Processing method of axial conical pin hole for small gap of multiple stages of wheel discs of steam turbine rotor

Abstract

The invention relates to a processing method of an axial conical pin hole for a small gap of multiple stages of wheel discs of a steam turbine rotor. The processing method comprises the following steps of 1, determining the depth and size of each stage of step bottom hole in the conical pin hole; 2, modifying drill bits according to the depth and size of each stage of step bottom hole; 3, using the drill bit I to drill in the to-be-processed position, with the depth equal to the depth of the first step bottom hole; 4, recording the coordinate of the radial position of the center of the drill bit I, and taking the drill bit I out through cutter retraction; 5, modifying the drill bit II, feeding the cutter according to the recorded radial coordinate, ensuring the coinciding of rotation centers of the two drilling bits, and thoroughly drilling according to the requirement of a drawing; 6, after the drill bit II (10) is taken out, selecting a reaming cutter with property length and the feeding tool to manually ream the taper of the conical pin hole. The method solves the problem that the conical hole in the wheel disc cannot be processed due to the too small gap between the two wheel discs when the steam turbine rotor is processed.

Description

technical field [0001] The invention relates to a processing method for steam turbine parts, in particular to a processing method for small-pitch axial taper pin holes on a multi-stage disc of a steam turbine rotor. Background technique [0002] Such as figure 1 As shown, the steam turbine rotor is mainly composed of a main shaft 1, blades 2, cone pins 3, and discs 4. During installation, after the blade 2 is packed into the wheel disc groove, the blade 2 and the wheel disc 4 are locked and fixed with the taper pin 3 to prevent the blade from loosening and coming off. In order to ensure that the blade and the wheel are locked and fixed, and to ensure safety, during the processing of the tapered pin hole of the wheel and the blade, it is necessary to first put the blade into the groove of the wheel, and then process and form the tapered pin hole from the same direction at one time. In order to ensure a high degree of fit between the taper pin hole and the taper pin. Since ...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the technical problems in the prior art that the distance between the adjacent two-stage discs of the steam turbine rotor becomes smaller, there is no space for normal drilling to place the power source, and it is impossible to directly use the steering power head equipped with the machine tool to directly realize drilling, the present invention provides a A machining method for small-pitch axial taper pin holes on multi-stage discs of steam turbine rotors. The method uses calculations to modify drill bits so that they can be easily placed between adjacent two-stage discs. The method of drilling twice is used to realize taper pin holes. Processing of pin holes

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