A Research On The Performance Of Dynamic Seal Based On The TEHL Theroy

Sealing failure is one of the most important factors restricting the normal operation of the swing electro-hydraulic motor.The theoretical studies of elastomeric sealing are very rare in the world due to the complexity and the difficulty to convergence.However,with the rapid development of the hydraulic system,comprehensive research towards the sealing performance becomes more and more important.The sealing performance research can provide the seal product design with theory basis,which has profound theoretical significance and practical value.This paper takes the dynamic sealing at the blades of electrohydraulic swing motor as the example.With the existing research on the mechanism of dynamic sealing,a numerical model based upon thermal elastohydrodynamic lubrication(TEHL)theory and a thermal-fluid-structure coupled model are established.Then the effects of thermal effect,surface roughness,and important operating condition parameters on the sealing performance are discussed.Compared with the previous model,the model in this paper is a three-dimensional model,which can analyze the influence of the thermal effect more comprehensively.The main contents of the paper are shown as follows:First of all,the numerical model to evaluate the dynamic sealing performance is established.With the existing research on the sealing principle of rubber O-ring and the rheological model of the rubber,a numerical model,which is based on the TEHL theory used to evaluate the dynamic seal performance,is established.The numerical model is implemented in 3D which consists of the generalized Reynolds equation,the energy equation and the film thickness equation.In order to obtain the convergent solutions from the nonlinear equations,the equations are transformed into a series of equations by using nondimensionalization and discretization,so that the equations can be solved by the numerical method.Then,the equations are calculated with the multiple grid method so that the thickness,the pressure,the temperature,and the velocity of the film can be solved.Then,the volume leakage,viscous friction and some other parameters which are related to the sealing performance are obtained.Also,the effects of the thermal effect,surface roughness,crucial operating condition parameters,and material mechanics property parameters on the sealing performance are discussed.Finally,in order to verify the numerical results obtained before,thermo-hydr aulic-structure coupling simulation and comprehensive analysis was conducted.A thermal-fluid-structure coupled model is established in ADINA and the results from MATLAB and ADINA are compared in various aspects.