Multi Row Tapered Roller Bearings

There are several types of multi row tapered roller bearings depending on your needs. For example, you can get double-cup bearings that have apexes facing inward to each other within the same outer raceway or thrust tapered bearings that have apexes that face outward.

Multi row tapered bearings are best suited for absorbing combination loads. They have high radial load capacities and can transmit axial loads as well.

Radial Load Capacity

The radial load capacity of multi row tapered bearings is far higher than that of comparable ball or thrust bearings. This is primarily due to the mirror-image arrangement of the rollers within each bearing assembly which spreads out the loads over a wider contact area.

This arrangement also allows for a high degree of osculation between the roller ends and flange. This reduces the stress that would be generated if the rollers made contact with each other at a single point as in a spherical bearing.

However, this increased capacity comes with the price of some additional distortion in the bearing housing. American can minimize this effect by utilizing computer analyses to determine the stress distribution and optimized roller crowning. This will help to maximize the bearing life and reduce distortion. Contact us if your application requires this type of analysis.

Axial Load Capacity

Unlike simple ball bearings, multi row tapered roller bearings can accommodate combined axial/radial loads with greater stability and longevity. This is due to the fact that all the load-bearing elements of a multiple-row tapered roller bearing are housed together in the same housing, giving them a larger overall surface area with which they can interface with equipment, enabling them to better transfer loads between each other and limit axial displacement.

These multiple-row bearings can be oriented in tandem, double-cup, or double-cone arrangements. Essentially, they’re single-row bearings separated by spacers within the same assembly.

The axial clearance of these multi-row bearings is typically pre-set at the factory and requires no user adjustment during installation. This saves time and allows for more flexibility in design and installation of the unit, as well as making maintenance inspections much easier. However, the axial clearance of these bearings will be affected by conditions such as temperature, lubrication, and exterior vibration, so this benefit needs to be considered carefully in a specific application.

Flexibility

The tapered shape concentrates loads to a point of contact, allowing a greater load rating than for cylindrical bearings. This is especially beneficial for applications in metal rolling mills where radial and one-sided axial loads are combined.

RKB double row tapered roller bearings are designed to support heavy combined radial and axial loads and provide stiff shaft guidance. They are supplied with a stated axial end play (also known as BEP) or given preload and are available in several confi gurations. Rings and rollers are manufactured from high chrome through hardening or case hardening carburizing alloy steels with special heat treatment to ensure size stability, fracture toughness and fatigue strength.

They can be fitted with pressed steel window-type cages or with steel pin-type cages that allow for a larger complement of rollers. For special operating conditions, they are also available with a higher accuracy class and with deviating tolerances. These options ensure an optimal combination of performance and reliability for your application.

Maintenance

As with other types of rolling bearings, multi row tapered roller bearings require proper installation, care and maintenance. When bearings are improperly installed or maintained, they will develop linear scars on the raceway and bone surfaces of the bearing that reduce the accuracy, precision and life of the bearing.

Bearing lubrication is vital to the effective operation of multi row tapered roller bearings. Lubrication helps reduce friction, noise and heat between rollers and the bearing races. Often, a small annular groove runs the circumference of the bearing cup to help facilitate lubricant proliferation.

Cages are common features of multi row tapered roller bearings. Unlike cages of other bearing types, they serve to evenly space the rollers and contain them in a single assembly. NEWORLD offers four-row tapered roller bearings with either pressed steel window-type or pin cages.