Perinskiy Maksim

Abstract on the theme of graduation

    The object of study - the executive body of the drive subsystem shearers (for example, KDK 500).
    Objective: To improve the reliability of subsystems drive of the executive body at the shearers through the establishment of the regularities of formation of heavy loads and justify ways to reduce them.

1 Topicality

    The maximum load in the drive of the executive body of the shearer arise in meeting the cutting tool with hard switching, which are quite common in the developed coal seams. Such an interaction in the transmission there are significant dynamic loads in excess of their load values at cutting coal seams a few times and lead to failures and reduce the longevity of mining machines.

Animation 1. Scheme destruction array chisel
Number of cycles - 10 shots - 17, volume - 144 KB

   1.1 Studies of the external load in the form of multiple pulses (from records of load on the tool)
    In the laboratory, cutting coal Institute of Mining of them. AA Skochinskiy were carried out research [1] aimed at studying the factors affecting the level of maximum loads, such as the nature of the relationship included an array type of interaction with the inclusion of a tool, the mineralogical composition of the inclusions, etc. The results of these studies were based on the materials of field experiments on cutting inclusions (with records of loads on the tool) with different and previously known strength and geometric characteristics. Have been previously identified three types of inclusions of different mineralogical composition, physico-mechanical properties and fracture behavior during cutting. These include pyrite, carbonate and carbonate-pyrite. Also taken into account and analyzed by way of contact with the inclusion of the tool. Of the options considered marginal cutting, central cutting, a touch of a pen, dug out of the array, as well as the removal of inclusion, along with the chips of coal. The latter type of contact does not cause the growth of dynamic components of load, since this type of contact is not broken connection coal and inclusion, but this type of contact is possible only when the value of the inclusions do not exceed the value of the chip. Experimental data and calculations presented in this work the formula showed that, as a basic model for determining the maximum loads should be central to cutting as a form of contact at which the relative magnitude of the maximum load has a maximum value and is approximately 1. The inclusions are of different nature of destruction. Found that when cutting the carbonate-pyrite inclusions there is only one peak force on the quantification of approximately equal strength when cutting carbonate inclusions. Pyrite inclusion of relatively small size, resulting in their destruction is the first interaction with the inclusion of a pen, while the level of peak force in the 1,5 - 1,7 times more compared with carbonate inclusions. However, in these works have not been studied zakonomernsti formation feedback-loads in the subsystems of the drive, which requires further targeted research.

   1.2 Investigation of dynamic processes in the external load in the form of single pulses (from records of load-response)
    Fig. 1 shows the moment of resistance in the form of a triangular pulse, which is discussed in the works DonNTU [2,3].


Figure 1 - Change of the resistance moment in time

This dependence was obtained on the basis of records of the torque as a result of field experiments of mine. However, it remains unknown degree of representativeness of the parameters of the inclusions and the type of slotting. The values of the moment of cleavage and the pulse duration is invited to rely on the technique [5]. The basic calculation was made by us as described in [3].

2 Analysis of the stress-response by the method DonNTU

    In implementing this approach, the calculations by the above methods, as well as the analysis of the influence of mid-level resistance moment and angle locking device to work vibroprotecting limiters deformations of elastic elements and the level of maximum loads in the drive of the executive body.



Figure 2 - Dependence of the maximum level and the dynamic moment from the corner locking device vibroprotecting and mid-level resistance moment

Figure 2 shows that with an increase in the average time decreases the time dynamic. As the angle locking ESD level dynamic moment is reduced to the greatest extent.

3 Development of a simulation of mathematical models of dynamic processes in the drive of the executive body of the shearer

    To achieve the objectives were reasonable assumptions and the mathematical model of the maximum loads in the drive of the executive body with the fundamental equations Park Goreva. The equivalent calculation scheme for the preparation of the mathematical model presented in Figure 3 [3,4].




Figure 3 - Equivalent design scheme subsystem drive executive body of the shearer

    A mathematical model is as follows:

    The system of differential equations was solved by the Runge-Kutta of order 4 using the package Matnsad 14 and obtained the following dependence, most fully reflect the operation of the subsystem (Figure 4). Comparing the numerical values obtained by the implementation technique [3] with the values obtained by solving the mathematical model, we can conclude that the difference between minor and included in the confidence interval. This proves that the results of the mathematical models are adequate. Results of computational experiment can be considered definitive.


Figure 4 - Dependence obtained by simulation

Figure 4 shows the dependence on time:
a) the elastic moment of transmission;
b) the angular velocity of the executive body;
c) the date of the electromagnetic motor;
d) the angular velocity of the rotor motor.
As shown in Figure 4 for cutting solids having loads fading with time. Convergence of the mathematical model with data from experiments carried out by introducing an additional term in the equation responsible for the damping of the array.

4 Directions for further research

    Further tasks of this work is to develop a mathematical model as a function of the way Cutter, as well as replacement of a linear friction in the nonlinear models that will complicate the mathematical models and will yield more correct results.

Bibliography