传统气压制动系统存在压缩机、制动油箱和空气管路,占据较大空间,而采用电子机械制动(EMB)系统代替,不但可以减小空间,还能实现对夹紧力的快速响应和精确控制。以纯电动城市客车为目标车型,讨论了EMB执行机构方案,根据传统气压盘式制动器最大夹紧力推导出电机的堵转转矩和空载转速。据此设计了永磁无刷直流驱动电机,堵转转矩为10 N·m,空载转速为370 r/min。在Maxwell 2D中搭建驱动电机有限元模型,分析电机在消除间隙阶段和夹紧力增加阶段的制动性能。结果表明所设计的驱动电机制动性能可满足要求。

The traditional pneumatic brake system occupies large space for the compressor, brake reservoir and air pipe. Replacing the pneumatic brake system with electromechanical brate (EMB) system could reduce the space significantly. In addition, it could reduce the latency time and control the clamping force precisely. Taking electric urban bus as the research target, the scheme of EMB actuator was discussed. The locked torque and the noload speed were deduced according to the maximum clamping force of the traditional pneumatic disc brake. Based on this, a permanent magnet brushless direct current (BLDC) drive motor was designed, with the locked torque of 10 N·m and noload speed of 370 r/min. Then the finite element model of motor was established by using Maxwell 2D, and the braking performance during the phases of eliminating clearance and clamping force increasing was analyzed. The results showed that the braking performance of the designed drive motor could meet the requirements.

TM 351