The performance of the roadheader is the key to determine the rapid excavation. Based on the existing results, this paper analyzes the main factors affecting the performance of the roadheader.
I. Analysis of the design, processing and manufacturing of the roadheader
1. Stability of the whole machine operation. The operational stability of the roadheader has a great impact on its work efficiency and work safety. Compared with the horizontal axis type roadheader, the vertical axis type roadheader has to achieve the same stability, and the weight needs to be increased by about 20%. When the roadheader is working, instability such as rollover, backturning, rotation along the vertical axis, and track slippage may occur. Increasing the weight of the fuselage can improve the stability of the roadheader operation, but on the one hand it will increase the cost, on the other hand, the roadheader will be prone to sag in a humid and low environment. According to statistics, during the work process, the downtime caused by the machine is not stable enough in space, up to 26%, and the downtime caused by the motor crash accounts for 20%. The stability of the roadheader directly affects the normal operation of other actuators. Therefore, it is important to enhance the overall stability of the roadheader, improve the mechanical performance of the roadheader, enhance its work efficiency and reduce the failure.
2. Coordination of motion of the star wheel loading mechanism. The loading mechanism is one of the main working mechanisms of the roadheader. Its function is to collect and arm the coal rock that has been broken by the cutting mechanism to the intermediate conveyor. The size of the loading capacity depends on the choice of loading mechanism parameters, which directly determines the production capacity of the whole machine. Therefore, continuous improvement and improvement of the loading mechanism of the roadheader is a prerequisite for improving the performance of the roadheader.
3. Comprehensive factors of cutting head and pick. The pick is the key component of the roadheader, and its material and manufacturing process will have a greater impact on the performance of the roadheader. With the expansion of the application range of the roadheader, the requirements for the hardness and fatigue strength of the pick-up have an increasing trend. At present, the domestic pick-up machine picks are mostly hard alloys, such as 35crmnsia, which has the disadvantage of large brittleness. Due to the complexity of the rock formation geological conditions of the roadheader, the picks are required to have high hardness, good impact resistance and wear resistance, thus ensuring the stable working ability of the roadheader when cutting quartz-rich rock. Not only the material of the pick is very important, but also the shape of the pick and the arrangement of the cutting head can not be ignored for the performance of the roadheader. Because the 截-shaped pick has good self-sharpness and impact resistance, it is widely used. The arrangement of the cutting head directly affects the stability and working efficiency of the whole machine.
4. The power of the roadheader. At present, the power of roadheaders in China is generally small, while the roadheaders in developed countries generally range from 200kw to 300kw, and the highest is close to 500kw. The small power is not conducive to cutting harder rocks and improving work efficiency. Therefore, China needs to strengthen the development of high-power roadheaders. In order to better utilize the performance of the roadheader, a certain reserve power must be left. From the current development trend of the roadheader, the high-power roadheader will inevitably become the main model of the mine.
Second, from the analysis of environmental factors
1. Rock bed dip. For a roadheader, the cutting speed is 8m3/h when there is no rock angle, and the cutting speed is 10m3/h when there is rock angle.
2. Tunnel inclination. A tunnel with a certain angle of inclination can better utilize the gravity of the medium carbon itself and is easy to load after being cut. At the same time, the coal can be prevented from circulating in the cutting head and the working surface, thereby enhancing the working efficiency and reliability of the roadheader.
3. Rock mass strength. The strength of the rock mass has a significant impact on the working efficiency of the roadheader. The strength of the rock mass is large, the energy required to cut a unit volume of rock will increase, and the working efficiency of the roadheader will also decrease. The literature reports that when the rock mass strength is 21mpa, the energy required to cut a unit volume of rock is 11.2mj/m3, and the working speed of the roadheader is 25m3/h. When the rock strength is 45mpa, the energy required to cut a unit volume of rock is 16.3mj/m3, and the working speed of the roadheader is 20m3/h.
4. The rock layer is filled with water. The wet rock layer and the dry rock layer have a great influence on the working performance of the roadheader. Through comparative analysis, the rock mass injected with 11 liters of water per minute is equal to the dry rock layer. When the rock mass strength is equal, the working efficiency of the former roadheader is 50m3/h, and the latter is 25m3/h. It can be seen that the moisture of the rock formation does have a great influence on the efficiency of the roadheader. However, its mechanism research is still in a blank stage. In addition to the above factors, there are still many geological environmental factors affecting the performance of the roadheader. The mechanism of action is quite complicated and needs further study.
Third, the conclusion
Based on the method of system analysis, the factors of the performance of the roadheader are comprehensively analyzed, that is, the internal factors of the roadheader and the external factors of the working environment. Internal factors include: stability of the whole machine operation, coordination of the action of the star wheel loading mechanism, comprehensive factors of the cutting head pick, power control system of the roadheader, hydraulic system, water supply system, walking system, etc.; external factors include: Rock bed dip angle, tunnel dip angle, rock mass strength rock layer moisture and other factors. For the comprehensive analysis of the performance of the roadheader, it has certain guiding significance for the design and use of the roadheader.
Concerned about surprises
Label: Comprehensive analysis of the main factors affecting the performance of the roadheader
Previous: The use of tin bronze Next: A brief analysis of three common LED dimming power supplies
Wood Door And Frame,Lowes Solid Wood Door,Latest Wood Door Design,Laminated Wood Door
Lemon Building Material Co., Ltd. , https://www.lemonbuilding.com