| Herringbone gear is widely used in the transmission device of energy equipment,large ships,high-speed aviation spacecraft and other important transmission devices,which has the advantages of high contact ratio,low axial force,high bearing capacity and steady transmission,etc.The meshing stiffness is the key parameter of the internal excitation and dynamic model of the gear system,which is related to the design parameters such as modulus,contact ratio,error and modification.It is very important to study the meshing stiffness,dynamic characteristics and the structure failure caused by the high load herringbone gear transmission.The research shows that the meshing stiffness with the change of contact position is the main source of gear noise and the basis of dynamic strength calculation and vibration analysis.Static contact analysis and dynamic loading contact analysis under the working condition of high speed and heavy load are analyzed based on finite element method.Time-varying meshing stiffness of herringbone gear with no error is calculated.Besides that,analysis for the influence of assembly errors,misalignment errors,tooth profile modification and lead crowning on meshing stiffness of gear is carried out.The main research contents are as follows:(1)Contact analysis for herringbone gear is carried out based on finite element method.According to the generating theory,tooth profile and tooth surface equations are established.The geometric model of herringbone gear is constructed to solve the data points of tooth surface which are fitted to curve and surface based on CATIA.The model is imported into ABAQUS to construct the finite element model,and then static contact analysis for herringbone gear and dynamic contact analysis for herringbone gear under high speed and heavy load are carried out.Rotational speed,contact force,contact area,contact stress and bending stress of herringbone gear under different working condition are obtained.Lastly,meshing characteristics of herringbone gear is analyzed.(2)Meshing stiffness of herringbone gear with no error is calculated.Meshing stiffness of herringbone gear is calculated based on finite element method,calculation for normal contact force and comprehensive elastic deformation amount are finished by using static contact analysis based on finite element method.Therefore,s ingle tooth meshing stiffness and total meshing stiffness are obtained.Comparing the meshing stiffness calculated by analytical method with the one calculated by finite element method.It is found that the result of the meshing stiffness calculated by analytical method is basically same as the one calculated by finite element method.Because of that,the correctness of meshing stiffness calculated by finite element method is verified.(3)Meshing stiffness of herringbone gear with assembly errors and misalignment errors is calculated.The finite element model of the herringbone gear with assembly errors and misalignment errors is established based on ABAQUS,and its meshing stiffness is calculated by finite element method.The influence of different error t ypes on the meshing stiffness of gears is analyzed.The results show that the gear load distribution is not uniform that leads to the meshing stiffness of the gear decreases.And the stiffness decreases with the increase of the error value.(4)Meshing stiffness for herringbone gear with modification is calculated.The finite element model of the herringbone gear with tooth profile modification and lead crowning is established based on ABAQUS,and its meshing stiffness is calculated by finite element method.The influence of two types of modification shape on the meshing stiffness of gears is analyzed.The results show that the meshing stiffness is larger than the one of the unmodified gears when the modification amount is small.However,the increasing extent of stiffness decreases with the increase of the modification amount.The meshing stiffness of the gears is smaller than the unmodified ones when the modification amount is large. |
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