Research And Analysis Of Meshing Transmission Characteristics And Strength Of Herringbone Gear

Herringbone gear has the advantages of high coincidence,high bearing capacity and smooth transmission,and is widely used in the transmission system of ships,aerospace,vehicles and other equipment.The meshing transmission characteristics and strength of the herringbone gear directly affect the reliability and stability of the transmission system of the herringbone gear.The strength analysis of herringbone gears is mainly based on ISO gear standard,which underestimates the transmission potential of herringbone gears.Secondly,the study of gear dynamics is inseparable from the gear stiffness.In the current analysis of herringbone gears,only the influence of tangential meshing stiffness is considered while the influence of axial meshing stiffness is ignored.In addition,the influence of tooth profile modification on the meshing between teeth and the direction of teeth is not considered in the stiffness analysis of the herringbone gear.Therefore,it is necessary to further study the meshing transmission characteristics and strength of herringbone gears.In this paper,the parametric equations of involute curve,transition curve and modified curve are established,and the precise three-dimensional parametric modeling of the herringbone gear and the tooth profile modified herringbone gear is completed in the software CREO.The finite element mesh model of herringbone gear was established by multi-point constraint method,and the validity and accuracy of the model were analyzed.The results show that the finite element model of herringbone gear established by this method can greatly reduce the number of grids,shorten the calculation time and reduce the calculation cost on the premise of ensuring the calculation accuracy.Then,from the Angle of theoretical calculation and finite element analysis,the method to determine the minimum mesh number satisfying the accuracy requirement is studied.Based on the energy method and the slice method,the time-varying meshing stiffness analysis and calculation method of the herringbone gear considering the axial stiffness was established.For the contact stiffness,the calculation accuracy of the three methods is compared and analyzed.For the stiffness of gear wheel body,the coupling effect is considered by finite element method.By comparing the method with the finite element method and ISO gear standard calculation method,the effectiveness of the method is demonstrated,and the influence degree of the axial stiffness on the comprehensive meshing stiffness results increases with the increase of helix Angle.At the same time,on this basis,the analysis and calculation method of transmission error,tooth orientation and load distribution between teeth and their variation rule are studied.Then,the effects of gear parameters on meshing stiffness,transmission error and load distribution are studied.A method for calculating the time-varying meshing stiffness of herringbone gears with tooth profile modification was proposed,which considered the influence of tooth profile modification on both intertooth and tooth direction.The variation trend of the proposed method is the same as that of the finite element method,and the average mesh stiffness error is 8.04%,which verifies its effectiveness.Secondly,the analysis and calculation of the load of the herringbone gear with tooth modification show that the modification will aggravate the uneven distribution of the load on the contact line of the modified tooth profile or part of the modified tooth profile.Finally,the influence of modification parameters on meshing stiffness,transmission error and load distribution is studied.Combined with the ISO gear standard and the method of calculating and analyzing the load distribution,the calculation models of the bending stress at the root and the contact stress at the tooth surface of the herringbone gear and the tooth profile modified herringbone gear are established.By comparing the stress results of the proposed method with the ISO gear standard and the finite element method,the effectiveness of the proposed method is verified,and the calculation accuracy is better than that of the ISO gear standard.Therefore,this method can provide a more accurate reference for checking the bending stress of the tooth root and the contact stress of the tooth surface of the herringbone gear and the tooth profile modified herringbone gear.