Tapered Roller Bearing

Multi row tapered roller bearings feature a tapered inner ring raceway, tapered rollers as rolling elements and a resulting force transferring contact angle. In addition to very high radial forces, they can also absorb axial forces from both sides and are particularly suitable for combined loads. Multi row tapered roller bearings can be disassembled and are easily installed or uninstalled. They allow a very small compensation of angular misalignments. Multi row tapered roller bearings are mainly used for supporting rolls in hot rolling mills for low and medium rolling speeds.

Multi row tapered roller bearings are separable and non-latching bearings. In addition to very high radial forces, they can, due to the mirror-image arranged bearing pairs, also absorb high axial forces. For combined bearing sets there is a distinction between O-, X-, or tandem arrangement based on pressure line contact. Bearings in X-arrangement (TQO) are less suitable for the absorption of moment loads while the O-arrangement (TQI) is very rigid and only allows small overturning clearance.

The bearing clearance is chosen by customer and application and is adjusted by the manufacturer.

Multi row tapered roller bearings are not suitable for compensation of misalignments. Misalignments cause edge stresses between rolling elements and raceways and produce additional stresses in the bearing which reduce its operating life.

The kinematic limiting speed n_G is a practical mechanical limit value and is based on the mechanical fatigue strength of the rolling bearing as a function of its installation situation and lubrication. The limit speed must not be exceeded even under optimum operating conditions without prior consultation with KRW.

The DIN ISO 15312 (Rolling bearings - Thermal speed rating) does not specify a thermal speed rating nth for these bearings.

For dynamically loaded bearings

The service life formula according to ISO 281 L₁₀ = (C/P)^p for dynamically loaded bearings requires an equivalent load (P) from constant direction and size. To calculate P, calculation factors and the ratio of axial and radial load are required.

Equivalent Dynamic Bearing Load P

The equivalent bearing service life for the tapered roller bearings depends on the ratio F_a/F_r . The equivalent dynamic bearing load can be determined using the following formula:

For statically loaded bearings

Dynamic dimensioning loses its validity for bearings rotating at very low speeds (n x d_m ≤ 4000 mm/min). The static load safety factor S₀ is calculated as follows:

Static load capacity

A minimum load is required for the reliable operation of a rolling bearing. If the minimum load is not reached, slippage may occur. The minimum radial load for tapered roller bearings is roughly assumed to be 2% of the static load rating C₀ of the bearing. If the value falls below this value, please consult KRW Application Technology.