Talk about how to prolong the service life of rolling bearing in motor Zhao beautiful Inner Mongolia Baotou power plant Abstract: discusses the selection of bearing, how to prolong the service life of the bearing Keywords: rolling bearing; lubricating grease; assembly A device for motor as the industry to provide power, plays an important role in the factory, it is a kind of rotating equipment, bearing is an important part of the rotating part, so it is very important. If the bearing selection is not good, improper installation, maintenance is not in place, will affect its service life, maintenance workload increased workers, affecting the normal production. Here, I talk about the motor bearing selection, installation, maintenance experience, he summed up a power plant in Baotou motor class work methods, to prolong the service life of rolling bearing in motor. Selection of a rolling bearing, motor The first to introduce a kind of rolling bearing in motor: According to the types of rolling body can be divided into two categories: 1, ball bearings (ball bearings), the rolling body is a ball. 2, roller (roller bearing), the rolling body is cylindrical. According to the load direction of the bearing can be divided into the following categories: 1, radial bearing: can bear radial load (such as radial short cylindrical roller bearing), or can bear radial load and axial load, small (such as radial ball bearing) 2, a radial thrust bearing: can bear radial and axial joint load, and the radial load and axial load 3, the centripetal thrust bearing: can bear axial load, but also subjected to axial load, radial load to bear 4, the thrust bearing: only can withstand the axial load According to the load direction and types of rolling bearing rolling body, can be divided into ten categories: 1, 2 ball bearings, spherical ball bearing 3, radial short cylindrical roller bearing, spherical roller bearing 4, 5 concentric cylindrical roller bearing and radial needle roller bearing 6, centripetal spiral roller bearing 7, centripetal thrust ball bearing 8, a centripetal thrust tapered roller bearing, thrust ball bearing and 9 angular contact thrust ball bearings, thrust roller bearings 10 and centripetal thrust roller bearing. Initially, we receive the bearing from the factory supply department, just check the type, not careful examination, brought back to the class, when used directly installed or only a cursory examination, but found in practical applications, no bearing after careful examination of higher probability of failure in operation. We will lead a bearing on the accumulation of some of the experience: supply by the housing bearing has simple packaging, packaging standard, like the northwest bearing company, Wafangdian City bearing company product packaging is very normal, but quality is good, almost can't pick out the unqualified bearing, but for those who simply packaging bearing, must to strictly check. Method for examination of two: first, visual inspection. Ball, roller surface, the raceway should be smooth, clean, no crack, discoloration of pits, bead frame does not shake, flexible rotation. Two, by measuring the ball pressure wire method frame radial clearance. Fuse with diameter of 1 to 1.5mm, uniformly along the circumference of three point bearing pressure, with micrometer measurements, three point deviation does not exceed 10%, and the bearing of different sizes have allowed different gap, we must according to the table below to determine the size of the ball rack radial clearance is qualified or not. Bearing inner ring (mm) radial clearance (mm) The new ball bearing roller bearing 20~30 0.01~0.02 0.03~0.05 35~50 0.01~0.02 0.05~0.07 55~80 0.01~0.02 0.06~0.08 85~120 0.01~0.02 0.08~0.10 130~150 0.05~0.06 0.10~0.12 And the experienced teacher in the selection of bearing, summarizes can pick more than bearing table size 0.02~0.03mm, also is the bearing gap is too large a point can be used, it has also been verified in practice. But the gap is too small, is not good, easy in operation, fever, too big or not, is easy to produce noise and increase the vibration. There's one thing to note, is the lead wire, sometimes with broken filaments in bearings, must be cleared out. For example, our factory has imported bearings, in very few motor, 8 grate powder machine on the selection of a Swedish bearing No. 0 machine, exciter used Japan bearings, the use effect is very good, very durable. But the higher prices of imported bearings, general than similar domestic bearing price 4~5 times higher, so a lot of use in our enterprises are difficult, although we have access to imported bearings, but the understanding of it is not very deep, as motor professional personnel, still need further study it, know it, accumulation more experience. A qualified bearings, no assembly and excellent skills, if improper operation maintenance, motor, bearings are prone to failure, below I will talk about in the motor repair, prevent some experience, early aging method of effective bearing. Two, the motor bearing assembly The new bearing before use must be white cloth Sassafras net, pay attention to the thread not clip in bearings. Then they can bearing heating, a power motor class we use electromagnetic bearing heater for heating, the heating process, attention should be paid to monitor the bearing temperature, general control in 100 degrees Celsius temperature, can be measured by infrared thermometer, thermometer. Heating temperature control is very important, the heating temperature is too low, bearing expansion volume small, easy to cause difficult to install bearings, sometimes half appearance, be in a nice hobble situation; the heating temperature is too high, easy to cause bearing change, material change, bearing expansion although gone, but accelerated bearing aging. Through long-term practice, we summed up in the process of heating temperature control in the 90~100 degrees C range, bearing installation and durability are reliable. Fit bearing, but also with the caliper to measure the head size, check with the size and bearing. If the. If the shaft cap is slightly worn, the plating or coating method is plated with a layer of chromium in the bearing block, to ensure the shaft and bearing preload in 0.02~0.03mm, and belongs to the forward bias. Beyond this range, difficult to install bearings, preload is too small, the bearing inner ring will go, bearing block wear will increase. Install bearing well heated, to quickly and accurately push into the bearing platform, and pay attention to wear gloves, prevent scald the hand. Slow down, will cause the bearing temperature, diameter shrinkage, may lose a good opportunity. Bearing installed, and so the temperature dropped to room temperature, it can be used to clean gasoline cleaning, cleaning, rotating bearings from time to time, to ensure that all parts are cleaned, washed with clean cloth, wipe clean, ensure the bearing. Then, they can add the lubricating grease. Here it is necessary to talk about the selection of a lubricating grease: Appearance identification 1, calcium base grease, characteristics and application occasions By the natural fatty acid calcium soap made from mineral oil based greases of medium viscosity. Appearance identification: from light yellow to dark brown, smearing grease 1~2mm layer thickness on the piece of glass, a transparent examination without block Zhuang. Characteristics: strong water resistance, good stability, short fibers, and pumping sex good, not high temperature resistant; if it is used in high temperature applications, when running at 100 degrees Celsius, then gradually soft and even loss, cannot guarantee lubrication, causing damage to the bearing, causing the accident, long-term use of general permits bearing 60 degrees Celsius when the. According to penetration into five code, run the upper temperature were: 2G-1 ZG-2 55 degrees Celsius 60 degrees; ZG-3 ZG-4; ZG-5 65 degrees Celsius Application: used for general working temperature, light load high speed, in contact with water; lubrication, the load speed closed motor rolling and sliding bearing. Appearance identification 2, sodium base grease, characteristics and Applications Mineral oil, sodium base grease into benzene viscosity by natural sodium fatty acid soap. Appearance identification: from deep yellow to dark brown uniform ointment. Features: no water resistance, good stability, the fiber is long, high temperature resistance, good protective property, strong adhesion, resistance to vibration; if it is used very wet places, when grease touching the water after hydrolysis and thinning erosion, also can cause bearing damage early. According to the penetration of three code, run the upper temperature were: ZN-2 ZN-3 110 ZN-4 120 degrees Celsius Applications: at the higher working temperature, clean and free of moisture conditions, medium, medium load, low speed, high load open type or closed type motor rolling and sliding bearing lubrication. Appearance identification 3, calcium sodium grease, features and Application By the natural fatty acid calcium soap, sodium soap made of medium viscosity mineral oil calcium sodium grease. In the calcium sodium grease of calcium oxide and sodium oxide ratio, according to the 1:3.5 or 1:4 mixed evenly. Appearance identification: from yellow to dark brown uniform ointment. Features: water resistance with calcium base grease, and sodium base Appearance identification 4, lithium base grease, features and Application From natural lithium fatty acid soap made of medium viscosity mineral oil lithium base grease, belongs to a relatively new domestic products. Appearance identification: from light yellow to dark brown uniform ointment. Feature: added in lithium base grease antioxidant, anti rust agent, and extreme pressure agent, has become a multi effect long-life grease, can replace the use of calcium, sodium and calcium sodium grease. The water solubility of lithium is very small, with good water resistance, also has two phase transition temperature: from pseudo gel -- gel state -- the - melt, colloidal, temperature changes by 170 degrees ~200 degrees C process, used in the -60 degrees +120 degrees Celsius, long-term, short-term use can improve 20~30 degrees celsius. According to the penetration of four code, run the upper temperature were: ZL-1 170 degrees Celsius to 175 degrees Celsius; ZL-2; ZL-3 180 degrees Celsius to 185 degrees Celsius; ZL-4. Application: Y series motor, and the derived series motor seal bearing lubrication, according to the national standards are the use of lithium base grease, can reduce the maintenance workload, increase the bearing service life, reduce maintenance costs. Because lithium base grease has good performance, wide applicable temperature range, so we plant the widespread use of this kind of motor bearing grease. To the bearing with grease, not simply to the surface of a coating even if finished, and to hand pressure on bearing rotating each gap portion of the extrusion, and rotation of the bearing from time to time, let the oil evenly into the various parts of the effect of such lubrication, the best. Three, bearing maintenance experience, method 1, preloaded bearing Fault phenomenon: when the bearing inner ring is sheathed in the shaft neck strong position, the light at the bottom of the spherical raceway wear track is serious, or are in the slideway, outer ring and ball on the cracks and peeling. Fault inducement: ball and raceway gap pressure is too small, so that the torque increase, friction, bearing operating temperature rise, wear and fatigue failure to accelerate. Methods: to prevent the restoration of the radial clearance of bearing ring, reduce the amount of interference. If the shaft neck diameter should be greater than the bearing inner diameter 0.02mm properly, the end cover bearing mounting hole diameter, with size should be less than the bearing outer diameter of 0.02mm was the best ideal. Bearing assembling quality inspection Visual method: when the motor end cover bearing chamber is provided with a bearing, rotating end cover by hand, bearing rotation along the stress direction freely, flexible, no vibration and shaking up and down as qualified. Check with feeler gauge method: motor with bearing end cover, assembled on the frame rabbet, check with the feeler bearing ring 0.03mm thick radial clearance between a week, if the maximum gap position in the median azimuth (horizontal installation motor), it is considered that the correct assembly and reliable. Otherwise, belonging to poor installation, should be appropriately adjusted gap or transform the end cap position, re assembly, until the meet the requirements so far. 2, bearing grease failure Failure phenomenon: the bearing ball, gripper, inner ring and shaft neck, brown or blue. The fault cause: a serious lack of grease, or grease dry aging, belonging to the long-term use and without adding lubricating grease caused. Because the motor running in high speed, friction, the bearing operating temperature is too high, parts subject to oxidation discoloration fever. Method: according to prevent running time, the motor temperature, load condition and grease quality and other factors, to determine the motor runs supplement and changing the lubricating grease time. Time to run the record in 6000~10000 hours, should fill grease once, 10000~20000 hours should be fat again. 2 pole or 4 pole above motor changing the lubricating grease, bearing cavity 1/2, should be 2/3. Using high quality lithium base grease, named ZL-2 3, bearing mounting misalignment Fault phenomenon: not only with a concave bearing slideway bead mark, but the ball wear trace inequality, but also generate deflection, check with the feeler bearing on both sides of the circle of radial clearance range, range of difference value is larger, installation misalignment. Fault inducement: deviation greater than 1/1000 cause bearing operating temperature rise, with the slide and the ball badly worn; shaft bending; pressing surface and screw axis is not perpendicular to the oil cap bolt; directly strike the bearing outer ring hammer, drive belt (gear) pull too tight; so that the driving wheel and the axial center line is motivated not parallel. Method: to prevent by the surface is smooth, and the inner ring of the bearing wall thickness is almost equal to the steel pipe sleeve pressing, uniform stress, not too much force, the bearing is pressed into the correct position on the clean journal. Then press the motor speed inspection shaft extension allows radial runout values. 4, the bearing cover mouth and end cover bearing mounting hole clearance is too large and loose Fault phenomenon: Grease mixed with impurities, the rolling friction and the ball speed, abnormal noise. Fault inducement: dust, motor operation place gravel, iron powder and other debris, into the bearing chamber from the bearing cover check clearance, aggravate the wear. Methods: to prevent the bearing cleaning regularly, until thoroughly clean so far, replacing the grease qualified; improve the operating space of the motor, to avoid contamination of the invasion; check the bearing cover mouth, and a shaft hole clearance is in accordance with the requirements of sealing. 5, angular contact bearing assembly error caused the reverse loading Fault phenomenon: angular contact bearing cross section of the groove wear The fault cause: contact area of angular contact ball bearing with oval, thrust in one direction only. If the bearing assembly in the opposite direction, the ball in the rolling and sliding groove on the edge, to make the stress cross section of the groove wear. Methods: to prevent the assembly angular contact bearings, installed in the correct direction. 6, the motor vibration caused by bearing loose Fault phenomenon: open the bearing cover, the cover and the bearing sleeve contact edge rust. The fault cause: installation bearing tightening force is not enough or running motor vibration, make the bearing sleeve by Zhen Song. Methods: to prevent the assembly must check the force bearing sleeve. The motor cover sleeve size is too large, should brush plating, to increase the stress on the bearing sleeve. 7, the motor axial vibration caused by bearing friction small cap mouth edge. Fault phenomenon: the runtime can hear the motor cover by the impact of the roll. Stop check found, small motor cover stopping edge of the wear scar. Fault inducement: motor axial vibration, make the bearing axial force and small cap mouth edge friction. The axial vibration of mechanical failure caused by large. Motor magnetic center deviation Treatment methods: magnetic center processing machinery fault or re looking for motor. Also can be used to make a small cap mouth edge equal electrical board, between the motor and the small cover and the bearing, can buffer the axial force, reduce the friction of bearing and the small cover. 8, motor end cover mounting misalignment Fault phenomenon: during operation of the motor bearings overheating Fault inducement: motor end cover installation without leveling, the bearing load deflexion, lead to overheating. Processing method: re install the motor end cover or by adjusting the motor end cap screws to the end cover of the motor installed in place, the middle. Similarly, the outer bearing small cover installation deviation, also can cause bearing heating, so that the electric motor, minor repairs, attention must be paid to the motor cover screws in place, avoid the screw is not screwed in place and the small cover deviation cause bearing heating conditions. Above all, as long as the quality is good, good bearing installation quality, do daily maintenance, motor bearing service life will be extended. Author introduction: Baotou first thermal power plant electrical workshop in the motor repair work. 91~94 graduated from the Inner Mongolia electric power staff secondary school power plants and power systems professional. 2002~2004 years in Baotou staff university computer information management system of graduation, work actively participate in the activities of QC group in class, and got "the elimination of No. eight boiler of ethylene pulverizer motor overheating" QC activity in 2000, won the authority of science and technology progress award two; 98 years of "reduce bearing QC results" by the results of the national QC award, 2001 to participate in the activities of QC class, also entered the ranks of outstanding achievements of bureau of canal of QC.