In this paper, the reliability allocation and index of overall cost of rotary ultrasonic vibration-assisted EDM machine tool were studied. The failure rate of each module of the rotary ultrasonic vibration-assisted EDM machine tool can be accurately predicted by the maximum entropy ordered weighted average algorithm so that the corrected maintenance cost can be predicted. And effective control of preventive maintenance costs can be achieved by selecting the best maintenance times under the premise of reliability. The cost of corrective maintenance can be reduced by improving modules with a high failure rate, so as to realize the purpose of cost optimization under the premise of determining the maintenance time and reliability. The reliability function of the rotary ultrasonic vibration-assisted EDM machine tool is established according to the series-parallel relationship of each module. The results showed that the reliability of rotary ultrasonic vibration-assisted EDM machine tool is stabler at the non-fixed maintenance period according to the comparison between the non-fixed and the fixed maintenance period.

本文研究了旋转超声振动辅助电火花加工机床的可靠性分配和总成本指标。通过最大熵有序加权平均算法可以准确预测旋转超声振动辅助电火花加工机床各模块的故障率，从而预测修正后的维修成本。并且在保证可靠性的前提下，选择最佳的维修次数，可以有效控制预防性维修成本。可以通过改进故障率高的模块来降低纠正性维护的成本，从而在确定维护时间和可靠性的前提下实现成本优化的目的。根据各模块的串并联关系建立旋转超声振动辅助电火花加工机床的可靠性函数。非固定维修期与固定维修期的对比结果表明，旋转超声振动辅助电火花加工机床的可靠性在非固定维修期较为稳定。