| The mechanical seal of the communication device operates in a low-speed and light-load environment.Due to the insufficient dynamic pressure effect,the dynamic and static rings keep a contact state,which makes the end surface vulnerable to thermal deformation,wear,and instability,and seriously affects the thermal control effect and reliability of the communicational equipment operation.Therefore,it is extremely urgent to explore the thermal damage characteristics of the mechanical seal friction pair interface.First of all,the friction pair composed of dynamic and static rings are taken as the research object,and the problem of direct thermal coupling and surface contact setting is solved.The radial path of the friction pair and the heat and stress evolution of the interface are obtained and discussed at multiple times.The results show that the temperature rise of Si C-Si C and Si C-Si C reached 22.165°C and 22.122°C,respectively at 100 r/min and 0.3 MPa.The lowest temperature area of Si C-Si C is the outer diameter of non-contacting moving ring.At the outer diameter of the wall,the stress reached 2.39 MPa and 6.63 MPa,respectively.The area affected by stress is mainly concentrated in the inner ring of the seal ring.Overall,the wear of Si C-Graphite is about three times that of Si C-Si C.Secondly,based on the three-dimensional profile profilometer,the surface reconstruction technique is used to smooth,fit and positively process the three-dimensional discrete data of the surface topography;establish the real rough surface model of the contact surface,to obtain the law of contact area,stress,transient changes in heat flux and wear.The research results show that:the heat flux of Si C-Graphite fluctuates greatly;the contact area of Si C-Si C is generally lower than that of Si C-Si C and the non-asperity area affected by stress is smaller;the amount of wear is2.16×10-11 mg at the silicon carbide-graphite interface,and the wear of Si C-Si C is0.718×10-11 mg.Subsequently,the simulation calculation results were verified by the end-face friction and wear tester,three-dimensional white light interference profiler,scanning electron microscope,and micro-wear tester.The friction coefficient and the amount of wear were tested and analyzed.The results show that the test wear value is higher than the simulation result that considering the friction pair wear of the rough surface,but the trend of theoretical result is consistent with the test results,which indicated that the thermal damage model under the rough surface has certain reliability.Finally,in order to further explore the friction pair structure with excellent friction reduction and moisturization in the field of low speed and light load,a comparative experiment was established to establish unidirectional texture patterns and surface composite texture configurations.The test results show that the friction coefficient of the triangle-spiral groove group is 59.69%lower than that of the triangle-ellipse,and the temperature rise is 3.8℃.The frictional performance of the triangle-spiral groove group is better than that of the triangle-ellipse group and the smooth surface group.This thesis systematically expounds the sliding contact characteristics of the friction pair in the low-speed and light-load service environment from the three perspectives of the mechanical seal’s macro-interface thermal damage,the micro-interface thermal damage,and the end-face friction test under realistic conditions.The research results have laid a solid foundation for the high reliability,long life,and low maintenance of mechanical seals for communication radars in low-speed and light-load environments in the future. |
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