中文摘要：

以工程实例（孤齿锥齿轮一斜齿圆柱齿轮三级减速器）为研究对象，构建混合式齿轮减速器优化模型，该模型中含有离散型变量（模数）、整型变量（齿数）和连续型变量（齿宽、螺旋角等），是一种复杂的混合非线性规划问题。在优化求解中，提出了一种新的优化求解算法，该算法实现了模数、齿数等变量的离散取值，弥补了以往优化设计中将离散变量作为连续变量求解的不足。优化结果表明：优化方案符合工程设计的需要，并在减小减速器体积、节省材料等方面具有显著的现实意义。该离散优化算法在上海振华港机的齿轮箱设计中得到成功应用，并作为相关设计的重要参考资料。

英文摘要：

Taking the engineering project （triple gear--box assembled with spiral--bevel and helical- spur gears ） as a research target, an optimization model was established, which included discrete variables（module） ,integer variables（teeth number）and continuous variables（tooth width, spiral angle, etc. ）, featuring a complex nonlinear programming problem. A new optimization solution algorithm was proposed to obtain the discrete solution of module and teeth number, thus the deficiency of treating discrete integer variables as continuous variables was offset in traditional optimization design of gear reducer. The optimization results manifest that this optimization scheme meets the needs of engineering design and has a critical practical significance in decreasing reducer volume and saving materials. Moreover, this discrete optimization algorithm has been applied successfully in the design of gear box of shanghai zhehua heavy Industry Co. ,Ltd. （ZMPC） and compiled into important reference for relevant designs.