| Drive shaft is an important component in the powertrain of automobile.It transmits motion and power between the transmission and the wheels.The ball-cage type universal joint is a constant velocity universal joint commonly used on a drive shaft,which is connected to a wheel hub.With the development of the automotive industry,the requirements for lightweight design of automotive parts and low energy consumption have become higher and higher,which have put forward higher requirements for the strength of drive shafts and high-efficiency transmission performance.In this article,the dynamic characteristics of the ball cage type universal joint in the drive shaft of the automobile are calculated,including the change of the contact force of the internal structure of the universal joint and the transmission efficiency,and a more detailed analysis of the influencing factors is made.The main work of the paper is as follows:(1)Based on the structure and working principle of the ball cage type universal joint,a coordinate system is established on the universal joint,and the various kinematic characteristics and changes of the ball cage type universal joint are calculated and analyzed.The change rule of the position of the contact point between the ball and the track.(2)A multi-body dynamics model of the double-center arc ball cage type universal joint is established.The contact parameters between the internal components of the gimbal model are determined,and the contact stiffness was selected based on the Hertzian contact theory.Friction between components of multi-body dynamics model is characterized by modifying the Coulomb friction model.A multi-body dynamics model is established to analyze the influence of various parameters on the calculation results,and the multi-body dynamics model was optimized.The correctness of the model is verified by theoretical calculations and experimental results.(3)Calculate the contact force between the internal structure of the ball cage type universal joint,including the contact force between the steel ball and the track and the ball and the cage,and analyze its change characteristics with the rotation angle of the universal joint.The influence of the number of balls and the offset of track on the contact force of the structure is analyzed.The dynamic characteristics of the deflection bending moment of the universal joint and the influence parameters are calculated and analyzed simply.(4)The transmission efficiency of the ball cage type universal joint was analyzed in experiments,and the dynamic characteristics were calculated and compared to analyze the influence of the number of balls on the transmission efficiency of the ball cage type universal joint.Through orthogonal test design,the influence of friction coefficient between various structures inside the universal joint on the transmission efficiency is analyzed.The results show that the friction coefficient between cage and inner race,cage and outer race is the main influencing factors of transmission efficiency.The research methods and influencing factors analysis results of the dynamic characteristics of ball cage type universal joints in this article have guiding significance for the design and development of ball cage type universal joints. |
PDF Full Text Request