Tapered roller bearings are separable bearings, and the inner and outer rings of the bearing have tapered raceways. This type of bearing is divided into different structural types such as single row, double row and four row tapered roller bearings according to the number of rows of rollers installed. Single row tapered roller bearings can bear radial loads and axial loads in one direction. When the bearing bears the radial load, an axial component force will be generated, so another bearing that can bear the axial force in the opposite direction is needed to balance it.

Introduction

Tapered roller bearings refer to radial thrust rolling bearings whose rolling elements are tapered rollers. There are two kinds of small cone angle and large cone angle. The small cone angle mainly bears the combined radial and axial loads dominated by radial loads. It is often used in pairs and installed in reverse. The inner and outer races can be installed separately, and the radial and axial clearances can be adjusted during installation and use; The large cone angle mainly bears the combined axial and radial loads, which are mainly axial loads. Generally, it is not used to bear pure axial loads alone, but can be used to bear pure radial loads when arranged in pairs (the ends with the same name are installed opposite to each other).

Classification of tapered roller bearings

Single row tapered roller bearings have an outer ring, an inner ring assembly consisting of an inner ring and a set of tapered rollers enclosed by a basket-shaped cage. The outer ring can be separated from the inner ring assembly. According to the ISO tapered roller bearing external dimension standard, any standard type of tapered roller bearing outer ring or inner ring assembly should be able to achieve international compatibility with the same type of outer ring or inner ring assembly. exchange. That is to say, the outer dimensions and tolerances of the same type of outer ring must comply with the provisions of ISO492 (GB307), and the cone angle of the inner ring components, the diameter of the cone of the components, etc. must also comply with the relevant regulations for interchangeability.

Usually, the taper angle of the outer ring raceway of a single row tapered roller bearing is between 10° and 19°, which can bear the combined action of axial load and radial load at the same time. The larger the cone angle, the greater the ability to withstand axial loads. For bearings with a large cone angle, add B to the post code, and the cone angle is between 25° and 29°, which can withstand large axial loads. In addition, single row tapered roller bearings can adjust the size of the clearance during installation.

The outer ring (or inner ring) of double row tapered roller bearing is a whole. The small end faces of the two inner rings (or outer rings) are similar, and there is a spacer in the middle. The clearance is adjusted by the thickness of the spacer, and the pre-interference of the double row tapered roller bearing can also be adjusted by the thickness of the spacer.

Four-row tapered roller bearings, the performance of this type of bearing is basically the same as that of double-row tapered roller bearings, but it bears a larger radial load than double-row tapered roller bearings, and the limit speed is slightly lower. It is mainly used for heavy machinery.

Multi-sealed double and four-row tapered roller bearings, ZWZ provides long-life, multi-sealed double and four-row tapered roller bearings. Carry out a new personalized design for the bearing, change the traditional design method of the fully sealed bearing, and adopt a new type of sealing structure combining sealing and dustproof to improve the sealing effect and performance. Compared with open structure bearings, multi-sealed double and four-row tapered roller bearings have a 20% to 40% increase in life and 80% reduction in lubricant consumption.

Main application

Tapered roller bearings are widely used in automobiles, rolling mills, mines, metallurgy, plastic machinery and other industries.

Installation method

Adjust the axial clearance. For the installation axial clearance of the tapered roller bearing, it can be adjusted by adjusting the nut on the journal, adjusting the gasket and the thread in the bearing seat hole, or by preloading the spring. The size of the axial clearance is related to the arrangement of the bearings during installation, the distance between the bearings, the material of the shaft and the bearing seat, and can be determined according to the working conditions.

For tapered roller bearings with high load and high speed, when adjusting the clearance, the influence of temperature rise on the axial clearance must be considered, and the clearance reduction caused by temperature rise must be estimated, that is, the axial clearance It should be adjusted appropriately.

For low-speed and vibration-bearing bearings, clearance-free installation or preload installation should be applied. Its purpose is to make the rollers and raceways of tapered roller bearings have good contact, distribute the load evenly, and prevent the rollers and raceways from being damaged by vibration and impact. After adjustment, check the size of the axial clearance with a dial gauge.

Installation of four-row tapered roller bearings (installation of roller bearings)

1. The cooperation between the inner ring of four-row tapered roller bearings and the roll neck is generally with a gap. When installing, first put the bearing into the bearing box, and then put the bearing box into the journal.

2. The outer ring of the four-row tapered roller bearing and the hole of the bearing box also adopt dynamic fit, and the outer ring A is first installed in the bearing box. When leaving the factory, characters and symbols are printed on the outer ring, inner ring and inner and outer spacers. When installing, they must be installed in the bearing housing in sequence according to the arrangement of the characters and symbols. Cannot be interchanged arbitrarily to prevent changes in bearing clearance.

3. After all the parts are loaded into the bearing box, the inner ring and the inner spacer, and the outer ring and the outer spacer are axially tightened.

4. Measure the width of the gap between the end face of the outer ring and the cover plate of the bearing box to determine the thickness of the corresponding sealing gasket.