Structural Analysis And Design For Weak Rigidity Combination Planetary Disc Of Precision Ball Transmission

The precision ball transmission is achieved by using cycloid ball reducer meshingpair and ball equal speed meshing pair. In the process of transmission, real-time wearclearance and interference of thermal expansion existing in two kinds of ball meshing pairbring backlash and abnormal meshing. Weak rigidity combination planetary disc as a newkind of clearance adjusting device, which can achieve real-time circumferential rigidrotation and micro axial displacement, make the precision ball transmission no real-timebacklash. The innovation design and performance analysis of connection pair in weakrigidity combination planetary disc are studied in the paper, which provide theoreticalsupport for the research of real-time precision ball transmission.According to the requirement of connection pair and the structure type of prismaticpair, three types of weak rigidity combination planetary disc including pin connection,spline joint and ball joint are designed. Then, the structural and force analysis are carriedout. The friction formula of connection pair is derived. The calculation and check ofstrength are accomplished by analyzing the main failure forms of connection pair.Considering the clearance of pin connection pair, radius errors of distribution circle,clearance distribution error and other factors, the analysis model of backlash is established.The calculation formula of backlash is derived. The factors which influence the backlashin weak rigidity combination planetary disc connected by pins are analyzed. The factorsare simulated by Monte Carlo method. The statistical calculation and distribution ofbacklash is accomplished through the software MATLAB.Parameter optimization is accomplished through the MATLAB optimizationprocedures by establishing multi-objective optimization mathematical model of weakrigidity combination planetary disc connected by pins with the smallest backlash andradial dimensions based on the multi-objective optimization theory. Then, the3Dparametric models and virtual assembly are accomplished through the software Pro/E.Therefore, parametric design of weak rigidity combination planetary disc connected bypins is completed.