Analysis Of Backlash In NGW Planetary Gear Reducer

Today, precision planetary gearing is being used more and more frequently in servo systems. Backlash in planetary gearing is one of the essentials that affecting the stabilization and sensitivity of servo-loop. Because of structural complexity and various factors contributing to backlash, at home, it has not yet been brought to a successful issue that how to analyze and synthesize the backlash in planetary gearing.This paper focuses on the NGW planetary gear reducer. The author makes a comprehensive study of factors that affecting backlash, including the manufacturing and assembly errors in the main components of reducer, the thermal changes and deflections. The causes and control criteria of main backlash resources and the mathematical relationship between errors and corresponding backlash are discussed systematically. Then, the fundamental equations for calculating the backlash in a planetary gear reducer is established. Furthermore, by applying statistical analysis, the type of the distribution that each backlash source follows is determined, the expected value and standard deviation of corresponding backlash are derived. As a result, the author develops the statistical formulas for the calculation of the backlash in NGW planetary gear reducers. Also, the validity of this method is verified by a concrete case. In the end, practical measures to control backlash on determination of gear parameters, choose of components and structure design during the course of design, assembly and adjustment are presented.Although this paper is only the first step toward the successful solution to the analysis and synthesis of NGW planetary gear reducer, it can provide for necessary reference for the purpose of designing this type reducer or controlling backlash in it. This paper also lays a basis for relative researches.