Research on a Tolerance Allocation Method for Cycloid-Pin Transmission Based on Monte Carlo Simulation

To achieve reasonable tolerance allocation for key components of cycloid-pin transmission while satisfying transmission accuracy requirements, this paper proposes a tolerance optimization method based on Monte Carlo simulation. First, on the basis of an error-analysis model for cycloid-pin transmission, the maximum lag angle and transmission-ratio fluctuation are selected as performance evaluation indices, and the pin radius error, pin-slot clearance error, pin circumferential position error, cycloidal gear machining error, and bearing clearance error are taken as tolerance design variables. Then, with the objective of reducing manufacturing difficulty, a tolerance allocation model subject to transmission accuracy constraints is established, and the optimized result is randomly verified by Monte Carlo simulation. Finally, an RV-110E cycloid-pin transmission mechanism is analyzed as a case study. The optimized tolerance combination is Δr=0.0100 mm, Δd=0.0099 mm, Δε=0.0100°, Δa=0.0500 mm, and Δd2=0.0171 mm. In ten Monte Carlo random verifications, the maximum lag angle ranges from 0.045° to 0.052°, and the transmission-ratio fluctuation ranges from 0.085 to 0.100; both satisfy the specified accuracy requirements. The results provide a reference for manufacturing tolerance design of cycloid-pin transmission mechanisms.