PURPOSE: To manufacture a titled rotor having a cooling pipe which is capable of forcibly cooling a rotor tooth part, at a low cost, by laminating a tooth form thin plate having a hole whose size is different from each other in adjacent thin plates, by shifting its phase, inserting a pipe into the hole, and expanding it.

CONSTITUTION: A hole 3 is made on a tooth form part of a press punching tooth form plate 1. The tooth form plate 1 having a large hole 3 and the tooth form plate 1 having a small hole are alternately laminated around a shaft part 2 by shifting the phase. Subsequently, a flexible annealed copper pipe 4 is inserted into the rotor tooth form part through-hole 3 constituted by combining in this way, the copper pipe inserted rotor is detained by clamping it with a jig, and hydraulic pressure is put onto the inside of the pipe 4, and it is expanded. As a result, in the place of the large hole 3, the pipe 4 is expanded and fitted in, therefore, each tooth form plate 1 is positioned and fixed by the pipe 4. Subsequently, only the tooth form part 1 of both ends is brazed or arc-welded to the shaft 2.