自动变速器行星齿轮机构的优化设计

Optimal Design of Planetary Gear Mechanism for Automatic Transmission

根据自动变速器行星齿轮机构的特点和要求,在保证传动比合理和体积减小等40个约束条件下,以行星齿轮机构中各齿轮强度均等或接近于优化目标,建立齿轮齿面接触疲劳应力差值最小和齿根弯曲疲劳应力差值最小的优化模型,并用MATLAB进行优化计算。与原设计比较,优化设计的行星齿轮机构的齿面接触疲劳应力和齿根弯曲疲劳应力的最大值、应力差值以及整体应力都下降,特别是齿根弯曲疲劳应力最大值减小了12.24%,而且所有齿轮的齿根弯曲疲劳应力几乎相等,优化效果明显。优化设计的行星齿轮机构体积比原设计小3.54%,而且在传动比、尺寸参数和工艺参数方面,优化设计也都有优势。

According to the characteristics and requirements of automatic transmission planetary gear,taking equal or close strength as optimization objective,optimization model of considering to minimize gear contact fatigue stress difference and bending fatigue stress difference is built under 40 constraint conditions including keeping reasonable transmission ratio,volume decrease,etc. And optimization calculation is performed by using MATLAB. Compared to the original design,the maximum value of planetary gear contact fatigue stress and bending fatigue stress,stress difference and integral stress decrease after optimization,especially the maximum value of bending fatigue stress decrease 12. 24% and all gears root bending fatigue stress are almost the same,the optimization effects are significant. The volume of optimized planetary gear mechanism is 3. 54%smaller than the original design,and the optimal design is superior in transmission ratio,dimension and processing parameters.