一、前言长叶片是汽轮机的关键部件之一,对于长叶片,不仅要求其气动性能、强度振动特性优良,而且要求叶根必须安全可靠。为此,长叶片叶根的设计是一项很重要的工作。目前,随着国内外大功率汽轮机的发展,末级叶片的长度也在不断增加,使得叶根承受的离心力显著增大。解决这一问题的途径是:采用枞树形叶根,增加叉型叶根的叉腿及轮缘宽度,增加叉型叶根的叉腿数量,采用等强叉型叶根或者采用外包式叉型叶根 I. INTRODUCTION Long blade is one of the key components of steam turbine. For long blade, it not only requires its aerodynamic performance but also has excellent strength and vibration characteristics. It also requires that the root must be safe and reliable. Therefore, the design of long leaf blade root is a very important task. At present, with the development of high-power turbines both at home and abroad, the length of the final stage blades is also increasing constantly, resulting in a significant increase in the centrifugal force on the blade roots. The way to solve this problem is to use Fir Tree Roots to increase the width of the forks and rims of the fork roots, increase the number of forks of the fork roots, Roots