Study On Meshing Characteristics And Efficiency Of Two-step Electromechanical Intergrated Sine Movable Tooth Drive

Sine movable tooth drive has smaller radial size,simple structure and high operating efficiency,which is suitable for oil drilling machine and robot arm,etc.For electromechanical intergrated two-step sine movable tooth drive,a small radial size and large speed ratio can be realized simultaneously.In this paper,meshing analysis,force and output torque analysis,lubrication and efficiency analysis are done.A model machine is produced by which the relative parameters are measured.According to spatial meshing principle,meshing equations,tooth-surface equations,limit functions and average velocity are deduced.Induced normal curvatures and principal curvatures are calculated,and its changes along with the system parameters are investigated.According to force analysis of the movable tooth meshing elements,force equations in two-step sine movable tooth drive are deduced,forces and directional angles between the meshing elements are calculated.The output torque equation is given,and its fluctuation is investigated.Analysis of contact stress in the drive is done.The results show: to reduce fluctuation of the output torque,a reasonable speed ratio distribution should be used.From Dowson-Higginson's equation,the minimum film thickness in electromechanical intergrated two-step sine movable tooth drive are calculated,the lubrication state between the movable tooth meshing elements is investigated.The pressures of oil film are calculated,and finite element stress model of the drive based on elasto-hydrodynamic lubrication is created.The power loss equations of two-step sine movable tooth drive are given,thus the operating efficiency of the drive system are calculated,and its changes along with the system parameters are investigated.The results show: to increase the operating efficiency of the drive system,a large speed ratio,large axial amplitude and small radius of the sine ball tracks should be used.A model machine is produced by which output torque,operating efficiency and speed fluctuation are measured.The results show that the measured torque and efficiency of the model machine is near to calculated values which illustrate the calculated results in this paper.