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Maintenance and adjustment of dryer rollers 1. The role of horizontal drum dryer rollers and their inherent shortcomings: 1. The role of horizontal drum dryer rollers: 1.1 Support the entire drum and enable the drum to rotate flexibly. 1.1 Relying on the installation angle of its own center line relative to the center line of the drum to generate axial force, the dryer with an installation slope of 1% can move flexibly between the upper and lower thrust wheels with the load. 2. The inherent shortcomings of the horizontal drum dryer roller itself: 2.1 After debugging, the roller ring and the idler roller have uneven contact along the axial direction due to the installation angle, uneven stress and even partial overload, resulting in premature wear. 2.2 Due to the installation angle between the axis of the drum and the idler, sliding friction occurs when rotating, which accelerates wear and increases power consumption. 2.3 There cannot be effective lubrication between the idler roller and the roller ring, because lubrication will accelerate the decline of the roller. 2.4 It is necessary to frequently pay attention to and adjust the installation clamp angle of the roller to prevent excessive force on the single-side thrust wheel. 2. Precautions for roller assembly and on-site installation: 1. Things to note when assembling rollers: 1.1 When assembling the roller, the bearing and bearing box are divided into fixed end and expansion end. The one located at the lower end of the dryer is the fixed end. There is a limit ring (200/215×3.5thk) between the bearing outer ring and the bearing box end cover. The expansion end is located at the high end of the dryer. The outer ring of the bearing should be installed in the middle of the bearing seat to ensure that there is a certain expansion gap on both sides. 1.2 In order to ensure that the relative position between the bearing and the bearing seat does not change when the assembled roller is hoisted in place, a positioning semi-circular ring must be installed between the labyrinth shaft seal of the roller and the labyrinth groove of the bearing box. After the roller is installed in place, open the bearing box and take out the positioning ring. 2. Precautions when installing rollers: 2.1 There are longitudinal and transverse center lines for roller positioning on the basic platform of the rolling station. The axial width of the roller surface is 228mm. First of all, it is necessary to ensure that the axial direction of the roller surface is evenly distributed on both sides of the transverse center line. 2.2 Secondly, make the distance between the two rollers equal to the longitudinal centerline, and ensure that the center distance of the two rollers is 1369mm, the diameter of the roller is 457mm, and the distance between the centerline of the roller and the basic platform is 145mm. Therefore, the distance between the rollers and the basic platform can be determined by a distance rod with a length of 912mm (1369-457=912) and two supports with a height of (145-r) mm (r is the radius of the distance rod). 3. Inspection work before adjusting the roller: 3.1 Check the clearance on both sides of the thrust wheel and rolling ring: The sum of the clearances on both sides of the thrust wheel and rolling ring is 12mm. This data must be checked. Otherwise, the normal operation of the dryer will be affected. 3.2 Inspection of the contact between the roller and the rolling ring: Before adjusting the roller, the contact between the roller and the rolling ring must be checked using the light transmission method or the paper pressing method. Because there is a certain amount of wear on the rolling ring, the contact between the new and old rollers must be checked before readjustment, and then the position of the roller is adjusted with the help of the top screw to make the contact more even. Notice: Each adjustment amount must be less than 0.1mm. 4. Specific steps and precautions for roller adjustment: 4.1 Judgment of adjustment direction: Make the bending direction of the four fingers of your hand consistent with the direction of rotation of the drum, and the thumb points to the direction that the drum needs to be adjusted. Determine whether the left or right hand meets the conditions. If the right hand meets the conditions, then the axis of the roller will deviate to the right, consistent with Figure (a) ； If the left hand complies, then the axis of the roller will deviate to the left, consistent with picture (b). According to the different rotation directions of the cylinder, it can be divided into the following two situations: ； Facing the lower end of the cylinder, when the cylinder rotates clockwise, adjust the four rollers as shown in the figure (a) to cause the cylinder to generate upward force. ； When the cylinder rotates counterclockwise, adjust the four rollers as shown in (b) to generate upward force on the cylinder. 4.2 Specific steps for roller debugging: After the initial installation of the dryer, run it idling for 10 minutes and observe the position of the rolling ring between the thrust wheels. The normal position is that the rolling ring is close to the lower thrust wheel. This position should be stable. Otherwise, the initial installation of the roller does not meet the technical requirements. Loosen the locking nuts for the eight adjusting jackscrews of the four rollers as shown in the figure above, and ensure that the jackscrew roller bearing seats are adjusted. Place the dial indicator on the bearing seat at the top screw position and set it to zero. 4.3 Screw the adjusting jackscrews (2), (3), (6), and (7) each into 0.20mm, tighten the bearing seat bolts, and complete the first adjustment. Observe the operation for 10 minutes. If the drum still does not change the axial position, loosen the bearing bolts, set the dial indicator at the (1), (4), (5), and (8) positions. Unscrew the adjusting jackscrews by 0.20mm each and tap the rear of the bearing seat with a hammer to make the bearing seat rest on the adjusting jackscrew. Tighten the bearing seat bolts, complete the second adjustment, and observe the operation for 10 minutes. 4.4 After the second adjustment, if the position of the drum is still not ideal, you should adjust it repeatedly according to the above steps until the unloaded drum can "float" between the thrust wheels, and slightly upward or lightly contact the upper thrust wheel, and is in a stable position of dynamic balance. 4.5 When the drum is loaded with materials, due to the increase in weight, the drum has a tendency to slide downward. At this time, the roller needs to be re-adjusted to ensure that the drum "floats" between the thrust wheels or lightly contacts the lower thrust wheel. 4.6 Adjustment precautions: 1. The axis of each pair of rollers must always be parallel; 2. The adjustment screw must be screwed in or out by the same amount; the first adjustment amount cannot be greater than 0.25mm; 3. Between the two adjustments, you must wait patiently for 10 to 20 minutes for the drum and the roller to find a new balance. It takes longer for the roller ring and roller with worn surfaces to reach the new equilibrium position. 5. Adjustment of the meshing gap of the gear and ring gear.: The center distance between the gear and the ring gear is 1408mm. You can refer to the minimum backlash reference value of the gear pair in the table below. It can be controlled at 0.55~0.7mm under cold conditions. Because the ring gear has been worn, the backlash is not checked. The head clearance requirement is 2.66mm (see maintenance. Install. Operation Manual 14), but according to domestic design parameters C * The value is 0.25, and the gear and ring gear modulus m=16, so the top clearance C=C * m0.25×16=4mm. The top clearance on the real side is 2.1~5.1mm due to the wear of the ring gear, installation and deformation. The top clearance can be checked by pressing wire, feeler gauge, etc., and can be changed by adjusting the position of the reducer. It must be controlled within the above range. Category center distance mm 630 800 800 1000 1000 1250 1250 1600 1600 2000 2000 2500 2500 4000 Small side gap μm 200 230 260 310 370 440 600 Medium side gap μm 320 360 420 500 600 700 950