Gear Dynamics Characteristics Considering The Tooth Surface Friction Based On Stribeck Model

Gear drive system is main drive system of all kinds of mechanical systems and equipments whose dynamic characteristic can affect the performance and working reliability of the whole system directly. So, the study of dynamic character of gear system is beneficial to reduce the vibration noise and to improve the overall level of manufacturing equipment industry in our country.The analysis object of this paper is a pair of meshing spur gears. The effect of friction of tooth surface, stiffness excitation, error excitation and tooth backlash on the dynamic characteristics of gear transmission system can be analyzed with the theory of nonlinear dynamics. The major research contents of this article are as follows:(1) The research situation of gear dynamics is introduced and the effect of tooth surface friction for dynamics characteristics is analyzed. Then, introduce different calculation methods of meshing tooth face friction, the disadvantages of which are pointed out. Finally, the tooth surface friction factor can be calculated reasonably by Stribeck model, and the research direction of this paper can be determined.(2) The change of tooth surface friction factor is analyzed based on the Stribeck model. As the Stribeck friction model is depend on speed, first of all, analyze relative sliding speed between meshing tooth surfaces, and then calculate the tooth surface friction factor.(3) According to the difference of meshing gear logarithm, the double meshing gear system vibration differential equation is established. The influence of system dynamics can be obtained by time displacement diagram, phase diagram, spectrum diagram and Poincare diagram with fourth order variable step Runge-Kutta method.(4) Estabish and numerical the dynamic differential equation of single meshing area. By analyzing Coulomb friction model’s different effects on gear dynamics, the damping ratio, excitation frequency, load and backlash for system dynamics can be studied. And the influence of time-varying friction factor, fixed friction factor and without friction on the system can be gained.(5) Based on ANSYS/LS-DYNA software, the meshing impact in the process and the influence of the meshing gear dynamics analysis by speed, friction factor and external load can be analyzed, and the accuracy of the modeling analysis can be checked.The study shows that:increasing the damping ratio, drying away from the resonance area, increasing load, reducing the backlash, can decrease the amplitude of sports, weaken the collision impact, and add the dynamic stability. In gear dynamic analysis, the tooth surface friction should not be neglected whicn benefits to reduce system movement amplitude, increase the system stability. The time-varying tooth surface friction factor affecets the system apparently with small damping ratio, closing to the resonance area, small load, large clearance based on the Stribeck model compared with Coulomb friction, whicn can increase the system motion amplitude and system harmonics, and reduce the stability of the system.