The so-called flying cone, in popular parlance, is that the cone has no normal swing number and swing stroke, and the rotation number per minute exceeds the specified number of revolutions. General cone rotation speed n=10-15r/min as the crusher no-load limit speed, when the cone rotation speed exceeds this specified value, it is flying cone. When the crusher has a flying cone failure, the oil of the spherical bearing will be thrown out, and the ore entering the crushing chamber will “fly”, and the crusher can not play the role of crushing ore. In severe cases, it will cause damage to the spindle and other components, affecting the normal operation. In order to eliminate this fault, we should first understand the cause of the flying cone, in order to take the correct maintenance measures. There are many reasons for the flying cone, and each reason contains a variety of influencing factors, which are more complex, so it is necessary to analyze each influencing factor, find out the main cause of the fault, and put forward preventive measures.
1, bowl tile and cone spherical poor match Because the crusher works for a long time in a dusty, vibration environment, the moving cone spherical body long-term wear bowl tile, so that the thickness of the bowl tile gradually reduced, the inner ring of the bowl tile contact, the moving cone decline, thus destroying the stable working conditions of the moving cone, change the normal running track of the cone.
When the equipment is running, the spindle will collide with the lower part of the cone bushing, resulting in stress concentration, so that the lower end of the cone bushing wear speed increases, gluing occurs, and even rupture, resulting in flying cone. In order to ensure the normal operation of the cone, it is necessary to make two-thirds of the contact area of the entire bowl tile in the outer ring, one-third of the inner ring and the cone surface are not in contact, so that the spindle and the cone bushing are in contact with the upper part of the cone bushing height, and the wear of the contact surface is observed during the maintenance of the crusher. If the spherical bearing is not in contact with the moving cone sphere along its outer ring, but along its inner ring, and the conical spindle is in contact with the cone bushing at the lower part, it can be considered that the production of the flying cone is related to the abnormal contact between the spherical bearing and the moving cone sphere, and the main solutions are: ① Increase the groove area of the inner ring of the bowl tile, the width of the contact belt is (0.3R-0.5R)(R is the horizontal radius from the center line of the spherical bearing to the outer ball), and the groove depth h=6.5mm. ② The inner ring of the ball tile is scraped and processed, and the contact point is not less than 3-5 points on the 25mm*25mm area, and the wedge gap of the non-contact part is 0.3-0.5mm. After processing and assembly in this way, it can ensure that the outside area of the sphere can be contacted.
2, cone spindle and cone bushing poor contact cone bushing and spindle contact characteristics are large spindle journal and small assembly gap, small shaft diameter and assembly gap, spindle and cone bushing along the full length of uniform contact or along the upper half of the cone bushing uniform contact, then the cone can be stable and normal operation. When the eccentric bushing skews in the straight bushing, the contact between the spindle and the cone bushing is poor, it will cause the flying cone and the bushing to break.
There are several reasons for the deviation of eccentric bushing:
(1) The crusher body is not installed in place. The levelness error of the body and the verticality error of the center must be accurately measured, and the levelness tolerance should not be greater than 0.1mm per meter length. The verticality is based on the center line of the inner hole of the center sleeve, measured with a suspension hammer, and the allowable deviation of the verticality is not more than 0.15%. The overdifference of levelness and verticality will damage the transmission components in the crusher. In this case, it is necessary to re-align the crusher foundation vertically and horizontally, adjust the gasket of each group, use electric welding to spot the gasket, and then tighten the anchor bolt and pour cement. (2) Uneven wear of the thrust disc. Due to the high speed of the outer ring, the wear of the outer ring is more serious than that of the inner ring, and the eccentric bushing is skewed. The deviation of the eccentric shaft sleeve increases the wear of their outer ring, and the two influence each other to make the wear more serious, the more severe the deviation. Therefore, in the daily maintenance, the thrust disc is regularly dismantled and inspected, and when it is found to be worn, it can be continued to use the lathe according to its standard size “long meat”.
(3) Adjust the uneven thickness of the bevel gear gap gasket. When adjusting the tooth gap, the thickness of the gasket added under the thrust disc is uneven, or when there is debris mixed in the middle of the gasket during installation, the eccentric bushing will be skewed. Therefore, when the crusher is repaired, the cylinder sleeve is sealed to prevent dust and debris from entering, and the gasket is wiped clean with cloth.
(4) Improper installation of the thrust disk. When the upper thrust disc is installed, the round pin does not fully enter the pin hole at the bottom of the eccentric shaft sleeve and causes it to tilt. Therefore, each time the depth of the thrust disk is measured, the corresponding position of the round pin is marked to ensure complete assembly. 3 Improper clearance between the components The main installation clearance of the crusher includes the gap between the body sleeve and the vertical shaft, the main shaft and the cone bushing. When the crusher is in normal operation, a reliable lubricating oil film should be formed between the various friction surfaces to compensate for the manufacturing and assembly errors of the components to prevent thermal expansion and deformation, and there must be a suitable gap between the surfaces.
Among them, the body sleeve gap is 3.8-4.2mm, and the upper mouth gap of the cone bushing is 3.0-3.8mm and the lower mouth gap is 9.0-10.4mm, so that the upper mouth is small and the lower mouth is large. The gap is too small, easy to heat and cause flying cone; The gap is too large, will produce shock vibration, greatly reduce the service life of each component. Therefore, the lead pressing method is used to measure the gap size of each part during each installation to meet its parameter requirements.
4, poor lubrication crusher in the operation process, the friction between the surfaces that contact each other and have relative motion requires the intervention of lubricating oil to form hydrodynamic lubrication. Adequate lubrication of the machine will improve the friction between parts, reduce wear, and ensure the normal operation of the machine. However, if the oil temperature, oil pressure and oil amount of the lubrication system are not enough, especially the crusher working environment is harsh, the dust is large, and the dustproof system, if it can not play its due role, will seriously pollute the lubricating oil and cannot form an oil film, so that the lubricating oil not only does not play a lubricating role, but will aggravate the wear of the contact surface and cause flying cone.
In order to avoid flying cone caused by poor lubrication, it is necessary to regularly check the oil quality of the lubrication station, and use the oil filter to clean the lubricating oil when NAS1638 is higher than 8 level; Check the cone dust ring, dust sponge and dust washer regularly, and replace it in time if it is worn or cracked to minimize dust and dust; Strengthen daily spot inspection and post operation, the crusher must check whether the dust-proof water is opened before starting to prevent dust from entering the lubricating oil.
Through the above fault analysis and the adoption of corresponding measures, can effectively prevent and solve the conical broken fly cone failure, while strictly standardize the daily operation, maintenance and overhaul, strengthen equipment management and on-site maintenance, grasp the quality of each link, correct use, careful maintenance, effectively avoid the occurrence of fly cone failure, or even no occurrence.
Post time: Oct-14-2024