Nonlinear dynamic model of yaw-torsion coupling was established for involute spur fixed-drive and planetary gear drive respectively, and a non-linear dynamic engagement model was put forward. Vibration characteristics test and model verification were carried out for two-stage fixed-shaft gear drive and single-stage planetary gear drive respectively. Single-stage gear drive was analyzed based on yaw-torsion coupling non-linear dynamic model.Dynamic and non-linear dynamic characteristics of stage gear drive system under steady-state and no-load conditions; for single-stage gear drive system, the influence of profile modification parameters on static and dynamic characteristics is analyzed, and the optimal design of profile modification is carried out; for tracked vehicle gear drive system, the dynamic characteristics of gear drive system under gears are systematically analyzed and established.An optimization model considering the dynamic characteristics of each gear is developed and the optimization design is carried out.The main research results and conclusions are as follows:
(4) Under steady-state condition, with the change of engine speed, the system resonates when the meshing frequency and its frequency multiplication approach any natural frequency, resulting in a significant increase of dynamic load; with the increase of center distance deviation, the dynamic load of the gear increases approximately linearly; the central support stiffness has a significant influence on the dynamic characteristics of the gear transmission system; with the change of the central support stiffness, the dynamic load of the gear transmission system increases significantly.The natural frequency of the system also changes. When the natural frequency of any order approaches the meshing frequency of the system, the dynamic load of the system increases.In the design of gear drive system, the engagement frequency and its frequency multiplication should be avoided as far as possible to approach any natural frequency of the system.
(5) Under no-load condition, with the increase of no-load speed, there is no obvious change trend of maximum dynamic load on tooth surface and back, but the mean square root value of dynamic meshing force increases; with the increase of backlash or center distance deviation, the maximum impact load on tooth surface and back increases generally, but there are local peaks under individual parameters, while the mean square root value of meshing force approximates.Linear increase.In the design and assembly of gear drive system, dynamic load under no-load condition can be reduced by increasing the common normal length or reducing the center distance deviation without jamming.
(6) Gear drive system under full throttle condition is a complex long-period motion, while gear drive system under no-load condition is a chaotic motion.It is difficult to distinguish long-period motion from chaotic motion from phase plane, so it needs to be judged by combining spectrogram, mapping map and maximum index.