| Cycloid bevel gear is one of the two significant kinds of spiral bevel gear andKlingelnberg spiral bevel gear is an important direction of development of spiralbevel gear. Klingelnberg spiral bevel gear is being increasingly widely used in theheavy-duty and high power transmission field such as truck, aviation, heavy-dutymachine tools and so on. With the increasingly development of mechanicaltransmission system towards high-speed and precise direction, the dynamiccharacteristics of spiral bevel gear, which is the key transmission components oftransmission system, will more significantly affect the transmission performance oftransmission system. Researching the dynamic characteristics of Klingelnberg spiralbevel gear is practically valuable and academic significant for designing andmanufacturing high quality transmission components with high precision, betterdurability and low noise characteristics.Based on the project funding of National Nature Science Foundation of China:Study and identification of damage mechanism of heavy-duty cycloid bevel gear undernon-steady-state (Authorize No.:51075006), the dissertation focuses on thetransmission system of swing angle milling head of a heavy-duty CNC machine tool,studies torsion-vibration stiffness model of Klingelnberg spiral bevel gear and studiesthe nonlinear vibration characteristics of Klingelnberg spiral bevel gear caused bycommon gear errors. The dissertation mainly includes following chapters:(1) The nonlinear vibration theory of Klingelnberg spiral bevel gear is researched,and the torsion-vibration model of a Klingelnberg spiral bevel gear transmissionsystem with lumped parameter method is established. The paper describes the varioustypes excitation source of gear vibration, including the mesh stiffness excitation, errormotivation and engagement impact excitation.(2) The paper presents a new polynomial function time-varying mesh stiffnessmodel that is based on the Klingelnberg bevel gear for time-varying stiffness of theKlingelnberg bevel gear and builds the time-varying mesh stiffness model ofpolynomial function by the analysis of the speed, load torque and the damping factor,and builds the nonlinear dynamic equations of the Klingelnberg bevel gear. The resultfinds that the polynomial time-varying mesh stiffness model is much closer to theactual characteristic of the time-varying stiff in the small damping and overloadcondition.(3) Gear errors during transmission induce gear ratio changes which causedecreased transmission stability. To avoid this problem, a comprehensive study oftime-varying gear ratio for a Klingelnberg spiral bevel gear was required. Three typesof errors: tooth pitch error, relative tooth profile error, and gear-pair periodic error intooth frequency were introduced into the governing dynamic equations using thetime-varying gear ratio caused by gear errors. A non-linear dynamic model usingtime-varying gear ratio for a Klingelnberg spiral bevel gear was obtained.(4) A five-order Runge-Kutta algorithm was used in the dynamic analysis, Matlab simulation, and calculation of the parameters for this Klingelnberg spiralbevel gear with constant ratio and time-varying ratio. We obtain displacementresponses, inner impact force, frequency responses and other figures forKlingelnberg spiral bevel gear with three errors, and analysis the dynamiccharacteristics. The impact principle of errors for the gear transmission stabilitywas illustrated.(5) This paper develops a new error loaded contact analysis method for a cycloidbevel gear which considers elastic deformation of the gear pair, supporting systemdistortion, tooth manufacturing errors, and machine setting errors. With V-H-J settingparameters and machine setting parameters we can compensate for error impact toimprove the transmission performance and to modify the size and position of thecontact area. The numerical results show that the method is a reasonable and efficientway to enhance the transmission characteristics of a cycloid bevel gear. |
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