| 摘要 |
A rolling tool for both expanding and reforming the dented end of a tube within the tubesheet of a nuclear steam generator is disclosed herein. Generally, the tool comprises a rotatable roller cage having a diameter which is approximately the same as the minimum diameter across the dented tube end, a plurality of rollers rotatably mounted within pitched slots in the roller cage, a tapered mandrel slidably movable within an opening in the cage for rotating, orbiting and radially extending the rollers, and a ring which circumscribes at least a substantial portion of the cage for providing a surface around and against which the rollers may rotate when the roller-driving mandrel is rotated. In the preferred embodiment, the cage is rotatably mounted within a collar and the ring is detachably mountable around the proximal end of the roller cage. The tool further includes a table assembly for supporting the roller cage collar, a frame for supporting the drive means of the mandrel, and a guide rod and ball-bushing arrangement for slidably mounting the table assembly to the frame. A single, hydraulic cylinder is used to selectively slide the table assembly into a tube-engaging position. In the method of the invention, successively larger roller cages and rings are used to reform and finally expand severely dented tubes.
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