Research On The Friction Performance Of Friction Torque Load Simulator

The friction torque is one of the main outside loads of nozzle, its changes insize greatly influences the performance of the nozzle. Based on the previousresearch on load simulator, this paper designs a friction load simulator, in orderto complete the friction torque load simulation of nozzle, and carried out theresearch on the friction performance of nozzle. This paper focuses on the frictiontorque calculation of the load simulator, the selection of friction materials usedon load simulator, parameter determination, and effect of parameters on frictionperformance, to lay the foundation for further research on the nozzle per-formance.This paper introduces the structure and principle of friction torque loadsimulator, compared with the traditional simulator, the load simulator per-formances better in eliminating the surplus force and improving the systembandwidth. Using the concentrated stress calculation algorithm and the calculusmethod to achieve the formula derivation of the friction torque. By calculatingthe friction torque fluctuation in size of different shapes, different sizes anddifferent groups friction plate, we can analyze the law that how different frictionplates in shape, size and group affect the friction torque. The results show that,the large size, multiple numbers, and square friction plate is preferred. But, thelarge size will occupy more space and the square will need additional constraintnodes when used. It will increase the complexity of the system. On the basis ofthis, summarying the advantages and disadvantages of each parameter and theapplication. This will provide the reference for the selection of the friction plateparameters and the simulation of the friction heat of the system.The paper discusses the coupling problem in the temperature field and stressfield between friction parts. Through the analysis of the friction heat transfer lawbetween interfaces in loading process, and establish the heat conduction equ ationof three-dimensional transient temperature field between friction interfaces, thenuse the friction interface heat exchange coefficient and the heat flow densitydistribution coefficient as the boundary condition to calculate the numericalsolution of temperature field. Simulate the friction torque loading processnumerically by using the finite element software, discussion on the influence ofthe pressure and swing frequency of the ball and the friction material specificheat capacity and the heat exchange coefficient on the temperature of friction pair value rules. It provide a theoretical basis for the selection of frictionmaterials. The results show that, in order to prevent the temperature too highfrom impacting the system performance. We should select the friction plate ofwhich have the high specific heat capacity or improve the heat exchangecoefficient between the ball and the surrounding air. This can reduce thepemperature of the system.Through the friction test machine to test metal based, semi-metal based andC/C composite friction materials, we summarized the influence of pressure androtating speed on the various materials friction coefficient. Using the infraredthermometer test the temperature of the contact surface and analyzing thefluctuation of the friction coefficient under different temperature. The resultsshow that, The friction performance of metal material will be influencedobviously under the pressure, the speed and the temperature. The material basedmetal’s hot recession is very obvious. So, it only affected by temperature.These two material which is mentioned above apply to the situation that thefriction coefficient is high and the stability is not high. The sability of the brass+graphite material and the C/C materials’ friction coefficient is relatively good.They apply to the situation that the low coefficient and the high stability required.Just the C/C material is easy oxitated.So, it will be fitted with anti-oxidateddevice when used.