Research On The Meshing And Dynamic Characteristics Of Herringbone Gear Systems Considering Assembly Errors And Tooth Surface Faults

Herringbone gear transmission is widely used in the transmission systems of ships,automobiles and aero-engines because of its advantages of high stability and high bearing capacity.Due to the complex structure of the herringbone gear,the system is easy to appear assembly errors,leading to an unequal distribution of loads of the left and right helical gear pairs loads and stress concentration;In addition,assembly errors and complex working environment,tooth surface faults often occur,affecting the smooth operation of the whole system and even causing economic losses.In this paper,the effects of profile relief with secondary parabolic and lead crown,different degrees of shaft angular misalignment error and center distance error,wear and spalling on the meshing characteristics of the herringbone gear system are studied.The dynamic finite element model of the herringbone gear system is established,and the meshing stiffness and no-load transmission errors including the assembly errors and tooth surface faults are introduced into the dynamic model to analyze their effects on the dynamic characteristics.The time domain and frequency domain signals obtained from simulation and test are compared and verified for wear and spalling faults modeling.The main research contents are as follows:(1)Taking helical gear pair and herringbone gear pair as the research object,the influences of profile relief with secondary parabolic and lead crown,shaft angular misalignment error and center distance error on no-load transmission error and contact pattern of gear pair are analyzed based on tooth geometric contact analysis(TCA)method.The results are in good agreement with those obtained by MASTA,KISSsoft and LTCA under light load condition.(2)Combining the loaded tooth contact analysis(LTCA)method with the gear tooth geometric contact analysis(TCA)method,the effects of the profile relief with secondary parabolic and lead crown,shaft angular misalignment error and center distance error on the meshing characteristics of helical gear pair and herringbone gear pair is verified.And by comparing the results obtained with the results of literature,ANSYS,MASTA and KISSsoft,the validity of the simulation results in this chapter is verified.(3)Based on the loaded tooth contact analysis(LTCA)method,combined with the wear and spalling morphology in the test,the influence of different degrees of wear and spalling faults on the meshing characteristics of herringbone gear pairs under variable torque is analyzed.By establishing the same fault morphology as in the literature,the meshing stiffness and load distribution of the gear pair with surface faults are calculated.The results of comparison with the literature show that the results in this chapter are closer to the finite element results than the contact line equivalent method.(4)Timoshenko beam element is used to simulate the herringbone gear shaft,and the spring-damping element is used to simulate the bearing,and the dynamic finite element model of the herringbone gear system is established The meshing stiffness and no-load transmission error of herringbone gear pair including assembly errors are introduced into the dynamics model,and the influence of different degrees of assembly errors on the dynamic characteristics of the gear system is analyzed.The simulation results show that the existence of assembly errors is more likely to stimulate the resonance of the system at low speeds.(5)The dynamic finite element model of the herringbone gear system is established based on the parameters of the test bench.The meshing stiffness and no-load transmission error of the gear pair including wear and spalling are introduced,and the influence of the different degree of wear and spalling under different torques on the time-domain waveform and frequency characteristics of the herringbone gear system are studied.The influence of torque on the fault characteristics of the system is analyzed by using time-frequency domain statistical indexes,and the validity of the fault indexes in this chapter is verified by comparing with the test results.