Mechanics Analysis on Piston in Hydraulic Hammer

摘要

The piston is one complex and important component in a hydraulic hammer and tends to fail easily due to terrible working environment. This paper provides a mechanics model of the piston acceleration process to obtain the initial movement condition of piston before it impacts the rod. With finite element analysis, we analyze the impact process and obtain the piston stress cloud chart and the stress variation curve at the nose of the piston. Based on the Strength contact theory, we can determine the piston hardness parameter for choosing appropriate material and heat treatment methods. The analysis indicates that the edge of the piston is easier to be deformed or broken because of maximum stress at the edge. Therefore, the structure of the piston in one kind of hydraulic hammer is modified with analysis results.