LIMA Fish Feed Machine,Chicken Feed Machine
According to the different working conditions of the outer ring of the bearing during use, the rolling bearing can be divided into: the outer ring is stationary relative to the load direction and the outer ring rotates relative to the load direction. For the latter, the bearing inner ring is stationary relative to the load direction, and the rotation load acts in the bearing outer ring, the bearing of the ring molded machine rotor is in the form of the rotation. Figure 1 shows the rotor assembly of the ring type granulator, wherein the spindle is stationary, the rotor rotates under dynamic action, and the rotation load acts on the bearing outer ring. A bearing in the form of transmissions usually has a tightly in-housing with the outer casing. The rotor bearing machine in the process of the ring model is too high, and the bearing wear is severe and the life is short.¡¡¡¡The fit of the inner and outer rings of the rolling bearing and the radial working clearance have a great influence on the bearing life, temperature rise, noise, etc. The cooperation of the rolling bearing and the outer ring and the radial working overshoot is analyzed. 1. Fit 1.1 Fitting between the bearing outer ring and the housing hole When the outer ring rotates under load, friction occurs between the bearing rolling element and the raceway, and both the bearing and the casing are thermally expanded. However, due to the difference in the expansion coefficient and heat dissipation speed, when the expansion of the casing is greater than that of the bearing outer ring, the interference will Reduced, there will be harmful relative sliding in the circumferential direction between the bearing outer ring and the housing hole. This phenomenon is called creep phenomenon. Once creep occurs, obvious wear will occur on the mating surface and the bearing outer ring or housing will be damage. Therefore, the coordination of the bearing outer ring and the outer casing must satisfy the minimum overference ymin. In addition, the interference should not be too large. Under the action of the working load, the bearing will cause the radial clearance of the bearing to decrease and the clearance The reduction will cause the bearing to heat up and the temperature will rise. At the same time, the large interference will also bring difficulties to the installation and disassembly of the bearing. Therefore, the appropriate interference should be selected according to the load conditions. 1.2 The fit between the bearing inner ring and the shaft is usually a clearance fit between the bearing inner ring and the shaft. The size of the fit gap depends on the load on the bearing, the fit between the bearing outer ring and the shell hole, and the choice of bearing clearance. The fit of the shaft also affects the radial working clearance of the bearing. 2. Radial working clearance Clearance is an important parameter of rolling bearing coordination, which directly affects the technical performance of bearing load distribution, vibration, noise, wear, temperature rise, service life and mechanical operation accuracy. Based on the bearing volume changes with the size of the gap. The number of working degradation is too large, the number of rolling, the bearing carrying capacity will be reduced, the stress of the rolling contact surface is increased, the operation accuracy of the bearing is lowered, the vibration and noise increases, the life of the bearing is shortened; the work is too small It will cause the bearing to fever, the temperature is increased, and even the bearing occurs during the operation. Influencing factors of the clearance: ¢Ù The outer ring of the bearing and the housing hole are assembled by interference, therefore, assembly stress is generated at the mating surface, the outer ring is elastically deformed, and the inner raceway of the outer ring shrinks inwardly, thereby reducing the radial clearance. ; ¢Ú Under the action of the working load, the rotating load acts on the outer ring of the bearing, and the radial force makesThe outer ring is contracted and the elastic contact deformation is contracted, causing the radial working clearance to decrease; 3 bearing operation When the temperature increases on the radial working overshoot, the temperature increase causes the bearing inner ring to expand, so that the radial work The swag is reduced; the bearing outer ring and the outer casing are thermally expanded, but due to the difference in the material, the extent of the expansion coefficient is different, and the heat dissipation speed affects the extent of the expansion, the outer ring expansion is smaller than the outer casing, and the radial operation is reduced. The radial working gap is increased; 4 bearing at operation, the grease will be in the rolling body and the outer ring to form the elastic fluid dynamic oil film, the existence of the oil film thickness reduces the radial gap, and the pressure oil film The thickness is related to the viscosity of grease. 3 examples Apply a model ring mold granule, the spindle journal D, the inner hole diameter D, the bearing is the SKF spherical roller bearing, the bearing standard swing 95 ~ 145 ¦Ìm, the upper deviation of the spindle journal D, down deviation – 25 ¦Ìm, the upper deviation of the inner hole diameter D of -14 ¦Ìm, and the lower deviation of – 60 ¦Ìm. The bearing outer ring and the inner hole in the outer casing are overbound. The mating of the bearing inner ring and the shaft is excessively fitted. In the process of use, the bearing temperature is high, and the bearing service life is short. The tolerance strip of the rotor spindle journal D is modified, and the case is improved, the case is improved in the normal range, and the bearing is operating normally. CAUSE The gap is reduced; the inner ring produces contraction deformation under radial force, and the radial working overshoot is increased, but since the excessive cooperation, the deformation is small, the radial working clearance increase is small, and the radial direction is operated The clearance is smaller than the minimum oversight required by the bearing, therefore, the bearing temperature rise is high. After increasing the inner ring and the journal, the inner ring generates contraction deformation under radial force, and the radial operation is increased. At this time, the radial working clearance satisfies the minimum oversight required by the bearing normal operation. When the bearing is running out of operation, the temperature of the outer ring shaft is relatively stable, and the radial working clearance is also stabilized, and the final bearing reaches stable operation. Therefore, it is necessary to select a suitable bearing inner ring and the journal of the gap size to the rock molded machine rotor bearing. 4 Inside the tissue rolling bearing, the coordination selection and radial working overall size of the outer ring plays an important role in the normal operation of the ring mold granulator rotor bearing, and there is an interaction between the above influencing factors, so when doing similar structural design, according to The bearing situation of the bearing determines the size of the appropriate bearing radial gap, to consider the bearing, the outer ring is in the bearing, the elastic deformation, temperature rise, and the outer shell The influence of expansion and dynamic oil film thickness on the bearing radial wrap, the fit of the outer ring and the shell hole, the inner ring of the bearing and the shaft.
