Firtree -type bucket root steam turbine rotor blades and its locking notch vane

Abstract

The invention provides a fir-tree type blade root rotor blade of a steam turbine and a stepped blade thereof. The rotor blade comprises an overall structure of a blade shroud, a blade body and a blade root which is provided with a root-type part and an intermediate part, wherein the intermediate part is shaped like a Chinese character 'tu', the width of a lug boss is equal to the width of the prior blade root intermediate part in the same specification, the width of a pedestal is more than the width of the lug boss, the width of the root-type part is equal to the width of the pedestal; the stepped blade comprises a stepped rotor blade and an adjacent stepped rotor blade both of which comprise the blade root, and the blade root is provided with a standard stopping piece and a blade axial positioning structure; the blade axial positioning structure is: a vertical slot is arranged on an opposite fitting plane between the pedestal of the blade root intermediate part of the stepped rotor blade and the pedestal of the blade root intermediate part of the adjacent stepped rotor blade, in which a vertical stopping part is arranged; a vertical slot and a level slot are arranged on the opposite fitting plane between the pedestal of the blade root intermediate part of the adjacent stepped rotor blade and the blade root intermediate part of the stepped rotor blade, wherein the level slot corresponds to the waist part of the vertical slot. The structure does not damage the root type part, but improves the security of blades and has high positioning accuracy.

Description

technical field [0001] The invention relates to steam turbine moving blades, in particular to steam turbine moving blades with fir tree blade roots and locking blades thereof. Background technique [0002] Due to many factors such as high temperature, heavy load, and partial steam intake, the regulating stage moving blades of steam turbines, especially the regulating stage moving blades of high-power steam turbines, have very bad working conditions, and their safety is of particular concern. Sufficient strength, and requires the blade root to be firmly combined after being installed in the impeller. But the moving blade of fir tree type blade root, the root type part of its blade root compares with the root type part of other form blades, and appears geometric dimension is little, and intensity is lower, and safety is poorer. In addition, due to the tortuous and complex shape of the fir tree blade root, it is difficult to guarantee the machining accuracy. There will always ...

AI Technical Summary

Problems solved by technology

another such as figure 2 As shown, screw holes and screws 7 are set on the matching line of the blade root intermediate of the lock blade and the blade adjacent to the lock to realize the axial positioning of the blade, and the processing is very inconvenient. If the screw holes are processed in advance, it will be difficult to assemble. Ensure that the screw holes of the two halves are aligned. If the screw holes are processed after assembly, the work efficiency will be low

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