Research on the electro-magnetic-thermal–mechanical characteristics of shearer cables

Cables provide power and control signals for the shearer, playing a crucial role in ensuring the reliable operation of the shearer. Utilizing MCP0.66-1.14 (3*95 + 1*35) and control wire core cross-sectional areas of 4mm², 6 mm², and 10 mm² as the specifications for shearer cables, a 3D model of the cable is developed utilizing the theta and trajpar functions. A four-field coupling simulation model for the electrical, magnetic, and thermal characteristics of shearer cables is established based on the fundamental principles of electric and magnetic fields, temperature fields, and structural mechanics. An orthogonal experiment was designed to investigate the electromagnetic loss characteristics of cable control wire core under various influencing factors. The results suggest that among the three factors: cable pitch-to-diameter ratio, cross-sectional area, and current-carrying capacity, the cross-sectional area significantly affects the magnetic flux density mode, current density mode, and volume loss density of the control wire core. A cable motion simulation experiment was conducted with a shearer traction speed of 6 m/min along cable to obtain the characteristics of cables of different specifications. The variation patterns of these characteristics were then analyzed. The research results indicate that: During the straight segment of the cable, as the cross-sectional area of the control wire core conductor increases, the equivalent stress, temperature, current density mode, and volumetric loss density gradually decrease, while the magnetic flux density mode shows a slight increase. In the bending segment of the cable, an increase in the cross-sectional area of the control wire core conductor leads to a gradual increase in equivalent stress, while temperature, magnetic flux density mode, volumetric loss density, and current density mode all gradually decrease. Using cables of the same specifications, the influence of the cable section-to-diameter ratios (4, 5, 6, 7, and 8) on cable characteristics was investigated. The results indicate that as the cable section-to-diameter ratio increases, equivalent stress increases, temperature decreases, and magnetic flux density mode, current density mode, and volumetric loss density slightly decrease. Experiments were conducted using the cable bending test machine developed by the Yankuang Group. The experimental results demonstrated a strong agreement between measured and simulated values of the cable's outer sheath surface temperature and equivalent stress. The maximum deviation between experimental and simulated values for the outer sheath surface temperature was 2.40%, and for the equivalent stress, 4.66%. These findings are significant for improving the overall performance of shearer cables and provide theoretical guidance for their design and development.