Technical analysis of engine sliding Koyo bearing
Technical analysis of engine sliding Koyo bearing
2022年5月14日
Difference between dynamic load rating and static load rating of SKF Bearing
Difference between dynamic load rating and static load rating of SKF Bearing
2022年5月15日

The higher the importance of INA Bearing

Fat cup method importance of INA Bearing

  • There are four main methods for injecting lubricating grease into Koyo bearings, which are grease cup method, coating method, grease gun method and centralized grease feeding method.
  • Open a small hole next to the Koyo bearing to the grease cup, and the grease in the cup will continuously supplement the bearing. 
  • The grease overflow valve shall be set for the high-speed bearing to throw out the excessive grease in the bearing through the centrifugal force during bearing rotation, so as to reduce the friction of the bearing and the temperature rise caused by high-speed rotation.

 smear method  importance of INA Bearing

  • Special tools shall be used when applying, and bare hands are not allowed. The grease amount shall meet the above requirements, and the lubricating grease shall cover all bearing surfaces that need to be lubricated. After the grease has been used for a certain period of time, it needs to be changed or supplemented.

  grease gun method  importance of INA Bearing

  • The grease gun is used to drive the grease into the bearing through the greasing hole through pressure. This method is mostly used to supplement the grease.

 concentrated fat feeding method INA Bearing

  • The grease is uniformly transported to the parts of each Koyo bearing by the pump through the pipeline. The flow route of the newly added grease shall be able to squeeze out the old grease, so as to supplement the new grease into each lubrication point.
  • The fit clearance between Koyo bearing and shaft must be appropriate to make the service life of Koyo bearing longer. The radial clearance of Koyo bearing can be detected by the following methods:The higher the importance of INA Bearing
  •   Race rule detection method
  • For Koyo bearings with large diameter, the clearance is large, so it is proposed to use a narrow feeler gauge for direct detection. For Koyo bearing with small diameter, the clearance is small, which is convenient to measure with feeler gauge, but the side clearance of Koyo bearing must be measured with feeler gauge with appropriate thickness.
  • Using lead pressure method to detect the clearance of Koyo bearing is more accurate than using feeler gauge, but it is more troublesome. The aluminum wire used for testing should be soft and moderate in diameter.
  •  It should not be too large or too small. The ideal diameter is 1.5 ~ 2 times of the gap. In practical work, soft lead wire is usually used for testing.
  • During the inspection, first open the Koyo bearing cover, select the lead wire with appropriate diameter, cut it into small sections with a length of 15 ~ 40mm, put it on the journal and the interface between the upper and lower Koyo bearings.
  • cover the Koyo bearing cover, tighten the fixing bolts according to the specified torque, then loosen the bolts, remove the Koyo bearing cover, use a micrometer to detect the thickness of the flattened lead wire, and calculate the average value of the top clearance of the Koyo bearing.
  • If the top clearance is too small, a pad can be added on the joint surface of the upper and lower tiles. If it is too large, the pad shall be reduced, scraped or the tile shall be poured again.
  • Adjustment of bearing bush tightening force: in order to prevent the possible rotation and axial movement of the bearing bush in the working process, in addition to matching the interference and stop parts, the bearing bush must also be compressed with Koyo bearing cover.
  •  The measurement method is the same as the top clearance measurement method. In addition to measuring the thickness of soft lead wire, the bearing bush tightening force can be calculated.
  • Generally, the pressing force of bearing bush is 0.02 ~ 0.04 mm. If the pressing force does not meet the standard, it can be adjusted by increasing or decreasing the thickness of the gasket at the joint surface of Koyo bearing and Koyo bearing seat, and the pad back is not allowed to be padded.
  • In addition to radial clearance, sliding Koyo bearing should also ensure axial clearance. When detecting the axial clearance, move the shaft to an extreme position, and then measure the displacement of the shaft from one extreme position to another with a feeler gauge or dial indicator, that is, the axial clearance. 
  • When the clearance of sliding Koyo bearing does not meet the requirements, it shall be adjusted. Split Koyo bearings often use gaskets to adjust the radial clearance.
The higher the importance of INA Bearing

Lead pressure detection method importance of INA Bearing

  • consolidate with the stationary part (usually NTN bearing seat) and rotating part (usually shaft) of the installation part respectively, so as to realize the basic task of transmitting load in the rotating state and limiting the position of the moving system relative to the stationary system. The higher the importance of INA Bearing
  • On the shaft and in the NTN bearing seat, the rolling NTN bearing is required to fix its position in three directions: radial, axial and tangent directions. Radial and tangential positioning is realized through tight fit of NTN bearing ring, and tight fit is adopted for axial positioning only in a few cases; Generally, axial limit parts, such as end caps and retaining rings, are used to limit the axial position within the clearance range.
  • Ina bearing is magnetized, that is, INA Bearing has residual magnetism. The residual magnetism of INA Bearing has a great influence on the service life of INA Bearing. INA Bearing with residual magnetic flux is not easy to clean the metal powder remaining on the working surface of INA Bearing, and even the iron powder produced in the operation of some equipment can be adsorbed on the working surface of INA Bearing, which will accelerate the wear of INA Bearing and reduce the service life of INA Bearing.
  • The reason for the residual magnetism of ina bearing is that with the continuous innovation of INA Bearing processing technology, the magnetic clamping process has been widely used for INA Bearing parts, such as the welding and electric riveting process of electromagnetic centerless fixture and cage, which will produce a magnetic field for ina bearing or other parts. 
  • Although the parts are demagnetized after processing, there may be missing demagnetization or residual magnetism due to improper demagnetization operation. INA Bearing shall be demagnetized before assembly and finished product demagnetization after assembly. 
  • The residual magnetic intensity of INA Bearing shall be less than the standard specified in the finished product inspection of INA Bearing.
  • The finished ina bearing is generally far away from the magnetic field and is rarely magnetized. If the ina bearing is stored in an inappropriate position before installation and is magnetized in contact with other magnetic products, or when the product is in use due to the passage of current inside the INA Bearing, the INA Bearing may be magnetized or damaged by electric corrosion. High speed, overload and insufficient lubrication will not magnetize the INA Bearing, but will make the working surface of the INA Bearing excessively tired and fail.

The matching function of NTN bearing is to make the stationary ring and rotating ring of importance of INA Bearing

 
  •   Damage and crack: the fag bearing is improperly installed and disassembled. There are no necessary tools and auxiliary tools in the installation process of fag bearing. Directly knock the fag bearing with tools such as hammer. Excessive force or uneven knocking force will cause cracks or damage to the end face, retaining edge and other parts of fag bearing.
  •   Fatigue crack: the Journal of fag bearing during installation has poor contact with the inner hole of fag bearing, FAG bearing seat and the outer cylindrical surface of fag bearing, and the contact of the stressed parts of raceway is uneven, resulting in cracks in fag bearing ring or rolling element.
  •   Hard brittle crack; This kind of crack is caused by the poor quality of fag bearing in the manufacturing process or the internal defects of the material and the high hardness of heat treatment.
  •   Vibration crack: crack caused by large impact load of fag bearing in use. The ferrule and rolling element of rolling fag bearing are generally made of high carbon chromium fag bearing steel. The hardness of ferrule and rolling element is high. Although they can bear large impact load, excessive impact load will cause severe vibration of fag bearing during operation, resulting in damage and crack of fag bearing.
  • The main reasons for fag bearing metal peeling are as follows:
  •  The axial matching step surfaces of the inner and outer rings of fag bearing are not vertical, the rotating shaft is bent, and the inner holes of fag bearing are not concentric, which leads to the installation deflection of the inner and outer rings of fag bearing, which makes the raceway of fag bearing bear excessive load and leads to metal peeling.
  •   Fag bearing bears impact force and alternating load, which is easy to cause fatigue spalling on the surface of raceway and rolling element. The repeated change of contact stress on the surface of rolling element will also cause metal fatigue, pitting and fine peeling on the surface of rolling element. This kind of spalling starts from very small, and then dents will appear and gradually expand, showing large-area flake spalling.
  •   Iron filings or hard sundries fall between the fag bearing inner ring and the shaft or between the outer ring and the mating surface of the seat hole, causing the deformation of the raceway during fag bearing installation, making the local load on the raceway of fag bearing too heavy, resulting in metal peeling.
  • NSK bearing fit
  •   Choice of cooperation
  • The inner diameter and outer diameter of rolling NSK Bearings are manufactured according to standard tolerances. The tightness of the fit between the inner ring and the shaft, the outer ring and the seat hole of NSK Bearings can only be achieved by controlling the tolerance of the journal and the seat hole. The matching of NSK bearing inner ring and shaft adopts the base hole system, and the matching of NSK bearing outer ring and seat hole adopts the base shaft system.
  • To correctly select the fit, we must know the actual load conditions, working temperature and other requirements of NSK bearing, which is actually very difficult. Therefore, in most cases, the matching is selected according to the use of fine grinding.
  •  Load size
  • The win-win amount between the ferrule and the shaft or shell depends on the size of the load. The heavier load adopts the larger win-win amount, and the lighter load adopts the smaller win-win amount
  • Precautions for use
  • Rolling NSK bearing is a precision part, so it is required to be cautious in use. Even if high-performance NSK bearing is used, if it is not used properly, it can not achieve the expected performance effect. Therefore, pay attention to the following matters when using NSK bearing:
  •   Keep NSK Bearings and their surroundings clean. Even if very small dust enters the NSK bearing, it will aggravate the wear, vibration and noise of NSK bearing.
  •   The installation shall be careful. It is not allowed to press strongly, directly knock NSK bearing and transfer pressure through rolling element.
  •    Use the correct installation tools, use special tools as much as possible, and try to avoid using things such as cloth and short fiber.
  •    To prevent the corrosion and rust of NSK Bearings, do not directly hold NSK Bearings by hand. Apply high-quality mineral oil before operation. Pay special attention to rust prevention in rainy season and summer.

  Choice of cooperation  importance of INA Bearing

  • The dimensions of rolling NSK Bearings are manufactured according to standard tolerances. The fit tightness of NSK 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 NSK bearing inner ring and shaft adopts the base hole system, and the matching of NSK bearing outer ring and seat hole adopts the base shaft system.
  • To correctly select the fit, we must know the actual load conditions, working temperature and other requirements of NSK bearing, which is actually very difficult. Therefore, in most cases, the matching is selected according to the use of fine grinding.
  •   Load size
  • The win-win amount between the ferrule and the shaft or shell depends on the load. The heavier load adopts the larger win-win amount, and the lighter load adopts the smaller win-win amount.
  • Rolling NSK Bearings are precision parts, so it is required to be cautious when using them. High performance NSK Bearings are used. If they are not used properly, they can not achieve the expected performance effect. Therefore, the following matters should be paid attention to when using NSK Bearings:
  •   Keep NSK Bearings and their surroundings clean. Even if the invisible smile dust enters the NSK bearing, it will increase the wear, vibration and noise of the NSK bearing.
  •   Use and install carefully. It is not allowed to punch with force, directly knock NSK bearing with hammer and transfer pressure through rolling body.
  •   Use proper and accurate installation tools, try to use special tools, and try to avoid using cloth and short fiber.
  •   Prevent the corrosion of NSK Bearings. When taking NSK Bearings directly 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.

The main causes of cracks on follows:importance of INA Bearing

  • Cleaning of INA Bearing: when disassembling INA Bearing for maintenance, first record the appearance of INA Bearing, confirm the residual amount of lubricant, and clean ina bearing after sampling the lubricant for inspection. As a cleaning agent, gasoline and kerosene are commonly used. 
  • The cleaning of the removed ina bearing is divided into coarse cleaning and fine cleaning, which are placed in the container respectively. 
  • First, put the metal mesh bottom so that the INA Bearing does not directly contact the dirt of the container. During rough cleaning, if ina bearing rotates with dirt, it will damage the rolling surface of INA 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 ina bearing while rotating in cleaning oil. In addition, the cleaning oil should always be kept clean
  • Maintenance and judgment of INA Bearing: in order to judge whether the disassembled ina bearing can be used, it should be checked after the ina bearing is cleaned. 
  • Check the state of raceway surface, rolling surface and mating surface, the wear of cage, the increase of INA Bearing Clearance and the damage related to the decline of dimensional accuracy.The higher the importance of INA Bearing
  •  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 are separable bearings, and the raceway surfaces of rolling elements and outer rings can be inspected 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 ina bearings, the more careful the inspection is.
  • The market requirements for various mechanical devices and instruments using rolling bearings are becoming more and more strict, and the conditions and performance required for ina bearings are becoming more and more diversified. In order to select the suitable ina bearing from a large number of structures and sizes, it needs to be studied from various angles. 
  • When selecting ina bearings, generally, the ina bearing structure is roughly determined by considering the difficulty of arrangement, installation and disassembly of ina bearings as shaft system, the allowable space and size of ina bearings, and the marketability of ina bearings. 
  • Secondly, while comparing and studying the design life of various machines using ina bearings and various durability limits of ina bearings, the size of ina bearings is determined. When selecting ina bearings, it is often inclined to only consider the fatigue life of ina bearings.