Tolerance analysis and allocation of precision rotary table based on Jacobian-Torsor statistical model

Abstract

Numerical control(NC) rotary table is the core part of the machining center. Due to the existence of multi-source deviation and multi-point assembly of the same part in the assembly of the rotary table, the tolerance chains are more complex, and the assembly result depends on workers to correct during installation at site, resulting in low efficiency and low assembly accuracy. A three-dimensional tolerance modeling method was established based on the Jacobian-Torsor theory. A parallel assembly model was established under multi-point assembly, and the relationship between various deviation sources and assembly deviations is obtained. The contribution of each dimension chain error to the total error is obtained by Monte Carlo analysis, which provides a basis for the designer to allocate tolerance. After several times of iteration procedure, the calculated FR meets the threshold required for product assembly. This method can effectively improve the efficiency of assembly.