Abstract:In order to study the mechanical properties of hydrogenated nitrile rubber used as stator bushing material,the heat aging test of hydrogenated nitrile rubber was designed.The parameters of MooneyRivlin and Yeoh constitutive models were fitted based on the experimental data,and the fitting accuracy of two constitutive models was evaluated.A finite element model of the stator bushing of the PDM (Positive Displacement Motor) was established,and the variation law of the displacement of the stator cavity under different well depths was analyzed.The results show that compared with the MooneyRivlin model,the Yeoh model can more accurately reflect the mechanical properties of hydrogenated nitrile rubber.The displacement of the stator cavity without considering aging is larger than that of considering aging,and the difference is increased with the rising of temperature.Therefore,the influence of aging should be considered in the simulation analysis.The displacement amplitude of the stator with constant wall thickness at different depths is much smaller than that of the conventional stator.Therefore,the stator with constant wall thickness can meet the sealing requirements with less interference,which can reduce the wear of the stator bushing and improve the singlestage bearing capacity.