Abstract:

The existing emergency rescue equipment has the problem of single function and low flexibility, which is difficult to meet the needs of emergency operations under earthquake, geology and other disaster conditions. A kind of electromechanical hydraulic quick coupling device is studied, which can realize fast change of attachments and free adjustment of position and pose. The device can be quickly integrated into emergency rescue equipment to complete the high-mobility multi-function rescue task. The extreme load characteristics, stress and strain situations during operation of the device are analyzed. The weak part and load spectrum are determined. The reliability theoretical models considering cyclic damage strength degradation under deterministic and random periodic stress are deduced and established. The mapping relationship between the reliability and failure rate of the rotating mechanism is determined. Based on linear elastic fracture mechanics, the crack propagation of the weak part is analyzed. The fatigue life of the device is determined by the local stress strain method to ensure that the device can meet the application requirements. The developed device is integrated into the walking rescue robot. The test results show that it can realize the rapid switching of various attachments such as bucket and gripper, with a switching time of less than 15s. The increased ±40° yaw and ±360° rotation degrees of freedom can meet the needs of flexible operation. The research results can provide significant theoretical reference for the design of similar devices, which is of great significance for improving China's disaster rescue and emergency response capabilities.

Key words: emergency rescue, quick coupling device, reliability analysis, crack propagation, fatigue life