Tapered roller bearings are individual components consisting of inner and outer rings with tapered raceways.
This type of bearing is classified into various structural categories, including single row, double row, and four row tapered roller bearings, depending on the number of rows of rollers used.
Single row tapered roller bearings can support both radial and axial loads in one direction. However, when a radial load is applied, an axial component is generated. To balance this force, another bearing that can withstand the opposite axial force is required.
Definition
The capacity of a single row tapered roller bearing to handle an axial load is determined by its contact angle, also known as the outer ring raceway angle. The greater the angle, the higher the bearing’s ability to withstand axial loads.
Single row tapered roller bearings are the most commonly used type of tapered roller bearings.
In the front wheel hub of a car, a compact double-row tapered roller bearing is utilized.
Four-row tapered roller bearings are employed in heavy machinery, such as large hot and cold rolling mills.
Structural features
The type 30,000 tapered roller bearing is a separate bearing.
In general, the outer ring and inner component of the tapered roller bearing are 100% interchangeable within the size range involved.
The angle of the outer ring and the diameter of the outer race have been standardized to the same dimensions and cannot be altered during design and manufacture.
This allows for universal interchangeability of the outer ring and inner component of the tapered roller bearing worldwide.
Tapered roller bearings are primarily used to support combined radial and axial loads, with a focus on radial loads.
Compared to angular contact ball bearings, tapered roller bearings have a higher load-bearing capacity and a lower limiting speed.
They are also capable of withstanding axial loads in one direction and can limit axial displacement in one direction of the shaft or housing.
Classification
A single row tapered roller bearing consists of an outer ring, an inner ring assembly, and a set of tapered rollers in a basket cage.
The outer ring and inner ring assembly can be separated.
As per the ISO tapered roller bearing dimensions standard, any standard type of outer ring or inner ring assembly can be interchanged with the same type of ring, as long as it meets the requirements of ISO492 (GB307) and the external dimensions and tolerances are followed.
The inner ring assembly’s taper angle and component cone diameter must also comply with the interchange provisions.
Typically, the outer ring raceway of a single row tapered roller bearing has a cone angle ranging from 10° to 19° and can support both axial and radial loads. The larger the cone angle, the greater its capacity to bear axial loads. For instance, large cone angle bearings with the code “B” and a cone angle between 25° and 29° can withstand heavy axial loads.
The clearance of single row tapered roller bearings can be adjusted during installation.
In contrast, the outer ring (or inner ring) of a double row tapered roller bearing is a single unit. The two inner rings (or outer rings) have similar small end faces and spacers in between, and the clearance is adjusted using the spacer’s thickness. The spacer’s thickness can also be used to adjust the pre-interference of the double row tapered roller bearing.
Four-row tapered roller bearings perform similarly to double row tapered roller bearings. However, double row tapered roller bearings have a greater radial load capacity and a slightly lower speed limit, making them suitable for heavy machinery.
ZWZ offers long-life multi-sealed double and four-row tapered roller bearings, with a personalized new design that improves the sealing performance by combining sealing and dustproofing. These bearings have a 20% to 40% longer life compared to open-frame bearings and reduce lubricant consumption by 80%.
Application
Tapered roller bearings are designed to support radial and axial loads combined. The load-carrying capacity of the bearing depends on the raceway angle of the outer ring, with a larger angle providing greater capacity.
These bearings come in three types, depending on the number of rolling elements in the bearing: single row, double row, and four row. The clearance for single row tapered roller bearings must be adjusted by the user during installation, while the clearances for double-row and four-row bearings are specified at the time of delivery and do not require user adjustment.
Tapered roller bearings feature a conical inner ring and an outer ring raceway, with tapered rollers arranged between the two. The projection lines of the conical surfaces meet at a single point on the axis of the bearing, making these bearings particularly suited for composite loads.
The axial load capacity of the bearing is largely determined by the contact angle, with a larger angle providing greater capacity. This angle is expressed as a calculation coefficient, with a larger coefficient indicating a larger contact angle and greater applicability to axial loads.
Tapered roller bearings are separable, meaning the conical inner ring assembly, consisting of the inner ring, rollers, and cage, can be mounted separately from the outer bevel (outer ring). These bearings are widely used in industries such as automobiles, rolling mills, mining, metallurgy, and plastic machinery.
