Machining process for marine propeller shaft with length of 22 metres and hollow middle

Abstract

The invention relates to a machining process for a marine propeller shaft with a length of 22 metres and a hollow middle. The machining process comprises the following steps: the propeller shaft to be machined is taken and fixed on a lathe and subjected to rough turning machining; then the propeller shaft to be machined is fixed on a boring machine and bored; a machining manner of reversely pulling a floating hole twice is adopted, and the middle-section position of the propeller shaft is sunken 1mm, and the parallelism degree of the axis of a pull rod of the boring machine and the axis of the propeller shaft is less than 0.5mm during a boring process; run-out and roundness of a transition sleeve, a central frame, a frame position gear and a machining frame position needing to be used during machining are controlled to be in set ranges, and then semi-finish machining and finish machining are carried out; the propeller shaft is hoisted and placed on a machining fixture through a crane; and a Y-axis direction and a Z-axis direction are verified, and then holes of a flange of the propeller shaft are drilled and bored by a boring die to complete machining. The machining process disclosed by the invention has the following advantages: the phenomena of deflection and cutting thermal deformation bending during drilling can be effectively avoided when the propeller shaft is machined by virtue of the process disclosed by the invention, thus the excircle roundness is ensured.

Description

technical field [0001] The invention relates to the field of ship manufacturing, in particular to a process for processing a 22-meter-long hollow ship stern shaft. Background technique [0002] At present, the length of the stern shaft of the same type of ship in China is generally about 12000mm, that is, the aspect ratio is about 28. At present, some ships need to use a stern shaft with a length of about 22000mm. It has the following defects: the traditional stern shaft processing is relatively short in length, and the drilling hole is not easy to deflect, while the 22-meter long shaft will cause a large deflection in cutting due to the cutting force and the gravity of the drill pipe, and there is a processing scrap The increase in the length of the shaft will lead to a decrease in rigidity, and thermal deformation and bending will occur during the cutting process. The difficulty of ensuring the concentricity and roughness of the inner hole and the outer circle is more diff...

AI Technical Summary

Problems solved by technology

[0002] At present, the length of the stern shaft of the same type of ship in China is generally about 12000mm, that is, the aspect ratio is about 28. At present, some ships need to use a stern shaft with a length of about 22000mm. It has the following defects: the traditional stern shaft processing is relatively short in length, and the drilling hole is not easy to deflect, while the 22-meter long shaft will cause a large deflection in cutting due to the cutting force and the gravity of the drill pipe, and there is a processing scrap The increase in the length of the shaft will lead to a decrease in rigidity, and thermal deformation and bending will occur during the cutting process. The difficulty of ensuring the concentricity and roughness of the inner hole and the outer circle is more difficult than that of the traditional stern shaft. several times higher

Images