| Non circular gear hydraulic motor is a new type of low speed and high torque motor,which has the characteristics of large unit displacement,stable operation,strong oil resistance,and high volumetric efficiency.Due to the difficulty of design and processing,the practical application of this type of motor is restricted.This topic takes3-4 steps non circular gear hydraulic pressure as the research object,and conducts research on four parts: the body structure design of the gear train,the motion law analysis of the gear train,the output characteristic analysis of the motor,and the optimal design of the motor.The purpose is to provide a theoretical basis for the engineering application of this type of motor.Firstly,the components of a noncircular gear hydraulic motor are a group of variable center distance NGW gear trains.By analyzing the geometric relationship of the noncircular planetary gear train and giving a solar gear pitch curve that meets the conditions for uniform distribution of gear teeth,the conditions that need to be met for the inner gear ring pitch curve and the inner gear ring pitch curve formula are derived.According to the pure rolling motion relationship and spatial position between the cutter and the gear blank,a coordinate transformation matrix is established,and a three-dimensional solid model of the core components of the non circular gear hydraulic motor is obtained through the envelope method.Secondly,by analyzing the motion law of the planetary gear during operation,it is determined whether there is a rigid impact during the operation of the motor.The speed and acceleration changes of the planetary gear of the shaft transformation motor and the shell transformation motor are compared.Based on the design theory of the valve plate,the range of the sun wheel rotation angle corresponding to the presence of hydraulic torque in each cavity of the motor is obtained.Thirdly,based on the analysis of the gear tr ain motion law and the flow distribution law,the pulsation rate of the angular displacement is used as a physical quantity to measure the stability of the motor during operation.The operation stability of two types of motors,namely,the higher order ell ipse and the Pascal spiral,is analyzed and compared at the same parameter level.Based on the gap flow theory,the calculation formula for the volumetric efficiency of the motor is derived.Considering the force exerted by hydraulic fluid on the sun wheel,a more accurate formula for the motor output torque is derived.By analyzing the coincidence degree of non circular gear pairs,it is verified whether the motor has oil trapping phenomenon.Finally,based on the cubic design theory,the entire design pro cess of the motor is carried out,with the average displacement of the motor as the objective function,the volume of the motor,the radius of planetary gears,and the coincidence of non circular gear pairs as constraints.Error perturbation is applied to the pitch curve.Through statistical analysis of the SN ratio,the contribution rate of each parameter level to the error perturbation is obtained,and the optimal parameter combination that meets the design requirements is determined.This article provides a theoretical basis for the engineering application of this type of motor by analyzing the structure design,output characteristics analysis,and design process optimization of the motor body. |
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