| Compound Coupled Hydro-mechanical Transmission(CCHMT for short)is a kind of hydro-mechanical hybrid transmission,which has two planetary gear trains interacted on each other in working process.Compared with the traditional HMT,CCHMT has a wide range of speed regulation,high applicability,flexible structure and so.It can effectively adjust the transmission characteristics of the system according to the application conditions,which makes it has broad application prospects.However,because of the complex structure,the dynamic characteristics of CCHMT are very complex.In addition,the vibration of complex gear transmission system is harmful to many aspects of the system,especially for the CCHMT system with two planetary gears coupling each other.This situation not only affects the reliability and service life of the system,but also restricts the popularization and application of CCHMT.Therefore,the research on the dynamic characteristics of CCHMT has academic significance and application value.Firstly,this paper briefly introduces the Hydraulic-Mechanical Hydraulic Composite Drive,summarizes the research results and development direction in recent years.The main problems existing in the dynamic analysis of CCHMT are presented,and the main research contents of this paper are determined.Secondly,according to the coupling relationship,this paper establishes the dynamic differential equation of mechanical transmission part of CCHMT.Then,simplify the equations to a new,dimensionless,positive definite and linearized expression.Finally,use IHB and Newton iteration method to solve the dynamic differential equation,and the time domain characteristics of the mechanical transmission part are obtained.Then,a new dynamic differential equation of CCHMT system is established based on the volume control loop.According to the solution result of the equation,this paper has studied the influence of hydraulic circuit on the vibration characteristics,the influence of different displacement ratio of the volume control loop on the vibration characteristics,the natural frequency,the modal and the stability of the system is analyzed according to the phase diagram.Finally,the system model of CCHMT is established by AMESim software.Considering the influence of inertia,meshing stiffness and meshing damping of each component of the system,the sub-models and parameters of each component are set up to realize the dynamic simulation of the system.According to the simulation results,the natural frequencies,time-domain characteristics and frequency-domain characteristics of the system are analyzed,and the relationship between the dynamic characteristics of the system and the displacement ratio is studied.The simulation results prove the reliability of the mathematical method. |
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