Abstract: Deviation during the operation of the sintering machine trolley is a common problem in the sintering machine equipment. By analyzing various reasons for the deviation of the sintering machine trolley and proposing corresponding treatment methods, the deviation of the sintering machine has been effectively improved, reducing the air leakage rate of the sintering machine, and ensuring the normal operation of the sintering machine.
Keywords: sintering machine trolley; Slide; Deviation; Star wheel adjustment
0 Preface
Since its production in December 2009, the 400m2 sintering machine at the Laigang Section Steel Ironmaking Plant has experienced slight deviation of most of the trolleys after a year of operation, resulting in a phenomenon of catching up during the operation of the trolleys. Therefore, multiple adjustments have been made to the head star wheel, but the effect is not significant. In February 2012, the deviation of the trolley began to gradually intensify. During the forward movement of the trolley from the nose to the tail, the distance between the south side wheel edge of the trolley and the track gradually decreased, and even squeezed each other. The friction and compression between the south side wheel edge of the trolley and the track intensified from the return operation to the head, and the wear on the entrance bend of the head return reached 20mm. The deviated trolley squeezes the tracks and curves during operation, causing increased resistance and frequent damage to the trolley wheels, resulting in severe wear and tear on the tracks and curves. To fundamentally solve this problem, technical personnel conducted a comprehensive analysis and calculation of the reasons for the deviation of the sintering machine, formulated and implemented a series of improvement measures, and achieved good results.
1 Analysis of the reasons for the deviation of the sintering machine trolley
There are many reasons that affect the deviation of the sintering machine trolley. After observation and analysis, it is believed that the main reasons for the deviation of the sintering machine are: the teeth on both sides of the star wheel are not synchronized, the balance weight of the tail moving pendulum is insufficient, the slide, track, and bend are severely worn, and the elevation of the star wheel teeth is inconsistent.
1.1 Impact of track and slide on trolley deviation
1.1.1 Inconsistent elevation of tracks or slides on both sides
The elevation of the rails or slides on both sides of the sintering machine trolley is inconsistent, and there is a tendency for the trolley to slide towards the lower side during operation, leading to the occurrence of deviation of the sintering machine. This type of defect is not easy to occur during installation, mostly in single flue sintering machines. Due to factors such as thermal expansion and the weight of the flue, it is easy to determine the wear status of the trolley slide by simply lifting the trolley out of the machine while it is stopped.
1.1.2 Deviation of longitudinal centerline of sintering machine
There are two forms of longitudinal centerline deviation of the sintering machine: one is the translation deviation between the actual centerline of the sintering machine and the theoretical centerline of the sintering machine, as shown in Figure 1. The translation deviation between the actual centerline of the sintering machine and the theoretical centerline of the sintering machine is distance a; Another form is the deviation between the actual centerline of the sintering machine and the theoretical centerline of the sintering machine, as shown in Figure 2. The deviation between the actual centerline of the sintering machine and the theoretical centerline of the sintering machine is b. The occurrence of these two phenomena is mainly due to the initial installation data error of the sintering machine. The most effective control method is to strictly control the construction and installation quality, and strictly follow the technical standards for installation inspection and acceptance during the installation process.
1.2 Impact of head star wheel on trolley deviation
1.2.1 There is an angle between the centerline of the head star wheel and the longitudinal centerline of the sintering machine
There is an angle between the centerline of the sintering machine head star wheel and the longitudinal centerline of the sintering machine, as shown in Figure 3. The centerline of the sintering machine head star wheel has an angle c with the longitudinal centerline of the sintering machine. This situation leads to the inability of the tooth plates on both sides of the sintering machine head star wheel to contact the trolley at the same time. From the operation of the sintering machine trolley to the point where it is about to detach from the head star wheel, the trolley will slip on the upper plane of the sintering machine, resulting in deviation during the operation of the sintering machine from head to tail.
1.2.2 There is a deviation in the elevation of the bearing pads on both sides of the head star wheel
There is a deviation in the elevation of the bearing pads on both sides of the star wheel at the head of the sintering machine, which also causes the trolley to deviate during operation on the upper plane.
1.2. The two toothed plates of the 3-star wheel are not synchronized
Even if the installation of the star wheel at the head does not exceed the standard, the phenomenon that occurs if the two tooth plates of the star wheel are not synchronized is the same as in section.
1.2.2. During the overhaul of the sintering machine, measurements were made and recorded as follows:
1) The right track of the sintering machine slide was worn off by the trolley wheel for about 15-20mm due to the deviation of the sintering machine. The left sliding plate and sliding plate groove (along the length direction of the sliding plate groove) have almost worn away two-thirds of the original thickness of the sliding plate, forming an angle between the sliding plate and the sliding plate groove.
2) The measurement of the sintering machine slide, track, center distance, and elevation is shown in Table 1. The defect form is consistent with sections 1.1.1 and 1.1.2.
3) The tooth plate of the head planetary gear is severely worn and out of sync, with the right tooth profile averaging 5-8mm ahead of the left tooth profile. Consistent with sections 1.2.1, 1.2.2, and 1.2.3.
1.3 Impact of rear star wheel on trolley deviation
The main reasons for the asynchronous tooth plates on both sides of the sintering machine's tail wheel are: there is an error in the installation of the tail wheel hub and the shaft wedge key; Misalignment of wheel hub positioning holes; The positioning holes of the toothed plate are misaligned; There is a deviation in the tooth shape of the tooth plate. To adjust the deviation of the trolley, the inclined tooth plate with a large deviation was first processed and reinstalled before measurement. After measurement, the height difference of the corresponding points on both sides of the tooth plates was reduced from 12mm to 2.1mm, achieving the expected deviation adjustment effect. Immediately remove the remaining tooth plates for corresponding processing, install and tighten them in a timely manner after processing, and measure each tooth plate (based on the interface surface on the tooth plate).
2 Processing plan
Based on the above detection data and analysis, a deviation correction plan for the sintering machine has been formulated. Firstly, verify the longitudinal centerline of the sintering machine, the centerline of the head wheel, and the horizontal elevation line of the tail wheel center. Then, use steel wire to lay out the line, and align and correct the head wheel, tail wheel, tail moving frame, head and tail bending rails, slides, and tracks of the sintering machine, to control the error within the limit deviation range.
2.1 Head wheel deviation correction
The distance between the bearing seat and the bearing base, as well as the distance between the bearing base and the sintering machine frame, must be adjusted with a pad, but half of the pad is not allowed. After the bolts are tightened, they should be tightly fitted and checked with a 0.05mm thick feeler gauge. The inserted area should not exceed one-third of the contact area.
2.2 Head Bend Correction
Based on the center of the head wheel and testing data, adjust the spacing between various parts of the bend:
1) The deviation between the tooth roots of the sprocket plates on both sides and the arc guide rail at the corresponding positions should be controlled within the range of technical requirements.
2) The distance between the fixed head bend and the sprocket plate should be consistent at the corresponding points on the upper, middle, and lower corners on both sides.
3) Review the distance between the outer rail, inner rail, tooth plate, and tooth base to ensure they meet the technical requirements, as shown in Figure 4 and Figure 5. Provide the standard dimensions of the distance between the outer rail, inner rail, tooth plate, and tooth base on the head and tail of the machine, which are also years of empirical data. One of the main tasks of each maintenance, scheduled repair, and major repair is to record and count data, and when adjusting the bending rail, it is required that the error range of the upper and lower bending rail gauge should not exceed 10mm, and the horizontal displacement error range of the bending rail should not exceed 5mm.
4) Adjust with a shim pack to control the center distance error of the track within 1mm, and control the symmetrical distance deviation from the curves on both sides to the longitudinal centerline of the body within 2mm.
5) During assembly, the segmented inner and outer curved rails and straight rails are placed on the inner and outer curved rails and straight rail seats. After adjusting the shim pack, each stop block is welded to the corresponding position of the rail seat.
6) Adjust the curves on both sides based on the centerline of the head wheel, and the deviation between the center line and the centerline of the head wheel should be controlled within 1mm.
2.3 Middle track deviation correction
1) The extremely high tolerance of the upper and lower return tracks should be controlled within the upper limit of 1mm.
2) Adjust the tracks on both sides based on the centerline of the head wheel, and use a dedicated sample rod to check the gauge and track position. When the center of the sample rod is consistent with the longitudinal centerline of the sintering machine, the limit deviation of the track centerline is ± 1mm, and the limit deviation of the gauge is ± 2m.
3) The height difference between the two tracks at the track joint should not exceed 0.5mm, and the reserved thermal expansion gap should meet the technical requirements.
4) The symmetrical centerline of the track should coincide with the longitudinal centerline of the sintering machine, and the deviation should be controlled within 1mm.
2.4 Installation requirements for translational tail bends
1) The maximum deviation between the left and right curves and the longitudinal centerline of the sintering machine is ± 2mm.
2) The limit deviation of curve elevation should be controlled within ± 2mm, and the height difference between the upper and lower corresponding points of the left and right curves should be controlled within 2mm.
3) Use a plumb bob to check the distance between one side of the bend and the plumb line, with a limit deviation of ± 2mm.
4) After the installation and adjustment of the tail bend, weld each inner and outer rail seat onto the left and right hanging brackets of the mobile frame, continuously welding, with a welding foot height of 7mm.
5) After adjusting the tail bend, weld the left and right stop blocks onto their respective track seats for continuous welding, with a welding foot height of 4mm.
6) When installing and adjusting the bend, if there is any collision between the adjusting shims, appropriate cutting and adjustment should be carried out on site.
7) The curve must be parallel, and its symmetrical centerline should coincide with the centerline of the sintering machine. The limit deviation is 2mm, and the elevation limit deviation of the curve is ± 1mm. The elevation difference between the upper and lower corresponding points of the left and right curves should not exceed 2mm.
8) Use a plumb bob to check the distance between one side of the bend and the plumb line, and control the deviation within ± 2mm.
2.5 Installation and Sealing of Slide
1) The symmetrical centerline of the sealing slide should coincide with the longitudinal centerline of the sintering machine, with a tolerance of 1mm. The deviation between the centers of the two slides should be controlled within ± 2mm.
2) The elevation limit deviation of the sealing slide should be controlled within ± 1mm.
3) The reserved thermal expansion gaps in various parts of the sealing slide should meet the technical requirements.
After this deviation adjustment, the elevation difference between the corresponding points of the tooth plates on both sides is between 0 and 2.1mm. After the backfilling of the trolley was completed, the test drive was carried out, and the deviation of the trolley was greatly alleviated. The misalignment of adjacent carriages at the exit of the tail bend was basically eliminated.
3 Conclusion
After a series of deviation adjustment treatments, the deviation phenomenon of the 400m2 sintering machine has been improved to a certain extent. In order to prevent deviation caused by installation size errors, various technical standards should be strictly followed during the maintenance and installation of the sintering machine. In the daily production of sintering machines, it is necessary to carefully observe the operating status of the sintering machine and the wear status of related elements, eliminate them one by one, identify the true cause, and adopt the correct treatment method. The ideas and experience of this deviation adjustment provide a reference for the maintenance of this type of sintering machine deviation adjustment and similar equipment in the future.
More about VAFEM Shock absorber bearings：
Shock absorber bushings come in common forms – rubber and metal. Rubber bushings are at the top and bottom of the shock absorber and are used to attach the shock to the vehicle’s frame and control arm. These bushings are sometimes spherical plain bearings or rod ends in a rubber housing.
As a precious high quality shock absorber bearings manufacturer and supplier in China, VAFEM can guarantee the quality and precision of the products through complete testing technology and advanced equipment. Please come to buy shock absorber bearings at the best price and quality from VAFEM. Please contact us for any questions!
2023-06-05