Based On The Fractal Theory Of Dry Gas Seal C-ring Wear Micro Analysis Research

Dry gas seal is a kind of advanced, novel rotating shaft seal It has the advantages of small wear,low power consumption,small amount of leakage,compared to traditional mechanical seal. It can adapt to the actual harsh conditions such as high temperature and high pressure. Dry gas seal is mainly used in pump, compressor and expansion machine and gas turbine rotating machinery. It is also widely used in the refrigeration equipment.Since the dry gas seal is often used in high-pressure,high-speed operating conditions,its ring will be friction and wear.It makes increase leakage,affect the stability of the primary seal, even failure of the whole seal.Therefore, the performance of the secondary seal has a great influence on the entire seal system.Although the C-ring seal is a secondary seal, it play an important role in the dry gas seal systems.C-ring usually works in the condition of high pressure and high speed. It has high vibration frequency,small amplitude and especially suitable for using the fretting wear theory to study.Traditional contact characteristics fretting theory is mostly based on the integers geometric dimensions of Euclidean geometry.It is difficult to accurately reflect the geometric shape and the friction surface of friction.The fractal theory is mainly studied by the complex irregular geometric shape, thus resorted fractal theory to study fretting model is more accurate.In this paper, the fretting wear process of C-ring is divided into three stages, the initial wear stage, the transition stage of adhesive wear and the stability of abrasive wear.Based on fractal theory for different wear stages, different wear models are established to explain the wear mechanism of C-ring.At first, this paper considers that the initial fretting wear stage of the C-ring is running in and wear, which is different from what is adhesive wear. Based on the fractal theory, this paper presents a C-ring fretting running-in wear model, and does simulation analysis for it. At the same time, this paper deducts the wear loss algorithm of C-ring, and find out the key factor which affects wear loss. Furthermore, it explains the related practical problems.Secondly, the wear characteristics in the running-in wear stage are introduced,through the established model, we point out that oxidative factors can be ignored during C-ring adhesive wear process. The reason that Large amount of wear on C-ring surface is explained.The paper then explained the wear mechanism of C-ring when the C-ring is in the fretting stabilization phase.And based on fractal theory, the abrasive wear modelis established, the algorithm of the wear is deduced, the wear characteristics of material is analyzed at this stage.Finally analyzed the two-dimensional and three-dimensional graph of C-ring surface contour by the C-ring fretting wear test and get the following conclusions:The fretting wear process of C-ring has three stages, namely, running in wear, adhesive wear and abrasive wear;The surface morphology of the materials at different stages showed different characteristics;Different stages of the main factors affecting the amount of wear and the amount of wear trends are different. But the characteristics of each stage are presented in line with the proposed wear model, the proposed wear model can also explain the test, therefore, we believe that the establishment of relevant theories and models used in this paper is reasonable.