在牵引电器试验中,经常有各类交、直流接触器需进行通断试验、电寿命试验和机械寿命试验。而电寿命试验一般需试数万次,机械寿命试验一般需试数十万次,试验次数多,周期长。过去进行这类试验,一般是采用一组胶木圆盘,在多个圆盘上钻有圆孔,用以安装胶木块,以形成凸轮机构,通过电机带动胶木圆盘转动,使胶木块触动控制触点 In the traction electrical test, often have all kinds of AC, DC contactor to be on-off test, electrical life test and mechanical life test. The electrical life test generally takes tens of thousands of tests, the mechanical life test generally need to test hundreds of thousands of times, the test frequency, long cycle. In the past for such experiments, a set of bakelite discs was generally used to drill round holes in a plurality of discs for installing bakelite blocks to form a cam mechanism. The bakelite discs were driven by the motor to rotate and control the bakelite blocks Contact