Analysis of time-varying reliability in worm-and-worm gear transmission precision

Worm-and-worm Gear is one of the key components of rotary table, and its transmission accuracy affects the quality and reliability of the whole rotary table. In this paper, the reliability model of worm-and-worm gear transmission accuracy is established by considering the influence of random factors such as manufacturing and fit errors of worm-and-worm gear and external load on transmission accuracy; the reliability of transmission accuracy is calculated by adopting the Monte Carlo method (MCS) and the extreme value method respectively; and the sensitivity of each parameter to the failure phenomenon of the system is then calculated; the difference between the results of the MCS and the extreme value method is within the permissible range, which verifies the correctness of the reliability model. The results show that with the increase of worm-and-worm gear service time, the errors caused by worm shaft hole clearance and worm gear hole clearance have more and more influence on the reliability, and the radial comprehensive error of worm gear has less influence on the system reliability.