| 摘要 |
PROBLEM TO BE SOLVED: To smoothly operate an inside rolling roll even when it is used in a high temperature area by using a rolling bearing as a bearing of the inside rolling roll of a rolling device which can be mounted/dismounted in the inside of a welded or pressure-welded steel pipe and pressurizes a seam part of the steel pipe from the inside. SOLUTION: An inside bead at a seam part of a steel pipe is rolled with an inside rolling roll 8. A roll shaft 12 of the inside rolling roll 8 is supported by a needle bearing 16. It is preferable that the material of the needle bearing 16 is one kind of carburized or high-frequency-quenched high chromium bearing steel, carbon tool steel, nickel molybdenum steel, chromium steel, chromium molybdenum steel and nickel chromium steel, or silicon nitride or alumina. A piston is activated by gas pressure, and a lubricant supplying means for supplying the lubricant to the needle bearing is arranged to a roll supporting bogie. Furthermore, the lubricant supplying means is covered with a water cooling jacket.
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