Research On Dynamics Inherent Characteristics Of RV Reducer

With the rapid development of modern industry, the market has increased requirements for Mechanical equipment. As an important part of the modern mechanical equipment, precision gear is important to ensure the quality of products. As a new type of two stage planetary reducer, RV reducer has been widely used in the field of robot because of its particularities are similar to both of involute gear and cycloid drive, i.e. compact structure, large transmission ratio and high transmission accuracy. In order to improve the performance of RV reduction device, it is necessary to investigate the characteristics of torsional vibration system. The investigation results as follows:The generating methods of outer Cycloidal Tooth profile curve of RV reducer and the conditions of the cycloid continuous transmission have been studied. And then deduced the parameter equation of cycloid tooth profile. On the basis of the Hertz theory, the stiffness of cycloid meshing transmission part was studied. For further studying on the vibration characteristics of system, the torsion stiffness mathematical model and its calculation equation were derived.Considering the transmission characteristics of RV system, the rotation freedom of cycloid gear and the crank shaft and the eccentric angle of cycloidal gear as well as other factors have to be taken into account to build a torsional vibration dynamics model, which can modified RV reducer by using the lumped parameter method. The natural frequency and corresponding modal shapes of the system have been calculated and analyzed. The results showed that the change of cycloid gear’s eccentric angle can influence the even order inherent characteristics of system.To study the dynamic characteristics of RV reducer, the effect of the change of the system’s stiffness on the first-order inherent characteristics of system was quantitatively studied based on the characteristics of RV reducer’s inherent characteristics, and then the main factors affecting the first-order natural frequency of system were analyzed. The Sensitivity of natural frequency to moment of inertia and stiffness was calculated on the basis of the partial derivative method. The results showed that the key factor influencing the natural frequency is the bearing stiffness and the rotational inertia of the planetary frame, which provides a theoretical reference for the dynamic optimization design of speed reducer.The inherent characteristics of RV reducer’s shaft parts were analyzed by the finite element modal analysis. And then analyzed the characteristics of its inherent characteristics and the occurrence of resonance. Finally, the torsional deformation of the cycloid pin wheel drive is simulated by constructing the finite element contact analysis model, and its meshing stiffness was derived by the deformation which can verify the correctness of the cycloid meshing stiffness model.