Drilling Pump Piston's Improvement Design

In the article, the present research of drilling bump piston and the expiration form of it are summarized.The piston is mainly made up of incompressible rubber materials, which is highly non-linear with geometry and physics.In the mean time, the question of the electrometric-sealing element of piston is highly non-linear in state of contact as well.In the paper, stress and strain of three kinds of mechanics behavior of rubber material are tested by three experiment methods.These three experiments are: pull with single axis, pull with double axises and shear.According to tested data, the real constant inside the theories of Mooney-Rivilin can be computed. And by the soft of the finite element method,which is ANSYS, Large deformation of rubber is computed. We can acquire the fields of stress, strain and displacement, and know the trend of grains flow and understood varied mechanics characteristics of piston under press function.What's most, distributing of contact stress and friction stress along contact area can be known .We can find out district of high stress. And point out the basic reason that the pistons of drilling pump lose efficacy. So this paper provides reliable foundation for piston's improvement design. At last, changing shape of the ring and steel hub of the piston, hope to prolong the service life of the piston, and at the same time ,mention some other improving measures in the article.