INA Bearing Jacket and seal cover have large clearance, grease overflow, discoloration, bearing outward movement, crack damage, corrosion, etc. Once the appearance fault features are found during the inspection, it is necessary to make careful judgment and determine the exact location of the fault. Inspection and analysis of damage causes of ina joint bearing
If the clearance between the outer ring at the shaft end and the two sealing covers is too large, and it is found that the clearance between the front and rear ends of the bearing outer ring and the sealing cover is too large, and there is more grease overflow, the outer ring of the spherical plain bearing is cracked. Inspection and analysis of damage causes of ina joint bearing
Inspection and analysis of damage causes of ina joint bearing
Excessive stripping load: check the size of the load. Correct load conditions. Poor installation (non-linearity) check the size of the load and re study the ina bearing used. Correct load conditions.Inspection and analysis of damage causes of ina joint bearing
Moment load foreign matter intrusion and water inflow: improve the sealing device and prevent rust during shutdown. Improve the surface finish of paired rolling parts. There are many small cracks on the surface with slight peeling, and there are many small cracks (5-10m deep) on the installation surface. Improve the sealing device.
Poor lubrication and inappropriate lubricant: use lubricant with appropriate viscosity and improve lubrication method. The surface finish of paired rolling parts is not good. Foreign matter has entered the lubricant. Select the appropriate lubricant.
Improper bearing clearance. Poor accuracy of bearing housing and uneven rigidity of bearing housing: check the accuracy of shaft and bearing housing. Check the play.Inspection and analysis of damage causes of ina joint bearing
The deflection of the shaft is large, rust, erosion point, scratch and indentation. Check the accuracy of the shaft and bearing housing. When the plain bearing rotates under load, the raceway surface or rolling surface of the inner ring and outer ring presents fish scale peeling phenomenon due to rolling fatigue. Inspection and analysis of damage causes of ina joint bearing
The so-called card injury is the surface damage caused by the collection of minor burns in the part of the sliding surface injury. Poor lubricant causes rough surface. Peeling lubricant is not suitable. Improve lubricants and lubrication methods.
INA Bearing Grease is usually expressed by apparent viscosity or similar viscosity. When describing the viscosity of grease, the temperature and shear speed must be indicated. Similar viscosity indexes can be used to control its low-temperature fluidity and pumpability.Inspection and analysis of damage causes of ina joint bearing
One of the important indicators to measure the low-temperature performance of bearing grease is the low-temperature torque, that is, the degree to which the grease blocks the rotation of low-speed flow joint bearing at low temperature (- below 20 ° C). The Low-Temperature Torque of grease is expressed by the average value of starting torque and torque after rotating for 60mm.Inspection and analysis of damage causes of ina joint bearing
The evaporation (degree) of INA Bearing Grease indicates the degree of volatilization of grease oil when the grease is used for a long time under high temperature conditions. The smaller the evaporation, the better. The evaporation of grease mainly depends on the properties and fraction composition of lubricating oil.
The inner diameter dimension and outer diameter dimension of INA Bearing are manufactured according to the standard tolerance. The fit tightness of bearing inner ring and shaft, outer ring and seat hole can only be realized by controlling the tolerance of journal and seat hole. The matching of bearing inner ring and shaft adopts base hole system, and the matching of bearing outer ring and seat hole adopts machine shaft system.Inspection and analysis of damage causes of ina joint bearin
Keep INA Bearing and its surrounding environment clean
Even if the dust invisible to the naked eye enters the bearing, it will wear the linear bearing. To put it bluntly, you can’t rub any sand in your eyes. It’s a truth!
Second, careful and accurate installation shall be carried out during use and installation
It is important not to press with force, not to knock the bearing directly with a hammer, and not to transfer pressure through the body.Inspection and analysis of damage causes of ina joint bearing
Third, use appropriate and accurate installation tools
Try to use special tools and try to avoid using things such as cloth and short fiber.
Fourth, prevent the corrosion of INA Bearing and do not use blisters
The bearing is made of refined steel, but it is also afraid of water. When taking the linear bearing by hand, fully wash the sweat from your hands and apply high-quality mineral oil before operation. Pay special attention to rust prevention in rainy season and summer,Inspection and analysis of damage causes of ina joint bearing
To correctly select the fit, we must know the actual load conditions, working temperature and other requirements of linear bearing, which is actually very difficult. Therefore, in most cases, the matching is selected according to the use of fine grinding.Inspection and analysis of damage causes of ina joint bearing
Size limitations. Generally, the space where ina bearings can be installed is limited. In most cases, the shaft diameter (or bearing inner diameter) is limited by mechanical design or other design. Therefore, the selection of bearing type and size is determined according to the inner diameter of universal joint bearing. Therefore, the main dimension tables of standard bearings are compiled according to the inner diameter dimensions of international standards.Inspection and analysis of damage causes of ina joint bearing
There are many sizes and forms of scale bearings. Scale bearings are used in the design of mechanical devices. The nature, size and direction of the load of bearings and the load imposed on bearings are changeable. In general, the rated base load is shown on the dimension table. Inspection and analysis of damage causes of ina joint bearing
However, axial load and radial load are also important factors in selecting suitable bearings. When the size of the ball and needle roller bearing is commensurate, the needle roller bearing usually has high load capacity and bears large vibration and impact load.Inspection and analysis of damage causes of ina joint bearing
The speed and allowable speed are determined according to the type, size, accuracy, cage type, load, lubrication mode, cooling mode and other factors of INA Bearing. The table of universal joint bearing lists the allowable speed of scale precision bearing under oil lubrication and grease lubrication.Inspection and analysis of damage causes of ina joint bearing
In general, deep groove ball bearings, self-aligning ball bearings and cylindrical roller bearings are all suitable for high-speed operation.Inspection and analysis of damage causes of ina joint bearing.Inspection and analysis of damage causes of ina joint bearing
Mix the engine oil to be checked and drop it on the white paper (filter paper) to form oil spots. The oil spots gradually diffuse from the center to the outside for about 2 ~ 3 hours to form three concentric rings. According to the color, width and shape of these three areas, the state of oil can be identified.Inspection and analysis of damage causes of ina joint bearing
Take out a little oil from the low oil shell, apply it to your fingers and twist it with your fingers and thumb. If you feel impurities in the oil or no viscosity like water, even astringent or sour, the oil has deteriorated.
If you can see small shiny metal grinding on your fingers after twisting, it indicates that there are serious wear parts of the engine, and it also indicates that the oil must be replaced immediately.Inspection and analysis of damage causes of ina joint bearing
Selection of bearing model: the bearing model is generally selected by the user’s technicians according to the service conditions and load of supporting products. Business personnel mainly know whether the actual load of the user is consistent with the selected bearing. Inspection and analysis of damage causes of ina joint bearing
If the combined bearing fails to meet the use requirements, they should advise the customer to change the model as soon as possible, but there will be no problem in selecting the model unless special products.Inspection and analysis of damage causes of ina joint bearing.Inspection and analysis of damage causes of ina joint bearing
Selection of bearing clearance: when purchasing bearings, users generally only tell what model and grade they are in, and rarely put forward requirements for bearing clearance. Business personnel must ask about the service conditions of bearings, including the speed, temperature and fit tolerance of combined bearings, which are directly related to the selection of bearing clearance.
Generally, CM clearance is adopted for motors with speed below 3500 rpm. For example, relatively large clearance is required for high-temperature and high-speed motors. After assembly, the bearing clearance will be reduced due to the increase of inner hole and the reduction of outer circle.
The reduction of clearance = interference × 60% (unless the bearing housing is aluminum). For example, the clearance before and after assembly is 0.014mm. Theoretically, the noise and service life of the bearing reach the state of zero clearance, but considering the problems such as temperature rise in actual operation, the clearance of the bearing after assembly is 0.002mm-0.004mm.
Selection of grease: the selection of grease is generally based on the speed, temperature resistance, noise requirements and starting torque of the combined bearing. The business personnel are required to understand the performance of various grease.
Selection of bearing sealing type: bearing lubrication can be divided into oil lubrication and grease lubrication. Oil lubricated bearings are generally bearings, and grease lubricated bearings are generally sealed with dust covers or rubber seals. The dust cover is suitable for parts with high temperature or good service environment.
The seals are divided into contact seal and non-contact seal. The contact seal has good dust-proof performance but large starting torque, and the non-contact seal has small starting torque, but the sealing performance is not as good as the contact seal.
If there are bruises, rust layers, grinding debris, sand particles, dust and soil on the assembly surface of the bearing and the surface of the matched parts, it is difficult to install the bearing, resulting in the incorrect assembly position; Second, these attachments form the working surface of abrasive and easy to wear composite bearing, which affects the assembly quality.
Therefore, before installation, carefully inspect the surface of journal, bearing housing hole, shoulder end face and the mating surface of connecting parts such as bushing, washer and end cover. If there is any rust layer, file it off with a fine file and polish it with a fine abrasive cloth. At the same time, remove the attachments on the bearing assembly surface and its connecting parts.
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