Guide
What does “speeding†mean? Some people will have doubts. In short, it is the illusion that the cone-shaped moving cone auto-transmission speed is getting faster and faster, so that it has to “flyâ€. Then why is there a "speeding car"? The consequences are very serious? How do you deal with it? Today, Xiaobian will talk with you about the cone-breaking "speeding"!
The so-called "speeding"
When the cone crusher is in no-load, the taper sleeve on the thin side of the eccentric bushing is in contact with the main shaft. The friction torque generated at the contact point drives the cone to rotate in the same direction (unsynchronized) as the eccentric bushing. If the frictional moment and the reverse frictional moment of the bowl-shaped bearing acting on the spherical surface of the cone are equal, the constant rotation of the cone can be maintained. For some reason, the balance of the cone is broken, its rotation speed is getting faster and faster, and finally "flying", this is what we call "speeding."
So what are the reasons for the speeding? Follow the small series to find out!
"Speed" reason
-1-
There is less contact point between the taper sleeve and the main shaft, and a “flying†occurs in the breakage gap of the crusher , which actually belongs to the “running†of the dry running. If the pressure is still not applied after the feeding, the speed of the spindle rotation will be lost.
-2-
The taper sleeve is cracked during operation, the contact surface with the spindle becomes smaller, and the oil film is destroyed, thereby "flying" due to a sharp increase in dry friction temperature.
-3-
When the cone sleeve is operated, it is affected by the non-crushed material (over- iron ), causing the load to be too large, and the zinc filling is detached, causing the taper sleeve to smash, and the gap between the main shaft and the taper sleeve becomes smaller and “flyingâ€.
-4-
When the crusher is running, a large amount of heat is generated between the transmission members, and the heat is normally released through the heat exchanger, thereby achieving thermal balance of the system. If the heat is too large, exceeds the cooling capacity of the cooler, or there is a problem with the cooler, the heat transfer efficiency is lowered and the heat balance is broken. The oil temperature continues to rise, the oil film strength decreases and dry friction occurs, and even burns occur in sliding contact portions such as bowl-shaped bearings, vertical sleeves, taper sleeves, and bushings. The hoop between the taper sleeve and the main shaft causes a "flying".
Occasionally, the oil supply is interrupted due to the failure of the thin oil system, and the interlock protection of the pressure relay does not function, so that the sliding contact portion is rapidly and severely burned, accompanied by a violent "flying". This is a very dangerous situation and can cause serious consequences if not stopped in time.
-5-
The installation clearance between the main shaft and the taper sleeve is too small, or the wear of the bowl-shaped bearing is thinned for a long time, and the cone sinks to cause the gap to become smaller, resulting in additional load between the taper sleeve and the main shaft, and the contact stress is greatly increased, causing damage to the oil film. Flying."
-6-
The outer circular surface of the main shaft is seriously worn, and even the grooves of different depths appear, causing the contact between the shaft and the taper sleeve to deteriorate and causing a "flying".
Note: In any case, the “flying car†will have a taper sleeve burn, and most of the burns will occur on the side of the thin side of the eccentric bushing, and it will occur in the range of 1/4 length from the upper mouth. It can be said that the origin of the "speeding" accident is between the main shaft and the taper sleeve.
"Speed" consequences
1. When the crusher runs under load, it will be “flyingâ€, and the broken ore will not be discharged, and the ore in the previous process will be continuously fed. This will inevitably lead to mine closure, causing the crusher to overload, causing accidents such as burning of the main motor or the bevel gear teeth.
2. The “flying†of the crusher will also cause the lubricating oil to become thinner and be thrown out from the bowl-shaped bearing. If the treatment is not timely, the oil will be lost too much, the oil level will be reduced, and the oil supply will be interrupted, causing damage to the transmission parts.
3. The cone runs at high speed and is extremely unstable, causing severe vibration, which makes the bowl bearing bear a huge impact load. If it is not parked in time, the bowl bearing will be cracked and damaged.
4, the crusher for a long time intense "speeding", will also cause the taper sleeve to crack or burn out, the spindle and the taper sleeve burning point will form a circular groove of different depth on the main shaft.
5. The contact area between the eccentric bushing and the burning point will expand inward due to heat, and will not fully recover after cooling, resulting in permanent inward convex deformation. If the taper sleeve is loaded without treatment, the cone hole deformation will not be in place, and a gap will occur between the taper sleeve and the eccentric shaft hole.
6. The eccentric bushing is sometimes deformed by the external deformation of the outer side of the thin side, so that the bevel gear and the eccentric bushing are loosened, and even the large gear is detached.
"speed" processing
PART
01
The proper clearance between the main shaft and the taper sleeve is critical to the operation of the crusher. The gap is too small to cause heat, and the axle is caught to produce a "flying car". If the gap is too large, a large impact and vibration will be generated.
PART02
For the copper taper sleeve, it is necessary to check the contact between the side of the thin side and the spindle during inspection. If there are only a few contact points (the range is less than 1/4 of the height of the taper sleeve), the angle of the inner hole is polished with an angle grinder, and the direction of the inner hole of the inner hole of the grinding edge is detected with the edge of the steel ruler, so that between the ruler and the busbar Uniform contact, visual inspection without gaps, rough grinding to meet the requirements. After loading the cone for about 10 minutes, lift the inspection and polish it according to the contact point.
PART
03
If there is a crack along the busbar in the upper end of the eccentric bushing, the length does not exceed 200mm, and it does not affect the contact and clearance between the bushing and the main shaft, and can still be used. But to make a crack hole of φ8~φ10 at the lower end of the crack.
PART04
If the thin side of the eccentric bushing is convex inward due to heat, the inner hole should be polished with a sander, and the edge of the steel taper should be detected along the direction of the taper hole, and the copper taper sleeve can be inserted into the taper hole. Repeat the grinding according to the contact condition until the taper sleeve can be installed in place, and the gap between the eccentric shaft hole and the eccentric shaft hole does not exceed 0.1 mm.
PART
05
After the eccentric shaft hole and the taper sleeve are subjected to the above treatment, the "speeding" may occur in the dry running test, but if there is a stable period of more than 30 minutes, the clearance between the detecting spindle and the taper sleeve is appropriate, the contact point meets the requirements, and there is no obvious burning. Point, can carry out load test. After the load is running, the transmission components, especially the taper sleeve and the bowl tile, can be further ground, and the rotation speed of the cone can be gradually stabilized.
PART06
The contact between the cone ball and the bowl bearing affects the stability of the cone operation and, to a certain extent, controls the rotation of the cone. In addition, the bowl-shaped bearing wears too much (the bottom of the oil groove is flattened), so that the cone is lowered more, the main shaft and the taper sleeve are too small, and a new bowl-shaped bearing should be replaced.
PART
07
The lubrication system plays an important role in the operation of the cone crusher. A large amount of lubricating oil lubricates the various transmission parts, and at the same time, the friction of each point goes tropical. It is required that the lubricating oil between the taper sleeve and the main shaft should have sufficient viscosity to maintain the strength of the oil film, and sufficient flow rate and low oil supply temperature to take away the frictional heat to achieve heat balance.
PART08
The use of nylon taper sleeves can better control the occurrence of "speeding". This is because on the one hand, the smaller inward convex deformation of the eccentric bushing can be compensated by the plastic deformation of the nylon sleeve, keeping the taper sleeve and the tapered hole in good contact; on the other hand, the nylon sleeve is glued to the main shaft. The "welding" strength is much lower than that of the copper sleeve, so the power to produce the "flying" is much smaller.
1.Welding materials
In Welding, substances called filler materials or consumables are used. As the name implies, these substances provide filler or a body of molten materials that provides a strong bond to be formed between the base metals used. Most welding processes will also require some form of shielding to protect both the main components and filler from being oxidized during the process.
The type of welding materials used during welding depends on the nature of the job intended. Electrodes draw the necessary energy in order to perform welding applications. Luoyang Golden Egret Company has any kind of welding materials include CTC Welding Rod /rope, SCTC welding rod/rope, TC electronic welding rod, Ni-based welding rod, flux-cored Welding Wires, solid welding wires and etc.
Welding can be applied in different kinds of industries such as building and construction, oil and gas, marine, power generation, steel, mine tools, automobile, transportation and etc.
2. Welding rod
1)Cast tungsten carbide based tubular rod
The hard phase of the rod is cast tungsten carbide which leads to higher hardness and better wear-resistance.
Wear resistance: the wear resistance is 6-7 times better than others. Tested by ASTM G65
Mainly used for Mining machinery, Geological tools, Petroleum drilling tools etc, by Oxy-Acetylene with weak carburizing flame.
Product recommendation:
GT1103 (CTC, 60-80 mesh),
GT1103-1(CTC, 20-30 um),
GT1103-2(CTC, 40-60 um)
2)The hard phase of tube rod is carbide pellets which leads to higher impact resistance and better wear resistance than CTC cloase rod.
Wear resistance: the wear resistance is 6-7 times better than others. Tested by ASTM G65 wear test.
Mainly used for mining machinery. Geological tools etc; by Oxy-acetylene with weak carburizing flame.
Product recommendation:
GT2102 (Cemented carbide grit, 30-60mesh)
GT2102-2(Cemented carbide grit, 30-40mesh)
GT2102-3(Cemented carbide grit, 40-60mesh)
3)Tube rod is composited by Cemented carbide pellets, Spherical CTC and CTC. The layer has higher impact resistance, better wear resistance and good fluidity than other rods.
Wear resistance: the wear resistance is 6-7 times better than others. Tested by ASTM G65.
Mainly used for oil method drill bits, such as Tri-cone bit, Steel tooth bit, PDC bit, etc. By Oxy-Acetylene with weak carburizing flame.
Product recommendation:
GT3302 (carbide pellets, 20-40mesh)
GT3302-1(carbide pellets, 14-40um)
4)The hard phase of the rod is monocrystal WC, the welding layer has a higher wear resistance and better impact resistance.
The wear resistance is 6-7 times better than others, tested by ASTM G65 method.
Mainly used for the repair and strength for oil drills bits, such as PDC bit diameter holding by Oxy-Acetylene with weak carburizing flame.
Product recommendation:
GT4104 (Monocrystal WC, 80-200mesh)
3. Welding Rope
Made form mixture of CTC and self-fluxing nickel alloy covering on nickel wire. The CTC is in spherical or irregular with good wear resistance; the nickel alloy is in spherical or nearly spherical shape with good wettability and erosion resistance and better corrosion resistance than tubular rod.
Recommend to use Petroleum drilling tools, Concrete mixing blade, Mud pump, Coal sluice, Coal drill pipe, Tunnel drilling machinery etc.
By Oxy-Acetylene Welding with weak carburizing flame.
Product recommendation:
GS110450N (CTC, 4mm, HRC 47-55)
GS110550N (CTC, 5mm, HRC 47-55)
GS110650N (CTC, 6mm, HRC 47-55)
4. Welding Bar
The rod is sintered by CTC and Ni-based powders. The CTC(Cast Tungsten Carbide) is in irregular or spherical shape with better wear resistance and the nickel alloy is in spherical or nearly spherical shape and has good wettability with cast tungsten carbide. The cladding layer has a higher impact resistance and better wear resistance.
Its wear resistance and corrosion resistance is between tube rod and flexible rope.
Mainly used on the Steel PDC bit, Concrete mixer blade, Mud pump, Miner chute, Miner drill stem and Mechanical parts of Tunnel rock drill machine etc.
Welded by Oxy-Acetylene with weak carburizing flame.
Product recommendation:
GD4025253-3(CTC, SCTC, 4*600/6*600)
GD4030303-3(CTC, SCTC, 4*600/6*600)
5. Welding wire
Intensified molybdenum titanium vanadium composite chromium carbide welding wire can improve layer`s bonding strength and tenacity. This wire can use for multilayer welding which has no peel off, and it can maintain good wear resistance under certain impact working condition.
Product recommendation:GSQD671Mo-4(1.6mm)
Medium carbon and high chromium wear resistance welding wire has a higher hardness, stronger wear resistance, and excellent toughness by adding a certain amount of molybdenum alloys and boride. It has a better impact resistance and strip resistance than high chromium cast iron type materials
Product recommendation: GSQD621Mo-4(1.6mm)
With high sphericity & excellent alloy organization, cemented carbide pellet is mainly used in welding, as an adding material of PTA Powder , tubular welding rod, to improve the wear resistance of the workpieces greatly.
Product recommendation: GQ06
Cemented carbide grit with different percent of cobalt has good abrasive resistance and is widely used for making grinding, polishing and cutting tools.
Product recommendation: GS08A
Weld Materials,Tubular Welding Rod,Welding Electrodes,Stainless Steel Welding Rod
Luoyang Golden Egret Geotools Co., Ltd , https://www.lyshieldcutters.com