Modeling,Optimization And Experimental Study Of The Differential Velocity Vane Pump Driven By The Different Higher-Order Fourier Non-circular Gears

Displacement pumps are widely used in industrial and agricultural machinery because of many advantages,but these pumps are some key technical problems.The reciprocating displacement pumps have such problems as small displacement,obvious pressure pulsation and large noise.The rotor displacement pumps have the problems of unbalanced radial force,easy leakage,easy wear under high pressure,large fluid noise and the problem of fluid trapped.After many years of domestic and surgical technical research,the displacement pumps have been greatly improved in these aspects.But there are still many problems to be studied and solved,such as the ratio of displacement to volume is small and the pulsation is large.Therefore,the innovation and breakthrough of the displacement pumps are of great significance to promoting the renewal and replacement of the product of the displacement pumps and improving the technical level of the domestic displacement pumps.This paper is also supported by the National Natural Science Foundation of China(NSFC).The project is "modeling,optimization and experimental research of high-performance differential velocity vane pump driven by Fourier non-circular gear for plant protection"(51305403).In this paper,the differential velocity vane pump driven by the different higher-order Fourier non-circular gears is proposed.Based on the study of the transmission characteristics of non-circular gears,the basic research on pump performance and pump structure parameters,as well as the internal correlation,optimization method and test of drive system is carried out.The main contents and results of this paper are as follows:1)Study on the domestic and foreign typical displacement pump status and problems.The principle and structure of the differential velocity vane pump is an ideal form.The current situation of new multi-blade differential velocity vane pump is mainly studied,and the characteristics of common driving mechanism of the pumps are summarized.It is found that the differential velocity vane pumps are suitable for the use of non-circular gear drive mechanism.The application of Fourier curve expression to the design of non-circular gear curve is beneficial to the performance optimization of the pump.So a differential velocity vane pump driven by the different higher-order Fourier non-circular gears is proposed.2)In order to design the optimal pumps,establishment of the higher-order Fourier non-circular gears curve calculation model and transmission calculation model,The establishment of the higher-order Fourier non-circular gear pairs transmission ratio and the driven non-circular gear curve calculation model,establish the higher-order Fourier non-circular gears’ center calculation model,established the pitch curve closed condition,concavity analysis model,pressure angle calculation model and the maximum modulus of undercutting discriminant model.Comprehensive analysis of the effect of Fourier curve parameters on the transmission characteristics of the section.In order to realize the combination design of the drive mechanism of the pumps,on the basis of the calculation and analysis of high order denatured Fourier non circular gear,a differential velocity vane pump driven by a different high-order Fourier non-circular gear is proposed.The working principle of differential pump driven by different high-order Fourier non-circular gear is summarized.The basic relationship between order and the pump blade parameters is established,and the geometric relationship between non-circular gear pitch curve parameters and inlet and outlet is established.The basic model of the calculation of the structural parameters of the differential pump is set up.Based on the model established,the auxiliary analysis software for the characteristic of the differential pump is designed.The influence of different higher-order Fourier curve parameters on the pump discharge,instantaneous flow rate and pulsation rate is comprehensively analyzed,which provides a theoretical basis for subsequent differential velocity vane pump optimization.3)According to the different types of non-circular gear,the mode of the pump driven by the elliptic non-circular gear,the eccentric circular non-circular gear,the Blaise Pascal non-circular gears and the sinusoidal non-circular gears is established.Based on the established mathematical model,the 4 types of auxiliary analysis software for the pumps driven by non-circular gear are designed.Comparison of the displacement,instantaneous flow and pulsation rate of the pumps which are respectively driven by Fourier non-circular gears and 4 others non-circular gears mechanisms.It is concluded that the different higher-order Fourier non-circular gears driven differential velocity vane pump has good performance.4)The displacement,pulse rate and not undercut maximum modulus as the target,the comprehensive evaluation function is built by using of MATLAB genetic algorithm toolbox.A multi-objective optimization model for the performance of the pump driven by different higher-order Fourier non-circular gears is established and the multi-target parameter optimization software is designed.Optimization of the performance of different differential order pumps.Comparisons with the 2 to 2 order,3 to 1 order,1 to 2 order.It is found that 2 to 2 order is the worst.According to the optimization result,the 1 to 1 order performance is the best.5)The differential velocity vane pump driven by the 1 to 2 order Fourier non-circular gears as the research object,the numerical calculation of flow field,analysis of the suction and discharge fluid flow conditions and the pump trapped flow field.The simulation of coupling dynamic of the non-circular gears with blades resistance moment,found the resistance moment of the pump leaves in a rotating period is alternated.Due to suction and discharge port is closed instantly,pump will generate water hammer effect.The blade moment of resistance increased instantaneously.Calculating the unidirectional coupling of the fluid and the blade in the pump,found the resultant moment and speed in the same direction,driven non-circular gears drive the driving non-circular gears.When the resultant moment in the opposite direction,active non-circular gears drive the driven non-circular gears.So the non-circular gears drive system and the fluid has FSI and back driving phenomenon.The above research provides a reference for improving the pump driven by Fourier non circular gears.6)The optimum parameters of the pumps and the driving non-circular gears are obtained according to the genetic algorithm optimization results,and the design structure and the three-dimensional modeling are made.According to the design drawings of the pumps and drive non-circular gear transmission parts,1 to 2 order Fourier gears ratio test platform built to verify the theoretical transmission ratio accuracy.The displacement test platform of the pump is set up to study the characteristics of displacement with the change of speed.In certain speed range,the theoretical value of displacement is in agreement with the experimental value.Build a test platform for input torque.Determination of the variation characteristics of impeller torque with the working condition of differential pump.The correctness of the FSI simulation results is verified.It is revealed that the periodic vibration of differential pump mainly comes from the torsional vibration caused by FSI of fluid and blade.The test results show that the calculation theory and the design method of the pumps are correct.