| Shaft hoisting system plays a significant role in underground mining industry, which is used to transport ore, equipment and personnel. Compared with fixed guides, rope guides offer a lot of advantages, such as shorter installation time, lower capital costs, lower maintenance requirements and smooth travel. The design of rope guided systems has been commonly based on empirical rules, which have evolved from empirical information in existing reasonably shallow shafts. Factors that affect conveyance lateral motion such as conveyance velocity, ventilation airflow, tension of rope guide, payload etc. are not adequately addressed in the rules. So it is significant to investigate the lateral oscillation behavior of rope guided conveyances and reveal the oscillation mechanism of rope guided conveyances.The lateral equivalent mass and the equivalent stiffness of guide ropes, hoisting ropes and tail ropes for lateral oscillation were studied. Based on Rayleigh’s method, the results showed that the lateral equivalent mass of guide ropes, hoisting ropes and tail ropes are a third of their quality. Based on the continuous mechanical theory, the deflection curve equations of guide ropes, hoist ropes and tail ropes were established. Then the logarithmic formula and derivative formula of equivalent stiffness were obtained, and the numeric results showed that the errors between two formulas is very less. With the mass of rope taken into consideration, the lateral vibration model of tensioning rope was established and the lateral natural frequency formula was derived. The lateral natural frequency formula shows that after considering the quality of the rope, its lateral natural frequency varies with the position. Furthermore, when the mass of rope taken into consideration, the phase velocity and the group velocity of lateral disturbance in the tensioning rope is not equal, so dispersion phenomenon occurs, and the lateral disturbance damped when spread in the tensioning rope. Respectively, in Daping coal mine production shaft and Zhenxing second mine production shaft, the propagation time of lateral disturbance were measured, and the results showed that the derived formula improves accuracy.In order to predict the lateral oscillation behavior of rope guided conveyances under disturbing force, namely aerodynamic force and Coriolis force, non-smooth lateral oscillation model and non-smooth torsional vibration model are established based on Newton’s second law and the laws of rotation separately. In order to let the conveyances be hoisted as specified speed curve and calculate aerodynamic forces acting on conveyances, parallelized user-defined function(UDF) was written. With user-defined function loaded, ANSYS FLUENT 14.5 was employed to calculate the aerodynamic forces acting on moved conveyances especially when conveyances cross each other based on k-??SST turbulence model. Based on non-smooth lateral oscillation model and non-smooth torsional vibration model, Matlab was used to numerical calculate the lateral oscillating displacement of rope-guided conveyance under the dynamic disturbing force. With the Yaoqiao skip hoisting system taken as an example, the numerical result was compared with the experimental data in the literature to verify the model.Based on flow-induced oscillation model, lateral oscillating characteristics of rope-guided conveyances in three typical layouts, a single conveyance with a counterweight, double conveyances and four conveyances, were investigated. Pressure contours, velocity vectors and pathline around the rope-guided conveyances were obtained when conveyances cross each other. The results showed that there is a significant aerodynamic buffeting force when conveyances cross each other. The aerodynamic force acting on the third layout is much less than that on the second layout, and the aerodynamic force acting on the second layout is less than that on the first layout. In addition, the piston effect of the first layout, a single conveyance with a counterweight, is strongest, and the piston effect of the third layout, four conveyances, is weakest. From an aerodynamic standpoint, the third layout, four conveyances, is recommend preferentially, and the first layout, a single conveyance with a counterweight, is recommend last.Based on flow-induced oscillation model, the influence of hoisting speed, ventilation speed, clearance between the guide shoe and the rope guide, tension and payload on oscillation of rope-guided conveyances were investigated respectively. The results show that the aerodynamic force acting on the conveyance is proportional to the square of the hoist speed and ventilation speed, and the lateral oscillation amplitude of the conveyance increases with the increase of hoist speed and ventilation speed. With the increase of the clearance between the guide shoe and the rope guide, the lateral oscillation amplitude of the conveyance also increases. Curve Fitting Toolbox of Matlab was used to fit the aerodynamic buffeting force acting on the conveyance based on Fourier Analysis when conveyances cross each other, and the fitting results show that the second harmonic cosine function and sine function can fit the aerodynamic buffeting force well. The sensitivity analysis of factors affecting oscillation of conveyance shows that, the hoisting speed is most sensitive, the sensitivity of tension is less than the hoisting speed, the sensitivity of ventilation air speed is less than the tension, the sensitivity of clearance between the guide shoe and the rope guide is less than the ventilation air speed, and the payload is the least sensitive.In order to confirm the accuracy of the theoretical work, Australia advanced navigation company’s fiber optic gyro inertial navigation system, Spatial FOG INS, is used to measure the trajectory of cages in Longshou mixed shaft and Longshou second western service shaft. The experimental data was compared with the numerical result, and the result show that theoretical work proposed in this paper is correct. |
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