Fits Introduction of tapered roller bearings

Nov 02, 2023

Taper roller bearing is a commonly used mechanical component in machinery and equipment. Its primary function is to support the shaft and parts on the post so that the rod can withstand radial load, axial load, and combined load. Therefore, the fit of tapered roller bearings has a significant impact on the performance and service life of the bearing. The following will detail the three aspects of fit selection, fit interference, and fit tolerance of tapered roller bearings.

Matching selection of tapered roller bearings

The fit selection of tapered roller bearings should consider factors such as the bearing's working load, rotation speed, size, and material of the tapered roller bearing housing hole. Usually, you can choose based on the following principles:

For high-speed and light load conditions, a smaller interference amount can be selected to reduce friction and wear;

For low-speed and heavy load conditions, a more significant interference amount can be chosen to improve the bearing capacity and stability;

For cases where the bearing seat hole is smaller, or the material is softer, a smaller interference amount can be selected to avoid crushing the bearing seat hole;

For situations where the axial position of the bearing needs to be adjusted, a more significant interference amount can be selected to ensure the fixed effect of the direction.

The picture above shows a four-row tapered roller bearing (tapered roller bearing uses) used for rolling mill rolls.

Fitting interference of tapered roller bearings

The fit interference of a tapered roller bearing refers to the interference between the inner ring of the direction and the shaft and between the outer ring and the seat hole. The selection of interference amount should consider the following factors:

Bearing size and type: Bearings of different sizes and types have different fit interference ranges;

Materials and sizes of shaft and seat holes: Shafts and seat holes of other materials and dimensions require various fit interferences;

Working load and speed: Working load and speed will affect the fit interference;

Appropriate tolerance: The size of the reasonable tolerance will affect the selection of fit interference.

The picture above shows the Inch size four-row tapered roller bearing BT4B 328842, which adopts a sealed design.

Fitting tolerances of tapered roller bearings

Tapered roller bearings' fit tolerance refers to the dimensional deviation between the rings and the corresponding components. The selection of fitting tolerances should consider the following factors:

Types and sizes of bearings: Different types and sizes of approaches have different appropriate tolerance ranges;

Working load and speed: Working load and speed will affect the fit tolerance;

The thermal expansion coefficient of material: The thermal expansion coefficient of material will affect the appropriate tolerance;

Installation accuracy requirements: In situations where installation accuracy is high, stricter fit tolerances must be selected.

To sum up, the fit selection, fit interference, and fit tolerance of tapered roller bearings are all critical parameters. When selecting, comprehensive considerations need to be made based on specific circumstances. OEM manufacturers' engineers should be consulted when necessary to ensure that the performance and service life of the bearings are optimal. At the same time, to provide the regular operation of the direction, you need to pay attention to the following points:

Before installing the tapered roller bearing, check the appearance quality of the direction to ensure there are no defects;

During the installation process, special tools and equipment should be used to avoid damage to the bearings;

During use, the working status of the directions should be checked regularly, and if any abnormalities are found, they should be dealt with promptly;

Regular replacement of bearing grease, as specified in the manual, ensures proper function during service.