Study on Nonlinear Dynamics of RV Transmission System Used in Robot Joints

Abstract

The nonlinear dynamic characteristics of RV transmission device was investigated according to dynamics theory, mass centralized method was used to establish the nonlinear dynamical model of RV transmission device, which was composed of inertial component, elastic element and damping element. The influence of the nonlinear factors as meshing stiffness varying with time (though the variation in the number of meshing teeth), backlash of gear pairs and errors were considered. Movement differential equations of system were derived, and these equations were changed to non-dimension, which were solved by Runge-Kutta method. Influences of excitation frequency and damping on system dynamic characteristics were analyzed. As the excitation frequency increased, the system would vibrate from single periodic motion to harmonic motion, chaotic motion. Along with the reduced damping, chaos vibration occurs gradually after a doubling periodic of bifurcation, as the system gradually gets into the chaotic state. The impact is also changed from coexistence of non-impact and the unilateral impact to coexistence of the non-impact, unilateral impact and bilateral impact.

Modal Analysis and Optimization of Typical Parts of 2K-V Reducer

“…It is mainly composed of main components such as cycloidal gear, crankshaft, planetary gear, planet carrier, the needle wheel and sun gear. The transmission system uses a secondspeed reduction mechanism, wherein the first stage speed reduction mechanism is an involute cylindrical gear planetary speed reduction mechanism, and the second stage speed reduction mechanism is a cycloidal pinwheel planetary speed reduction mechanism [3,4].…”

Study on Nonlinear Dynamic Characteristics of RV Reducer Transmission System

“…In response to this, researchers have undertaken studies on the nonlinear dynamic characteristics of RV reducers under the influence of nonlinear backlash excitations [19][20][21][22][23]. Shan et al [26,27] considered the impact of gear backlash, established a torsional nonlinear dynamic model for RV reducers, and analyzed the dynamic response of the system as the excitation frequency varied. Han et al [28] proposed a method for establishing the dynamic model of a 2K-V reducer, considering the nonlinearity introduced by installation clearances.…”

“…Through sensitivity analysis, the primary factors inducing system vibration were identified. Although the gear backlash is considered in [26][27][28][29][30], there is still a lack of analysis on nonlinear dynamic characteristics. The existing studies mainly focus on analyzing the transmission accuracy and vibration response of the system under the influence of nonlinear factors, but do not deeply explore the nonlinear dynamic characteristics of the system.…”

“…Currently, papers on the nonlinear dynamic characteristics of gear transmission systems primarily focus on involute gears [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], with some scholars researching chaotic and bifurcation characteristics related to cycloidal gears [40][41][42][43][44]. Blankenship and Kahraman [31][32][33] established a single-degree-of-freedom dynamic model for gear pairs with tooth-side clearance.…”