| Anti-backlash gear is usually applied in precision mechanism and instrument, especially in inertial stabilized platform(ISP) widely. As the development trend of ISP is higher accuracy, higher reliability, and anti-harsh environment, it is urging to maintain and enhance the transmission precision and dynamic performance of the anti-backlash gear system. It is proved that the assembly parameters and errors are able to raise the resonance vibration, instability and other dynamics problem, thus the dynamic performance of system is hard to be controlled, even not to be controlled. Based on these, the study on dynamic characteristic and the effect factor of dynamic performance of anti-backlash gear system was launched. The effect mechanism of assembly parameters and errors on system dynamic characteristic was analyzed theoretically. The dynamics model of anti-backlash gear transmission system with multiform nonlinear parameters was proposed, and the effect laws of assembly parameters and errors on the system dynamic characteristic were deeply studied. A test and experimental platform based on virtual instrument technology was proposed and developed for dynamic characteristic test and experimental verification of the anti-backlash transmission system, and some research conclusions were verified by the platform. The primary coverage and innovative contents are as follow.(1) The mappings among assemble parameter, dynamics parameter and dynamics performance were studied, the influence mechanism of assemble parameters on dynamics performance of anti-backlash gear system. The mappings among assemble parameter, dynamics parameter and dynamics performance were defined, and the mapping from assemble parameters to system dynamics performance was created. Based on this, the system preload, shrink range and clearance, parallel misalignment, friction and some parameters of gear were established and analyzed, and the influence mechanism of these parameters on the dynamics performance of anti-backlash gear system.(2) The principle of anti-backlash gear connection was analyzed in detail, the nonlinear dynamics model of anti-backlash gear system was established, and the transmission characteristic and the influence laws of relative parameters on dynamics performance were deeply studied. On the basis of ordinary gear meshing principle, considering the mesh characteristic, the meshing status of each gear pair of anti-backlash gear system was analyzed in depth; a method for determining the single or double gear meshing area of each gear pair was proposed. The nonlinear dynamics model of anti-backlash gear system with multiform vary-time parameters was proposed, and the effects of friction, damping and stiffness of torsional spring and preload of torsional spring on the transmission system vibration characteristics of anti-backlash were analyzed in detail.(3) Taking a single stage anti-backlash gear transmission system as study example, the effects of bearing assembly parameters on anti-backlash gear system were deeply studied. The equivalent meshing stiffness model of anti-backlash gear was proposed and established. Based on the classic calculation formula of gear meshing stiffness, the calculation formula of anti-backlash gear synthesis meshing stiffness was derived. Considering the shrink range and preload of bearing, a simplified algorithm of angular contact ball bearing contact stiffness was proposed. The calculation formula and algorithm flow chart of the bearing radial stiffness were derived. The dimensionless anti-backlash geared rotor-bearing transverse-torsional dynamics differential equations with synthesis meshing stiffness and bearing radial stiffness was established, and the effect laws of bearing assembly parameters on system frequency characteristics were obtained by numerical analysis.(4) The rigid–flexible coupling dynamics model of anti-backlash gear system was established, the effects of partly assembly parameters and errors on dynamics performance of system were deeply studied. Based on the gear 3D contact dynamics theory, using the flexible body finite element modeling technology of ADAMS/Flex, and the rigid-flexible coupling dynamics model of anti-backlash gear transmission system based on ADAMS/View was established which enhanced the dynamics analysis accuracy of anti-backlash. A virtual experiment method based on sweep frequency stimulate for anti-backlash system was proposed. The effects of preload, axle base and the parallel misalignment on vibration and frequency characteristics of the single-stage anti-backlash gear transmission system were analyzed, and the effect laws were obtained.(5) Taking an anti-backlash reducer as experimental subject, using the test method based on virtual instrument for system dynamic characteristics, the test and experiment for system dynamics performance of anti-backlash gear system carried out. A reducing mechanism with anti-backlash gears for testing and experiment was designed, manufacture and assembled. A platform for dynamic performance testing of anti-backlash gear transmission system based on virtual instrument was developed. A method for testing starting voltage and resonance frequency of the reducing mechanism was proposed, and the testing stability of the platform was examined. Some experiments for verifying the portion of whole conclusions were completed by using the platform, and the research conclusions were verified. |
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