第三章 伺服系统课件.ppt

Its performance directly determine and influence the CNC system‘s rapid, stability and accuracy. 其性能直接决定和影响CNC系统的快速性、稳定性、精确性 Servo system, also known as position servo system, drive system, servo mechanism or servo unit. 数控机床伺服系统又称为位置随动系统、驱动系统、伺服机构或伺服单元。 3． Rapid Response It can follow the instructions pulse quickly, and can start, stop, reverse frequently. It can eliminate the load disturbance as soon as possible. Rapid response is an important indicator of the dynamic quality of the servo system ,it reflects the system‘s tracking accuracy 。 快速响应 快速跟随指令脉冲，可频繁起、停、反向；尽快消除负载扰动。快速响应是伺服系统动态品质的重要指标，它反映了系统的跟踪精度。 4． A wide speed range Speed range means the ratio of maximum speed and minimum speed that required. It should be more than 10000:1 and hold Stability. 调速范围宽 调速范围是指生产机械要求电机能提供的最高转速和最低转速之比。 10000：1以上，且稳定性好 。 5．Large torque in low speed The servo control of feed coordinates belongs to Constant Torque Control. Large torque should be maintained in the entire speed range. 低速大转矩 进给坐标的伺服控制属于恒转矩控制，在整个速度范围内都要保持这个转矩 No cumulative error 误差无累积 （2）Electric servo motor servo system 电气伺服系统伺服电机 advantage: Operation and maintenance are convenience and high reliability. 优点：操作维护方便，可靠性高。 1） DC servo system The feed motor system uses a large inertia wide speed range permanent magnet DC servo motor and small inertia DC servo motor. The primary motor system uses separately excited machine. 直流伺服系统 进给运动系统采用大惯量宽调速永磁直流伺服电机和中小惯量直流伺服电机；主运动系统采用他激直流伺服电机。 advantage : Speed performance is good. defection : There are brush, the speed is not high . 优点：调速性能好。缺点：有电刷，速度不高。 2） AC Servo System Asynchronous servo motor AC induction (Generally used in spindle servo system ) and Permanent mag