There are two main factors that cause the cone crusher "flying car" and three preventive measures
Cone crusher has the obvious advantages of high crushing yield, low energy consumption and wide application range, and is widely used in mining.
However, due to various reasons, cone crusher will appear in the use of the car fault, on the raw ore mining, production schedule will cause different degrees of adverse impact.
In order to reduce the probability of failure of the cone crusher, the first thing to do is to understand the cause of the failure of the flying car, and then in view of the causes of these failures, take corresponding preventive measures.
01. Cause analysis of the fault of the cone crusher
1. Cause of airframe failure of flying car
When the cone crusher is in the state of idling, in the side where the eccentric sleeve is relatively thin, the spindle and the cone sleeve will contact, and this contact position will generate friction torque, pushing the moving cone and the eccentric sleeve to rotate in the same direction. When the friction torque is equal to the friction torque in the opposite direction of the moving cone body, the moving cone will maintain a constant rotation.
Because the eccentric sleeve speed is very high, up to 250 revolutions per minute, much faster than the spindle rotation speed, this determines the spindle and cone sleeve contact position will change, when the number of contact position decreases, the contact position will be increased.
In this case, when the force on the contact position is greater than the strength of the oil film, it will lead to dry friction phenomenon of oil film rupture.
However, it should be noted that this is not the only reason for the rupture of oil film. Poor quality or small amount of lubricating oil may also affect the formation of oil film, resulting in dry friction of oil film rupture.
The influence of dry friction is very big, it will lead to a rapid rise in the temperature of the contact position, serious spindle and copper sleeve will appear gluing phenomenon, causing an increase in the friction torque, break the balance, resulting in the increase in the speed of the moving cone. When the dry friction between the spindle and the cone sleeve causes the temperature of the contact position to rise, it will cause the expansion of the cone sleeve, causing serious consequences.
Since the temperature value of the eccentric sleeve is usually less than that of the copper sleeve, and the wall is relatively thick, the steel is a little smaller in terms of the expansion coefficient, so the expansion is relatively light and the overall influence is small, which means that when the expansion occurs, the expansion direction can only be inward.
This situation will lead to a narrowing of the distance between the cone sleeve and the spindle, the inner hole will also become smaller, the heating will be further intensified, the gluing between the spindle and the cone sleeve will also worsen, leading to the formation of a vicious circle, making the spindle speed faster and faster, and then the car fault.
2. External factors influencing the occurrence of flying car faults
Generally speaking, the external factors influencing the failure of flying car mainly include:
1) the inner wall of the cone sleeve is not up to standard, which causes contact between the cone sleeve and the spindle, damages the oil film, and causes the spindle speed out of control;
2) the clearance between the spindle and the cone sleeve is unscientific. Too large clearance will lead to the collision between the cone sleeve and the spindle.
3) the spherical shape is seriously damaged or the quality of the bowl-shaped tile is not up to the standard;
4) problems occurred in the cooling system of the body, which could not release heat in time, resulting in thermal imbalance, high oil temperature rise and weakened oil film strength;
5) excessive load of the cone sleeve causes the spindles to fall off, thus reducing the gap between the spindle and the cone sleeve and causing the phenomenon of "axle holding";
6) the thrust disc is seriously worn due to long-term use of the machine;
7) the clearance between the top and side of the tooth when the machine is installed is not reasonable.
02. Suggestions for preventing the malfunction of flying cars
1, spindle and cone sleeve clearance should be reasonable, not too large and too small
Too small clearance can easily lead to fever and lead to the fault of the flying car; Too large and easy to lead to an increase in the impact force, resulting in body vibration.
Generally speaking, the clearance should be controlled within a reasonable range, to a certain type of cone crusher as an example, the clearance of the cone sleeve upper mouth and spindle had better control in 2.74 mm to 3.2 mm, the lower end and cone sleeve clearance to control in the range of 7 mm to 8 mm, the data must be particularly accurate.
Clearance maintenance is generally just upper clearance, the method used is to use 2 fuses in the cone cover thin edge and thick edge paste put one, but should pay attention to the thickness of the fuse should meet the requirements.
When the cone is mounted, the spindle should be put into the cone hole slowly to ensure that the sphere of the cone can be really compacted on the bowl tile. When the thickness of the two fuses is tested, it should be noted that the summation value of the two fuses is used as the actual gap between the upper end and the spindle.
When the gap between spindle and cone sleeve needs to be adjusted, the thickness of the cushion can be changed. When testing the clearance between large and small bevel gears, note that the heavy edge of the eccentric sleeve should be on the pinion side.
2. Choose high-quality lubricating oil
Because lube oil has important influence to the happening of flying car accident, therefore, must pay attention to the choice of lube oil. Selection should be based on the requirements of the cone crusher, pay attention to consider the index of lubricating oil and the real demand, especially the viscosity of lubricating oil, liquidity to be considered as the key.
Considering the influence of temperature and climate on lubricating oil, in order to ensure the scientific selection of lubricating oil, heating method can be adopted to test the fluidity of lubricating oil in cold winter or areas with severe climate. When using it, it is also necessary to pay attention to preheating in advance to ensure the service performance. Due to the oil quality of the lubricating oil will cause gear acceleration, therefore, in order to avoid the grinding of the shaft sleeve, it is necessary to pay attention to ensure that the grease standards meet the specified requirements.
A reasonable inspection period should be set for the dustproof device to ensure that the damage of the retaining ring and ring can be found as soon as possible and replaced in time to prevent the lubrication system from being affected by dust.
3. Use the cone crusher scientifically
In the use of the machine, to care for the machine, reflected in the specific operation is even feeding. Due to uneven feeding will increase the power consumption of the machine, damage the machine, therefore, in order to extend the service life of the cone crusher, also in order to minimize the occurrence of machine failure, in use, must ensure that the feeding as uniform as possible.
In addition, in order to meet the lubrication requirements of the body, the lubrication system, the feeder and the main motor should be interlocked. Before the main motor start, must first start the oil pump, and pay attention to after the oil pump stopped working, when the pressure value and oil temperature exceed a certain limit, pay attention to stop the main motor, feeder, to prevent damage to the machine. The oil tank can not be cooled only by its nature, but must use heat exchanger for reasonable temperature control to ensure heat balance.
There are many reasons for the failure of cone crusher, which bring great inconvenience to construction or production. Because the price of the cone crusher is relatively expensive, the maintenance cost is relatively high, once the failure, will produce a huge economic loss, increase the production cost. Therefore, it is very important to take necessary preventive measures in daily maintenance, which can not only prevent accidents, but also improve production efficiency.