Fault inspection of NTN imported bearing in operation
Fault inspection of NTN imported bearing in operation
2022-04-20
Influence of common IKO bearing damage state
Influence of common IKO bearing damage state
2022-04-20

Treatment of vibration excitation of Koyo bearing

  • Rolling bearings use a variety of mechanical equipment, Timken bearings are required by the increasingly stringent market conditions, equipment and other properties, and the performance is also increasingly diversified. In order to select suitable bearings from a large number of structures and sizes, different angles are required.Treatment of vibration excitation of Koyo bearing
  •  In the selection of bearings, it is generally believed that as a bearing, the difficulty arrangement of installation and removal, bearing, size and bearing market, etc. space allows, the bearing structure is generally determined. Treatment of vibration excitation of Koyo bearing
  • The design life of various machines and various durable bearings limit the comparative study of bearings, and determine the bearing size at the same time. In choosing bearings, bearings tend to think that the grease life, fatigue life, wear resistance and low noise also need to be fully studied.Treatment of vibration excitation of Koyo bearing
  • In addition, according to different uses, it is necessary to select specially designed bearings with requirements on accuracy, clearance, cage structure, grease and so on. However, there is no certain order and rules for the selection of Timken bearings. Priority should be given to the conditions, performance and related matters required by the bearings, especially practical.Treatment of vibration excitation of Koyo bearing
  •  As long as the bearings in order to maintain the original performance as intact as possible, they should be maintained and maintained in the first place, so as to prevent accidents, ensure the reliability of operation, improve productivity and economy. Corresponding mechanical operation and maintenance operation standards, regular operation and maintenance conditions. Treatment of vibration excitation of Koyo bearing
  • This includes monitoring the operation status, replenishing or changing lubricants, and regular inspection and removal. As a problem of maintenance operation, bearing rotation sound, vibration, temperature, lubrication conditions, etc.Treatment of vibration excitation of Koyo bearing
  • Bearing cleaning: remove the bearing for repair, record the appearance of the bearing for the first time, confirm the remaining amount of lubricant, and clean the bearing with the lubricant used after sampling inspection. As a cleaning agent, gasoline and kerosene are generally used. Treatment of vibration excitation of Koyo bearing
  • Remove the bearing for cleaning, cleaning and fine washing, and place it in the container. Put the metal mesh bottom of the container so that it does not directly contact the dirt of the bearing.Treatment of vibration excitation of Koyo bearing
  •  Rough washing, if the bearing rotates dirt and damages the bearing rolling surface, attention should be paid to it. In crude oil cleaning, brush with a brush to remove grease, viscous materials, general cleaning and washing into a fine. Fine washing is to wash the oil carefully while rotating the bearing on one side. In addition, the cleaning oil must be kept clean
  • Maintenance and judgment of Timken bearing: determine whether it can be used to check the bearing after cleaning and remove the bearing. Check the raceway, raceway, surface condition, cage wear, bearing clearance and improvement of dimensional accuracy, irrelevant damage and abnormality. Non separable small ball bearing, inner ring, support level with one hand, rotate the outer ring to confirm smooth.Treatment of vibration excitation of Koyo bearing
  •  Tapered roller bearings, such as separable bearings, can roll the body, and the outer race raceway surface has been inspected. For large bearings, because they cannot rotate by hand, pay attention to check the raceway, cage and wall of the rolling element, such as appearance. For the importance of higher bearings, they should be checked more carefully.Treatment of vibration excitation of Koyo bearing
  • When inspecting the rivet head, the main observation is whether there is a relationship between skew and loose welding position is incorrect. Welding quality. Whether the welding point is too small, whether there is welding or welding, the problem caused by solid ball card. Bearing testing requires special attention in the process. There are also some problems that need attention.Treatment of vibration excitation of Koyo bearing
  • Let’s share with you the experience of many years in the local bearing inspection. Timken bearing’s secondary inspection of the environment should be in the light environment, which is astigmatism, so as to better observe the appearance of the bearing on the surface and be free of cracks and other abnormalities. In the process of cloud like mechanical wear, scratches and touch pressure, the bearing equipment will lead to displacement, poor equipment position, flat bearing shape, load and stress concentration, and reduce accuracy and service life.Treatment of vibration excitation of Koyo bearing
  • In addition to paying special attention to the pollutants in the working environment or water, which may lead to bearing rust, rust is to lead to bad Timken bearing installation, early wear will lead to more serious waste. Therefore, special attention should be paid to the moisture in water, of course. Bearing raceway sound and its control method raceway sound is a smooth and continuous sound made by the rolling body rolling on the raceway surface when the imported bearing is running. Treatment of vibration excitation of Koyo bearing
  • 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. Its main frequency does not change with the speed, but its total sound pressure level increases with the speed. Treatment of vibration excitation of Koyo bearing
  • 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.Treatment of vibration excitation of Koyo bearing
  •  The greater the rigidity of the bearing pedestal, the lower the total sound pressure level of the raceway sound. If the radial clearance is too small, the total sound pressure level and dominant frequency of raceway sound will increase sharply with the decrease of radial clearance. Treatment of vibration excitation of Koyo bearing
  • The methods to control the sound of raceway are: select low-noise bearings, that is, bearings with small waviness, and carefully select the service conditions. Raceway noise often affects the noise of the whole machinery. Reducing raceway noise can reduce the noise of the whole machinery.Treatment of vibration excitation of Koyo bearing
  • Impact sound of rolling element and its control method when the ball bearing or cylindrical roller bearing of larger model runs at low speed under pure radial load, due to the small centrifugal force of the rolling element, the rolling element in the non load area will impact the cage or raceway and make noise. But as the speed increases, the sound will disappear. The control methods of impact sound of rolling elements are: appropriately reduce the radial clearance, and use the bearing of cage with reasonable structure and flexible material.Treatment of vibration excitation of Koyo bearing
  • The rolling sound of imported bearings and its control method rolling sound is the harsh metal friction sound that can occur in cylindrical roller bearings on all occasions. Most of it occurs in larger types of grease lubricated bearings, which is more likely to occur in greases with degraded base oil performance, and almost does not occur in oil lubrication. In addition, it is easy to occur in winter.Treatment of vibration excitation of Koyo bearing
  •  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.Treatment of vibration excitation of Koyo bearing
  •  If necessary, this kind of bearing can be selected, or the radial clearance of the bearing can be appropriately reduced, the lubricating grease with excellent performance can be used and the rigidity of the parts matched with the bearing can be improved.Treatment of vibration excitation of Koyo bearing
  • Standard class (g) tolerance bearing;Treatment of vibration excitation of Koyo bearing
  • Radial bearing only bears radial load and thrust bearing only bears axial load;
  • 0.1C (C is the basic rated dynamic load of the bearing);Treatment of vibration excitation of Koyo bearing
  • Rigid bearing pedestal and shaft;Treatment of vibration excitation of Koyo bearing
  • The lubrication and cooling conditions are normal.Treatment of vibration excitation of Koyo bearing
  • When the imported bearing operates under the load of 0.1C, the contact stress between the rolling element and the contact surface of the raceway increases, resulting in the increase of the working temperature of the bearing and the relative deterioration of the performance of the lubricant. Therefore, the limit speed of the bearing will be reduced accordingly.Treatment of vibration excitation of Koyo bearing
  • For the range of c/=10, the limit speed reduction is very small, so it can not be considered, that is, f1=1.Treatment of vibration excitation of Koyo bearing
  • For the radial bearing under combined load, due to the increase of the number of rolling elements under load, the increase of friction resistance, the increase of calorific value, the deterioration of lubrication and cooling conditions, and the increase of force acting on the cage, the limit speed of the bearing must be multiplied by a reduction factor F2 according to the bearing type and load angle.Treatment of vibration excitation of Koyo bearing
  • If the limit speed of the selected imported bearing cannot meet the use requirements, some improvement technical measures can be adopted to improve it, so as to meet the more satisfactory requirements. Such as improving the bearing tolerance level; Appropriately increase the clearance; Change to special materials and improve the structure of cage; Treatment of vibration excitation of Koyo bearing
  • Change the lubrication mode, such as oil-gas, oil mist and jet lubrication; Improve cooling conditions, etc. Regular maintenance of mechanical equipment is very important for production. As a precision accessory of mechanical equipment, the regular inspection of SKF imported bearings is particularly critical. Here is the necessity and key steps of bearing regular inspection.Treatment of vibration excitation of Koyo bearing
  • It is important to keep the bearings and lubrication clean
  • Before inspection, clean the surface of the machine, and then remove the parts around the SKF inlet bearing. The oil seal is a very fragile part, so it needs to be disassembled carefully. Do not apply excessive force, and then carefully check the oil seal and its surrounding parts. If there are bad symptoms, be sure to replace it. The bad oil seal will lead to bearing damage and strict equipment shutdown.
  • Check the lubricant of the bearing
  • Rub a little lubricant between your fingers. If there are pollutants, you can feel it, or apply a layer of lubricant on the back of your hand, and then seal it for light inspection.
Treatment of vibration excitation of Koyo bearing

Treatment of vibration excitation of Koyo bearing

  • After draining out the old oil, if possible, refill fresh oil into the oil lubricated bearing and let the machine rotate at low speed for a few minutes. Make the engine oil collect residual pollutants as much as possible, and then drain the engine oil. The engine oil is filtered before use.Treatment of vibration excitation of Koyo bearing
  • For grease lubricated bearings, the arbor used when replacing grease should avoid connecting the angle of cotton to any part of the bearing, because these residual fibers may wedge between the rolling parts and cause damage, especially for the application of small bearings.Treatment of vibration excitation of Koyo bearing
  • Cover exposed bearings
  • When inspecting bearings, never expose SKF imported bearings to pollutants or moisture. If the work is interrupted, the machine shall be covered with oil paper, plastic sheet or similar materials.Treatment of vibration excitation of Koyo bearing
  • If it is possible to clean the naked bearing without disassembly, clean it with a brush coated with white spirit, and then dry it with a piece of lint free cloth or blow dry with compressed air (be careful not to start the rotation of the bearing assembly). For example, the noise of centripetal ball bearing is lower than that of short cylindrical roller bearing, and the noise of short cylindrical roller bearing is lower than that of tapered roller bearing.Treatment of vibration excitation of Koyo bearing
  • During the operation of the rolling bearing, it bears a certain load, even static load, but for the steel ball and raceway, its stress is cyclic, and the material will have rolling fatigue, so as to make the imported bearing reach its service life. The phenomenon is that a part of the rolling surface material suddenly falls off like a fish scale. This phenomenon is called fatigue flaking.Treatment of vibration excitation of Koyo bearing
  • For the bearing of household appliances, the load borne by the bearing is very small and the service life of the bearing is very long. However, after the shaft rotates for a period of time, it will also produce wear, increased vibration and noise, deterioration of lubricating grease, etc. Treatment of vibration excitation of Koyo bearing
  • Due to the strict requirements on the bearing noise of household appliances, when the bearing noise exceeds the allowable range, it is considered that SKF Bearing can no longer be used. The total time of bearing low noise operation is called bearing noise life.Treatment of vibration excitation of Koyo bearing
  • The bearings of household appliances are usually grease lubricated sealed bearings without maintenance. Although only a small amount of lubricant is needed for bearing lubrication, the bearing lubrication is poor due to the deterioration and leakage of grease after a long time of operation, resulting in bearing failure. The total operation time of SKF Bearing under good lubrication is called bearing life.Treatment of vibration excitation of Koyo bearing
  •  In general, Koyo bearing, as a world bearing, will not be excited, but if it is excited, you must check the situation well. Let’s explain the truth of the excitation. Vibration excitation may occur when the bearing is partially damaged. A small number of bearing raceways and rolling elements may be damaged due to incorrect operation or installation. During operation, rolling over damaged bearing parts will produce specific vibration frequency. Vibration frequency analysis can identify damaged bearing components.Treatment of vibration excitation of Koyo bearing
  • Vibration excitation may occur when the waviness of Koyo bearing is not necessarily deformed. In the case of close fit between the bearing ring and the bearing seat or transmission shaft, the bearing ring may be deformed by matching with the shape of adjacent components. If deformation occurs, vibration may occur during operation. Therefore, it is important to machine the bearing pedestal and drive shaft to the required tolerances.Treatment of vibration excitation of Koyo bearing
  • In addition, the excitation behavior will also occur in applications. In many applications, the stiffness of the bearing is the same as that of the surrounding structure. Because of this feature, as long as the bearing (including preload and clearance) and its configuration in the application are correctly selected, it is possible to reduce the vibration in the application.Treatment of vibration excitation of Koyo bearing
  • There is also the excitation generated when the number of loaded rolls changes. When a radial load is loaded on a bearing, the number of rolling elements bearing the load will change slightly during operation, that is, this causes the deviation of the load direction. The resulting vibration is inevitable, but can be reduced by axial preloading, which is applied to all rolling elements (not applicable to cylindrical roller bearings). Treatment of vibration excitation of Koyo bearing
  • Let’s introduce three small methods that can reduce the vibration of Koyo bearing. Change the stiffness of the structure, so as to change the critical frequency. Critical excitation vibration is removed from the application. Suppress the critical excitation vibration between the excitation part and the resonance part.Treatment of vibration excitation of Koyo bearing
  • The selection of specifications, dimensions and accuracy according to the service parts, service conditions and environmental conditions, and matching with appropriate Koyo bearings are the premise to ensure the service life and feasibility of bearings.Treatment of vibration excitation of Koyo bearing
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