Research Of Design And Dynamic Performance For Driving Axle Of Motor Wheel Mining Truck

Electric wheel mining truck has played a significant role in mining machinery filed. In the course of developing mining truck, drive axle, as a necessary component, requires to spend many efforts in research design aspects. So far, most of domestic designers prefer buy or follow the foreign products to design new hub motor and wheel reductor. There are few detailed materials about the domestically developed drive unit for electric wheel mining truck. As a result, this thesis mainly states the configuration and control for hub motor and the performance and inherent characteristic of hub wheel reductor. To implement the dynamic design for drive unit, the vibration performance and dynamic performance of drive unit should be made an intensive study.The configuration has been defined by actual conditions of mining truck. The modeling and analysis have been introduced, which are based on vector control algorithm in AC asynchronous motor. We have also simulated in combination with real car’s start from static position. According to analysis of simulation results, rotor-field-oriented vector control can resolve problem of real-time control to output torque in the dynamic operation of mining electric-wheeled self-dumped truck. Meanwhile, we have proved that the method has qualities such as fast response speed, strong robustness and perfect stability, which is able to cope with various working conditions in vehicle operation.According to the vector-control strategy, the experiment platform has been established to test the wheel hub motor with required system devices. With complicated road conditions of mining trucks, we have simulated working conditions in situations such as electric motor’s accelerated start from static position, accelerated driving first and decelerated driving afterwards, uphill and downhill driving, starting free-running motor. The statistics has illustrated that inverter with this kind of control algorithm conforms to various changes of the load and copes with complicated road conditions for mining electric-wheeled self-dumped truck.The output torque from hub motor drives the mining truck through the wheel gear reductor to tires. The gear ratio of wheel gear reductor varied along with the size of mining truck. By using the parameters of mining truck, a two stage wheel gear reductor and a three stage one are designed. By analyzing two types of wheel gear reductor in terms of statics, performances and efficiencies, a configuration specification for wheel gear reductor of mining trucks is proposed. The research for these two kinds of wheel gear redactors has become a reference for configuring the wheel gear reductor. Furthermore, the three stage gear reductor solves the problem for large tonnage dumping mining truck.Since the traditional static states model cannot achieve the requirement of wheel gear reductor, the dynamic performances should be developed deeply. Considering the special working character, the torsional dynamic model of three stage reduction gear has been set up after the analysis to relative displacement and kinematics and statics. Inherent characteristic of the reductor system was analyzed, and the inherent frequency sensitiveness and mode of vibration have obtained towards meshing stiffness and the component quality. It provides the quantitative reference value for designing the wheel gear reductor system.The dynamic of wheel gear reductor is relatively complicated for affecting by frequently disturbance and incentive, which has an influence on operational stability of drive unit. By utilizing the Lagrange equation, the dynamic model of wheel gear reductor has been built for the distribution rules of inherent frequency affecting by time-varying meshing stiffness. With known mathematic models, the drive unit has modeled by the software Simulink to simulate the actual working conditions. According to the input load of hub motor, the dynamic response and the characteristics of gear vibration frequency spectrum are analyzed with considering the internal incentive. To choose the right working condition for wheel drive unit, the relationship between gear vibration and the output speed of hub motor has been found with dynamic responses of system.