Double row tapered roller bearings can carry heavy loads and are stiff. They are suitable for the accommodation of combined (radial and axial) loads and can locate a shaft axially in both directions with a given axial clearance or a given preload. Their main use is in gearboxes, hoisting equipment, rolling mills and machines used in the mining industry, e.g. tunneling machines. Double row tapered roller bearings are produced in two configurations and in several different designs:

Taper Roller Bearings Design

The configuration bearings of the configuration have one double row outer ring (cup) & two inner rings with roller & cage assembly (cones). The TDI configuration which comprises one double row inner ring with two roller & cage assemblies and two outer rings Both these configurations are produced in several different designs.

Misalignment
Angular misalignments of the outer ring(s) relative to the inner ring(s) of double row tapered roller bearings can only be accommodated by force between the rollers & raceways. This causes appreciably higher bearing loads and should be avoided. If misalignments cannot be ruled out and if the application permits, the configuration bearings with their rows of rollers arranged face-to-face are not so stiff as the bearings, and should be used.

Minimum load
In order to guarantee satisfactory operation, double row tapered roller bearings, like all ball and roller bearings, must always be subjected to a given minimum load, particularly if they are to operate at high speeds, or are subjected to high accelerations or rapid changes in the direction of load. Under such conditions the inertia of the rollers, cages and friction in the lubricant, can have a detrimental influence on rolling conditions in the bearing arrangement. It may also cause sliding movements to occur between the rollers and raceways. When starting up at low temperatures or when the lubricant is highly viscous, even greater loads may be required. The weights of the components supported by the bearing, together with the external forces, generally exceed the requisite minimum load. If this is not the case, the double row tapered roller bearing must be subjected to an additional radial load. This is particularly easy to apply with tapered roller bearing arrangements by adjusting the inner or outer rings against each other to give an axial pre-load.