First of all, the impact sound of the rolling element and its control method. When the larger model ball bearing or cylindrical roller bearing operates at low speed under pure radial load, the rolling element in the non load area will impact the cage or raceway and make noise due to the small centrifugal force of the rolling element. But as the speed increases, the sound will disappear.Solution and principle of IKO high temperature bearing noise
The second is the raceway sound of high-temperature bearing and its control method. The raceway sound is a smooth and continuous sound made by the rolling body rolling on the raceway surface when IKO bearing is running. It is a unique basic sound that will occur in all rolling bearings.
The general bearing sound is the sound of raceway plus other sounds. The raceway sound of ball bearing is irregular, and its frequency is above 1000Hz. Solution and principle of IKO high temperature bearing noise
Its main frequency does not change with the speed, but its sound pressure level increases with the speed. For the bearing with loud raceway sound, the sound pressure level of raceway sound decreases with the increase of viscosity; For bearings with low raceway noise, the sound pressure level changes from decrease to increase when the viscosity increases to more than 20mm2 / s. The greater the rigidity of the bearing pedestal, the lower the sound pressure level of the raceway sound.Solution and principle of IKO high temperature bearing noise
If the radial clearance is too small, the sound pressure level and dominant frequency of the raceway sound will increase sharply with the reduction of the radial clearance. If you don’t want it to have sound, you can use some measures to greatly reduce the noise of the bearing. Solution and principle of IKO high temperature bearing noise
Generally speaking, to control the noise impact of the rolling bearing, you must take countermeasures against the root causes of these noises in order to get the curative effect. The main methods are:Solution and principle of IKO high temperature bearing noise
Choose IKO bearing with low noise; This depends on buying high-quality high-temperature bearings. Generally, good bearings are made of high-material steel, which has the characteristics of high density and high durability;Solution and principle of IKO high temperature bearing noise
Solution and principle of IKO high temperature bearing noise
Try to eliminate the noise from the application link of IKO bearing, that is, add lubricating grease on the link. Be sure to select the lubricating material, which can get twice the result with half the effort;Solution and principle of IKO high temperature bearing noise
Avoid resonance with the host and avoid resonance sensitive speed; This requires professional installation and commissioning, which can avoid resonance problems;
If other methods fail, take additional measures for sound insulation and silencing, install some sound control equipment, etc,Solution and principle of IKO high temperature bearing noise
Rolling sound of bearing and its control method rolling sound is the harsh metal friction sound that can occur in cylindrical roller bearings on all occasions. It mostly occurs in larger types of grease lubricated bearings, but it is more likely to occur in greases with degraded base oil performance, which hardly occurs in oil lubrication. In addition, it is easy to occur in winter. Solution and principle of IKO high temperature bearing noise
When bearing pure radial load, it is easy to occur in the case of large radial clearance, and it is easy to occur in a specific speed range with different models and sizes, both continuously and intermittently. Special processing methods for the outer ring raceway can prevent the occurrence of rolling sound. Solution and principle of IKO high temperature bearing noise
If necessary, this high-temperature bearing can be selected, or the radial clearance of IKO bearing can be appropriately reduced, the lubricating grease with excellent performance can be used and the rigidity of parts matched with the bearing can be improved.Solution and principle of IKO high temperature bearing noise
First of all, the impact sound of the rolling element and its control method. When the larger model ball bearing or cylindrical roller bearing operates at low speed under pure radial load, the rolling element in the non load area will impact the cage or raceway and make noise due to the small centrifugal force of the rolling element. But as the speed increases, the sound will disappear.Solution and principle of IKO high temperature bearing noise
The second is the raceway sound of high-temperature bearing and its control method. The raceway sound is a smooth and continuous sound made by the rolling body rolling on the raceway surface when IKO bearing is running. It is a unique basic sound that will occur in all rolling bearings. The general bearing sound is the sound of raceway plus other sounds. Solution and principle of IKO high temperature bearing noise
The raceway sound of ball bearing is irregular, and its frequency is above 1000Hz. Its main frequency does not change with the speed, but its sound pressure level increases with the speed. For the bearing with loud raceway sound, the sound pressure level of raceway sound decreases with the increase of viscosity; For bearings with low raceway noise, the sound pressure level changes from decrease to increase when the viscosity increases to more than 20mm2 / s. Solution and principle of IKO high temperature bearing noise
The greater the rigidity of the bearing pedestal, the lower the sound pressure level of the raceway sound. If the radial clearance is too small, the sound pressure level and dominant frequency of the raceway sound will increase sharply with the reduction of the radial clearance. If you don’t want it to have sound, you can use some measures to greatly reduce the noise of the bearing. Solution and principle of IKO high temperature bearing noise
Generally speaking, to control the noise impact of the rolling bearing, you must take countermeasures against the root causes of these noises in order to get the curative effect. The main methods are:Solution and principle of IKO high temperature bearing noise
Choose IKO bearing with low noise; This depends on buying high-quality high-temperature bearings. Generally, good bearings are made of high-material steel, which has the characteristics of high density and high durability;
Try to eliminate the noise from the application link of IKO bearing, that is, add lubricating grease on the link. Be sure to select the lubricating material, which can get twice the result with half the effort;
Avoid resonance with the host and avoid resonance sensitive speed; This requires professional installation and commissioning, which can avoid resonance problems
If other methods fail, take additional measures for sound insulation and silencing, install some sound control equipment, etc,
Rolling sound of bearing and its control method rolling sound is the harsh metal friction sound that can occur in cylindrical roller bearings on all occasions. It mostly occurs in larger types of grease lubricated bearings, but it is more likely to occur in greases with degraded base oil performance, which hardly occurs in oil lubrication.
In addition, it is easy to occur in winter. When bearing pure radial load, it is easy to occur in the case of large radial clearance, and it is easy to occur in a specific speed range with different models and sizes, both continuously and intermittently. Special processing methods for the outer ring raceway can prevent the occurrence of rolling sound.
If necessary, this high-temperature bearing can be selected, or the radial clearance of IKO bearing can be appropriately reduced, the lubricating grease with excellent performance can be used and the rigidity of parts matched with the bearing can be improved.
Fatigue spalling fatigue spalling is the scale spalling of the bearing working surface caused by rolling fatigue.
When the bearing works, the load on the rolling element and inner ring (or outer ring) is not constant, but changes repeatedly with the operation of the bearing. This load is alternating load; Because the contact area between the rolling element and the inner ring (or outer ring) is very small, the contact stress is very large. At high speed, under the repeated action of huge alternating contact stress, the metal will fatigue.
At first, small cracks are visible at the parts where the stress is concentrated. Due to the action of lubricating oil and metal corrosion, the cracks gradually expand. When they expand to a certain extent, the surface metal will peel off and form small pits, similar to pitting. When we disassemble and inspect the plastic IKO bearing, we often find pitting and metal peeling on the inner or outer ring and rolling body surface, which is the phenomenon of metal fatigue peeling.
If the bearing fatigue spalling occurs after long-term operation, it shall be regarded as natural damage. If it occurs in the middle or early stage of bearing use, it shall be regarded as unnatural spalling. At this time, the cause of spalling shall be found out.
2. Unnatural spalling unnatural spalling is caused by human factors, which occurs in the middle or early stage of bearing use.
The main cause of unnatural peeling is due to improper selection of bearing type or improper installation.
If the bearing type is not selected properly, spalling may occur in the early stage due to large axial load. Spalling mainly occurs in the raceway, which makes the rolling track of the rolling body move towards the ball loading port, and even roll through the ball loading port, resulting in serious spalling damage to the raceway. The measure to prevent this kind of damage is to reasonably select the bearing according to the working conditions of plastic bearing.Solution and principle of IKO high temperature bearing noise
Peeling due to improper installation
During installation, the shoulder of the shaft and the shell is not perpendicular to the mating surface, or the inner and outer rings are skewed due to the bending of the shaft, which will cause excessive contact stress on the rolling surface and lead to spalling.
The outer ring is installed in the oval or conical seat hole. When the rolling element passes through the irregular raceway, it will increase the contact stress, resulting in the early spalling of the raceway and rolling element.Solution and principle of IKO high temperature bearing noise
During installation of cylindrical roller bearing, the inner or outer ring roll is injured due to installation skew and excessive force during knocking.Solution and principle of IKO high temperature bearing noise
When the deep groove ball bearing is installed on the shaft with interference, if the applied pressure is transmitted through the outer ring and the steel ball, it will inevitably cause pits at the place where the raceway contacts the steel ball. These pits are the source of spalling, which develops rapidly and will soon make the bearings obsolete. Therefore, when installing the inner or outer ring with interference, force can only be applied to the end face of the installed inner or outer ring.
In addition, if IKO bearing is installed too tight, too loose or improperly adjusted, it will also cause early peeling of the bearing.Solution and principle of IKO high temperature bearing noise
When the worn bearing works, the main movement between the rolling element and the raceway is rolling and rarely sliding. Therefore, under normal circumstances, the wear of bearing parts is not serious. However, when impurities invade or poor lubrication, the wear will accelerate rapidly.Solution and principle of IKO high temperature bearing noise
Impurities invade the impurity particles (sand, dirt, etc.) mixed in the lubricating oil invade the bearing, and abrasive wear will occur on the raceway and rolling element. In this case, no peeling of metal can be seen, but uneven scratches can be seen on the working surface. Due to abrasive wear, the clearance between the inner or outer ring and the rolling element increases significantly, the raceway loses luster and uneven scratches appear.Solution and principle of IKO high temperature bearing noise
The lubricating oil is insufficient or deteriorated. When the lubricating oil is insufficient or deteriorated, the lubrication of plastic bearings cannot be guaranteed. In this case, serious consequences will be caused. Since the heat generated in the working of the bearing can not be taken away by the lubricating oil, IKO bearing will lose its original mechanical properties due to overheating, and the hardness will be greatly reduced. Therefore, the wear is extremely rapid, which destroys the normal operation of the bearing.Solution and principle of IKO high temperature bearing noise
Improper use it should be pointed out that the severe wear of IKO bearing is mainly caused by improper use. Therefore, in the use of bearings, the reliability of the installation of bearing sealing device should be ensured, and the working condition and lubrication condition of bearings should be systematically monitored to ensure that the bearings work in a good lubrication state.
There are two kinds of bearing rupture: one is the rupture caused by fatigue, and the other is the rupture caused by improper installation.
The bearing parts bear great alternating load due to fatigue. Due to the material defect of plastic bearing or other reasons, the stress concentration occurs in a certain part of the bearing.
When the stress is greater than the strength limit, there will be small cracks. The continuous action of alternating load and the action of oil wedge of lubricating oil cause the crack to expand continuously. When the crack expands to a certain extent, it will break.
The more common cause of bearing rupture caused by man-made is man-made. For example, hard knocking during disassembly and assembly and hard particle impurities invading the interior of the bearing may cause the inner and outer rings and cages to crack.
The clearance adjustment of tapered roller bearing is too tight, which usually breaks at the big end of tapered roller; If the clearance is adjusted too much, it usually breaks at the small end of the conical roller.
Corrosion forms dark black spots and ulcers on the surface of bearing parts. The main causes of corrosion are:
Moisture or moisture is immersed inside the bearing.
The use of lubricants with poor properties can also cause corrosion.
Another kind of corrosion is called contact corrosion, which mainly occurs on the contact surface between the non rotating inner and outer rings and the rolling element.
Other injuries in addition to the above injuries, there are other injuries.
Spark melting: for example, the current passes through IKO bearing. At the contact point between raceway and rolling element, the current passes through a very thin oil film to cause sparks, resulting in local surface melting and pits on raceway. These small pits gradually expand due to wear until the whole bearing is damaged.
Sliding, oxidation and grinding when the bearing does not rotate, it is vibrated by the nearby punch and air compressor or the protective measures are not good during transportation, resulting in relatively repeated small sliding between the rolling element and the inner or outer ring, causing some small particles to fall off from the surface.
Once oxidized, these small particles can become abrasives and accelerate the wear of the contact surface. Increase the bearing noise and affect the normal operation of the equipment.
Unreasonable design and unreasonable design structure cause bearing damage; If the outer ring is fastened with set screw on the bearing seat or the groove is ground on the bearing, it will cause local stress concentration and fracture the raceway.
The cage is damaged. The bearing cannot be used due to wear, breakage and fracture of the cage.
Residual magnetism adsorption: the residual magnetism causes the adsorption of metal debris, which makes the shaft suffer damage, etc.
Bearing maintenance
In order to maintain the original performance of the bearing in good condition for as long as possible, it is necessary to maintain and repair in order to prevent accidents, ensure the reliability of operation and improve productivity and economy. Maintain the operation standard of corresponding mechanical operation conditions and carry out it regularly. The contents include monitoring the operation status, replenishing or changing the lubricant, and regular disassembly inspection. As maintenance items in operation, there are bearing rotation sound, vibration, temperature, lubricant state, etc.
Maintenance of bearing
Bearing cleaning: when disassembling the lower bearing for maintenance, first record the appearance of the bearing, confirm the residual amount of lubricant, and wash the bearing after sampling the lubricant for inspection. As a cleaning agent, gasoline and kerosene are commonly used. The cleaning of the removed bearing is divided into coarse cleaning and fine cleaning. They are placed in the container respectively.
First, put the metal mesh bottom so that the bearing does not directly contact the dirt of the container. During rough cleaning, if the bearing rotates with dirt, it will damage the rolling surface of the bearing, which should be paid attention to. In the coarse cleaning oil, use a brush to remove the grease and adhesion. After it is roughly clean, turn to fine cleaning. Fine cleaning is to carefully clean the bearing while rotating in the cleaning oil. In addition, the cleaning oil should always be kept clean.
Maintenance and judgment of bearing: in order to judge whether the disassembled IKO bearing can be used, it shall be checked after the bearing is cleaned. Check the state of raceway surface, rolling surface and mating surface, the wear of cage, the increase of bearing clearance and the damage of irrelevant dimensional accuracy, which are abnormal.
For non separable small ball bearings, support the inner ring horizontally with one hand and rotate the outer ring to confirm whether it is smooth. Tapered roller bearings and other separable bearings can inspect the raceway surfaces of rolling elements and outer rings respectively.
Since large bearings cannot be rotated by hand, pay attention to the appearance of rolling elements, raceway surfaces, cages, edge retaining surfaces, etc. the higher the importance of bearings, the more careful the inspection is.
Chat with us
Chat with us
Questions, doubts, issues? We're here to help you!
