Tapered Roller Bearings

Tapered roller bearings are a type of widely used rolling bearings. Their structural design allows them to withstand both large radial loads and unidirectional axial loads, making them prevalent in automobiles, machine tools, engineering machinery, and other fields. Below is an introduction covering their structure, series, and common models:

Structural Features

The core structure of a tapered roller bearing comprises four key components:

Inner ring: Its raceway is tapered, matching the conical surface of the rollers. The inner ring is typically fixed to the shaft via an interference fit.

Outer ring: Its raceway is also tapered, usually fitting with the bearing housing or casing. The outer ring is separable in some models.

Tapered rollers: Rollers are frustoconical in shape. The quantity of rollers is determined by the bearing size and load requirements, and they are evenly spaced by a cage.

Cage: Mostly made of stamped steel or solid materials (e.g., copper alloy, phenolic resin), it functions to separate rollers, guide their rolling, and reduce friction.

The tapered design ensures that the vertices of the conical surfaces of the rollers, inner ring, and outer ring converge at a single point on the bearing's axis, enabling pure rolling during operation and minimizing frictional loss.

Series Classification

Tapered roller bearings are classified by the number of roller rows into three main series:

Single-row tapered roller bearings: The most common type. They consist of one outer ring, and an inner ring assembly (including the inner ring, a set of tapered rollers, and a basket-type cage). They can only bear unidirectional axial loads and are often used in pairs to balance bidirectional axial forces (e.g., automobile hub bearings).

Double-row tapered roller bearings: Composed of two rows of rollers, with an integral outer ring (or inner ring). The small end faces of the two inner rings (or outer rings) are adjacent, with a spacer in between. Clearance is adjusted via the spacer's thickness, and pre-interference of the bearing can also be adjusted this way. They withstand larger radial and axial loads, offer higher rigidity, and are suitable for heavy machinery (e.g., rolling mills, cranes).

Four-row tapered roller bearings: Featuring four rows of rollers, they have extremely high load-carrying capacity. They are primarily used in scenarios with extremely large radial loads (e.g., work rolls of large rolling mills).

Common Models

Single-row	Double-row	Four-row
32924	352930	3077776
32024	352030	77748
32224	352130	77752
32324	352230	77196
30224	351976	777/650
30324	351160	7771750
31324	352930	10777/500
31038	351068	2077156