Abstract:

A hypercompressor is essential part of low density polyethylene production. Designing and manufacturing hypercompressors requires further research and improvement. Packing cups are crucial components in hypercompressors. Design of interference fit of packing cups is of great importance and lacks a complete method in China. Interference fit is designed with two purpose which includes to obtain compressive state for the inner cup and to minimize the equivalent stress of overall packing cup. A simplified model of a packing cup is built for theoretical analysis to determine interference fit. In theoretical analysis, the inner cup can be in compressive state when its maximum circumferential stress becomes compressive; The maximum circumferential stress of the inner cup decreases and turns compressive stress from tensile stress as the interference fit increases, while the overall maximum equivalent stress goes up after decline with the rise of interference fit. Finite element analysis on a packing cup without structure simplification has the same conclusion with the theoretical analysis. In theoretical analysis, interference fit, that makes the maximum circumferential stress of inner cup turn compression, and, that obtains the minimum of overall maximum equivalent stress, are derived. The conclusion is that the design of interference fit should be the larger one between and. This conclusion can be a reference for designing packing cups for hypercompressors.

Key words: finite element analysis, interference fit, packing cup, hypercompressor