Flow Field Simulation And Study Of Rotor Vibration Characteristics Of Vane Pump

As a kind of displacement pump,vane pump has a broad application prospect due to its simple and compact structure,high pressure and high volumetric efficiency.But there are also problems such as high flow fluctuation and high rotor vibration.In order to reduce the flow fluctuation and rotor vibration,this paper takes the vane pump as the research object,and analyzes qualitatively and quantitatively the effects of different stator curve,rotor structure and rotational speed on the average flow rate,flow fluctuation and rotor vibration of the vane pump through the method of fluid simulation and dynamics calculation.Experiments are also designed to verify the results of fluid simulation and dynamics calculations.The main works are as follows:(1)To address the problem of relatively low flow rate of single-acting vane pump,a double-acting stator curve with the same area as the single-acting curve is designed based on the cosine helix against the parameters of the single-acting curve.The mathematical model of the stator curve is established,and the theoretical flow rate is calculated by the method of double integration.And from the kinematic point of view,the dynamic performance of the two curves is compared.The results show that the designed double-acting stator curve can improve the theoretical flow rate by 76%under the same speed condition,and the transmission performance is better than that of the single-acting curve.Although the impact of the vanes on the double-acting stator is more than three times that of the single-acting curve,the radial speed of the vane changes continuously without sudden change.(2)In the simulation of the vane pump,it is difficult to mesh the fluid region and the convergence is not guaranteed.Based on the CFD software Xflow,which adopts boltzmann method,the fluid region of the vane pump is meshed and the fluid simulation of the vane pump is carried out.Based on the simulation results,the effects of different stator curves,different rotor structures and rotational speeds on the average flow rate and flow fluctuations of the vane pump are analyzed.The results show that the rotational speed has a linear relationship with the average flow rate of the singleacting vane pump,but the pulsation rate does not vary linearly with the rotational speed;The designed double-acting stator curve can reduce the flow fluctuation,and the effect of the designed double-acting stator curve on the flow rate is verified by the fluid simulation;The odd and even number of vanes does not affect the average flow rate of the single-acting vane pump.However,the overall use of an odd number of vanes can reduce the flow fluctuations of single-acting vane pump,while the use of an even number of vanes can exacerbate the flow fluctuations of single-acting vane pump.(3)In view of the relative lack of research on the rotor vibration of the vane pump,this paper takes the basic equations of dynamics as the theoretical basis and establishes the dynamics model of the rotor of the vane pump based on the rotor force data obtained from fluid simulation.And combined with the 4th order Longe-Kutta method,the dynamics equations satisfied by the rotor are solved numerically to predict and analyze the effects of different stator curves,different rotor structures and different rotational speeds on the rotor vibration.The results show that the effect of rotational speed on the rotor vibration of single-acting vane pump is complex and nonlinear.In general,the rotor vibration in the steady phase decreases with increasing rotational speed.The designed double-acting stator curve reduces the radial force on the rotor,but the odd number of vanes causes the rotor to vibrate strongly during the stabilization phase.After adjusting the number of slides to an even number(6 vanes for example),the rotor vibration of the double-acting vane pump is reduced significantly;for the single-acting vane pump,the increase in the number of vanes can significantly reduce the vibration of the rotor in the stabilization phase.(4)An experimental bench was built and flow rate experiments and rotor vibration experiments were conducted for different structures of the slide vane pump under different rotational speed conditions.The average flow rate and rotor vibration of the vane pump were verified to be affected by the rotational speed,stator curve and rotor structure.The experimental results show that the experimental results are consistent with the theoretical calculations and prove the rationality of the analysis method and the accuracy of the theoretical calculations.