Time：2020.06.15 Source：Roller Bearings Suppliers
Tapered roller bearings mainly bear radial and axial combined loads. Bearing load capacity depends on the raceway angle of the outer ring, the greater the angle, the greater the load capacity. This type of bearing is a separate bearing. It is divided into single-row, double-row and four-row tapered roller bearings according to the number of rows of rolling elements in the bearing. The clearance of single-row tapered roller bearings needs to be adjusted by the user during installation; the clearances of double-row and four-row tapered roller bearings have been given at the factory according to user requirements, and no user adjustment is required.
Tapered roller bearings have tapered inner ring and outer ring raceways, tapered rollers are arranged between the two. The projection lines of all conical surfaces converge at the same point on the bearing axis. This design makes tapered roller bearings particularly suitable for bearing compound (radial and axial) loads. The axial load capacity of the bearing is mostly determined by the contact angle α; the larger the angle α, the higher the axial load capacity. The size of the angle is expressed by the calculation factor e; the greater the value of e, the greater the contact angle, the greater the applicability of the bearing to bear axial loads.
Tapered roller bearings are usually separated, that is, the tapered inner ring assembly consisting of the inner ring with roller and cage assembly can be installed separately from the tapered outer ring (outer ring).
Tapered roller bearings are widely used in automotive, rolling mill, mining, metallurgy, plastic machinery and other industries.
The secondary causes of tapered roller bearings in the process of installation are: the bearing is in the process of assembly and assembly, the inner ring and the outer ring are skewed; or perhaps the emergence of the charge in the process of installation and assembly of the charge and the formation of the bearing.
Although the quality of tapered roller bearings and other aspects are relatively good, but rolling bearings are precision components, and their use must be carried out accordingly. No matter how high-performance bearings are used, if not used properly, the expected high performance will not be obtained. Regarding the use of bearings, there are the following:
(1) Keep the tapered roller bearing and its surroundings clean.
Even small dust that is invisible to the eyes can have a bad effect on bearings. Therefore, keep the surrounding clean, so that dust will not invade the bearing.
(2) Use with care.
When the tapered roller bearing is given a strong impact during use, it will cause scars and indentations, which will cause the accident. In severe cases, cracks and breaks may occur, so care must be taken.
(3) Use appropriate operating tools.
Avoid using existing tools instead, you must use appropriate tools.
(4) Pay attention to the corrosion of tapered roller bearings.
When operating bearings, sweat on your hands can cause rust. Pay attention to use clean hands, try to wear gloves.
Tapered roller bearings use hearing to identify irregular operation is a very common method, such as using an electronic stethoscope to detect abnormal noise of a part is used by experienced operators. If the bearing is in good operating conditions, it will emit a low whine, and if it emits sharp hissing tapered roller bearings, squeaks, and other irregular sounds, it usually indicates that the bearing is in poor operating conditions. Wuxi Spark Bearing share WSBC 31312/DF bearings .
1.Corrosion of tile surface: Spectral analysis found that the concentration of non-ferrous metal elements is abnormal; many sub-micron wear particles of non-ferrous metal components appear in the iron spectrum; the moisture content of the lubricant exceeds the standard and the acid value exceeds the standard.
2.Strain on the surface of the journal: there are iron-based cutting abrasive particles or black oxide particles in the iron spectrum, and the tempered color exists on the metal surface.
3.Corrosion of journal surface: Spectral analysis found that the concentration of iron is abnormal. There are many submicron particles of iron in the iron spectrum. The moisture content of the lubricant exceeds the standard or the acid value exceeds the standard.
4.Surface strain: cutting abrasive particles are found in the iron spectrum, and the abrasive particles are made of non-ferrous metals.
5.Fretting wear on the back of the tile: Spectral analysis found that the iron concentration is abnormal. There are many iron components in the iron spectrum, including submicron wear particles, and the moisture and acid value of the lubricating oil are abnormal.
The sharp creaking noise may be caused by improper lubrication. Improper bearing clearance can also cause metallic noise. The dents on the outer ring of the tapered roller bearing will cause vibration and cause a smooth and crisp sound. If the knocking scars caused by the installation will also generate noise, this noise will vary with the bearing speed. If there is intermittent noise, it means that the rolling parts may be damaged. The sound of the tapered roller bearing occurs when the damaged surface is rolled. If there are pollutants in the bearing, it will often cause hissing noise. Serious bearing damage will Irregular and loud noise is produced.
Precautions for maintenance life of tapered roller bearings
When judging whether the dismantled bearing can be used again, please check after cleaning the tapered roller bearing, carefully check the state of the raceway surface, rolling surface, mating surface, wear of the cage, whether the bearing clearance increases and whether it affects the size Damage and abnormality with reduced accuracy. For non-separable small ball bearings, etc., use one-hand flat-end inner ring and rotate the outer ring to check whether it is smooth.
Separate bearings such as tapered roller bearings can be inspected separately for the rolling elements and the raceway surfaces of the outer ring.
When judging whether the bearing can be used again, it should be determined according to the relevant factors such as the degree of damage of the bearing, mechanical performance, importance, operating conditions, inspection cycle and so on. However, if the following defects are found during the inspection, the bearing cannot be used any longer and a new bearing needs to be replaced.
1.Lubrication conditions The viscosity forms a lubricating film between the rolling contact surfaces that is sufficient to separate the two surfaces. The lubricant must maintain a certain minimum viscosity at normal operating temperature to reduce bearing friction and increase bearing life. The influence of the average diameter of tapered roller bearing and the working speed. The viscosity of the working viscosity lubricant at the working temperature is determined by the viscosity at the working temperature t4℃ according to the viscosity-temperature curve and the viscosity ratio is an indicator of the ability to form the oil film. Factors such as have a great influence on the bearing life. When the operating condition becomes worse (temperature rises, the speed decreases, the amount of contaminants increases), the bearing life may be greatly polluted and the range will be reduced.
2. Calculation of bearing life correction factor and analysis method of influencing factors correction factor calculation method. Analysis of a basic factor that affects the correction factor of various bearing bearing life, so that the bearing gets better lubrication conditions, should be greater than or equal to but the viscosity ratio It should not be too large, otherwise the increase in viscosity may increase the working temperature of the tapered roller bearing. When the lubricant containing extreme pressure additives should be used, the pressure between the moving surfaces will also change the viscosity of the lubricant. The operating conditions (operating temperature, speed, load and size, and the effect of lubrication on bearing life are considered).