Kinetic Study Of Gear With Small Number Of Teeth

Based on its advantages of high transmitting ratio,gear with small number of teeth is beginning to be widely used in many important fields,such as precise instrument and aerospace.The tooth deformation and the time-varying stiffness as well as the dynamics and the modification method of gear with small number are studied in this paper,and the main research contents of this paper are as follows:(1)There is a test designed to measure the meshing stiffness of gear with small number of teeth according to gear engagement principle,through which the deformation characteristic and the change rule of gear tooth meshing stiffness are obtained.And at the same time,those are analyzed based on finite element method.There is a comparison made between results obtained from these two methods,which verifies the correctness of the method to measure the meshing stiffness of gear pair with small number of teeth.(2)By analyzing bending,axial and torsional vibration of the gear transmission system composed of gear and shaft,the dynamic model based on gear error is set up by Newton equation,and vibration differential equation with six degrees of freedom is given with time-varying coefficients,which are solved by NewMark-? method.The effects of gear error and time-varying stiffness on the dynamic responses of this gear system are discussed in this paper.Dynamic simulation is made for this gear system,by which the correctness of theoretical analysis of gear transmission system with small number of teeth is verified.(3)The modification method of gear with small number of teeth is studied,and the helix angle modification aimed at its deformation characteristics is conducted.The contact performance of tooth surface before and after helix angle modification is analyzed by finite element method,and the results show that helical angle modification can improve the meshing performance of the gear pair with small number of teeth.