Simulating Research For AT Driving Belt Conveyor

As the most important equipment for the bulk material transportation, belt conveyors increasingly trend towards the direction of longer distance, higher speed, larger capacity and higher power, which makes the research of the start ways and dynamic natures in the start process more and more important. The current driving systems are expensive, complex and difficult to maintain. As an important member in the automatic transmission field, Automatic Transmission (AT) combines the characteristics of hydraulic transmission and mechanical transmission, and has already showed its value of application in the vehicle start process. Given the similarity between the vehicle start and belt conveyor start, this paper presents a soft-start idea for belt conveyors, using an Automatic Transmission with a three-phase asynchronous motor as a drive device, and the feasibility of the idea is verified through computer simulation.The dynamics of conveyor belts is studied, and the characteristics of two typical viscoelastic models (Maxwell model and Kelvin model) are systematically analyzed. By comparison, the dynamic model of conveyor belts is established on the basis of Kelvin model, and its responses for the ideal start curves are examined, the results of the dynamic changes of velocity and acceleration are given separately in different start-time situations, including 10s,20s,50s and 100s. According to the internal structures, the Automatic Transmission is divided into three sections (Torque Converter, Planetary Gear Trains, Wet Multi-plate Clutches and Brakes), and the transmissional properties of each section are studied separately, including the characteristic curves of Hydraulic Torque Converter, the forward gear ratios of the double-row planetary gear transmission system of Simpson type, and the engagement process of Wet Multi-plate Clutch. All of the work provides an essential theoretical basis for the simulation model building of an automatic transmission system.Based on certain assumptions and the platform of AMESim, a dynamic simulation model for the start process of belt conveyor system are established, which uses an Automatic Transmission and an AC motor as its drive device. The investigation and comparison of the dynamic start process of belt conveyor with different gears are made, and the dynamic simulation results in each different start process are presented, including the changes of velocity, acceleration, and tension in head and tail of a particular conveyor belt, the displacement changes of the tensioning device, and the speed changes of the motor. The soft-start feasibility of the AT-driven belt conveyor system is verified by the simulation results.