For the measurement of the coaxiality of the main bearing hole of the machine body, the coaxiality of the diesel engine body must be measured accurately, and the amount of runout of the crankshaft is measured. The thickness of the bearing bush is selected to make the oil lubrication gap reach the same in each axial position. . Where the diesel engine has been crushed, flying, etc., the coaxiality of the main IKO bearing hole must be tested before assembly. The total length of the ductile iron crankshaft is not more than 0.14mm, and the total length of the steel crankshaft is not more than 0.12mm. The roundness and cylindricity of the hole are also required. If it is beyond the limit, it is disabled. If it is within the limit, the grinding method is adopted (that is, the appropriate amount of red powder is applied to the bearing bush, and then the crankshaft is loaded and then rotated, and then the rod end joint bearing cap is removed to check the bearing bush. After the hard spot projecting portion is subjected to the scraping process, the amount of change in the dimension is measured, thereby ensuring the reliability of use.
1. Location: In order to check whether the installation is correct, check the operation. The small machine can be rotated by hand to confirm whether the rotation is smooth. The inspection items have poor operation due to foreign matter, scratches, and indentations. Due to poor installation, the torque generated by the mounting of the mount is unstable, and the torque is too large due to too small clearance, installation error, and sealing friction. Wait. If there is no abnormality, the power running can be started.
IKO bearings are suitable for bearing radial and axial combined loads with radial loads. They are usually paired with two sets of bearings, mainly for the front and rear hubs, active bevel gears, differentials, reducers and other transmission parts of the car. .
2. Allowable speed: In the environment with correct installation and good lubrication, it is allowed to be 0.3-0.5 times of the limit speed of the rod end joint bearing. Under normal circumstances, it is best to use 0.2 times the limit speed.
3, allow tilt angle: IKO bearings generally do not allow the shaft to tilt relative to the housing hole, if there is tilt, the maximum does not exceed 2'.
4, allowable temperature: under normal load, and the lubricant has high temperature resistance, and the lubrication is sufficient, the general bearing is allowed to work at -30 ° C -150 ° C ambient temperature.
When the IKO bearing is removed and intended to continue to be used, the appropriate removal tool should be used. To remove the ferrule of the interference fit, only the pulling force can be applied to the ferrule, and the disassembly force is never allowed to pass through the rolling element, otherwise the rolling body and the raceway will be crushed. Lubricants are important not only for bearings but also for all rod ends. However, please note that it is not advisable to add too much grease to the bearings. Then it is to replace the lubricant of the bearing. Bearings lubricated with oil should be refilled with fresh oil and allowed to rotate at low speed for a few minutes if the old oil is drained. As much as possible, allow the oil to collect residual contaminants and then vent the oil. For grease-lubricated bearings, when replacing grease, the cutter used should avoid any contact with the cotton end of the rod end joint bearing. Since these residual fibers may be wedged between the rolling elements and cause damage, especially the application of IKO bearings needs to pay attention to this problem.
2018年12月18日星期二
How to choose INA bearing type
When selecting the INA bearing type, the following five factors should be considered:
1) Direction, size and nature of the load: The radial bearing is mainly subjected to radial load, and the thrust bearing is mainly subjected to axial load. Angular contact ball bearings and tapered roller bearings are available for INA bearings when subjected to both radial and axial loads. Deep groove ball bearings can also be used when the axial load is small. Generally, the roller INA bearing has higher bearing capacity than the ball INA bearing and has a strong ability to withstand impact loads.
2) Rotating speed: The working speed of INA bearing should normally be lower than the limit speed n. The limit rotation speed of deep groove ball bearing, angular contact ball bearing and cylindrical roller bearing is higher, suitable for high speed operation, and the limit rotation speed of thrust bearing is higher. low.
3) Self-aligning performance: When the coaxiality of the two INA bearing housing holes is not guaranteed or the deflection of the shaft is large, the self-aligning ball bearing or spherical roller bearing should be considered.
4) Stiffness requirements: Generally, the rigidity of the roller INA bearing is larger than that of the ball INA bearing, and the angular contact ball bearing and the tapered roller bearing adopt the pre-tightening method to further improve the rigidity of the bearing.
5) Support limit requirements: The fixed support limits the axial displacement in two directions. INA bearings can be used to withstand the biaxial axial load. The one-way limit can be used with INA bearings that can bear the one-way axial load. Unlimited, cylindrical roller bearings with inner and outer rings can be separated.
1) Direction, size and nature of the load: The radial bearing is mainly subjected to radial load, and the thrust bearing is mainly subjected to axial load. Angular contact ball bearings and tapered roller bearings are available for INA bearings when subjected to both radial and axial loads. Deep groove ball bearings can also be used when the axial load is small. Generally, the roller INA bearing has higher bearing capacity than the ball INA bearing and has a strong ability to withstand impact loads.
2) Rotating speed: The working speed of INA bearing should normally be lower than the limit speed n. The limit rotation speed of deep groove ball bearing, angular contact ball bearing and cylindrical roller bearing is higher, suitable for high speed operation, and the limit rotation speed of thrust bearing is higher. low.
3) Self-aligning performance: When the coaxiality of the two INA bearing housing holes is not guaranteed or the deflection of the shaft is large, the self-aligning ball bearing or spherical roller bearing should be considered.
4) Stiffness requirements: Generally, the rigidity of the roller INA bearing is larger than that of the ball INA bearing, and the angular contact ball bearing and the tapered roller bearing adopt the pre-tightening method to further improve the rigidity of the bearing.
5) Support limit requirements: The fixed support limits the axial displacement in two directions. INA bearings can be used to withstand the biaxial axial load. The one-way limit can be used with INA bearings that can bear the one-way axial load. Unlimited, cylindrical roller bearings with inner and outer rings can be separated.
2018年12月14日星期五
Ntn flange bearing periodic inspection in the cause of troubleshooting
Regular inspections of ntn bearings are important to maintaining the bearing in its best condition and can also reveal problems. Matters and related knowledge about the use of bearings in use.
We want to emphasize that it is important to keep the flange bearings lubricated and clean. So before we inspect the ntn bearing, we should clean the surface of the bearing and then remove the parts around the bearing. It should be noted that the oil seal is a very fragile part, so extra care should be taken during inspection and disassembly. Do not apply excessive force to avoid damage to the parts. Then carefully check the bearing's oil seal and its surrounding parts. If it has been shown to be a bad symptom, be sure to replace it. A bad oil seal will cause damage to the bearing, causing the bearing to cloud abnormally and causing the machine to stop.
We also check the lubricant of the bearing. Lubrication is important, not for bearings, but for all flanged bearings. However, please note that ntn bearings should not be added with excessive grease.
Apply a little bit of lubricant to the friction between the two fingers. If there is any contaminant, it can be felt; or apply a thin layer of lubricant on the back of the hand and then check the light.
Bearings lubricated with oil should be refilled with fresh oil and allowed to rotate at low speed for a few minutes if the old oil is drained. As much as possible, allow the oil to collect residual contaminants and then vent the oil. Note: It is best to filter the oil before use. Bearings lubricated with grease should be replaced with any material that contacts the flange bearing when the grease is replaced. Since these residual fibers may be wedged between the rolling elements and cause damage, especially the application of small bearings requires attention to this problem.
Ntn bearing failures are often due to a variety of factors, all design and manufacturing process factors and bearing failures, and their analysis is not easy to determine. Under normal circumstances, in general, you can consider and analyze factors and internal factors.
The main factors used for adjustment are installation, use and maintenance, maintenance, etc. in line with technical requirements. The mounting conditions are one of the factors that use the bearing is the primary factor that often causes the change of state between the various parts of the installation package, the operation in the abnormal state and early failure. According to the flange bearing installation, use, maintenance, maintenance technical requirements of the bearing contact load, speed, temperature, vibration, noise and lubrication status monitoring and inspection, found abnormalities immediately find the cause, adjust back to normal.
The influence of the metallurgical quality of ntn bearing materials is the main factor in the early failure of rolling bearings. With the advancement of metallurgical technology (such as bearing steel, vacuum degassing, etc.), the quality of raw materials has been improved. The proportion of raw material quality factors in the flange bearing failure analysis has been significantly reduced, but it is still one of the main factors of bearing failure. The choice of properness is still a must for rolling bearing failure analysis.
We want to emphasize that it is important to keep the flange bearings lubricated and clean. So before we inspect the ntn bearing, we should clean the surface of the bearing and then remove the parts around the bearing. It should be noted that the oil seal is a very fragile part, so extra care should be taken during inspection and disassembly. Do not apply excessive force to avoid damage to the parts. Then carefully check the bearing's oil seal and its surrounding parts. If it has been shown to be a bad symptom, be sure to replace it. A bad oil seal will cause damage to the bearing, causing the bearing to cloud abnormally and causing the machine to stop.
We also check the lubricant of the bearing. Lubrication is important, not for bearings, but for all flanged bearings. However, please note that ntn bearings should not be added with excessive grease.
Apply a little bit of lubricant to the friction between the two fingers. If there is any contaminant, it can be felt; or apply a thin layer of lubricant on the back of the hand and then check the light.
Bearings lubricated with oil should be refilled with fresh oil and allowed to rotate at low speed for a few minutes if the old oil is drained. As much as possible, allow the oil to collect residual contaminants and then vent the oil. Note: It is best to filter the oil before use. Bearings lubricated with grease should be replaced with any material that contacts the flange bearing when the grease is replaced. Since these residual fibers may be wedged between the rolling elements and cause damage, especially the application of small bearings requires attention to this problem.
Ntn bearing failures are often due to a variety of factors, all design and manufacturing process factors and bearing failures, and their analysis is not easy to determine. Under normal circumstances, in general, you can consider and analyze factors and internal factors.
The main factors used for adjustment are installation, use and maintenance, maintenance, etc. in line with technical requirements. The mounting conditions are one of the factors that use the bearing is the primary factor that often causes the change of state between the various parts of the installation package, the operation in the abnormal state and early failure. According to the flange bearing installation, use, maintenance, maintenance technical requirements of the bearing contact load, speed, temperature, vibration, noise and lubrication status monitoring and inspection, found abnormalities immediately find the cause, adjust back to normal.
The influence of the metallurgical quality of ntn bearing materials is the main factor in the early failure of rolling bearings. With the advancement of metallurgical technology (such as bearing steel, vacuum degassing, etc.), the quality of raw materials has been improved. The proportion of raw material quality factors in the flange bearing failure analysis has been significantly reduced, but it is still one of the main factors of bearing failure. The choice of properness is still a must for rolling bearing failure analysis.
2018年12月12日星期三
Intermediate bearing installation process and requirements
1. Intermediate bearing frame and welding pad are welded
1.1 Before the cable is illuminated, the intermediate bearing frame is pre-positioned according to the hull reinforcement, and a pole is mounted at a distance of about 1 m from the frame to determine the front and rear position of the frame. When the cable is illuminated, the axis is sampled at the front and rear positions of the frame. The front and rear positions are positioned based on the benchmark
1.2 After the wire is illuminated, measure the distance between the axis and the floor, determine the margin in the height direction of the intermediate bearing frame, and then cut, and then position the welding intermediate bearing frame according to the size requirements of the drawing.
1.3 According to the requirements of the drawings, the welding gaskets shall be spot-welded and fixed on the middle bearing frame. After the process is confirmed, the welding may be carried out. When welding, pay attention to the inclination direction of the welding gasket, and then weld the gasket to achieve Matching process requirements
2. The intermediate bearing is temporarily fixed
2.1 Before the main shafting system is centered, pre-install four top-lifting top wire sockets at appropriate positions on the middle bearing frame panel, then install the intermediate bearing at the journal of the intermediate shaft, and pay attention to the center of the intermediate bearing housing to Distance requirement for the end face of the rear flange of the intermediate bearing
2.2 After the initial centering of the main machine, the front and rear left and right sides of the welding intermediate bearing are temporarily adjusted to the top wire seat and the card, code tooling
3 main shaft shaft load adjustment before the initial installation of the intermediate bearing
3.1 After the shafting is verified and the bolts are installed, the bearing cap is opened, the height of the four top wires of the bearing base is adjusted, and the top wire is temporarily adjusted. The gap between the bearing bush and the shaft neck is zero, and the left and right gaps are equal.
3.2 After the bearing is assembled with the journal, check whether the gap between the hole at the two ends and the journal is uniform.
3.3 Clean the joint surface and the upper inner control and apply clean lubricating oil.
3.4 Wipe the copper gasket of the intermediate bearing and place it correctly on the bearing joint surface.
3.5 Place the bearing cap on the bearing housing as a whole and position the bearing cap correctly with two taper pins
3.6 Insert the bearing cap and the fastening bolt on the bearing housing and tighten
4. Protection of intermediate bearing during main shaft load adjustment
The bearing cover is about 2mm high, and the gap between the bearing cover and the bearing housing must be covered with a color belt. The front and rear end faces are sealed with white buckle cloth to prevent dust, welding slag, water vapor and other impurities from entering the bearing housing. Inside
5. Installation of the intermediate bearing after the main body is glued
5.1 After the main machine is glued for 24 hours, according to the above requirements, the relevant parameters of the middle bearing installation of the accessory, after meeting the process requirements, the intermediate bearing is re-tested and must meet the process requirements.
5.2 No. Hole and Drilling of Intermediate Bearing Frame
5.3 Measure the gap between the bottom of the bearing seat and the welding pad at the four corners of each gasket. According to the experience, plus the gasket and the remaining amount, the thickness of the positive gasket is processed and the adjustment gasket is matched and matched. The inspection gasket can move the adjustment gasket out of the drill hole. After drilling, the adjustment gasket can be inserted between the bottom of the bearing seat and the welding gasket. Finally, the intermediate bearing anchor bolt is installed.
5.4 After the intermediate bearing anchor bolt is tightened, remove the four top-lifting top wires of the intermediate bearing base, and re-test the intermediate bearing load. After meeting the process requirements, the positioning pin can be processed and punched into the pin hole.
5.5 Remove the intermediate bearing before and after the temporary fixed top wire
5.6 Open the bearing cap and install the oil pan on the intermediate shaft in the oil cavity at the end of the bearing housing to adjust the distance between the sharp angle of the oil pan and the sharp angle of the bearing body to meet the technical requirements of the drawings.
5.7 Check whether the left and right clearances of the intermediate bearing are uniform, and check whether the total clearance meets the drawing requirements by using the lead wire method.
5.8 Thorough cleaning of the inner cavity of the bearing on the intermediate bearing
5.9 Place the bearing cap on the bearing housing and position the bearing cap correctly with two taper pins, install the fastening bolts and tighten them to ensure the integrity of the intermediate bearing installation.
5.10 Install rubber on the gap between the front and rear ends of the intermediate bearing and the intermediate shaft to prevent dust from entering the intermediate bearing.
1.1 Before the cable is illuminated, the intermediate bearing frame is pre-positioned according to the hull reinforcement, and a pole is mounted at a distance of about 1 m from the frame to determine the front and rear position of the frame. When the cable is illuminated, the axis is sampled at the front and rear positions of the frame. The front and rear positions are positioned based on the benchmark
1.2 After the wire is illuminated, measure the distance between the axis and the floor, determine the margin in the height direction of the intermediate bearing frame, and then cut, and then position the welding intermediate bearing frame according to the size requirements of the drawing.
1.3 According to the requirements of the drawings, the welding gaskets shall be spot-welded and fixed on the middle bearing frame. After the process is confirmed, the welding may be carried out. When welding, pay attention to the inclination direction of the welding gasket, and then weld the gasket to achieve Matching process requirements
2. The intermediate bearing is temporarily fixed
2.1 Before the main shafting system is centered, pre-install four top-lifting top wire sockets at appropriate positions on the middle bearing frame panel, then install the intermediate bearing at the journal of the intermediate shaft, and pay attention to the center of the intermediate bearing housing to Distance requirement for the end face of the rear flange of the intermediate bearing
2.2 After the initial centering of the main machine, the front and rear left and right sides of the welding intermediate bearing are temporarily adjusted to the top wire seat and the card, code tooling
3 main shaft shaft load adjustment before the initial installation of the intermediate bearing
3.1 After the shafting is verified and the bolts are installed, the bearing cap is opened, the height of the four top wires of the bearing base is adjusted, and the top wire is temporarily adjusted. The gap between the bearing bush and the shaft neck is zero, and the left and right gaps are equal.
3.2 After the bearing is assembled with the journal, check whether the gap between the hole at the two ends and the journal is uniform.
3.3 Clean the joint surface and the upper inner control and apply clean lubricating oil.
3.4 Wipe the copper gasket of the intermediate bearing and place it correctly on the bearing joint surface.
3.5 Place the bearing cap on the bearing housing as a whole and position the bearing cap correctly with two taper pins
3.6 Insert the bearing cap and the fastening bolt on the bearing housing and tighten
4. Protection of intermediate bearing during main shaft load adjustment
The bearing cover is about 2mm high, and the gap between the bearing cover and the bearing housing must be covered with a color belt. The front and rear end faces are sealed with white buckle cloth to prevent dust, welding slag, water vapor and other impurities from entering the bearing housing. Inside
5. Installation of the intermediate bearing after the main body is glued
5.1 After the main machine is glued for 24 hours, according to the above requirements, the relevant parameters of the middle bearing installation of the accessory, after meeting the process requirements, the intermediate bearing is re-tested and must meet the process requirements.
5.2 No. Hole and Drilling of Intermediate Bearing Frame
5.3 Measure the gap between the bottom of the bearing seat and the welding pad at the four corners of each gasket. According to the experience, plus the gasket and the remaining amount, the thickness of the positive gasket is processed and the adjustment gasket is matched and matched. The inspection gasket can move the adjustment gasket out of the drill hole. After drilling, the adjustment gasket can be inserted between the bottom of the bearing seat and the welding gasket. Finally, the intermediate bearing anchor bolt is installed.
5.4 After the intermediate bearing anchor bolt is tightened, remove the four top-lifting top wires of the intermediate bearing base, and re-test the intermediate bearing load. After meeting the process requirements, the positioning pin can be processed and punched into the pin hole.
5.5 Remove the intermediate bearing before and after the temporary fixed top wire
5.6 Open the bearing cap and install the oil pan on the intermediate shaft in the oil cavity at the end of the bearing housing to adjust the distance between the sharp angle of the oil pan and the sharp angle of the bearing body to meet the technical requirements of the drawings.
5.7 Check whether the left and right clearances of the intermediate bearing are uniform, and check whether the total clearance meets the drawing requirements by using the lead wire method.
5.8 Thorough cleaning of the inner cavity of the bearing on the intermediate bearing
5.9 Place the bearing cap on the bearing housing and position the bearing cap correctly with two taper pins, install the fastening bolts and tighten them to ensure the integrity of the intermediate bearing installation.
5.10 Install rubber on the gap between the front and rear ends of the intermediate bearing and the intermediate shaft to prevent dust from entering the intermediate bearing.
2018年12月8日星期六
Joint bearing heating device precautions
The additional sealing device supported by the joint bearing can effectively work the bearing under good conditions without being invaded by external dirt, but the additional sealing device increases the axial dimension of the mechanical mechanism and brings the use and installation of the bearing. Inconvenience, at the same time, the sealing performance of the additional sealing device is often affected by the machining accuracy and shape tolerance of the matching part of the journal and the housing. For this reason, the structure is compact and the sealing requirements are strict.
Commonly used heating methods are:
1. Electric heating plate heating method The bearing is placed on a hot plate with a temperature of 100 ° C for a few minutes. This method is the easiest, such as turning the bearing several times to make the bearing heat evenly, and the efficiency is also high, the size of the joint bearing can use this law.
2. Electric furnace heating method The bearing is placed in a closed automatic temperature control electric furnace for heating, uniform heating, accurate temperature control, fast heating, suitable for a batch of heating many bearings.
3. Induction heating method The induction heater can quickly, reliably and cleanly heat the joint bearing to the required temperature. This is especially suitable for the case where the inner ring is tightly fitted. Because the inner ring is heated, the outer ring is heated. Less, this can be easily mounted on the shaft and easy to fit into the seat hole.
4. Light bulb heating method uses 50W bulb to heat the joint bearing, which can guarantee the heating temperature is about 100 °C. The smaller bearing can be placed directly on the bulb. The larger bearing can be placed in the cone of the bulb. The cone cover can be prevented. The heat of the bulb is lost, and the heating evenly conical cover can be adjusted up and down. In a certain range, it can adapt to heating different sizes of bearings. If a far-infrared bulb is used, pay attention to the direction of the bulb should be downward, so that the infrared rays are not conducive to the human eye. A kind of bulb can be used for energy-saving bulb heating method. It is suitable for small quantity and not often needed; in the case of heating the bearing, the bulb can also be used for illumination, and no other equipment is needed.
5. Oil tank heating method This is a widely used traditional heating method. The oil tank is provided with a metal mesh at a distance of 50~70mm from the bottom. The bearing is placed on the net. The large bearing should be hung with a hook. The bearing should not be placed directly on the bottom of the groove to prevent the contact groove. The bearing parts of the bottom are partially heated too high, or the dirt deposited at the bottom of the tank enters the bearing oil tank. The points of attention of the heating method are as follows. Mineral oil with good non-corrosive thermal stability should be used, preferably transformer oil, oil and container should be The capacity of the clean oil tank should be determined according to the size and oil quantity of the heated joint bearing. If the container is too small, the temperature of the oil will drop rapidly when the machine is continuously operated, and the effect will not be good.
Shaft tolerance and selection and control of the TIMKEN bearing chamber: the bearing is not flexible after the rotary pressure. If the significant rotation is not flexible, the size of the shaft is too large and the tolerance is degraded. If the TIMKEN bearing is pressed into the hand, the obvious "sand" is steering the shaft in a certain sense. It may be that too many round shafts or shaft tolerances are not good. A good shaft center control room and bearing tolerances, so the roundness should also be controlled.
TIMKEN bearing assembly mode: Because the bearing is a high-precision product, such as improper assembly, easy to damage the channel bearing, resulting in bearing damage. TIMKEN bearings are assembled, there should be a special mold, can not be defeated, the thrust force can only be a small circle, the press only forces the circle. The assembly requires the use of air pressure or hydraulic pressure, when crimping the upper and lower molds, outside the national level, if the slope of the passage will cause the bearing to be damaged, due to the electric power, leave the guide ring of the production bearing TIMKEN.
Prevention of assembly of foreign objects: When the bearing is mounted on the rotor, it is easy to generate the dynamic balance of the bearing in the iron filings before installation, so it is best to do dynamic balancing. TIMKEN bearings put some oil or grease lubrication in the conference room, but operators often have difficulty controlling the amount. If the plot in the oil or grease bearing is left indoors, it is easy to rotate along the shaft to the inside of the TIMKEN bearing. The bearing chamber is preferably not oiled or greased. If it is not coated, there must be no conspiracy TIMKEN bearings to stay indoors.
Prevention of paint rust: Paint rust is characterized by a sealed motor, and multiple motors in the assembly sounds good, but in a warehouse for a while, the motor becomes very abnormal sound, removing the imported bearings from severe rust. Many manufacturers will be seen as problems with the front bearings, and now the major electrical plants are aware of the problem of varnish. The main problem is that the insulating paint emits volatile acid at a certain temperature, the corrosion and protection of the moisture metal, the formation of corrosive substances, and the corrosion damage caused by the channel TIMKEN bearing. The only problem now is to choose a good varnish and air dry for a while after assembly.
TIMKEN bearing life is closely related to manufacturing, assembly, and use, and must be made every step to enable the country to operate the best bearings, thereby extending the life of TIMKEN bearings.
Commonly used heating methods are:
1. Electric heating plate heating method The bearing is placed on a hot plate with a temperature of 100 ° C for a few minutes. This method is the easiest, such as turning the bearing several times to make the bearing heat evenly, and the efficiency is also high, the size of the joint bearing can use this law.
2. Electric furnace heating method The bearing is placed in a closed automatic temperature control electric furnace for heating, uniform heating, accurate temperature control, fast heating, suitable for a batch of heating many bearings.
3. Induction heating method The induction heater can quickly, reliably and cleanly heat the joint bearing to the required temperature. This is especially suitable for the case where the inner ring is tightly fitted. Because the inner ring is heated, the outer ring is heated. Less, this can be easily mounted on the shaft and easy to fit into the seat hole.
4. Light bulb heating method uses 50W bulb to heat the joint bearing, which can guarantee the heating temperature is about 100 °C. The smaller bearing can be placed directly on the bulb. The larger bearing can be placed in the cone of the bulb. The cone cover can be prevented. The heat of the bulb is lost, and the heating evenly conical cover can be adjusted up and down. In a certain range, it can adapt to heating different sizes of bearings. If a far-infrared bulb is used, pay attention to the direction of the bulb should be downward, so that the infrared rays are not conducive to the human eye. A kind of bulb can be used for energy-saving bulb heating method. It is suitable for small quantity and not often needed; in the case of heating the bearing, the bulb can also be used for illumination, and no other equipment is needed.
5. Oil tank heating method This is a widely used traditional heating method. The oil tank is provided with a metal mesh at a distance of 50~70mm from the bottom. The bearing is placed on the net. The large bearing should be hung with a hook. The bearing should not be placed directly on the bottom of the groove to prevent the contact groove. The bearing parts of the bottom are partially heated too high, or the dirt deposited at the bottom of the tank enters the bearing oil tank. The points of attention of the heating method are as follows. Mineral oil with good non-corrosive thermal stability should be used, preferably transformer oil, oil and container should be The capacity of the clean oil tank should be determined according to the size and oil quantity of the heated joint bearing. If the container is too small, the temperature of the oil will drop rapidly when the machine is continuously operated, and the effect will not be good.
Shaft tolerance and selection and control of the TIMKEN bearing chamber: the bearing is not flexible after the rotary pressure. If the significant rotation is not flexible, the size of the shaft is too large and the tolerance is degraded. If the TIMKEN bearing is pressed into the hand, the obvious "sand" is steering the shaft in a certain sense. It may be that too many round shafts or shaft tolerances are not good. A good shaft center control room and bearing tolerances, so the roundness should also be controlled.
TIMKEN bearing assembly mode: Because the bearing is a high-precision product, such as improper assembly, easy to damage the channel bearing, resulting in bearing damage. TIMKEN bearings are assembled, there should be a special mold, can not be defeated, the thrust force can only be a small circle, the press only forces the circle. The assembly requires the use of air pressure or hydraulic pressure, when crimping the upper and lower molds, outside the national level, if the slope of the passage will cause the bearing to be damaged, due to the electric power, leave the guide ring of the production bearing TIMKEN.
Prevention of assembly of foreign objects: When the bearing is mounted on the rotor, it is easy to generate the dynamic balance of the bearing in the iron filings before installation, so it is best to do dynamic balancing. TIMKEN bearings put some oil or grease lubrication in the conference room, but operators often have difficulty controlling the amount. If the plot in the oil or grease bearing is left indoors, it is easy to rotate along the shaft to the inside of the TIMKEN bearing. The bearing chamber is preferably not oiled or greased. If it is not coated, there must be no conspiracy TIMKEN bearings to stay indoors.
Prevention of paint rust: Paint rust is characterized by a sealed motor, and multiple motors in the assembly sounds good, but in a warehouse for a while, the motor becomes very abnormal sound, removing the imported bearings from severe rust. Many manufacturers will be seen as problems with the front bearings, and now the major electrical plants are aware of the problem of varnish. The main problem is that the insulating paint emits volatile acid at a certain temperature, the corrosion and protection of the moisture metal, the formation of corrosive substances, and the corrosion damage caused by the channel TIMKEN bearing. The only problem now is to choose a good varnish and air dry for a while after assembly.
TIMKEN bearing life is closely related to manufacturing, assembly, and use, and must be made every step to enable the country to operate the best bearings, thereby extending the life of TIMKEN bearings.
Selection of low noise bearings
(1) Rolling bearings with low noise requirements
Among the standard bearings produced in China, some single-row radial ball bearings and short cylindrical roller bearings have low noise types for power supply bearings. There are several varieties of ball bearings from the inner diameter φ2.5mm to φ60mm with three suffixes of Zl, Z2 and Z3, which respectively correspond to three different low noise requirements, and there are also eight models of roller bearings from N309 to N322. Variety made according to low noise standards.
These bearings are perfectly suited for use in other machines with low noise requirements and are inexpensive, as is the type and size of the two types of low noise bearings.
(2) Bearings with relatively low noise
When the above two types of low noise bearings cannot be used, bearings with relatively low noise can be used. The specific comparison is based on the following:
1) The noise of the ball bearing is lower than that of the roller bearing, and the (friction) noise of the bearing with less relative sliding is lower than that of the bearing with relatively relatively sliding;
2) The noise of the cage using the solid cage is relatively lower than that of the bearing using the stamped cage; the noise of the bearing using the plastic cage is lower than that of the bearing using the above two cages; the number of balls is large, the outer ring is thick, and the noise is Also small,
3) Bearings with high precision, especially those with higher precision rolling elements, have lower noise than low-precision bearings.
4) The noise of small bearings is relatively small compared to the noise of large bearings.
Among the standard bearings produced in China, some single-row radial ball bearings and short cylindrical roller bearings have low noise types for power supply bearings. There are several varieties of ball bearings from the inner diameter φ2.5mm to φ60mm with three suffixes of Zl, Z2 and Z3, which respectively correspond to three different low noise requirements, and there are also eight models of roller bearings from N309 to N322. Variety made according to low noise standards.
These bearings are perfectly suited for use in other machines with low noise requirements and are inexpensive, as is the type and size of the two types of low noise bearings.
(2) Bearings with relatively low noise
When the above two types of low noise bearings cannot be used, bearings with relatively low noise can be used. The specific comparison is based on the following:
1) The noise of the ball bearing is lower than that of the roller bearing, and the (friction) noise of the bearing with less relative sliding is lower than that of the bearing with relatively relatively sliding;
2) The noise of the cage using the solid cage is relatively lower than that of the bearing using the stamped cage; the noise of the bearing using the plastic cage is lower than that of the bearing using the above two cages; the number of balls is large, the outer ring is thick, and the noise is Also small,
3) Bearings with high precision, especially those with higher precision rolling elements, have lower noise than low-precision bearings.
4) The noise of small bearings is relatively small compared to the noise of large bearings.
2018年12月7日星期五
Improvement of pre-tightening force of thrust spherical roller bearing
The thrust spherical roller bearing is structurally closed, and the tight ring, the roller and the cage of the bearing are locked by the bushing into a non-separating whole, but the movable ring and the whole are separable. In the lower bearing of the vertical installation, the bearing, the shaft and the self-weight of the other parts on the shaft can be used to form a non-separated state between the tight and the live ring. However, in the vertical installation of the upper and horizontally mounted bearings at both ends, usually after pressing the pressed end cap, the compression bolts are retracted by a certain distance (0.2-1 mm) to avoid too small clearance. The bearing temperature is caused by the running temperature difference. {TodayHot}, however, if the gap occurs, if the gap is too large, the separation between the tight ring member and the ring will be formed, so a reasonable preload can prevent the spin and spin of the rolling element from slipping, and the rolling element can be maintained. The correct position in the raceway.
In order to ensure the normal operation of the bearing, a certain axial load must be applied, and the minimum axial load required is:
Fa mim= Coz/1000
Fa mim-------Minimum axial load (KN)
Coa-------------Basic Static Load Rating (KN)
In 2004, we produced a thrust spherical roller bearing 292/500 bearing for the 1700 rolling mill of Benxi Iron and Steel Co., Ltd., which was installed on the support roller of the rolling mill to support the axial force. It is mounted in the bearing seat horizontally in the face-to-face direction. In order to prevent the bearing from being stuck during operation, after the end plate cover bolt is pressed, the distance of 0.2 mm or more is released. At the same time, in order to avoid the radial force of the thrust bearing after the bending of the work roll, the matching gap between the shaft box hole and the outer diameter of the ring is >2mm, and under the intermittent force, it is more likely to be stuck, and even the bearing parts are replaced. It is damaged by local impact. {HotTag}
After analysis, we believe that this pressing method is unreasonable, but we can only find a way to design the bearing. After research, we designed 8 uniform spring holes on the end face of the bearing race, and installed 8 diameters of 3 mm. The spring, the maximum spring force of each spring is 800 Newtons, so that after the bearing is installed in the bearing housing and pressed against the cover plate, the spring force directly acts on the bearing housing and the cover end face so that the journal is in the direction of the journal. It is not floated when it is displaced left and right, it can ensure the correct position of the rolling elements in the raceway. Keep the roller and the raceway in good contact from beginning to end. The purpose of the pre-tightening can be basically achieved, and when the axial force is applied, the cylindrical shaft in the spring hole first contacts the bearing seat and the cover plate under the action of the spring force, and the axial force is buffered, so that the original bearing is The damage situation has been basically solved, the life of the bearing has been greatly extended, and the user's requirements have been met, which has been well received by users.
In order to ensure the normal operation of the bearing, a certain axial load must be applied, and the minimum axial load required is:
Fa mim= Coz/1000
Fa mim-------Minimum axial load (KN)
Coa-------------Basic Static Load Rating (KN)
In 2004, we produced a thrust spherical roller bearing 292/500 bearing for the 1700 rolling mill of Benxi Iron and Steel Co., Ltd., which was installed on the support roller of the rolling mill to support the axial force. It is mounted in the bearing seat horizontally in the face-to-face direction. In order to prevent the bearing from being stuck during operation, after the end plate cover bolt is pressed, the distance of 0.2 mm or more is released. At the same time, in order to avoid the radial force of the thrust bearing after the bending of the work roll, the matching gap between the shaft box hole and the outer diameter of the ring is >2mm, and under the intermittent force, it is more likely to be stuck, and even the bearing parts are replaced. It is damaged by local impact. {HotTag}
After analysis, we believe that this pressing method is unreasonable, but we can only find a way to design the bearing. After research, we designed 8 uniform spring holes on the end face of the bearing race, and installed 8 diameters of 3 mm. The spring, the maximum spring force of each spring is 800 Newtons, so that after the bearing is installed in the bearing housing and pressed against the cover plate, the spring force directly acts on the bearing housing and the cover end face so that the journal is in the direction of the journal. It is not floated when it is displaced left and right, it can ensure the correct position of the rolling elements in the raceway. Keep the roller and the raceway in good contact from beginning to end. The purpose of the pre-tightening can be basically achieved, and when the axial force is applied, the cylindrical shaft in the spring hole first contacts the bearing seat and the cover plate under the action of the spring force, and the axial force is buffered, so that the original bearing is The damage situation has been basically solved, the life of the bearing has been greatly extended, and the user's requirements have been met, which has been well received by users.
2018年12月5日星期三
Bearing vibration and temperature inspection
1, the vibration of the bearing
Bearing vibration is very sensitive to bearing damage. For example, peeling, indentation, rust, crack, wear, etc. are reflected in the bearing vibration measurement. Therefore, vibration can be measured by using a special bearing vibration measuring device (frequency analyzer, etc.). The size of the frequency can not be inferred from the specific circumstances of the abnormality. The measured value differs depending on the conditions of use of the bearing or the position at which the sensor is mounted. Therefore, it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard.
2, the temperature of the bearing
The temperature of the bearing, generally the temperature outside the bearing can be inferred. If the oil hole can directly measure the temperature of the bearing outer ring, it is more suitable.
Usually, the temperature of the bearing rises slowly as the bearing starts to run, and reaches a steady state after 1-2 hours. The normal temperature of the bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If the lubrication and installation parts are suitable, the bearing temperature will rise sharply and abnormal temperature will occur. At this time, it is necessary to stop the operation and take necessary precautions.
The thermal sensor can be used to monitor the operating temperature of the bearing at any time, and automatically alarm or stop the occurrence of a burning shaft accident when the temperature exceeds the specified value.
The high temperature often indicates that the bearing is in an abnormal condition. High temperatures are also harmful to the lubricant of the bearing. Sometimes the bearing overheating can be attributed to the lubricant of the bearing. Long-term continuous rotation of the bearing at temperatures above 125 °C will reduce bearing life. Causes of high temperature bearings include: insufficient lubrication or excessive lubrication, lubricants. Contains impurities, excessive load, bearing damage, insufficient clearance, and high friction caused by oil seals.
Therefore, it is necessary to continuously monitor the bearing temperature, whether it is measuring the bearing itself or other important parts. If the operating conditions are the same, any temperature change can indicate that a fault has occurred.
The periodic measurement of the bearing temperature can be carried out by means of a thermometer, such as a skf digital thermometer, which accurately measures the bearing temperature and displays it in °C or Fahrenheit.
The importance of the bearing means that when it is damaged, it will cause the equipment to stop. Therefore, it is better to install a temperature detector for this type of bearing.
Under normal conditions, the bearing will naturally rise in temperature after lubrication or relubrication and last for one or two days.
Bearing vibration is very sensitive to bearing damage. For example, peeling, indentation, rust, crack, wear, etc. are reflected in the bearing vibration measurement. Therefore, vibration can be measured by using a special bearing vibration measuring device (frequency analyzer, etc.). The size of the frequency can not be inferred from the specific circumstances of the abnormality. The measured value differs depending on the conditions of use of the bearing or the position at which the sensor is mounted. Therefore, it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard.
2, the temperature of the bearing
The temperature of the bearing, generally the temperature outside the bearing can be inferred. If the oil hole can directly measure the temperature of the bearing outer ring, it is more suitable.
Usually, the temperature of the bearing rises slowly as the bearing starts to run, and reaches a steady state after 1-2 hours. The normal temperature of the bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If the lubrication and installation parts are suitable, the bearing temperature will rise sharply and abnormal temperature will occur. At this time, it is necessary to stop the operation and take necessary precautions.
The thermal sensor can be used to monitor the operating temperature of the bearing at any time, and automatically alarm or stop the occurrence of a burning shaft accident when the temperature exceeds the specified value.
The high temperature often indicates that the bearing is in an abnormal condition. High temperatures are also harmful to the lubricant of the bearing. Sometimes the bearing overheating can be attributed to the lubricant of the bearing. Long-term continuous rotation of the bearing at temperatures above 125 °C will reduce bearing life. Causes of high temperature bearings include: insufficient lubrication or excessive lubrication, lubricants. Contains impurities, excessive load, bearing damage, insufficient clearance, and high friction caused by oil seals.
Therefore, it is necessary to continuously monitor the bearing temperature, whether it is measuring the bearing itself or other important parts. If the operating conditions are the same, any temperature change can indicate that a fault has occurred.
The periodic measurement of the bearing temperature can be carried out by means of a thermometer, such as a skf digital thermometer, which accurately measures the bearing temperature and displays it in °C or Fahrenheit.
The importance of the bearing means that when it is damaged, it will cause the equipment to stop. Therefore, it is better to install a temperature detector for this type of bearing.
Under normal conditions, the bearing will naturally rise in temperature after lubrication or relubrication and last for one or two days.
Rolling bearing hardness
Regarding the hardness of the bearing, the inner and outer rings of the rolling bearing and the rolling elements are made of high-chromium steel GCr15 or GCr15SiMn bearing steel. The hardness of the finished bearing ring is in Rockwell HRC60-65; the hardness of the finished bearing rolling element is in Rockwell HRC60-66. Among them, the hardness of the steel ball made of GCr15 bearing steel is in the range of Rockwell HRC62-66; the hardness of the roller made of GCr15SiMn bearing steel is in the range of Rockwell HRC60-64 and steel ball in Rockwell HRC60-66. Maybe you don't know what Rockwell hardness HRC is. For example, the hardness of the blade of a household kitchen knife is generally around HRC50. The steel of surgical tools and military cutters should be pure and the hardness is also within the Rockwell HRC60. . The hardness of the alloy cutter head for machine tool metal turning is also about 62 to 65 in Rockwell HRC. The hardness of the rolling bearing is relatively hard, and the finished bearing needs to be further processed with special equipment and tools.
2018年12月4日星期二
The cause of abnormal damage to the hub bearing
During the maintenance process, it is often found that some vehicles have large running noise, and the tires are checked for no abnormal wear, and there is no obvious abnormal sound when the wheels are turned on the lift.
This phenomenon is often caused by abnormal damage of the hub bearing. The so-called abnormality refers to the bearing damage caused by the installation.
The front wheel bearing of a car is generally a double row ball bearing. If the hammer is used for the installation when the bearing is installed, or when the bearing is installed into the bearing housing, the inner ring of the bearing is installed by the pressure bearing inner ring. damage. Noise is generated when the vehicle is running, and no significant noise is heard when the wheel is off the ground due to the better side of the raceway. Proper installation is the key to long bearing life
This phenomenon is often caused by abnormal damage of the hub bearing. The so-called abnormality refers to the bearing damage caused by the installation.
The front wheel bearing of a car is generally a double row ball bearing. If the hammer is used for the installation when the bearing is installed, or when the bearing is installed into the bearing housing, the inner ring of the bearing is installed by the pressure bearing inner ring. damage. Noise is generated when the vehicle is running, and no significant noise is heard when the wheel is off the ground due to the better side of the raceway. Proper installation is the key to long bearing life
2018年12月3日星期一
Radial spherical bearing model
(1) GE...E type: single outer ring, no lubricating oil groove. Can withstand radial loads and small axial loads in either direction.
(2) GE...ES type: single-slit outer ring with lubricating oil groove. Can withstand radial loads and small axial loads in either direction.
(3) GE...ES-2RS type, GEEW...ES-2RS type: single-slit outer ring with lubricating oil groove and sealing ring on both sides. Can withstand radial loads and small axial loads in either direction.
(4) GE...ESN type: single-slit outer ring, GE...XSN type: double-slit outer ring (split outer ring), with oil groove, and outer ring with stop groove. Can withstand radial loads and small axial loads in either direction. However, when the axial load is received by the retaining ring, its ability to withstand axial loads is reduced.
(5) GE...HS type: There are lubricating oil grooves in the inner ring and double outer rings. The clearance can be adjusted after wear. Can withstand radial loads and small axial loads in either direction.
(6) GE...DE1 type: the inner ring is hardened bearing steel and the outer ring is bearing steel. Extrusion during assembly of the inner ring, with lubrication grooves and oil holes. Bearings with an inner diameter of less than 15 mm, no lubrication grooves and oil holes. Can withstand radial loads and small axial loads in either direction.
(7) GE...DEM1 type: the inner ring is hardened bearing steel and the outer ring is bearing steel. When the inner ring is assembled, it is extruded. After the bearing is installed in the bearing housing, the end groove is pressed out on the outer ring to fix the bearing axially. Can withstand radial loads and small axial loads in either direction.
(8) GE...DS type: The outer ring has a fitting groove and a lubrication groove. Limited to large size bearings. Can withstand radial loads and small axial loads in either direction (the side of the mounting groove cannot withstand axial loads).
(2) GE...ES type: single-slit outer ring with lubricating oil groove. Can withstand radial loads and small axial loads in either direction.
(3) GE...ES-2RS type, GEEW...ES-2RS type: single-slit outer ring with lubricating oil groove and sealing ring on both sides. Can withstand radial loads and small axial loads in either direction.
(4) GE...ESN type: single-slit outer ring, GE...XSN type: double-slit outer ring (split outer ring), with oil groove, and outer ring with stop groove. Can withstand radial loads and small axial loads in either direction. However, when the axial load is received by the retaining ring, its ability to withstand axial loads is reduced.
(5) GE...HS type: There are lubricating oil grooves in the inner ring and double outer rings. The clearance can be adjusted after wear. Can withstand radial loads and small axial loads in either direction.
(6) GE...DE1 type: the inner ring is hardened bearing steel and the outer ring is bearing steel. Extrusion during assembly of the inner ring, with lubrication grooves and oil holes. Bearings with an inner diameter of less than 15 mm, no lubrication grooves and oil holes. Can withstand radial loads and small axial loads in either direction.
(7) GE...DEM1 type: the inner ring is hardened bearing steel and the outer ring is bearing steel. When the inner ring is assembled, it is extruded. After the bearing is installed in the bearing housing, the end groove is pressed out on the outer ring to fix the bearing axially. Can withstand radial loads and small axial loads in either direction.
(8) GE...DS type: The outer ring has a fitting groove and a lubrication groove. Limited to large size bearings. Can withstand radial loads and small axial loads in either direction (the side of the mounting groove cannot withstand axial loads).
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