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Linhai Baiai Metal Forgings Co., Ltd.

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07

2021

The importance of bearings and the current dilemmas facing the industry

Bearings are important basic components of various mechanical equipment. Its accuracy, performance, life and reliability play a decisive role in the accuracy, performance, life and reliability of the host. Among mechanical products, bearings are high-precision products, which not only require comprehensive support from many disciplines such as mathematics and physics, but also require material science, heat treatment technology, precision machining and measurement technology, numerical control technology, effective numerical methods and powerful computers Technology and many other disciplines serve it, so the bearing is a product that represents the country's scientific and technological strength.

07

2021

Bearing installation

Whether the bearing is installed correctly affects the accuracy, life and performance. Therefore, the design and assembly department must fully study the bearing installation. Hope to install in accordance with operating standards. The standard operation items are usually as follows:   (1) Clean the bearing and its related parts   (2) Check the size and finishing of related parts   (3) Installation   (4) Inspection after bearing installation   (5) Supply lubricant   It is hoped that the bearing package will be opened just before the installation. General grease lubrication, do not clean, directly fill with grease. Lubricating oil is lubricated, and cleaning is not usually necessary. However, the bearings for instruments or high-speed applications should be washed with clean oil to remove the anti-rust agent coated on the bearings. Bearings with anti-rust agent removed are easy to rust, so they cannot be left alone.   In addition, bearings that have been packed with grease can be used directly without cleaning. The installation method of the bearing varies with the bearing structure, fit, and conditions. Generally, because most of the shaft rotates, the inner ring needs an interference fit. Cylindrical bore bearings are usually pressed in with a press or hot-fitting method. In the case of a tapered hole, install it directly on the tapered shaft or install it with a sleeve.   When installed to the shell, there is generally a lot of clearance fit, and the outer ring has an interference. It is usually pressed in with a press, or there is also a shrink fit method for installation after cooling. When dry ice is used as the coolant, the moisture in the air will condense on the surface of the bearing when the shrink fit is installed. Therefore, appropriate anti-rust measures are required.

07

2021

Bearing form

Inch single row deep groove ball bearings: R    Inch single row deep groove ball bearing with flange: FR    Metric single row deep groove ball bearings: the symbol is omitted    Metric flanged single row deep groove ball bearings: F    Metric single row deep groove ball bearings of specific sizes: MR    Specific size metric single row deep groove ball bearing with flange: MF    Thrust bearing with groove: FM    Non-track thrust bearing: F    Sealing ring. Dust cover    Contact Teflon seal with retaining ring on both sides: TT    Steel dust cover on both sides: ZZ    Contact rubber seals on both sides: 2RS

07

2021

Bearing material

Whether the bearing is installed correctly affects the accuracy, life and performance. Therefore, the design and assembly department must fully study the bearing installation. Hope to install in accordance with operating standards. The standard operation items are usually as follows:   (1) Clean the bearing and its related parts   (2) Check the size and finishing of related parts   (3) Installation   (4) Inspection after bearing installation   (5) Supply lubricant   It is hoped that the bearing package will be opened just before the installation. General grease lubrication, do not clean, directly fill with grease. Lubricating oil is lubricated, and cleaning is not usually necessary. However, the bearings for instruments or high-speed applications should be washed with clean oil to remove the anti-rust agent coated on the bearings. Bearings with anti-rust agent removed are easy to rust, so they cannot be left alone.   In addition, bearings that have been packed with grease can be used directly without cleaning. The installation method of the bearing varies with the bearing structure, fit, and conditions. Generally, because most of the shaft rotates, the inner ring needs an interference fit. Cylindrical bore bearings are usually pressed in with a press or hot-fitting method. In the case of a tapered hole, install it directly on the tapered shaft or install it with a sleeve.   When installed to the shell, there is generally a lot of clearance fit, and the outer ring has an interference. It is usually pressed in with a press, or there is also a shrink fit method for installation after cooling. When dry ice is used as the coolant, the moisture in the air will condense on the surface of the bearing when the shrink fit is installed. Therefore, appropriate anti-rust measures are required.

07

2021

Selection of rolling bearing oil

Spindle bearing lubricants using rolling bearings are generally considered based on the product of the bearing inner diameter d and the spindle speed n, that is, the speed factor dn, the bearing operating temperature T, and the load P borne by the bearing. The variety of lubricating oil can choose COC high temperature resistant grease bearing oil, which can be determined according to product variety, working conditions and viscosity grade.   Bearing working temperature -30-0℃, normal load (3MPa) suitable oil viscosity (40℃) 18-32mm2/s, viscosity grade 22, 32; heavy load or shock load (3MPa-20MPa) suitable oil viscosity (40℃) ) 18-50mm2/s, viscosity grade 32, 46.   Bearing operating temperature 0-60℃, speed factor (dn value) below 15000mm.r/min, normal load suitable oil viscosity (40℃) 32-70mm2/s, viscosity grade 32, 46, 68, heavy load or impact load (3MPa-20MPa) Applicable oil viscosity (40℃) 70-192mm2/s, viscosity grade 68, 100, 150;   Speed ​​factor (dn value) 15000-75000mm.r/min, normal load suitable oil viscosity (40℃) 32-50mm2/s, viscosity grade 32, 46, heavy load or impact load (3MPa-20MPa) suitable oil viscosity ( 40℃) 42-90mm2/s, viscosity grade 46, 68, 100;   Speed ​​factor (dn value) 75000-150000mm.r/min, normal load suitable oil viscosity (40℃) 15-32mm2/s, viscosity grade 15, 32, heavy load or impact load (3MPa-20MPa) suitable oil viscosity ( 40℃)32-42mm2/s, viscosity grade 32; speed factor (dn value) 150000-300000mm.r/min, normal load suitable oil viscosity (40℃) 9-12mm2/s, viscosity grade 5, 7, 10, Heavy load or shock load (3MPa-20MPa) is suitable for oil viscosity (40℃) 18-32mm2/s, viscosity grade 15.   Bearing working temperature 60-100℃, speed factor (dn value) below 15000mm.r/min, normal load suitable oil viscosity 40℃110-192mm2/s (100℃9.3-12.5mm2/s), viscosity grade 150, heavy load Or impact load (3MPa-20MPa), suitable for oil viscosity (40°C) 195-240mm2/s (100°C 15-24mm2/s), viscosity grade 150;   Speed ​​factor (dn value) 15000-75000mm.r/min, normal load is suitable for oil viscosity 40℃70-120mm2/s (100℃5.6-9.3mm2/s), viscosity grade 68, 100, heavy load or impact load ( 3MPa-20MPa) suitable oil viscosity (40℃) 110-192mm2/s, viscosity grade 150; speed factor (dn value) 75000-150000mm.r/min, normal load suitable oil viscosity 40℃50-90mm2/s(100℃ 5.6-9.3mm2/s), viscosity grade 46, 68, 100, heavy load or shock load (3MPa-20MPa) suitable for oil viscosity (40℃) 70-120mm2/s, viscosity grade 100.

07

2021

Bearing storage

The storage of bearings must first fully consider the size and weight of the stored bearings, and secondly, consider the necessary handling space and equipment to ensure that the bearings will not be collided during storage and retrieval. Do not place the bearing directly on the ground.   Therefore, it is necessary to configure a proper shelf, and the bottom of the shelf should be 30cm higher than the ground. In the general packaging state, it varies with the storage environment, and the anti-rust effect is 13 years. When storage is required for nearly 10 years under special circumstances, the storage method can be immersed in oil such as turbine oil (as bearing lubricant).   (1) Work to install bearings   There are many ways to install the bearing, and the same work is done after installation. After the bearing is installed, the outer ring must be obliquely coated with lubricant for the bearing.   A. Application of lubricant   1. In the case of grease lubrication, apply lubrication to cover all roller surfaces, and restore the position of the outer ring after application.   2. For oil lubrication, coat all roller surfaces with oil, and restore the position of the outer ring after coating.   B. After coating, cover with plastic film to prevent dust.   (2) Precautions for disassembling the bearing   The disassembly of the bearing is carried out during regular maintenance or when the bearing needs to be replaced due to abnormal operation. When the bearings need to be replaced frequently during regular maintenance, the cause of the abnormality should be understood when disassembling the bearing to prevent the abnormality from recurring. At least the following items should be retained.   1. Collect and retain used lubricant.   2. Keep damaged bearings.   3. Keep records of abnormal events during operation.   4. Keep a record of the bearing condition during abnormal operation.

07

2021

Bearing maintenance

In order to give full play to the bearing and maintain its due performance for a long time, it is necessary to do regular maintenance. Through appropriate regular inspections, it is very important to improve productivity and economy to detect faults early and prevent accidents before they occur.   (1) Cleaning   When disassembling the bearing for inspection, first make a record of the appearance with photography or other methods. In addition, confirm the amount of remaining lubricant and sample the lubricant before cleaning the bearing.   The cleaning of the bearing is divided into rough washing and fine washing, and a metal mesh rack can be placed at the bottom of the used container. When rough washing, use a brush to remove grease or adhesions in oil. At this time, if the bearing is rotated in oil, be careful that the rolling surface may be damaged by foreign matter. Slowly rotate the bearing in oil during fine washing, and proceed carefully. Commonly used cleaning agents are neutral non-water-containing diesel or kerosene, and sometimes mild alkaline liquids are used as needed. But no matter what kind of cleaning agent is used, it must be filtered frequently to keep it clean. After cleaning, immediately apply anti-rust oil or anti-rust grease on the bearing.   (2) Inspection and judgment   In order to judge whether the removed bearing can be reused, it is necessary to check its dimensional accuracy, rotation accuracy, internal clearance, mating surface, raceway surface, cage, and sealing ring. Regarding the inspection results, it can be judged by those who use inertial bearings or who are proficient in bearings. The criteria for judgment vary according to the mechanical performance, importance, and inspection cycle. If the following damage occurs, the bearing must not be reused and must be replaced.

07

2021

Selection of centralized filtration and supply plan for grinding fluid in bearing processing

When the workpiece is being ground, high temperature is formed in the grinding area, which will wear the grinding wheel, deteriorate the surface integrity of the parts, and the machining accuracy of the parts is difficult to control. Therefore, the grinding fluid must be injected into the grinding area to reduce the grinding temperature. The grinding fluid not only has the function of lubrication and cooling, but also has the function of washing and rust prevention. The correct use of grinding fluid can prevent workpiece burns, improve the surface accuracy and roughness of workpieces, improve the rust-proof ability of workpieces and machine tools, and extend the service life of tools and machine tools. Therefore, reasonable use and maintenance of grinding fluid is crucial in the process of bearing processing. important.

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