Fault analysis of SKF imported bearing of cement machinery
Fault analysis of SKF imported bearing of cement machinery
2022年5月9日
How to identify NTN bearing quality
How to identify NTN bearing quality
2022年5月9日

Use and fit of SKF Bearing

Use and fit of SKF Bearing

  • Rolling SKF bearings make precision parts, so it is required to be cautious when using them. High performance SKF 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 SKF bearings:
  • Keep SKF bearings and their surroundings clean. Even if the invisible smile dust enters the SKF Bearing, it will increase the wear, vibration and noise of the SKF Bearing.
  • The use and installation shall be careful. It is not allowed to punch with force, directly knock the SKF Bearing with a hammer, and transfer pressure through the rolling element.
  • Use proper and accurate installation tools, try to use special tools, and try to avoid using cloth and short fiber.
  • Prevent the corrosion of SKF bearings. When taking SKF 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.

Fit of SKF Bearing fit of SKF Bearing

  • The inner diameter and outer diameter of the rolling SKF Bearing are manufactured according to the standard tolerance. The tightness of the fit between the inner ring and the shaft, the outer ring and the seat hole of the SKF Bearing can only be realized by controlling the tolerance of the journal and the seat hole. The fit between SKF Bearing inner ring and shaft adopts base hole system, and the fit between SKF Bearing Outer Ring and seat hole adopts machine shaft system.
  • To correctly select the fit, we must know the actual load conditions, working temperature and other requirements of SKF 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

Use and fit of SKF Bearing

  • Due to the large size and heavy weight of its components, and limited by various process conditions such as casting, forging, cutting and assembly, the working accuracy of the hydraulic press itself cannot be completely guaranteed by the machining itself, but must be adjusted in the assembly process to achieve its accuracy indicators.
  • The adjustment is carried out according to the specific requirements of Koyo bearing accuracy detection, and the maintenance and stability of accuracy depend on the relevant pre tightening and anti loosening means and measures. Use and fit of SKF Bearing
  • The hydraulic press used in all walks of life has different requirements for its working accuracy due to its different uses, and different industry standards are also used in production and manufacturing. In the same industry, due to different products, the required accuracy can not be consistent.
  •  Therefore, in the same industry standard, it is divided into several levels according to different working conditions, corresponding to each accuracy index. During the production of the factory, the technical department shall prepare the inspection outline and commissioning outline according to the accuracy standard of the production press, and issue them to relevant departments as guiding documents, which specify the detection methods and corresponding data of relevant items and parameters as the standards for installation, adjustment, inspection and acceptance.
  • Generally, it includes precision items that can be achieved only after adjustment in the process of assembling Koyo bearings. For example, in the hydraulic press, the levelness of the worktable, the deviation of column distance, the flatness of the worktable and movable worktable. Use and fit of SKF Bearing
  • The perpendicularity of the column and its connected upper and lower beams, the parallelism between the worktables, the perpendicularity of the main oil cylinder and the worktable within the working stroke, the contact rate of the internal and external nut joint surface between the column and the upper and lower beams, etc. fit of SKF Bearing
  • The process and results of Koyo bearing accuracy adjustment and testing can be passed only after being approved and signed by full-time personnel. The tools and tooling required in the process of detection and adjustment are designed by the corresponding professional process personnel during production and programmed into the production process according to the plan. Inspection outline and inspection adjustment operation are omitted.fit of SKF Bearing
Use and fit of SKF Bearing

Radial preloading method Use and fit of SKF Bearing

  • Ina bearings each have a certain rotation speed limit. When ina bearing rotates, as the rotation speed of INA Bearing accelerates, the temperature rise caused by the internal friction heat of INA Bearing also increases.Use and fit of SKF Bearing
  •  The rotation speed limit is the speed allowable value that can produce the experience of sintering, overheating and continuous operation. Therefore, the limit speed of various ina bearings varies according to the ina bearing structure, size, cage structure, material, ina bearing load, lubrication method, including the cooling around the INA Bearing.Use and fit of SKF Bearing
  • These aspects are the opposite of affecting and determining the speed of INA Bearing. The greater the limit speed, the greater the actual speed borne by INA Bearing and the higher the efficiency of mechanical equipment operation. fit of SKF Bearing
  • On the contrary, the lower it is. What’s more, when the speed of INA Bearing exceeds the limit speed, the heating leads to overheating, which is likely to lead to the sintering of INA Bearing, and the service life of ina bearing is over. Timken bearing preloading methods are divided into radial preloading method and axial preloading method, which are briefly introduced as follows:fit of SKF Bearing
  • Radial jacking method is mostly used in tapered hole Timken bearings bearing radial load. A typical example is double row precision short cylindrical roller Timken bearings. Nuts are used to adjust the axial position of this Timken bearing relative to the tapered journal to make the inner ring have appropriate expansion and obtain radial negative clearance. This method is mostly used in machine tool spindle and jet engine.fit of SKF Bearing
  • Axial preloading method
  • Axial preloading method can be divided into positioning preloading and constant pressure preloading.
  • In the positioning preload, the appropriate preload can be obtained by adjusting the size of bushing or gasket; The appropriate preload can also be adjusted by measuring or controlling the starting friction moment; You can also directly use the paired double Timken bearings with pre adjusted preload to achieve the purpose of preloading.fit of SKF Bearing
  •  At this time, it generally does not need to be adjusted by the user. In short, the relative position of Timken bearings with axial preload will not change during use.fit of SKF Bearing
  • Constant pressure preloading is a method to properly preload Timken bearing with coil spring, Belleville spring, etc. The rigidity of the preload spring is generally much smaller than that of the Timken bearing, so the relative position of the Timken bearing preloaded under constant pressure will change in use, but the preload is roughly the same.

Use and fit of SKF Bearing

 

  • Fag bearing configuration includes not only rolling fag bearing, but also components related to fag bearing, such as shaft and fag bearing seat. Lubricant is also a very important part of fag bearing configuration, because lubricant should be anti-wear and anti-corrosion, so that fag bearing can play its full role.fit of SKF Bearing
  •  In addition, the seal is also a very important component. The performance of the seal is very important for the cleaning of the lubricant. Keeping clean has a profound impact on the service life of fag bearings, which is why lubricants and seals have become part of the business.fit of SKF Bearing
  • Each individual decision will affect the performance, reliability and economy of fag bearing configuration. The amount of work required depends on whether you have similar fag bearing matching experience. In case of lack of experience, special requirements, or special consideration needs to be given to the cost of fag bearing configuration and any other subsequent shape, more work needs to be done, such as more accurate calculation and / or testing.fit of SKF Bearing
  • The designer of fag bearing configuration will see the necessary basic information provided in the order of general requirements. Obviously, it is impossible to include all the information required for every conceivable fag bearing application. fit of SKF Bearing
  • For this reason, we will mention comprehensive application engineering services in many places, including technical support for correct selection of fag bearings and how to conduct complete fag bearing configuration calculation. The higher the technical requirements for fag bearing configuration and the limited experience in using fag bearings in specific applications, the more this service should be used.fit of SKF Bearing
  • The information included in the comprehensive technical section usually applies to ordinary rolling fag bearings, or at least to a group of fag bearings. If only the exact information of a specific fag bearing is required, it can be found in the relevant text before the corresponding classification table section.
  •  It should be noted that the load and speed values and fatigue load limit values appearing in the product table are rounded approximate values. What is the friction torque of NTN bearing? If the inlet NTN bearing is selected according to its friction torque?fit of SKF Bearing
  • The friction of NTN bearing is mainly composed of dynamic friction and sliding friction between the moving elastic body and the ring raceway; The sliding friction between the cage and the moving body and the ferrule surface (the sliding friction between the moving bodies without the cage); fit of SKF Bearing
  • The sliding friction between the end face of the roller and the retaining surface of the ferrule; Viscous resistance of lubricant; The sliding friction of the sealing device depends on the type, size, load, speed, lubrication, sealing and other factors of NTN bearing.
  • In instruments and machines that need low friction torque, deep groove ball NTN bearings, cylindrical roller NTN bearings and self-aligning ball NTN bearings are usually selected to bear radial load; Single row thrust ball NTN bearing is selected to bear NTN bearing load. If it bears combined load, angular contact ball NTN bearing can be selected. When the load angle is basically consistent with the contact angle, small friction torque can be obtained; If the gap between the two angles is too large, it can be solved by assembling centripetal and thrust NTN bearings.
  • When selecting NTN bearing with low friction torque, contact sealing device should be avoided in structural design. At the same time, for NTN bearings with low friction torque, drip lubrication, oil mist lubrication and oil-gas lubrication should be adopted. RBR seal ring: This is a special rubber lip seal ring for INA Bearing of rolling mill, which has been widely used in recent years.
  •  The RBR sealing ring adopts the axial sealing method, and its lip is attached to the base surface of the gland, which is not affected by the roll runout. The grease inside the ina bearing can overflow, and the external cooling water, iron oxide scale and impurities are prevented from entering by the lip, which has a good sealing effect. Moreover, it is convenient to use. When changing the roll, the roll is installed into the ina bearing seat without any influence.
  • Contact skeleton oil seal: it is widely used in rolling mill. In order to increase the effect, two or three oil seals can be used in parallel. The oil seal is directional and cannot be installed reversely. The hot rolling mill is generally equipped with two oil seals, and the lips of the two oil seals shall face outside the ina bearing seat to prevent the immersion of external dirt. fit of SKF Bearing
  • The cold strip mill is generally equipped with three oil seals, and the lip of one oil seal close to INA Bearing shall be inward to prevent the overflow of lubricating grease and affect the quality of rolled products. Be careful when using the oil seal to avoid damaging the lip when installing the roll and affecting the sealing effect.fit of SKF Bearing
  • The sealing of ina bearing is divided into self sealing and external sealing. The external seal mainly adopts the combination of labyrinth and contact design. The more stages of the labyrinth (not lower than the two poles), the smaller the gap, and the better the sealing effect. The clearance of labyrinth is 0.6 ~ 1.5mm on one side of radial direction according to the size of INA Bearing; Axial 4 ~ 6mm.fit of SKF Bearing
  • Sealing is to maintain a good lubrication state inside the INA Bearing at the inlet, prevent cooling water, iron oxide scale and impurities from immersing into the working surface, and prolong the service life of INA Bearing. Because of the sealing problem of the INA Bearing of the rolling mill, the most damaged ina bearing is the part close to the roll body. The ina bearing is often worn, peeled or even broken on the working surface of the parts due to the pollution and loss of lubricating grease, especially the emulsion penetration of the cold rolling mill, which makes the lubricating grease fail faster.fit of SKF Bearing

Fit of SKF Bearing

  • Precautions for use
  • Rolling SKF bearings make precision parts, so it is required to be cautious when using them. High performance SKF 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 SKF bearings:
  • Keep SKF bearings and their surroundings clean. Even if the invisible smile dust enters the SKF Bearing, it will increase the wear, vibration and noise of the SKF Bearing.
  • The use and installation shall be careful. It is not allowed to punch with force, directly knock the SKF Bearing with a hammer, and transfer pressure through the rolling element.
  • Use proper and accurate installation tools, try to use special tools, and try to avoid using cloth and short fiber.
  • Prevent the corrosion of SKF bearings. When taking SKF 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 inner diameter and outer diameter of the rolling SKF Bearing are manufactured according to the standard tolerance. The tightness of the fit between the inner ring and the shaft, the outer ring and the seat hole of the SKF Bearing can only be realized by controlling the tolerance of the journal and the seat hole. The fit between SKF Bearing inner ring and shaft adopts base hole system, and the fit between SKF Bearing Outer Ring and seat hole adopts machine shaft system.
  • To correctly select the fit, we must know the actual load conditions, working temperature and other requirements of SKF 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