Diagnosis and Management of bearings, check the operation and troubleshooting-Wenzhou Bearing wholesale

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Bearing Knowledge

Diagnosis and Management of bearings, check the operation and troubleshooting

点击数：6300 日期：2014/4/4

To make rolling bearings in good condition to maintain long-term use , the bearing must be checked and maintenance, inspection and maintenance of such a failure early prevention is very important, depending on the operating conditions of a standard suitable for machine operation , regular inspection and maintenance, generally use the following method : 3.1 Check the operational state Check the rolling bearing according to the nature of sound, vibration , temperature checking and lubricant , supplement or replace the lubricant judgment time . 3.2 Bearing dismantling inspection Fully observe the periodic inspection and replacement of the machine and remove the bearing raceway surface condition and check for damage and the possibility of re-use. Fourth, check the operation and troubleshooting Check the operation of the project rolling bearing sound, vibration, temperature, lubrication status , as follows : 4.1 Bearing rolling sound Using sound measuring device for operation of rolling bearings of the size and quality sound check , bearing even a slight peeling damage, abnormal tone and irregular tone will be issued with a sound measuring device can distinguish. 4.2 bearing vibration Bearing vibration of the bearing damage is very sensitive, such as peeling , creasing , corrosion , cracks, wear , etc. will be reflected in the bearing vibration measurement , therefore, through the use of special bearing vibration measurements ( frequency analyzer, etc. ) to measure the vibration size , frequency can not be inferred by the abnormal situation. The measured values due to sensor mounting position of use of the bearing or the like, and therefore measured values required for each machine for analysis and comparison of the determined criteria . 4.3 bearing temperature Bearing temperature , generally bearing chamber outside temperature can be inferred that if the use of the hole can be measured directly bearing outer ring temperature, more suitable position . Typically , the operation starts with the bearing temperature rise slowly 2-3 hours to reach steady state. Normal temperature of the heat capacity of the bearing , heat capacity , speed and load of the machine to another. If lubrication, install the appropriate department , the bearing temperature will be rapid rise , there will be abnormally high , then you must stop running, take the necessary precautions. You can always use heat sensors to monitor bearing temperature , and automatically alert users to prevent or stop the burning shaft accident occurred when the temperature exceeds the specified value . 4.4 Lubrication 4.4.1 The role of bearing lubrication The fatigue life of rolling bearing lubrication and friction , wear, temperature, and vibration have important implications not properly lubricated , the bearing can not work. Analysis showed that causes bearing damage , bearing damage and about 40% are related to poor lubrication . Thus , a good lubrication of the bearing is an effective measure to reduce bearing friction and wear . In addition, the bearing lubrication as well as heat , rust , seals, and other effects to ease the impact of the role of bearing lubrication can be briefly described as follows : a. between the two rolling surfaces or sliding surfaces contact each other to form a film of the second surface spaced from the contact surface to reduce friction and wear. When b. When using oil lubrication , especially the use of circulating oil lubrication, oil mist lubrication and injection lubrication, oil can take away most of the heat inside the bearing friction , play an effective heat sink . c. When using grease lubrication , prevents external dust and other foreign matter from entering the bearing , closed role to play . d. lubricant has to prevent metal corrosion effect. e. extend the fatigue life of the bearing. 4.4.2 Comparison of grease and oil lubrication Bearing lubrication method is roughly divided into two lubricating grease and oil . 4.4.3 greased Grease is a lubricant base oil , thickener and additives composed . When selected , choose well suited to the conditions of use lip bearing grease , due to different trademarks , the performance will also be a great difference , so when the choice must be careful. Bearing grease commonly used calcium -based grease , grease , sodium , calcium and sodium based grease , lithium grease , aluminum grease and molybdenum disulfide grease . Number of bearing grease filled , to fill the space inside the bearing 1/2-1/3 as appropriate. Should reduce speed to 1 /3. Excessive grease will make the temperature increased. 4.4.4 Grease Selection When working temperature selection in accordance with grease , key indicators should be dropping point , oxidation stability and low temperature performance, drop point is generally used to evaluate the performance of high-temperature , bearing temperature should be lower than the actual drop point 10-20 ℃. The use of synthetic grease dropping point temperature should be below 20-30 ℃. Choose according to the load bearing grease , heavy duty should be selected on the small penetration of grease . In addition to the small penetration , but also have a higher film strength and extreme pressure performance when working under high pressure. According to environmental conditions to select grease, calcium grease easily soluble in water , less suitable for drying and moisture environment . 4.4.5 Oil lubrication In the high-speed , high-temperature conditions , greased oil lubrication is not suited to be used . By oil circulation , can take a lot of heat . Viscosity is an important characteristic of lubricating viscosity directly affects the size of the flow of the lubricant film thickness between the resistance and the friction surface is formed , the viscosity of the oil bearing operating temperature is generally 12-15cst. The higher the speed should be selected lower viscosity , heavier loads higher viscosity should be selected . Commonly used lubricating mechanical oil , high-speed machine oil, turbine oil, compressor oil, transformer oil , cylinder oil. Oil lubrication method comprising : a. an oil bath lubrication Lubrication oil bath lubrication is the most common method for low- , medium-speed bearings lubricated bearing part of the tank immersed in the lubricating oil by the rotation of the bearing parts from the tape , and then flows back to the oil tank should be slightly less than the minimum rolling of the central body . b. drip lubrication Drip lubrication oil rationing was needed for bearing components , usually every 3-8 seconds drip drop amount is appropriate , too much oil will cause the bearing temperature increased. c. circulating oil lubrication The filtered oil pump feeding oil to the bearing member , through the bearing lubricant and then filtered after cooling to use. As the cycle oil can be taken away some heat , the bearing cool down, therefore the method suitable for high speed bearing components. d. spray lubrication With dry compressed air and oil mixture formed by the spray mist , spray bearings, air can effectively cool the bearing and to prevent intrusion of impurities . This method is suitable for high-speed, high-temperature lubrication of the bearing components. e. spray lubrication With a high pressure oil pump through the nozzle hitting the bearings , oil injected into the bearing into the tank through the other end of the bearing . When the bearing is rotating at high speed , the rolling body and the retainer are relatively high rotational speed of the surrounding air to form an air flow difficult with the general method of lubrication oil to the bearings , then the lubricant must be sprayed with high-pressure injection method to the bearing , the position of the nozzle should be placed in the center of the inner ring and the holding frame . 4.4.6 Solid Lubrication In some special conditions , adding a small amount of solid lubricant grease , such as adding the 1st 3 to 5% molybdenum disulfide to reduce wear and improve compression heat capacity , for high temperature , elegant, high vacuum , corrosion , anti-radiation, as well as other special conditions of very low temperatures , the solid lubricant added plastic or powder metallurgy materials , can be made with self-lubricating properties of the bearing parts, such as by adhesive bonding in the solid lubricant raceway, the holding frame and the rolling elements , to form a lubricating film to reduce friction and wear on a certain effect . 4.4.7 Supplementary and replacement of lubricants a. grease supplement interval Due to increased mechanical action , aging and pollution filled bearing lubricating base configuration will gradually lose its lubricating properties. Therefore , the need for lubrication rank constantly replenished and updated. Interval due to the formation of the lubricant added to the bearing , the size and speed , etc., and Figure 4-1 illustrates the operation time interval generally require supplemental grease . When the bearing temperature exceeds 70 ℃ case , bearing temperature rise 15 ℃, then use complementary interval grease reduced by half. Double-sided enclosed bearing grease has been loaded in the manufacture of these products using a standard grease, total operating temperature range and other properties suitable for the requirements of the occasion, and fill with fat content corresponding bearing size , fat life generally over bearing life , except for special occasions , without added grease . b. lubricant replacement cycle Oil change intervals and oil due to different conditions , under normal circumstances , the operating temperature is 50 ℃, less good when dusty environments, replaced once a year , when the oil temperature reaches 100 ℃, to 3 months or less replaced once .

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