制冷压缩机及小型空气压缩机在现场的实际使用中经常发现进、排气孔口处舌簧阀片因弯曲疲劳而断裂。由于孔口的动态弯曲应力比等效的静态弯曲应力约大50％（1〕,因此正确设计静态时的弯曲应力对避免产生弯曲疲劳断裂仍不失为一项极其重要的设计工作。本文就圆形孔口阀片的简单支承的边界条件进行了分析,进而提出了孔口中心处的最大静态弯曲应力的计算方法。 Refrigeration compressors and small air compressors are often found in the actual use of the site, into the exhaust vent valve flaps due to bending fatigue fracture. Since the dynamic bending stress of the orifice is about 50% larger than the equivalent static bending stress (1), it is an extremely important design task to correctly design the bending stress at static state to avoid bending fatigue fracture.In this paper, The boundary condition of the simple support of the orifice plate is analyzed, and then the calculation method of the maximum static bending stress at the center of the orifice is proposed.