Cylindrical Roller Bearings
Overview
Cylindrical roller bearings (CRBs) have a simple structure of cylindrical rollers in linear contact with the raceways. They offer high load capacity under primarily radial loads. Low friction between the rollers and ring ribs makes these bearings suited for high speed rotation.
Single-row bearings are designated as NU, NJ, NUP, N, or NF, while double-row bearings are designated as NNU or NN, depending on if side ribs are used. All types allow the inner and outer rings to be separated.
Some CRBs used as free-end bearings have no ribs so that the rings can move axially relative to each other. When the inner or outer ring has ribs on both sides and the other ring has a rib on one side, these bearings can take some axial load in one direction.
Double-row cylindrical roller bearings have high radial rigidity and are used primarily for the main shafts of precision machine tools. Cages are typically made of pressed steel or machined brass, but molded polyamide resin cages are used for some models.
NMT offers a variety of CRB types to suit your needs.
Product List
Single-row cylindrical roller bearings are a type of rolling bearing primarily designed to withstand radial loads. Their rollers make linear contact with the raceway, resulting in an exceptionally high radial load capacity, typically 1.5 to 3 times higher than ball bearings of the same size.
A double-row cylindrical roller bearing is a type of rolling bearing designed to withstand heavy radial loads. Its core feature lies in the presence of two rows of rollers, which significantly enhances its load-bearing capacity and rigidity.
Full-complement cylindrical roller bearings have no cage to allow the maximum number of rollers possible, greatly increasing load capacity. However, this makes their high-speed performance slightly lower than that for bearings with cages.
Open single- and double-row types are mainly used in general industrial machinery with low speeds and high loads. Shielded double-row types are used primarily for crane sheaves.
Specially designed for the tough environments facing crane sheaves, these bearings offer excellent durability and resistance to outdoor elements. Easy to assemble and relubricate, CRBs for sheaves are designed with maintenance in mind.
Features
- Excellent sealing
Contact seals significantly reduce the entry of water and foreign matter. - High load capacity
These bearings can take the significant radial and thrust loads present in crane sheaves. - Corrosion-resistant
A phosphate coating improves resistance to rust and corrosion. - Easy grease replenishment
Lubrication holes supplied in the inner ring allow for grease in sealed types to be easily refilled and replaced. - Fewer mounting parts
Equipped with a locating snap ring, using these specialized bearings reduces the number of surrounding components, allowing for a more economical sheave structure.
FAQs
Loads are defined by their direction. Loads perpendicular to the shaft are called radial loads and loads parallel to the shaft are called axial (thrust) loads.
While DGBBs can handle axial loads in both directions, single-row angular contact ball bearings can only receive axial load in one direction.
Seals and shields offer additional protection for bearing components and help to improve and maintain lubrication. In terms of sealing performance, sealed bearings rank best, followed by shielded bearings, then finally open bearings. NMT uses supplementary designations D, DU, DW, and V (DD, DDU, DDW, VV) for sealed bearings and Z (ZZ) for shielded bearings. No supplementary designations are listed for open bearings.
