Method for machining turbine rotor with special-shaped center hole

Abstract

The invention discloses a method for machining a turbine rotor with a special-shaped center hole. The method for machining the turbine rotor with the special-shaped center hole comprises the followingsteps that a turbine disk and a turbine shaft are welded; heat treatment is conducted; a center hole is drilled, and the turbine disk outer circle and end face margin are removed; semi-finish turningis conducted on end faces of the turbine end of the turbine disk and the special-shaped center hole; turning is conducted on a technological choke plug; semi-finish turning is conducted on end facesof the air-compressing end the turbine disk and the outer circle and end faces of the turbine shaft and the outer circle; a turbine shaft inner hole is drilled; turning is conducted on a turbine shafttool withdrawal groove, chamfering and a shaft stair inner hole; heat treatment is conducted; the technological choke plug and the turbine disk are welded and fixed; the center hole is turned in thetechnological choke plug, and two end faces of the big outer circle of the turbine disk are turned; the big outer circle of the turbine disk and the outer circle M of the turbine shaft are ground; a turbine shaft threaded hole, a stair inner hole and taper are turned, and tapping is conducted; the big outer circle of the turbine disk and end faces, the outer circle of the turbine shaft and end faces, the small outer circle of the turbine disk and the turbine disk D face are ground; an air-sealing groove is turned; and the technological choke plug is removed.

Description

technical field [0001] The invention relates to the technical field of turbine rotor machining, in particular to a machining method of a turbine rotor with a special-shaped center hole. Background technique [0002] The turbine rotor is the main rotating component inside the turbocharger. The turbine rotor uses the steam generated by the heat recovery system to push the turbine blades to work through compression, and the turbine rotor is the most important rotating part that provides power in the entire system. [0003] The supercharger is installed on the exhaust side of the engine, so the working temperature of the supercharger is very high, and the speed of the rotor is very high when the supercharger is working, which can reach hundreds of thousands of revolutions per minute, so the unbalance of the turbine rotor must be very small. In this way, the requirements for the grinding run-out value during the machining process of the turbine rotor are very small. From the pe...

AI Technical Summary

Problems solved by technology

However, due to the needs of assembly and disassembly, the special-shaped central hole at the turbine end and tail of the turbine disc in the turbine rotor adopts a hexagonal inner hole. After long-term tracking and investigation, it is found that during the grinding process, the carbide tip will contact the inner hexagonal hole at the central hole. The sharp edges of the hexagon rub against each other to varying degrees, resulting in fluctuations in the runout value of the outer circle of each gear of the processed turbine shaft, and the circle runout is even as high as 0.1 or more; from a structural point of view, it is impossible to cancel the inner hexagon, or put the inner hexagon in the final processing There are also significant production constraints

[0006] In addition, during the machining process, the special-shaped central hole exists at the turbine end of the turbine disc, the material of the turbine disc is superalloy, and the material of the turbine shaft is 42CrMoA; in the case of limited production resources, we use the same grinding wheel to grind the turbine shaft (42CrMoA ) and turbine disc (superalloy), but the difference between the two materials leads to different forces on the center holes at both ends during grinding, especially the working conditions at the special-shaped center holes are getting worse

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