摘要
目的探究工程样机制作前行之有效的可靠性预计的分析方法。方法本文以放疗设备中关键子系统多叶光栅准直器为研究对象,首先根据其结构特点进行可靠性预计模型建立,再根据GJB/Z299C-2006指导方法计算电子元器件失效率数值,通过有限元法、实验法、全寿命分析等方法计算机械部件或关键零件的失效率,最后根据元器件计数法以及产品设计的串并联逻辑关系进行总失效率计算。结果产品设计初期的理论平均故障间隔时间(Mean Time Between Failure,MTBF)为376.5 h,未达理论预期指标500 h,经识别主要是源于系统中传动丝杆和传动丝母较高的失效率,成了整个系统的最薄弱环节。通过提高丝杆强度以及硬化工艺优化等手段提升了预期使用寿命,但传动丝母由于行业技术瓶颈难以降低失效率,因而需要通过定期更换以保障系统运行,故在产品维保策略中需将其定义为易损件。结论本文通过可靠性预计将发现的潜在风险点控制在工程实现前期,降低企业开发成本和迭代频率。文中对复杂机电系统总结出的详细和完善的分析方法,可作为工程技术人员进行可靠性预计工作的参考依据。
Objective To explore the effective reliability estimation analysis method before the design of engineering prototype.Methods In this paper,the key subsystem equipment multi-leaf collimator(MLC)was taken as the research object.At the beginning,the reliability prediction model was established according to MLC structural characteristics.The failure rate of electronic components was calculated according to the GJB/Z299C-2006,the failure rate of mechanical components was calculated by finite element method,experiment method,life analysis and other methods.In the last,the total failure rate was calculated according to the component counting method and the logical relationship of design.Results The results showed that the theoretical mean time between failure(MTBF)in the early stage of design was 376.5 h,which did not reach the theoretical expected index of 500 h.After identification that was mainly due to the high failure rate of the lead screws and nuts,which became the weakest components of the whole system.The expected service life was improved by improving the strength of the lead screw and optimizing the hardening process.However,due to the technical limiting,it was difficult to reduce the failure rate of the drive wire mother,so it needed to be replaced regularly to ensure the operation of the system,and it needed to be defined as the wearing part in the product maintenance strategy.Conclusion In this paper,the potential risk can be exposed in the early stage of product development by the reliability estimation,which can reduce the development cost and design cycle.The detailed and perfect analysis method for complex electromechanical system summarized in this paper can be used as a reference for engineering technicians in reliability prediction work.
作者
李君峰
LI Junfeng(Department of Research and Development,Accu Med Systems Co.Ltd.,Beijing 102200,China)
出处
《中国医疗设备》
2022年第12期53-57,共5页
China Medical Devices
基金
国家“十三五”重点研发专项(2016YFC0105200)。
