The Dynamic Simulation Analysis Of Tilting Device Of Converter Under The Abnormal Startup Condition

The steelmaking is mainly produced by converter, and tilting device of converter is akey equipment to ensure the production. Tilting device of converter adopts the full suspensionstructure form of meshing at four points. Four sets of reducers are driven by four motorsrespectively. In the normal case, four electric motors must open synchronously. However, in thepractical production process, considering the way of excitation power supply in the maintransmission, ramp rate of speed, PI value of speed loop and current loop which need artificialelectrical control parameters and objective situations of the plant, it is difficult to achieveabsolute synchronous transmission.210t converter tilting mechanism of a steel plant, in theprocess of production, fracture failure of the high speed shaft occurred. Later the test found thatfour motor start up at different time.To study the mechanism of asynchronous starting gear system in the short time, this paperuses the ADAMS dynamics simulation software to simulate the reducer of converter tiltingdevice under motor starting asynchronous condition. Studies have shown that, compared withthe synchronous condition, the vibration of the system is strong in the out-of-sync condition andthe maximum amplitude of the speed is1.5times of the synchronous condition. In addition, therotational torque between the four gear shafts and large gear reducer overall increaseddramatically and are uneven. From rotational torque direction, under synchronous startingcondition, rotational torque direction is the same. Under the asynchronous conditions, due to theimpact of abnormal start-up, the gear rotational torque at log gear shaft are opposite with theother three shaft.For achieve high quality element, this article use HyperMesh as pre-treatment software.Under abnormal start-up condition (containing the lag starting and early starting), this paperuse LS-DYNA to finish explicit dynamic analysis.Result shows that, in abnormal startworking conditions, high speed shaft is the most dangerous part of the whole system. After thecollision， transient stress of high-speed shaft is up to1941MPa.Lag starting of the motor,makes the whole system has been reciprocating before hysteresis motor is open.High frequencyreciprocating in such a short time makes the system constantly impact. Because of stresssuperposition of the gear, the longer the time lag, the greater damage system will receive.Under the early startup condition, collision unit of high speed shaft changes with the time, as a result, for high-speed shaft which start abnormally, lag startup is more dangerous than earlystart-up.