Under the impact of the ore, the apron feeder chain plate and its supporting mechanism are deformed, which makes the apron feeder bearing damaged frequently and the maintenance rate is very high. In this paper, the dynamic and static simulation analysis of the ore impact support mechanism (composed of channel steel and I-steel) is carried out by the finite element analysis software Abaqus. It is found that the stress at the rigid support of the chain plate is large during the impact process. The deformation of the chain plate and the supporting mechanism makes the original 5-point support become 2-point support at both ends, so the force on both sides of the bearing is increased, which aggravates the damage of the supporting bearing on both sides. By analyzing the impact characteristics of apron feeder chain plate support mechanism, the problems are found out, and then the apron feeder is improved to reduce the impact of ore on the bearing and improve the service life of the equipment. apron feeder is a kind of heavy equipment widely used in mine feeding, its main role is to send the ore falling from the ore funnel to the belt conveyor more evenly. In the process of work, under the impact of ore, the bearing in the chain plate and its supporting roller system is easily damaged, and the failure rate and maintenance rate are high. Through on-site observation and analysis, it is found that there are two direct factors affecting the failure of apron feeder: First, the ore directly impacts the apron feeder from a height of 10m, and the impact force is relatively large, which causes the deformation or even fracture of the apron feeder and the supporting channel steel; Second, under the impact force, after the use of the chain plate liner and the supporting base of the roller for a period of time, the middle part will deform and sink, resulting in the failure of 3 of the 5 supporting rollers in each row, and only the outer 2 rollers work, resulting in the outer rollers easily damaged. In this paper, the impact of ore on the chain plate and the supporting mechanism (I-beam, channel) is analyzed and studied, and the supporting mechanism is improved, so as to reduce the impact of ore on apron feeder and extend the service life of apron feeder.
1apron feeder structure and mechanical characteristics
1.1 Simplified impact model When the ore falls down, the impact force first passes through the chain plate to the bearing, and then passes to the support frame to deform it, so that the 5-point support becomes a 2-point support, so the chain plate is easy to damage. Therefore, the main reason for the failure of apron feeder is caused by the structural deformation of the support frame, so as long as the support mechanism is analyzed, the impact force can be simplified to the support frame.
In the ore impact, the support will have an elastic effect. According to the factory's annual output of 800,000 tons, the output per minute is Q= 800000000 364X24X60=1522kg, the residence time in the bunker is 5min, the impact time is 0.02s, and the maximum impact force P= Qv/gt=17.6MPa.
In the impact process of the ore, the stress at the support is very large, and the maximum stress occurs in the middle of the support (impact point) near the range, the stress will cause deformation of the support, so that apron feeder is changed from 5-point support to 2-point support, resulting in easier damage to the bearing. 2) The analysis results after improvement show that the force of the improved support has been significantly improved, the force is more uniform, and the damage effect of the impact force is significantly reduced. This scheme is proved to be feasible. This transformation mode is of great significance to the factory that has installed apron feeder. Under the condition that the existing conditions do not change, the construction time is short in this way, the transformation cost is low, the maintenance amount can be reduced, the production efficiency can be improved, and the maintenance cost is extremely important.