抽油机减速器圆弧齿轮的模糊可靠性设计

针对用传统方法设计的抽油机减速器圆弧齿轮安全系数偏大、齿轮重量大、减速器体积大的问题，用模糊可靠性理论分析了圆弧齿轮的应力和疲劳强度，并建立了数学模型。以减速器重量最轻为优化设计目标，把疲劳强度可靠性约束。齿宽和分度圆尺寸约束以及各设计变量上下界约束的取值范围视为设计空间上的模糊子集，得到了相应的约束条件。经实例计算表明，在疲劳强度的模糊可靠度不小于０．９９９的情况下，与原设计相比，齿轮的重量可减轻２３．９％。

Fuzzy reliability design for circular-arc gears on pumping unit reducers

In the light of the problems with the pumping unit reducers designed by the traditional method, that is,the safety coefficient of the circular-arc gears is somewhat high,resulting in their overweight and the reducer's oversize,the stress and fatigue strength of the gears are analyzed by using the fuzzy reliability theory, and a mathematic model is established. Taking the minimum weight of reducer as optimum object,and taking the constraints for fatigue reliability,tooth width,gear's reference circle and the thresholds of various design variables as fuzzy subsets,the relevant design constraints are obtained. Calculation shows that,as the fuzzy reliability of the fatigue strength is not less than 0.999,the gears are designed with 23.9% reduction in weight compared with that designed by the old method.