Design And Dynamic Characteristics Of Planetary Gear Transmission With Double Carriers

Mechanical transmissions have become widely used in the field of mechanical engineering,and there is a tendency to develop various new mechanical transmissions that meet the requirements of practical technical applications.Innovation and expansion of mechanical transmission mechanisms are important means for advancing the development of the mechanical equipment field.With the advent of new types of mechanical transmissions,the range of mechanical transmissions will be greatly expanded,facilitating breakthroughs and advances in mechanical devices.Planetary gears are a typical and very important type of gear for mechanical gears.It has many advantages,including:compact structure,stable operation,strong load capacity,etc.,can be widely used in fields such as military industry,medical equipment,and automobiles.This subject explores the design theory and dynamic characteristics of a new type of planetary gear transmission with double carriers.The planetary gear transmission with double cariers not only inherits the many advantages of the standard planetary gear system,but also has the advantages of breaking the traditional gearing conditions,realizing non-coaxial transmission,reducing vibration and noise,etc.,it is a new type of mechanical transmission with broad application prospects type.In the structure of the planetary gear transmission with double carriers,the second planet carrier is used to replace the ring gear of the standard planetary gear transmission structure to form a double planet carrier;in the form of movement,the planetary gear is restricted by the two planet carriers,and there is only revolving motion.Due to the particularity of the structure and motion form of the planetary gear transmission with double carriers,in-depth research on its kinematics principle,transmission type,transmission ratio and dynamic performance is conducive to the application and promotion of this transmission type.This paper mainly carried out the following research:(1)A theoretical study on the design of planetary gear transmission with double carriers is conducted.Based on the kinetic principle of the planetary gear transmission with double carriers,we analyze the kinetic relationship between the components and explain the internal principle of the coaxial and non-coaxial transmission type and the structural symmetry of the planetary gear transmission with double carriers;the expansion structure design of the planetary gear transmission with double carriers is carried out.and the calculation method of its transmission ratio is analyzed;the comparative analysis of the single-stage planetary gear transmission with double carriers and the single-stage 2Z-X type planetary gear transmission are completed;the transmission efficiency of the two transmission types is calculated according to the power mesh method,and the volume calculation formula is used to calculate the overall volume of the two transmission types.Finally,the performance of the planetary gear transmission with double carriers is objectively analyzed through the comparison of the schemes.(2)We create a translational-torsional dynamics model of the planetary gear transmission with double carriers and analyze its natural vibration characteristics and the influence of system parameters on the natural vibration characteristics.Based on the dynamic differential equations of the gear system,the natural frequency and the corresponding vibration vector are first solved by numerical simulation.The classification of the vibration modes of the system is completed based on the characteristics of the vibration vector of each component.Then,the influence of the gyro effect,the position of the planetary gear bearing and the meshing stiffness on the natural frequency and vibration mode of the planetary gear transmission with double carriers is analyzed.Research methods and results help avoid resonant reactions and specific vibration modes,analyze vibration characteristics,and predict structural dynamic characteristics.This forms the theoretical basis for further study of dynamic properties.(3)By constructing a non-linear dynamic model of the planetary gear transmission with double carriers,we will investigate the dynamic response and load distribution characteristics of the system,and the law of influence of system parameters.In the analysis of dynamic response characteristics,considering the influence of nonlinear internal excitations such as time-varying meshing stiffness,the dynamic model in the study of natural vibration characteristics is revised,and the nonlinear dynamic model of planetary gear transmission with double carriers is established;The system’s nonlinear dynamic differential equations are processed to be dimensioned,the dynamic response results are solved by the numerical integration method,and the meshing excitation frequency corresponding to the speed and the time-varying meshing stiffness between gear meshing pairs are analyzed.The influence law of the response characteristics provides a reference for the material selection,parameter design and dynamic response improvement of the gear system.In the study of load sharing characteristics,based on the solution results of dynamic response,the calculation method of gear system load sharing coefficient is introduced,and the influence of the system load sharing characteristics on the manufacturing and installation errors of each component is analyzed.The error design and optimization of the load sharing characteristics of the planetary gear transmission with double carriers have guiding significance.