Optimization Design And Simulation Analysis Of The Planetary Gear Reducer In Hose Reel Irrigator

With the advantages of convenient maintenance and high uniformity of spraying,the hose reel irrigator has become one of the most promising irrigation equipment in China.Most of the existing hose reel irrigators are driven by water turbines,which are inefficient under low operating conditions.Moreover,the transmission system of the hose reel irrigator driven by the water turbine is cumbersome and inefficient.In this article,the water turbine is replaced by the permanent magnet brushless DC motor.The original three-stage cylindrical gear drive can not meet the need of large transmission ratio.A planetary gear drive system is designed for the motor drive device.The three-stage planetary gear transmission system has compact structure,the corresponding planetary gearbox’s volume and mass are reduced,but the motor speed is higher,so the motor-driven gearbox needs stronger load-carrying capacity than the water turbine-driven gearbox.In order to improve the transmission performance of planetary gear reducer,prolong the service life of various parts and improve the economy of the reducer,in my paper,the following aspects are studied :1.The optimization design method of three-stage planetary gear transmission system was established,and the efficiency test of the optimized transmission system was carried out.The optimal design of the three-stage planetary gear transmission system of the hose reel irrigator was completed.Firstly,by selecting design variables,the objective function was established to minimize the volume of the three-stage planetary gear transmission system.At the same time,based on the design principle of the planetary gear transmission,the corresponding constraint function was determined.Then,the genetic algorithm toolbox in MATLAB was used to compile relevant programs and set corresponding parameters to optimize the three-stage planetary gear transmission.According to the obtained optimal solution and the design principle,the optimization results were rounded,and the optimization results showed that the overall volume of the transmission mechanism was reduced by 17.9%.Finally,the efficiency of the optimized planetary gear transmission system was tested,and the transmission efficiency was increased by about 6%,which verified the rationality of the optimization.2.The modeling process of three-stage planetary gear transmission system by usingRomax Designer was introduced in detail.The detailed model of planetary gear set and the definition of load spectrum were introduced,which laid the foundation for the subsequent simulation optimization.The model was simulated and analyzed.The modification method and amount were determined according to the load distribution map of the unit length of the tooth surface before modification.Finally,the micro-modification of the sun gear was carried out by the combination of tooth profile and flank profile modification.The unit length load diagram and the transmission error diagram of the first stage sun gear before and after modification were compared and analyzed.After modification,the maximum load per unit length of the tooth surface of the first-stage sun gear decreased from 328N/mm to159N/mm,which reduced by 51.5%.The transmission error decreased from 4μm to 0.15μm,and the load distribution on the tooth surface was uniform.The meshing quality was improved significantly,and the bearing capacity of the sun gear was improved.3.The modern design method was used to optimize the design of planetary gearbox.In SolidWorks,the parametric modeling of the gearbox was carried out,and on the basis of the parametric modeling,the key dimensions of the box were optimized.The basic principle of response surface optimization was elaborated,and then four gearbox design sizes were designed by using Workbench optimization module.The data fitting degree,sensitivity of design variables and target parameters,the relationship between target parameters,and the response lines and response surfaces of design variables to target parameters were analyzed.Finally,the results based on multi-objective optimization were obtained.The mass was reduced by 7.8%,the maximum deformation was reduced by 11.5%,and the maximum stress on the box was reduced by 19.9%.4.The finite element analysis method was used to compare the performance of planetary gearbox before and after optimization.Through static comparative analysis,the maximum stress of the optimized gearbox was reduced by 6400 pa and the total displacement of the gearbox was reduced by 9.48%.After optimization,the maximum stress and deformation of the gearbox were reduced,the strength and stiffness of the box were obviously improved,and the running performance of the box was improved.Through modal comparison analysis,the natural frequencies of each order increased to some extent,and the maximum relative deformation of the first five orders didn’t change much,but the maximum relative deformation of the sixth order decreased from 9.7136 mm to 6.6249 mm,which decreased by 31.8%,and the overall stiffness of the gearbox increased.The lowest natural frequency of the gearbox was 100.5Hz,which was much larger than the excitation response frequency caused by the maximum speed of the motor,and there would be no resonancephenomenon.Finally,the modal tests of the gearbox were carried out,and the relative errors of each order were less than 5%.The accuracy of the finite element model was verified.