Probability-theoretical approach to the accuracy of the component assembly of multilink mechanisms

Abstract

The technological process, ensuring the accuracy of mechanism assembly is formally a sequential summation of primary manufacturing errors and an analysis of obtained, generalized values to develop and implement specific technological methods to meet process requirements for the accuracy of the relative position of parts. To ensure the accuracy of crank mechanisms for misalignment of piston and cylinder axes, assembled from specific, randomly received component parts, production personnel deal with strictly defined crankshafts, connecting rods, pistons, cylinder blocks, and, consequently, with one or another manufacturing errors. To ensure the accuracy of these parts assembly in a mathematical sense, with such a sequence, will represent nothing more than an algebraic summation of primary errors and compilation of their numerical values with the maximum permissible values. A different situation arises in the implementation of assembly technological processes with automatic achievement of accuracy parameters by varying individual parts from their total number. As in this case fairly representative aggregates are analyzed, the final result of combining parts into assemblies will occur with a greater or lesser probability, especially when the sum of the maximum deviations of constituent links (parts) is not equal and not less than the maximum permissible total values.