| Three-ring reducer is a planetary gear transmission device with small tooth difference developed by our country,which has received extensive attention since it was invented,and has been widely used in petroleum,chemical industry,mining and other fields.Due to the similar number of teeth of internal and external gears,large transmission ratio can be achieved,and the maximum single-stage transmission ratio is 99.When the external gear engages with the internal gear,the actual pair of meshing teeth is about 3 to 5 pairs,which greatly improves the bearing capacity of the reducer.The inertia force produced by the translation of three ring gears is not distributed in the same plane,so the moment of inertia is unbalanced.Unbalanced moment of inertia with periodic change of direction is one of the reasons for the vibration and noise.In this paper,the development status of three-ring reducer is summarized,and the research status of three-ring transmission is described in detail from the aspects of balance,vibration,bearing capacity and meshing force.The composition and working principle of transmission mechanism are introduced.The analysis of transmission ratio and meshing force is completed.The assembly conditions of the three-ring reducer are analyzed,and the requirements of the number of teeth and the phase difference of the ring plate that meet the assembly conditions are obtained.In order to solve the unbalanced moment of inertia of three-ring reducer,a completely balanced three-ring reducer is designed.Based on the balance principle of mechanism and rotor,the balance design of three ring reducer is carried out by installing balancing mass,and the inertia force and moment of inertia are balanced after balance design.According to the basic parameters of SHC255 three-ring reducer,the modification coefficient of internal meshing gear pair is obtained by mathematical calculation software,and other parameters of gear pair are calculated.The dynamic characteristics of three-ring reducer are analyzed.The equation of planetary bearing force is established,and according to the condition of displacement and deformation,the supplementary equation of bearing force is established.The programs are written to solve the equations,and the force curves of the planetary bearing and the box bearing are obtained by mathematical software.According to the assembly conditions of the three ring reducer,the three-dimensional modeling and virtual assembly are completed.After interference analysis,there is no interference,and the model is accurate and reliable.The virtual prototype model of three-ring reducer is established.The three-dimensional model is imported into the dynamic analysis software,and the rigid body virtual prototype is established by adding constraints and setting the contact force parameters reasonably.Through the simulation analysis,the rigid body prototype meets the kinematic requirements.In order to make the virtual prototype more practical,the inner ring plate is processed flexibly.The modal neutral file of the inner ring plate is established by modal analysis in the finite element analysis software.In the dynamic analysis software,the rigid-flexible coupling virtual prototype is established by using the modal file instead of the rigid body ring plate.The virtual prototype of three-ring reducer which is more suitable for the actual situation is built by using bushing tool instead of kinematic constraint to simulate the bearing force.After simulation analysis,the dynamic parameters of the reducer are obtained.The simulation results show that the planetary bearing force and the meshing force of the gear pair are basically consistent with the theoretical analysis.After balanced design,the bearing force of gearbox has been weakened to a certain extent and the stress on the inner ring plate is reduced,which prove that the balanced design is accurate and reliable.It provides a certain theoretical basis for the further optimization design of the three-ring reducer. |
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