汽车变速器齿轮传动系统动态特性研究及优化

针对汽车在运行过程中汽车变速器的振动问题,以汽车变速器三挡为研究对象,通过MASTA软件对其进行载荷谱分析,再以提高齿轮的承载能力和尺寸的比值为目标,对三挡啮合齿轮进行优化设计,得到新的模数与螺旋角.综合考虑动态啮合刚度、齿侧间隙、轴承游隙、传递误差的影响建立斜齿轮弯扭耦合的6自由度非线性动力学模型并对传动系统的振动特性进行分析.根据优化前后的振动特性对比,提出了将振动时域信号转化为频域信号进行对比的方法,使得结果更加直观.通过快速傅里叶变换将振动时域信号转化为频域信号.结果表明,优化后齿轮的振动特性有明显的改善,尤其是z向振动减小达到1/4左右.本研究为汽车变速器的振动特性优化提供一定的理论依据.

Analysis and Optimization Design on Dynamic Characteristic of Gear Transmission System of Automobile Transmission

To study the vibration of the automobile transmission, the third gear of the automobile transmission was taken as the investigated subject. MASTA was used to carry out the load spectrum analysis. To optimize the module and helical angle of the third gear, the capacity ratio and the size of the gear transmission system of the third gear were improved. The new modulus and helix angle were obtained by the optimum design. Considering the gear meshing stiffness, backlash, bearing clearance and transmission error, a bending-torsion coupled nonlinear vibration model with 6-degree-of-freedom was established by the lumped mass method. The vibration characteristics were analyzed in detail. In order to compare the vibration characteristics before and after optimization intuitively, a method of translating the time-domain signal into the frequency domain signal was proposed by Fast Fourier Transform. The comparison of the frequency spectrum shows that the vibration characteristics are improved obviously. In particular, the reduction of vibration in z axial reaches about 1/4. It provides a theoretical basis for the vibration optimization of the automobile transmission.