Mechanism And Wear-resistant Strengthen Research On The Membrane Layers Of The Diaphragm Compressor

The diaphragm in the operation process of diaphragm compressor is the most important component. The diaphragm’s performance directly affects the reliability. Air cavity surface shape and diaphragm friction and wear between the layers are the main factors influencing the reliability of the diaphragm. In view of the domestic and foreign experts have been thorough research on the former, this paper will study on friction and wear between the layers of diaphragm, combining theory of practice, exploring diaphragm friction and wear mechanism between the layers, using to guide the design and manufacturing of the diaphragm, putting forward the reasonable wear-resisting reinforcement measures, improving the reliability of the diaphragm.According to the mechanical characteristics of the diaphragm, contact mechanics model between three layers of the diaphragm is set up. Through the theoretical calculation of the diaphragm’s deflection curve, radial stress, circumferential stress and mean main shear stress under the condition of different deflection. Preliminary judgment the rough area of interlayer glides of diaphragm, and finds out the influence factors which impact regional distribution of adhesive contact area and slip contact area.The distribution of stress value is calculated by using ANSYS finite element software under the different deflection of diaphragm, analyzed the most prone to the damaged area of diaphragm, compared with the theoretical calculation value, finding out that both have the same change trend and small numerical difference which show that the finite element method to calculate the credibility is high; The sliding distance of interlayer sliding contact surface area is calculated. In order to reduce the equivalent stress and sliding distance of the diaphragm, this paper changed material or thickness of the diaphragm for the finite element method, achieving the optimal design of the diaphragm.This paper built a dynamic strain testing system for different position of the diaphragm to measure the radial and circumferential strain values. The results show that the experimental study and theoretical analysis results are consistent. Using industrial inspection microscope to analyze microstructure of the worn surface, find out the distribution characteristics of the adhesive area and sliding area of the diaphragm. In adhesive area, stainless steel group at low contact pressures under the action of mild collapse. In sliding area, stainless steel is characterized by flake slipping and peeling, and crack of slippery edge. Friction and wear mechanism between the layers of the diaphragm are analyzed in detail.The experimental research indicated that the wear of the diaphragm has been decreased greatly. The service life has been increased under the same conditions and operation cycle by changing the thickness of the diaphragm. Integrating theory with practice, new wear-resisting reinforcement scheme is explored.The researches show that equivalent stress of the center and the edge position are maximum on the contact surface of the diaphragm, the center position is the adhesive area in the process of movement, and the edge position in the slip area. The main shear stress is the most important factor leads to interlayer sliding of diaphragm, if the main shear stress oversize which leads to plastic sliding of material crystal, the main shear stress will first exist within the contact area and then extends to the surface of the contact area, due to the edge area of diaphragm where exists the maximum main shear stress, therefore this area is most likely for the first crack occurrence and extension. The area at the center of the diaphragm exist contact pressure which is the second most likely for the second crack occurrence and extension.