Magneto-rheological technology based overload protection device for torque shaft of electric motor in coal mining machine

A magneto-rheological technology-based overload protection device for the torque shaft of the electric motor in a coal mining machine comprises a cutting part gear (3), bearings (2) installed at either end of the cutting part gear (3), a shaft coupling (4), a cutting part shell (6), a motor (8), a torque shaft II (1), a torque shaft I (7) and a magneto-rheological fluid overload protection device (5). One end of the torque shaft II (1) is connected with the cutting part gear (3) by means of a splined connection, the other end is connected with the magneto-rheological fluid overload protection device (5) via the shaft coupling (4). One end of the torque shaft I (7) is connected with the rotor (9) of the motor by means of a splined connection, the other end is connected with the magneto-rheological fluid overload protection device (5) via the shaft coupling (4). The magneto-rheological fluid overload protection device (5) is fixed on the cutting part shell (6) by a connecting piece (13). The overload protection device can automatically recover in case of overload without destroying any structure and replacing any component, thereby saving the time, improving the operating efficiency and reducing the production cost.