多机驱动在输送装备实现高速、长距离、大运量等方面起着至关重要的作用。直线电机因其具有不存在摩擦、无旋转传动部件、能够沿输送机长度方向任意布置和降低输送带张力等特点而成为特殊高性能带式输送机较理想的中间驱动方式。通过分析直线电机的工作原理,对直线电机与旋转电机的优缺点进行了比较;针对带式输送机用直线电机,对比确定了其次级型式,并进行了次级输送带结构设计;基于封闭式散料储运物料试验系统建立了静动态特性试验台,并运用欧拉公式及逐点张力法求得直线电机推力(输送带张力差),进而分别对电压、气隙与推力之间的比例关系进行了试验验证,并间接进行了动态试验(机械特性试验),得到了推力关于输送带速度的数学表达式;基于Belt Analyst带式输送机计算分析软件,对输送带稳定运行及启动过程的张力进行了仿真分析,并与试验张力进行了对比分析。试验结果表明:推力分别与电压平方、气隙倒数的平方成正比;电压、气隙与推力之间的理论曲线与试验值相符;直线电机的推力与输入功率的比值较大,并随着气隙的减小,比值越来越大;与旋转电机相比,此直线电机无临界转速,并显示出很软的机械特性;稳定运行时张力的仿真值与试验值基本吻合,其相对误差均小于2%,但启动过程中张力试验值与仿真值误差较大,间接表明保证启动过程气隙均匀的重要性。研究结果可适用于多机配合驱动超长距离带式输送机的改进与实际应用中。
Multi-motor driving plays a crucial role in the way of high-speed,long-distance and large-capacity for conveying equipment.Because of the advantages of no friction,no rotating drive components,arbitrary arrangement along the conveyor length direction and the reduction of the characteristics of belt tension,the linear motor becomes an ideal middle drive form in the high performance special belt conveyor.The merits and demerits of linear motor were compared with rotary motor based on its fundamental principle.The type of secondary structure was determined by comparative analysis for linear motor used in belt conveyor.And the secondary structure ofbelt was designed.According to the closed bulk handing material testing system,the test rig of static and dynamic characteristics were established.The thrust(tension difference of belt)of the linear motor was obtained using the Euler formula and the point by point tension method.Meanwhile,the proportional relationship between voltage and thrust was verified by experimental as well as air-gap and thrust.And the dynamic test(mechanical properties test)was carried out indirectly.Then the mathematical relationship between the thrust and belt speed was obtained.Moreover,the pulling force of stable running and starting process of belt were simulated based on Belt Analyst software and they also were compared with the experimental results.The experimental results showed that the thrust was proportional to the square of the voltage and the square of the reciprocal of air-gap respectively.It was also concluded that the theoretical curve between voltage and thrust(as well as air-gap and thrust)was consistent with experiment value.The ratio of thrust and input power on the linear motor was large,and the smaller the air-gap,the greater the ratio.In addition,compared with rotary motor,the linear motor had no critical speed,and it represented very soft for its mechanical properties.Ultimately,the simulation value of pulling force of stable running was basically consistent wit