with the values for this product (Cylindrical Roller Bearings for Backup Rolls of Multi-High Rolling Mills).

1. 1. Boundary dimensions that fit the shaft and housing

   This product: Inner diameter d 31.75～180 mm

   Select the bore diameter d to match the shaft diameter and the outside diameter D to match the housing bore, and determine the width B from the available installation space. Even with the same bore, there are dimension series with different outside diameters and widths, and wide-section types and types with thicker outer ring walls also exist. Confirm the boundary dimensions d×D×B combination against the bearing number.

2. 2. Select a rated load that suits the load conditions

   This product: Basic dynamic load rating Cr 99.3～2 940 kN

   The basic dynamic load rating Cr is the basis for life calculation; calculate whether the required life is met from the actual load and rotational speed. For large loads at standstill or low speed, or for shock loads, also check the basic static load rating C0r. Wide-section, double-row and full-complement types are options when greater load capacity is needed.

3. 3. Determine the type for fixed and free positions

   NU and N types allow relative axial movement between the inner and outer rings, making them suitable for the free side that absorbs thermal expansion of the shaft. If axial load is applied, choose NJ or NF types for one direction, or NUP types for both directions. First determine which bearing in the overall bearing arrangement locates the shaft axially.

4. 4. Select a clearance that suits fit and temperature

   Internal clearance is available in classes such as C2, CN and C3. Consider a larger clearance class where an interference fit or a temperature difference between inner and outer rings reduces the clearance during operation. Tapered bore double-row types allow clearance adjustment by the amount of push-in and are used in applications with strict clearance control, such as machine tool spindles.

5. 5. Match rotational speed with cage and accuracy grade

   For high-speed rotation, check the permissible rotational speed as well as the cage material (brass, steel sheet or resin) and the accuracy class. Full-complement types without cage have high load capacity but are unsuitable for high speed. Hybrid types with silicon nitride rollers offer low friction and support high-speed rotation.

6. 6. Check electrical erosion countermeasures and maintainability

   In inverter-driven motors and generators, current can flow through the bearing causing electrical erosion, so consider insulated-coated or ceramic-roller types. For outdoor use or locations that are difficult to lubricate, also check for sealed, grease-packed designs, rust-preventive treatment, and ease of disassembly and inspection.

This guide was written by AI based on the listed products' documents and specification items.

About Cylindrical Roller Bearings and all products

Description

To withstand high rolling loads, these bearings have increased dynamic load ratings and are manufactured to high precision. They are designed for installation of multiple units on a single shaft, with radial runout of the outer ring and the variation in assembled wall thickness kept small. If the outer ring outer surface is damaged by foreign matter, it can be ground and reused.

FAQ

Q. What are the bore and outer diameter ranges for cylindrical roller bearings for backup rolls of multi-high rolling mills?

A. The bore diameter d ranges from 31.75 to 180 mm, and the outside diameter D ranges from 76.2 to 406.42 mm.

Q. What is the basic dynamic load rating of cylindrical roller bearings for backup rolls of multi-high rolling mills?

A. The basic dynamic load rating Cr ranges from 99.3 to 2 940 kN.

Q. What applications are cylindrical roller bearings for backup rolls of multi-high rolling mills suited for?

A. They are used for backup rolls of multi-high rolling mills (rolling mill classifications such as ZR type). Because they operate under high rolling loads, they have increased load ratings and are manufactured to high precision.

Q. How many bearings are intended to be installed on one shaft for cylindrical roller bearings for backup rolls of multi-high rolling mills?

A. They are designed for installation of multiple units on a single shaft, with radial runout of the outer ring and the variation in assembled wall thickness kept small.

Q. What should be done if the outer ring of a cylindrical roller bearing for backup rolls of multi-high rolling mills is damaged by foreign matter?

A. If the outer ring outer surface is damaged by foreign matter, it can be ground and reused.

Written by AI based on the content of the source documents.

Source documents

• Catalog JTEKT 大形転がり軸受カタログ（技術解説・軸受寸法表） Open page 228
  Found on: https://koyo.jtekt.co.jp/support/catalog-download/
• Brochure 多段圧延機バックアップロール用円筒ころ軸受
  Found on: https://koyo.jtekt.co.jp/support/catalog-download/