Research On Dynamics And Load Sharing Characteristics Of Flexible Shaft Planetary Gear System In Shearer Cutting Unit

Planetary gear system is widely used in aerospace,ship,automobile and underground mining due to its compact structure,small mass and large carrying capacity.The study of planetary gear system dynamics becomes more and more in-depth due to the high precision,high power,high reliability,long life and other requirements of equipment.For planetary transmission equipment with low speed and large bearing capacity,the uneven load distribution in the transmission process of each planetary gear is seriously due to the influence of component processing accuracy and installation conditions.These factors increase the vibration and noise of the system,and reduce the bearing capacity,reliability and service life.In order to improve the bearing capacity and reduce the vibration impact of the system,the component floating structure is used to analyze the influence of component error and floating state on the dynamic response and load sharing characteristics of the system.The analysis results provide reference for system structure optimization.This paper takes the MG300/700-WD shearer as the research object,which is driven by chainless electric traction rocker gear box.Considering the combined floating characteristics of sun gear and planetary gear with flexible shaft structure,by using dynamic research method,the dynamic response and load sharing characteristics of planetary gear system are deeply analyzed under error and different floating states.The main content of this paper includes the following aspects:(1)Considering the structural characteristics and component floating types of planetary gear system,the dynamic model of planetary gear system with flexible shaft structure is established.Based on Newton’s second law,the dynamic equations of the system non-floating states and component-floating states are established by considering the influence of component error,torsional deformation and external load.(2)Considering the influence of component error and floating form,the manufacturing and installation errors,tooth profile errors,floating errors and comprehensive errors of the components are analyzed.And the calculation formula of dynamic meshing stiffness of the system is derived.Considering the influence of the comprehensive error on the gear meshing stiffness,the error range of the comprehensive error is determined.(3)The Runge-Kutta method is used to solve the dynamic response characteristics of the system under without error and different errors.And the influence of error and component floating form on the dynamic response of the system is analyzed from the perspective of time domain and frequency domain.(4)Based on the analysis results of system dynamic response and dynamic meshing force,the calculation formula of load sharing coefficient of the system can be obtained.By calculating the load sharing coefficient of the system in different floating states under the action of error,the load sharing characteristics of the system can be obtained as the variation of floating state and component error.Considering the relationship between error and floating clearance,the influence of the error on the floating clearance of the floating components under different floating states is studied.The results lay a theoretical foundation for the design of the floating component of planetary gear system.