Leakage Rate Analysis And Experimental Research On Metal Rubber Seal

The Metal Rubber (MR) made by rolling metallic thread is a kind of homogeneousporoelastic material which has combined properties of metal and rubber. The seal madeby MR can keep a series of excellent performances such as elasticity, sealing, dampingand noise reduction even under high pressure, high and low temperature, largetemperature difference, corrosion and other aggressive conditions. To achieve sealing,MR needs to be combined with other material, so many key technologies are required tostudy and now it becomes one of the most difficult projects in the field of MR.The background of the project and the research situation home and abroad wereintroduced in this thesis. The feasibility and distinct characteristics of the application ofthe MR in the sealing domain were stated. Two MR seals which coated by stainless steeland NBR were developed respectively. The MR dedicated test platform was debuggedand discussed in terms of control system, pressurized system, heating system and flowmeasuring system. Electronical flow measuring equipment was designed andmanufactureed which can achieve real-time monitoring of micro-flow in high pressure.The measurement accuracy of the test platform were improved and this can lay thefoundation for further sealing experimental study.The temperature property of MR were studied by thermal expansion experiment,and mechanical properties were studied by mechanical test. Based on the Navier-Stokesequations and the parallel-disc-gap mode, impacts of several important factors on thesealing character of the MR seal were studied, such as the temperature, relative density,pressure, thermal expansion coefficient. The leakage rate formula was derived for thestudy of sealing performance of the MR seal which provides a theoretical basis for itsexperimental study.Experimental research on leakage rate of MR seal was conducted to investigate theeffect of compression ratio, relative density, pre-tightening force. The main results areas follows: the leakage rate of MR seal decrease with the increase of compression ratio,relative density and the pre-tightening force. And when the MR seal is applied in thesmaller pressure conditions, the effect of parameters on the leakage rate are similar, sochoose the smaller value of the parameters respectively to achieve the preset sealingperformance. And in the greater pressure conditions, the effects of the parameters vary with the leakage rate, so reasonable allocation of the parameter values are required. Andwithin the test temperature range, the leakage rate increases with increasing temperature.The leakage rate of MR seal with one structure parameters was calculated by thederived leak rate calculation formula and compared with the experimental results, theresults show that within a certain range of temperature and pressure, the formula can bedirect to study the sealing performance of MR seal.