This study aims to develop an accurate calculation model of transmission torque and load-bearing capacity for hydro-viscous clutches(HVC)used in high-power vehicles,which is important to investigate the step-less spee...This study aims to develop an accurate calculation model of transmission torque and load-bearing capacity for hydro-viscous clutches(HVC)used in high-power vehicles,which is important to investigate the step-less speed regulation characteristics in a fan drive system.However,most of the existing models ignore the distribution differences of groove area along the radial direction,which may lead to significant deviations in calculating the mechanical property of friction pairs related to operating conditions and the engagement process.To fill this gap,a new calculation model for bearing capacity and frictional torque of friction pairs with different oil grooves is proposed,in which the traditional fixed contact area ratio coefficient for oil groove measurement is replaced by a more precise discrete micro-ring area ratio(DMAR)integration method.Then,a 32-degree-of-freedoms dynamic model of HVC at a fan drive system is established for the prediction of dynamic responses during speed regulation.Results show that friction pairs with different oil grooves have a direct influence on frictional torque and bearing capacity through the change of DMAR along the radial direction.The friction pairs with different groove structures have oscillation phenomena at the engagement steady-state boundary.Furthermore,a step-less speed regulation experimental setup is established to verify the correctness of the proposed model.It is demonstrated that the axial engagement force and the speed regulation curve predicted by the proposed method are in good agreement with the experimental data.The results could effectively predict the engagement dynamic characteristics.The numerical relationship among the structure parameters,the mechanical properties of friction pairs,and the speed regulation characteristics of the system are established through the proposed model,which lays a theoretical foundation for the structure design of friction plates and optimization of step-less speed regulation performance.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.52475089,52035002)National Key Research and Development Program of China(Grant No.2021YFB2011400)the Chongqing Natural Science Foundation(Grant No.CSTB2022NSCQ-MSX1243).
文摘This study aims to develop an accurate calculation model of transmission torque and load-bearing capacity for hydro-viscous clutches(HVC)used in high-power vehicles,which is important to investigate the step-less speed regulation characteristics in a fan drive system.However,most of the existing models ignore the distribution differences of groove area along the radial direction,which may lead to significant deviations in calculating the mechanical property of friction pairs related to operating conditions and the engagement process.To fill this gap,a new calculation model for bearing capacity and frictional torque of friction pairs with different oil grooves is proposed,in which the traditional fixed contact area ratio coefficient for oil groove measurement is replaced by a more precise discrete micro-ring area ratio(DMAR)integration method.Then,a 32-degree-of-freedoms dynamic model of HVC at a fan drive system is established for the prediction of dynamic responses during speed regulation.Results show that friction pairs with different oil grooves have a direct influence on frictional torque and bearing capacity through the change of DMAR along the radial direction.The friction pairs with different groove structures have oscillation phenomena at the engagement steady-state boundary.Furthermore,a step-less speed regulation experimental setup is established to verify the correctness of the proposed model.It is demonstrated that the axial engagement force and the speed regulation curve predicted by the proposed method are in good agreement with the experimental data.The results could effectively predict the engagement dynamic characteristics.The numerical relationship among the structure parameters,the mechanical properties of friction pairs,and the speed regulation characteristics of the system are established through the proposed model,which lays a theoretical foundation for the structure design of friction plates and optimization of step-less speed regulation performance.
