汽车变速箱齿轮传动系动力学振动特性的研究

建立发动机曲柄连杆系统的扭振当量模型,得到飞轮端动态转速波动及扭振角位移作为齿轮传动系主轴输入端的动态激励;采用多体动力学方法建立某五挡手动变速箱齿轮传动系动力学模型,以二档为例,分析了上档齿轮在齿面啮合时变刚度作用下产生的呜呜噪声(Gear Whine)特性,及未上档齿轮在其自由惯量和齿侧隙下产生的咔嗒噪声(Gear Rattle)特性;分析了发动机二档转速范围内齿轮传动轴各处轴承动态载荷的频谱特性;同时,利用实验测量的曲轴系扭振各阶次曲线验证了扭振当量系统模型的正确性,并利用实验表面振动速度法识别了转速范围内变速箱结构的振动速度级,验证了动力学仿真模型中得到的动态啮合冲击载荷的特性。

Vibration characteristics of transmission gear-train for a car

The equivalent torsion model of crank-train of a car was setup, the dynamical excitations of its transmission primary shaft, such as, speed fluctuation and angular vibration, were obtained.The dynamical simulation model of a five-level manual transmission was built using the multi-body-dynamics method.Based on the simulation results at the second gear level, the characteristics of gear whine caused by variable meshing stiffness, and the characteristics of gear rattle caused by free inertia and meshing clearance were both discussed.Meanwhile, the equivalent torsion model was verified by the experiment torsion vibration results.And the simulation result of dynamical bearing loads due to gear meshing was verified by gearbox's surface vibration speed experiments which were done over the whole engine speed range.