Research On Tribological Characteristics And Structural Design Of PEEK Based Composite Bearings

Bearings are important parts of mechanical equipment.The main function is to support the mechanical rotating body,reduce the friction coefficient during its movement,and ensure its rotation accuracy.Current research shows that bearings are the main influencing factors for the service life,maintenance period and reliability of water pumps.Most water pump damages are caused by friction damage of sliding bearings.Therefore,wear resistance is the most critical performance of water pump bearing materials.Therefore,it is of great significance to develop composite materials with excellent performance in sliding bearings.In this paper,the PEEK-based composite material was prepared by combining the cooperative modification mechanism of the multi-element composite additive,and its mechanical properties,physical properties and tribological properties were systematically studied,and the structure was designed using finite element software.Based on the principle of wear resistance and toughness of composite materials,carbon fiber(CF),polytetrafluoroethylene(PTFE)and nano-alumina(Al₂O₃)are selected as reinforcements to synergistically modify polyether ether ketone(PEEK),and theoretical analysis is adopted The effects of additive components and component ratios on the friction coefficient,mechanical properties,compressive strength and other properties of composite materials were studied.The composite material was prepared by vacuum hot-press sintering technology,and its mechanical properties were tested.The results showed that the performance of the composite material was significantly affected by the content of additives.The hardness of the composite material increases with the increase of CF content,and decreases with the increase of PTFE and Al₂O₃ content;The compressive strength increases with the increase of CF content,and decreases with the increase of PTFE content.It first increases and then decreases with the increase of Al₂O₃ content.When the content is 5%,it has the highest compressive strength.The friction and wear experiment of the composite material was carried out on the friction and wear testing machine.The results showed that the addition of additives can effectively improve the wear resistance of the composite material.The friction coefficient and wear rate of composite materials first decrease and then increase with the increase of CF and Al₂O₃ content;with the increase of PTFE content,the friction coefficient of composite materials gradually increases,and the wear rate first decreases and then increases.When the PTFE content is 5%,the composite material has the lowest wear rate.Among them,10%CF/5%PTFE/10%Al₂O₃/PEEK has the best wear resistance,and its friction coefficient and wear rate are respectively 0.125 and 8.03×10^-7cm³N^-1m^-1.The friction coefficient of the composite material increases with the increase of the load.It first decreases slightly with the increase of temperature,and then increases sharply when the temperature rises to 100?.Compared with dry friction,the friction coefficient and wear rate of composite materials under water lubrication conditions are both Decrease,the temperature has a greater impact on the friction coefficient and wear rate of the composite material.The friction surface of the material was tested by XRD,and its wear mechanism was discussed.Through theoretical analysis and simulation,the influence of the shape,quantity,size and distribution of the bearing water channel on the bearing performance is studied.Through theoretical analysis,the bearing structure is designed as:The overall structure of the bearing adopts a flat slat type,the ratio of length to diameter is 1,the shape of the water guide groove adopts a square groove,and the layout is a full slot.The simulation results show that an increase in the number of water channels will reduce the strength of the bearing and reduce the water film carrying capacity,but it is conducive to cooling and removing impurities.Therefore,the number of water channels should be comprehensively considered for the water film load.The ability to cool the bearing and the ability to remove impurities is selected.