Reasons and Treatment Methods of Cone Breaker Flying Cone Failure

The so-called flying cone, in layman's terms, means that the moving cone of the cone crusher does not have normal swing times and swing strokes, and the rotation per minute exceeds the specified number of rotations. Generally, the cone rotation speed n=10-15r/min is used as the limited speed of the crusher when it is not loaded. When the cone rotation speed exceeds this specified value, it is the flying cone.

When the crusher has a flying cone failure, the oil in the spherical bearing will be thrown out, and the ore entering the crushing cavity will "fly", and the crusher cannot play the role of crushing the ore. In severe cases, the spindle and other components will be damaged, affecting normal work. To eliminate this kind of failure, you should first understand the cause of the fly cone before taking correct maintenance measures.

There are many reasons for the occurrence of flying cones, and various reasons include a variety of influencing factors, which are complicated to intersect each other. Therefore, it is necessary to analyze each influencing factor specifically, find the main reason for the failure, and propose preventive measures.

Poor fit between the bowl tile and the conical spherical surface

Because the crusher works in a dusty and vibrating environment for a long time, the spherical body of the moving cone wears the bowl tile for a long time, so that the thickness of the bowl tile gradually decreases, the inner ring of the bowl tile contacts, and the moving cone descends, thus destroying the moving cone Stable working conditions change the normal running trajectory of the cone.

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When the equipment is running, the main shaft will collide and contact the lower part of the cone bushing, resulting in stress concentration, which increases the wear speed of the lower end of the cone bushing, causes gluing, or even cracks, resulting in flying cones.

In order to ensure the normal operation of the cone, two-thirds of the contact area of the entire bowl-shaped tile must be on the outer ring, and one-third of the inner ring must not be in contact with the cone surface, so that the main shaft and the cone bushing are in contact with the upper part of the height of the cone bushing. When overhauling the crusher, observe the wear of each contact surface. If the spherical bearing and the spherical surface of the moving cone are not in contact with the outer ring, but along the inner ring, and the main shaft of the cone and the cone bushing are in contact at the bottom, it can be considered that the occurrence of the flying cone is related to the abnormal contact between the spherical bearing and the spherical surface of the moving cone, the main solutions are:

① Increase the groove area of the inner ring of the bowl-shaped tile, the width of the contact band is (0.3R-0.5R) (R is the horizontal radius from the centerline of the spherical bearing to the outer ball), and the groove depth h=6.5mm.

② Scratch and grind the inner ring of the spherical tile, the contact points are not less than 3-5 points on the area of 25mm*25mm, and the wedge-shaped gap of the non-contact part is 0.3-0.5mm. After processing and assembling in this way, it is sufficient to ensure that the outer surface of the spherical surface is in contact with a large area.

Poor contact between taper spindle and taper bushing

The contact between the taper bushing and the main shaft is characterized by large upper journal and small assembly clearance, small lower shaft diameter and large assembly clearance, and the main shaft and the taper bushing are in uniform contact along the entire length or along the upper half of the taper bushing. At this time, the cone can run stably and normally. When the eccentric bushing is deflected in the straight bushing and the contact between the main shaft and the tapered bushing is poor, the flying cone and the bushing will be broken.

There are several reasons for the deflection of the eccentric bushing:

(1) The crusher body is not installed properly

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 of length. The verticality is based on the center line of the inner hole of the central sleeve, and is detected with a suspension hammer. The allowable deviation of the verticality is not more than 0.15%. The excessive levelness and verticality will damage all transmission parts in the crusher. In this case, the basic vertical and horizontal alignment of the crusher must be re-aligned, each group of backing plates should be adjusted, and the backing plates should be fixed by electric welding, and then tightened. Anchor bolts and pour cement.

(2) The thrust disc wears unevenly

Due to the large linear speed of the outer ring, the wear of the outer ring is also more serious than that of the inner ring, which makes the eccentric bushing deflect. The deflection of the eccentric bushings aggravates the wear of their outer rings, and the mutual influence of the two makes the wear more serious, and the deflection is more severe.

Therefore, in the daily maintenance, the thrust plate is regularly dismantled and inspected, and when it is found to be worn, the "long meat" of its standard size shall be machined to the standard size by lathe before it can continue to be used.

(3) Adjust the uneven thickness of the bevel gear gap gasket

When adjusting the tooth gap, the thickness of the gasket under the thrust plate is uneven, or when there is debris in the middle of the gasket during installation, the eccentric bushing is skewed. Therefore, when overhauling the crusher, seal the cylinder sleeve to prevent dust and debris from entering, and wipe it with a cloth when installing gaskets.

(4) Improper installation of the thrust plate

When the upper thrust plate is installed, the round pin does not fully enter the pin hole at the bottom of the eccentric sleeve, which makes it inclined. Therefore, measure the depth of the thrust plate every time, and mark the corresponding position of the round pin to ensure complete assembly.

Improperly sized gaps between parts

The main installation clearance of the crusher includes the clearance between the body sleeve and the vertical shaft, the main shaft and the cone bushing. During the normal operation of the crusher, a reliable lubricating oil film should be formed between the friction surfaces to compensate for the manufacturing and assembly errors of the components to prevent thermal expansion and deformation, and there must be appropriate clearances between the surfaces.

Among them, the clearance of the body sleeve is 3.8-4.2mm, the clearance of the upper port of the cone bushing is 3.0-3.8mm, and the clearance of the lower port is 9.0-10.4mm, so that the upper port is small and the lower port is large. If the gap is too small, it is easy to generate heat and cause fly cones; if the gap is too large, shock and vibration will occur, which greatly reduces 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.

Poor lubrication

During the operation of the crusher, the friction between the surfaces that are in contact with each other and move relatively requires the intervention of lubricating oil to form hydrodynamic lubrication. Sufficient 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 volume of the lubricating system are not enough, especially if the working environment of the crusher is harsh and the dust is large, if the dust-proof system cannot play its due role, it will seriously pollute the lubricating oil and cannot form an oil film, so that the lubricating oil cannot be formed. Not only does it not play a role in lubrication, but it will aggravate the wear of the contact surface and cause fly cones.

In order to avoid flying cones caused by poor lubrication, regularly check the oil quality of the lubrication station. When NAS1638 is higher than grade 8, use an oil filter to clean the lubricating oil; regularly check the cone dustproof ring, dustproof sponge and dustproof gasket. If there is wear or crack, replace it in time to reduce dust and dust to the maximum extent; strengthen daily inspection and post operation, and check whether the dustproof water is turned on before the crusher is started to prevent dust from entering the lubricating oil.

By analyzing the above faults and adopting corresponding measures, it is possible to effectively prevent and solve the failure of the cone crusher flying cone. At the same time, the daily operation, maintenance and repair of the cone crusher can be strictly standardized, equipment management and on-site maintenance shall be strengthened, the quality control of each link shall be grasped, and the correct use and careful maintenance shall be made. Maintenance, effectively avoid the occurrence of fly cone failure, or even not occur.