Abstract:In order to improve the tribological properties of nitrile rubber(NBR) water lubricated bearings,three kinds of composites were prepared by adding different amounts of ultrahigh molecular weight polyethylene (UHMWPE) powder (12%,50% and 100% of NBR respectively) based on NBR.The structure of the composites was analyzed,and the friction and wear properties of the composites under water lubrication were studied,and compared with those of NBR and UHMWPE materials.The results show that,in the prepared UHMWPE/NBR composites,UHMWPE is distributed in the NBR matrix in the form of dispersed phase,and the distribution is relatively uniform.The addition of UHMWPE improves the selflubricating properties of NBR material,and the friction coefficient of the composites is decreased significantly at low speed when the addition of UHMWPE is 50% and 100% of NBR content.The addition of UHMWPE improves the hardness of NBR matrix,improves the extrusion deformation of composites friction surface,and reduces the wear loss of composites.A certain amount of UHMWPE can significantly improve the tribological properties of NBR water lubricated bearings,and the optimum content of UHMWPE is 50% of that of NBR.