Estimation Method of Slip Ring Mechanical Strength in Current Collectors in Static Setting

Abstract

A performance capacity of ring-shaped current collectors is crucially important for power supply systems of various application mechanisms. As a rule, increasing the downforce acting on contact surfaces helps to improve electrical performance values of slip ring contacts and, above all, contact resistance. However, this could lead to the structural failure of the slip ring material and the current collector breakdown. This paper presents a method of analytical estimation of the slip ring stress state in a static setting that would ensure the slip ring mechanical strength. Bending stresses resulting from the slip ring compression and contact stresses at points of ring conjunction with the outer and inner current-collecting rings are considered in the estimation. The estimation results have revealed that bending stresses caused by compression of the slip ring have the most adverse effect on it. The estimation techniques developed for slip rings may be also used both to assess their mechanical strength within existing current collectors and to design new types of current-collecting devices. Comparative evaluations were conducted using the ANSYS application system following the finite element method for verification of the developed techniques, which demonstrated a good level of the repeatability of results.