Modal Analysis Of RV Reducer

RV reducer is a two-stage small teeth difference planetary gear unit containing a cycloid wheel. It is a 2K-V planetary transmission combined with 2K-H planetary transmission and K-H-V planetary transmission.It is developed on the basis of pin-cycloid planetary gearing and widely used in robotics,CNC machine tools,radar and other servo because of its advantages such as its small size,large carrying capacity,high impact resistance,low noise,low inertia,high transmission accuracy.The meshing tooth profile design is an important step in RV transmission design.According to the relationship among the basic geometry parameters of RV transmission and the different tooth profile characteristics of curtate cycloid and prolate epicycloid,the corresponding parametric design method was put forward and the parametric design software of typical RV transmission was developed by AutoLISP language based on AutoCAD software,including curtate cycloid drive with plus or minus one teeth difference,plus two tooth difference,plus three tooth difference and prolate epicycloid drive,which improved the design efficiency.According to the meshing theory of cycloidal drives, the corresponding general equations of curtate cycloid were put forward. The method of parametric modeling and modal analysis of RV reducer was based on APDL embedded into ANSYS and the spring-damper elements which were designed to simulate the bearings. The first four order natural frequencies and vibration modes of RV-40E were developed by simulation and verified by modal experiment. The maximum error between modal test results and the theory was 14.7%.The methods of parametric modeling and finite element analysis had many advantages, including small modeling workload, high efficiency and good results compared with modal test results. All this has important reference value for the study on influencing factors and rules of dynamic characteristics of RV reducer.Geometric parameters were defined according to structural features of RV reducer and the secondary development of ANSYS for parametric modeling was finished by ANSYS Parametric Design Language and User Interface Design Language based on general equations of curtate cycloid and involute. The parametric modeling was proved by kinematic analysis through Pro/E. The modal analysis on RV-40E was finished and the results coincided with the experimental modal analysis results. By changing the parameters, a study about influence factors of the first order natural frequency was conducted. The influence curves obtained can become the basis of improving dynamic properties. The method of parametric modeling of RV reducer could improve the efficiency of finite element analysis by reducing the workload of modeling and avoiding repeated modeling. The application in modal analysis has laid the foundation for the integration of parametric modeling and finite analysis of RV reducerThe operating frequency of various components of RV reducer was developed by kinematic analysis on the basis of ADAMS,providing a basis for the fault diagnosis technology of RV reducer.