Blade root of moving blade of large steam turbine

The invention discloses a moving blade root of a large steam turbine, which is a fir-tree-shaped blade root molded line, and the blade root is provided with a first pair of teeth, a second pair of teeth, a third pair of teeth and a fourth pair of teeth from a root platform to the root bottom according to a rule. Compared with the blade root wheel groove profile of the last-stage blade of the original 3000r/min thermal power steam turbine, the blade root wheel groove profile of the last-stage blade is characterized in that the length dimension relative value of the blade root wheel groove profile of the last-stage blade provided by the invention is optimally designed, so that the blade root wheel groove profile of the last-stage blade has higher bearing capacity, and the bearing capacity of a single blade reaches 1000 tons or more than 1000 tons. 本发明公开了一种大型汽轮机动叶片叶根，为枞树型叶根型线，叶根从根部平台至根底部按规律设有第一对齿、第二对齿、第三对齿和第四对齿。本发明与原有3000r/min火电汽轮机末级叶片叶根轮槽型线区别在于：本发明提供的末叶叶片叶根轮槽型线，长度尺寸相对值进行了优化设计，使之具备更强的承载能力，单只叶片承载能力达1000吨或1000吨以上。