伺服系统用反馈电位计故障分析及对策

Analysis and Countermeasures of the Fault for Feedback Potentionmeters in Servo System

电位计以其结构简单,性能稳定,能适应恶劣环境等特点,广泛应用于伺服系统中。然而在使用过程中时常出现输出信号异常或中断,使伺服系统性能下降或无法正常工作,严重影响伺服系统的使用。根据多年来伺服系统用反馈电位计的应用情况得知,引起电位计输出信号异常的故障原因主要有电刷断裂、铆钉松动、垫片断裂、引出线断裂、电刷与中心抽头银带接触以及电阻膜或导电条表面有异物或瑕疵点等。通过故障模式机理分析确定了故障的原因,给出了控制和消除故障的方法与建议,并应用于反馈电位计产品整个研制生产过程中,从而提高了伺服系统的可靠性和安全性。

Potentiometer with simple structure,stable performance,adapting bad environment characteristics,widely was used in servo system. However,the unusual and interrupt of potentiometer output signal caused the servo system performance degradation or not work,even seriously impacted on the use of servo system. According to the application situation of feedback potentiometer in the servo system over the years,the reason of potentiometer output abnormal mainly were brush fracture,loosen rivets,gasket rupture,wire fracture,join between brush and the center silver belt,having excess or defects on the surface of resistance film and conductive strip etc. The cause of the failure was determined by the failure mode analysis. The suggestions and methods of eliminating faults were presented,and were applied in the production process of feedback potentiometer. Thus the reliability and safety of the servo system have been improved.