精密轴承安装：1．精密轴承对相配机件的要求:由于精密轴承本身的精度在1

Precision bearing installation: <br><br>1. Requirements of precision bearings for matching parts: <br><br>Since the precision of the precision bearings is within 1μm, it is required to have high dimensional accuracy and shape accuracy with the matching parts (shaft, bearing housing, end cover, retaining ring, etc.) The accuracy of the surface should be controlled within the same level as the bearing, which is crucial, and it is also the most easily overlooked. <br><br>It must also be noted that if the matching parts of the precision bearing fail to meet the above requirements, the precision bearing often causes an error that is several times larger than the original bearing after installation, or even more than 10 times. The error of the machine parts is not simply superimposed on the error of the bearing, but is added after being amplified by different multiples. <br><br>2. Coordination of precision bearings: <br><br>In order to ensure that the bearing does not deform too much after installation, it must: <br><br>(1) The roundness of the shaft and the seat hole and the perpendicularity of the shoulder should be in accordance with the corresponding accuracy of the bearing. <br>(2) It is necessary to accurately calculate the interference amount of the rotating ferrule fit, as well as the appropriate fit of the fixed ferrule. <br>The amount of burning interference of the rotating ferrule should be smaller within the possible range. As long as the effect of thermal expansion at the operating temperature and the effect of centrifugal force at the highest speed are ensured, it will not cause creeping or sliding of the tight-fitting surface. According to the size of the working load and the size of the bearing, the fixed ring selects the smallest clearance fit or interference fit. Too loose or too tight is not conducive to maintaining the original accurate shape. <br><br>(3) If the bearing is operated under high speed conditions and the working temperature is high, special attention should be paid to the fitting of the rotating ferrules not to be too loose to prevent eccentric vibration, and the fit of the fixed ferrules must not have gaps to prevent the ferrules from Deforms under load and excites vibration. <br><br>(4) The condition of adopting a small interference fit for the fixing ring is that both the matching surfaces have high shape accuracy and small roughness, otherwise it will cause difficulty in installation and disassembly is more difficult. In addition, the effect of thermal elongation of the spindle needs to be considered .<br><br>(5) The main shaft using paired double angular contact ball bearings is mostly light in load. If the interference fit is too large, the internal axial preload will be significantly larger, causing adverse effects. The main shafts using double-row short cylindrical roller bearings and the main shafts of tapered roller bearings have relatively large loads, so the interference fit is also relatively large. <br><br>3. Methods to improve the actual fit accuracy: <br><br>In order to improve the actual fit accuracy when installing precision bearings, it is necessary to use the measuring method and measuring tools that do not deform the bearings to carry out actual precision measurements on the mating surface dimensions of the inner hole and outer circle of the bearing. All the measurement items related to the inner diameter and outer diameter are measured, and a comprehensive analysis of the measured data is used as a basis to precisely match the size of the bearing installation part of the shaft and the seat hole. When actually measuring the corresponding size and geometry of the shaft and the seat hole, it should be carried out under the same temperature conditions as when measuring the bearing. <br><br>In order to ensure a higher actual matching effect, the roughness of the surface of the shaft and the seat hole and the bearing should be as small as possible. <br><br>When making the above measurements, two sets of markings indicating the direction of the maximum deviation should be made on the outer and inner bores of the bearing, and on the corresponding surfaces of the shaft and seat bore, on both sides near the chamfer of the assembly, In the actual assembly, the maximum deviation of the two parties should be aligned to the same orientation, so that after assembly, the deviation of the two parties can be partially offset. <br><br>The purpose of making two sets of orientation signs is that the compensation for the deviation can be considered comprehensively, so that the rotation accuracy of the two ends of the support is improved, and the coaxiality error of the seat hole between the two supports and the journals of both ends is partially obtained. eliminate. Implementing surface strengthening measures on the mating surface, such as sand blasting, inserting the inner hole with a precision plug with a slightly larger diameter, etc., is conducive to improving the accuracy of the mating.

Precision bearing installation:<br><br>1. Requirements for matching parts for precision bearings:<br><br>Because the precision of the precision bearing itself is within 1 m, it is required to match the machine parts (shafts, housings, end caps, bezels, etc.) have a high dimensional accuracy and shape accuracy, especially the matching surface accuracy to be controlled within the same level as the bearing, this point is critical, and is the most easily overlooked.<br><br>It must also pay attention to the precision bearing matching parts if they do not meet the above requirements, often make precision bearings after installation than the original bearing error many times larger, or even more than 10 times the error, not called precision bearings, because the error of matching parts is often not simply superimposed on the bearing error, but with different multiples of magnification and added.<br><br>2. Fit for precision bearings:<br><br>In order to ensure that the bearings do not cause excessive deformation after installation, it is necessary to:<br><br>(1) The roundness of the shaft and the seat hole and the verticality of the shoulder barrier shall be required in accordance with the corresponding accuracy of the bearing.<br>(2) Not only to accurately calculate the excess amount of rotating collar match, but also to accurately calculate the appropriate amount of fixed collar.<br>The over-the-look amount of the rotating collar is also desirable to achieve a small amount within the possible range. As long as the effect of thermal expansion at operating temperature is effectively guaranteed, as well as the centrifugal force effect at the highest speed, it will not cause the peristalsis or slide of the tight lying surface. Fixed collar according to the operating load size and bearing size, choose a very small gap or over-the-bottom match, too loose or too tight are not conducive to maintaining the original precise shape.<br><br>(3) If the bearing sits at high speed, and the operating temperature is high, special attention should be paid to the coordination of rotating collars can not be too loose, to prevent eccentric vibration, and fixed collar strap mate can not appear gap, to prevent the collar deformation under load and stimulate vibration.<br><br>(4) The condition of taking a small over-the-counter fit for the fixed ring is that both sides of the matching surface have high shape accuracy and small roughness, otherwise it makes installation difficult and more difficult to remove, in addition, the effects of the spindle thermal elongation need to be considered.<br><br>(5) The use of pairs of double-angle contact ball bearing spindle, most of the load is lighter, its over-earnings, if the amount of excess, then its internal axial pretension will be significantly larger, resulting in adverse effects. Using the spindles of double-lined short cylindrical roller bearings and the spindles of conical roller bearings, the load is relatively large, so it is also relatively large.<br><br>3. Ways to improve the accuracy of actual mates:<br><br>In order to improve the actual fit accuracy of precision bearing installation, it is necessary to make use of the measurement method and measuring tool that do not deform the bearing, to make the actual precision measurement of the bearing inner hole and the outer circle of the mating surface size, the measurement items of the inner diameter and outer diameter can be measured, and the measured data are fully analyzed, as a basis, precisely used as the dimensions of the bearing installation site of the shaft and seat hole. The corresponding dimensions and geometry of the shaft and seat hole should be measured in the same temperature as when the bearing was measured.<br><br>In order to ensure a high practical fit effect, shafts and seat holes match the bearing surface, its roughness should be as small as possible.<br><br>In making the above measurement, the outer circle and inner hole of the bearing, as well as the corresponding surface of the shaft and seat hole, on both sides near the assembly chamfer, respectively, make two sets of marks that can indicate the direction of the maximum deviation, so that the maximum deviation of the matching two sides is aligned to the same orientation in the actual assembly, so that the deviation between the two sides can be partially offset after assembly.<br><br>The purpose of making two sets of directional markers is that the compensation of deviation can be considered comprehensively, not only to improve the rotation accuracy of the two ends supporting each other, and to partially eliminate the cosimilation error of the seat holes and the two ends of the shaft neck between the two supports. The implementation of surface enhancement measures on the mating surface, such as sand blasting treatment, with a slightly larger diameter of the precision plug column plug once the hole, are conducive to improving the accuracy of the cooperation.

Precision bearing installation:<br>1. Requirements for matching parts of precision bearing:<br>As the precision of the precision bearing itself is within 1 μ m, it is required to have high dimensional precision and shape precision with its matching parts (shaft, bearing seat, end cover, retaining ring, etc.), especially the precision of the mating surface should be controlled within the same level as the bearing, which is crucial, but also the most easily ignored.<br>It must also be noted that if the matching parts of precision bearing fail to meet the above requirements, the error of precision bearing after installation will be several times larger than that of original bearing, or even more than 10 times, which is not called precision bearing at all, because the error of matching parts is often not simply added to the error of bearing, but added after being magnified by different times.<br>2. Matching of precision bearing:<br>In order to ensure that the bearing does not produce excessive deformation after installation, it is necessary to:<br>(1) The roundness of shaft and seat hole as well as the perpendicularity of retaining shoulder shall be in accordance with the corresponding accuracy of bearing.<br>(2) It is necessary to calculate not only the interference of the fit of the rotating ferrule, but also the fit of the fixed ferrule.<br>It is also advisable to obtain a small amount of burning interference in the possible range. As long as the thermal expansion effect under the working temperature and the centrifugal force effect under the highest speed are ensured, the creep or sliding of the tight fitting surface will not be caused. According to the size of working load and bearing size, select the smallest clearance fit or interference fit, which is not conducive to maintaining the original accurate shape.<br>(3) If the bearing is running at high speed and the working temperature is high, special attention shall be paid to that the fit of the rotating ring shall not be too loose to prevent eccentric vibration, and the fit of the fixed ring shall not have clearance, so as to prevent the ring from deforming and exciting vibration under load.<br>(4) The condition of adopting small interference fit to the fixing ring is that both sides of the matching surface have very high shape accuracy and small roughness, otherwise it will be more difficult to install and disassemble, in addition, the influence of the thermal elongation of the main shaft needs to be considered.<br>(5) When the main shaft of double angular contact ball bearing is used, the multi half load is lighter. If the fit interference is larger, the axial preload in the main shaft will be significantly larger, which will cause adverse effects. The main shaft of double row short cylindrical roller bearing and the main shaft of tapered roller bearing have relatively large load, so the fit interference is relatively large.<br>3. Methods to improve the actual matching accuracy:<br>In order to improve the actual matching accuracy of the precision bearing installation, it is necessary to use the measuring method and measuring tools that do not deform the bearing to carry out the actual precise measurement of the matching surface size of the inner hole and the outer circle of the bearing. All the measuring items related to the inner diameter and the outer diameter can be measured, and the measured data can be comprehensively analyzed. On this basis, the precise matching can be used as the shaft of the shaft and the seat hole The size of the bearing part. When actually measuring the corresponding size and geometry of the matched shaft and seat hole, it shall be carried out under the same temperature condition as when measuring the bearing.<br>In order to ensure a high practical matching effect, the surface roughness of the matching surface of the shaft and seat hole and the bearing should be as small as possible.<br>When making the above measurement, two groups of marks shall be made on the outer circle and inner hole of the bearing, and on the corresponding surface of the shaft and seat hole on both sides close to the assembly chamfer to indicate the maximum deviation direction, so as to align the maximum deviation of the matching two sides with the same direction during the actual assembly, so that the deviation of both sides can be partially offset after the assembly.<br>The purpose of making two sets of directional marks is to comprehensively consider the compensation of the deviation, not only to improve the rotation accuracy of each end bearing, but also to partially eliminate the coaxiality error of the seat hole and the journal at both ends. The surface strengthening measures, such as sandblasting, inserting the inner hole with a small diameter precision plug post and so on, can improve the matching accuracy.<br>