Aiming to solve the problem of high-power magnetorheological fluid transmission heat dissipation, a new type of magnetorheological fluid drive disk is designed. The characteristics of the flow field and temperature field of high power MR fluid transmission devices are analyzed. Meanwhile, the influence of factors, such as rotating speed, inlet velocity, inlet position, diameter and number of magnetic columns, on the flow field are also investigated. Furthermore, the distribution characteristics of the ultimate slip power and the transient temperature field are obtained. The experimental platform of an MR fluid transmission device was established, and the torque transfer performance and heat dissipation performance were tested. The experimental results show that the device has good heat dissipation performance and can transfer high-power torque.

Magnetorheological fluid exhibits shear-thinning behavior when subjected to high temperature environments exceeding 100 °C, which will significantly compromise the operational stability and reliability of the associated mechanical systems. To enhance the performance of magnetorheological fluid, this study selects soft magnetic particles, base carrier fluid, and surfactants based on their resistance to high temperatures and shear-thinning effects. A novel magnetorheological fluid with enhanced thermal stability and shear stability is subsequently developed by carefully selecting flake-shaped carbonyl iron powder, dimethyl silicone oil, and surfactant exhibiting both sedimentation stability and high temperature resistance. The apparent rheological properties and mechanical performance of the fluid are systematically evaluated. Experimental results indicate that the sedimentation rate of the prepared magnetorheological fluid is 3.86% after standing for 10 days, the thermal expansion rate at 200 °C is 12.8%, and the evaporation rate following repeated high temperature applications is only 0.66%. The shear yield stress of the prepared magnetorheological fluid is 31.2 kPa under the magnetic field of 817 mT. The prepared magnetorheological fluid demonstrates excellent thermal stability and shear-thinning resistance, which holds significant potential for enhancing the performance of magnetorheological devices in future applications.

A hoist load monitoring method based on machine vision technology is proposed in this paper to address the frequent overloading accidents of mine hoists and the low safety and reliability of existing contact load monitoring technologies. The depth image of the skip undergoes time domain and spatial bilateral filtering algorithms for noise reduction, followed by conditional filtering and downsampling algorithms to remove redundant point cloud data. Point cloud recognition, extraction, segmentation, and alignment algorithms are then applied to quickly generate a skip point cloud model. A surface reconstruction optimization process combining greedy projection triangulation algorithm and void repair algorithm is proposed to obtain a smooth and complete sealing of the skip. The closed surface model volume is calculated using VTK volume function. Based on single-rope winding hoist, a load visual monitoring system is constructed for relevant experimental research. Results show that this method can accurately measure the loaded coal volume with a relative error range of 0.05%–4.13%, meeting practical application requirements while providing an effective way for non-contact accurate measurement of hoist loads in mines.

Aiming at the drawback of unstable torque output caused by heat generation due to slip in magnetorheological fluid transmission devices, this paper proposes a new type of non-coaxial conical disk magnetorheological fluid transmission structure and deduces its mathematical model of output torque. The magnetic circuit design was carried out based on the conical disk configuration. The electromagnetic field analysis of the transmission device was conducted by the finite element method, and the influence laws of parameters such as the coil current, magnetic conductive material, the conical angle of the disk, and the working gap on the distribution of the magnetic induction intensity in the working area were obtained. The test system for the non-coaxial conical disk type magnetorheological fluid transmission device was established, and experiments on electromagnetic fields, transmission performance, torque response, etc., were carried out. Research results show that the magnetic induction intensity in the working area increases with the increase of the current in the excitation coil, decreases with the increase of the working gap between the two conical disks, and is positively correlated with the magnetic permeability of the conical disk and the magnetic conducting ring materials. The effective working area range and magnetic induction intensity of the governor both decrease as the conical angle of the disk increases. The magnitude of the magnetic induction intensity on the center line is basically the same, but the effective working area range corresponding to different angles shows significant differences.

As an ideal alternative drive solution for mining belt conveyors, the torque output stability and anti-heavy-load disturbance capability of the mining Permanent Magnet Drum (PMD) are compromised by the harsh underground coal mine environment, characterized by high humidity, high dust levels, and strong vibrations, making long-term stable operation difficult to achieve. To address this, this paper employs the Extended Kalman filter (EKF) for real-time estimation of the rotor position and speed of the PMD, combined with the Recursive Least Squares with Forgetting Factor (RLS-FF) algorithm for online identification of the drum’s key electrical parameters, thereby enhancing its torque output stability and resistance to heavy-load disturbances. Simulation and experimental results indicate that under no-load conditions, the speed estimation error does not exceed ±0.63 r/min, and the rotor position error remains within ±0.007 rad. During startup, the belt speed transitions smoothly, and the output torque stabilizes at 1.1–1.2 kN·m. The method demonstrates good dynamic performance and disturbance rejection capability, effectively ensuring the stable and efficient operation of the mining belt conveyor and providing technical support for the practical underground application of mining PMDs.