Stability Analysis Of Guide Support System For Piston Rod Used In Labyrinth Reciprocating Compressor

Piston rod is an important part of labyrinth reciprocating compressor. In additionto bearing the axial piston force by cycle effect, the piston also suffer the periodiclateral force caused by the eccentricity in the process of movement. And it may have astrong resonance in the speed range of the compressor. Vibration too large can easilycause eccentric intensified of the piston rod and leakage increases. It may also leadthe instability of piston rod or the connection of threaded loose, and the rod vibrationfatigue failure occurs. Therefore, the rational design of guide support system is veryimportant for reducing vibration and improving stability of piston rod.In this paper, stability analysis of guide support system for piston rod used inlabyrinth reciprocating compressor is performed. First, using ANSYS finite elementanalysis method to calculate the displacement and stress distribution of piston rod bystatic structural analysis. On this basis, calculating the natural frequencies and modeshapes characteristic of the piston rod by modal analysis. The position and width ofthe guide support system has a great influence on the natural frequency of the pistonrod through a comparative analysis of different supporting position and the width ofthe guide bearing. To determine the effect of guide support system to the piston rodvibration, the horizontal and longitudinal amplitude, harmonic response analysis ofthe piston rod is performed. Then safety factor is calculated under the piston rodguide support role by buckling analysis. Finally, the support position and width ofguide support system are defined as input parameters. The maximum displacement ofthe piston rod, the maximum stress, the natural frequency of the first10order, themaximum horizontal and vertical amplitude of the vibration and its correspondingfrequency, safety factor are defined as output targets by surface response analysis of Workbench. To obtain the effect of guide support system to target parameters bycalculating100samples selected. And use the goal optimization module to find thebest design of the position and width of guide support system by defining the targetparameters.Through the analysis above, these can be concluded: supporting position andwidth of the guide bearings have a great impact on the vibration and stability of thepiston rod; find the change laws of each target and the best design of guide supportsystem by defining the parameter; reduce vibration of the piston rod while improvingstability.