Analysis Of Meshing Temperature Field Of Polymer-Metal Hybrid Gears And Experimental Verification

Past years have witnessed increasing practical utilizations of polymer gears,benefiting from their noiselessness,low density,self-lubrication,etc.However,there exists a fatal limitation that mechanical properties of polymers present a critical dependence on temperature,which will result in insufficient load-carrying capacity and severe wear damage or even worse,partial melting while accumulated contact-induced heat flux boosts bulk temperature elevation of teeth,especially local surface temperature elevation due to poor thermal conductivity of polymers,during motion transmission.Hence,it is essential to evaluate the accurate meshing temperature of polymer gears,so as to promote further application of plastic gears.A coupled process-structure finite element model designed for short fiber reinforced components has been established via three platforms,i.e.,Moldex 3D,Digimat and ABAQUS.This model could predict meshing temperature field of a multicomponent plastic gear comprised of nylon ring,short-fiber-reinforced nylon flange and metal hub,by considering the inhomogeneous distribution of fiber orientation,fiber length and fiber concentration emerging in injection molding process.The simulation procedure consists of heating contact analysis calculating heat flux generated during engagement and heat transfer analysis simulating dynamic temperature distribution.Besides,a viscoelastic material model was utilized in heat contact analysis to calculate the representative viscoelastic response of injection molded parts.Meanwhile,Fortran subroutines were coded to integrate the hysteresis effect.Engaging temperature field of multicomponent gear under different operating conditions such as torque and rotation speed,was analyzed.Subsequently,different simulation schemes were followed to investigate the influence of heat flux iteration on the accuracy of model.Finally,meshing temperature measurement via infrared thermometer on the customized gear rig was carried out to validate the simulation under a certain operating condition.Main conclusions are drawn as below:(1)Consideration of inhomogeneous distribution of fibers during injection molding process will enhance the prediction of mechanical response of short-fiber-reinforced part.(2)Predicted gear temperature will be underestimated if hysteresis dissipation is ignored.(3)Iteration of heat flux should be weighed to reduce calculation error and time consumption.(4)An acceptable agreement was achieved while comparing the simulation result with experimental measurement under a certain operating condition and the model proved to be preliminarily valid.