Roll assembly, for rolling tubes into tube-plates - where rolls are forced radially outwards by conical mandrel in roll housing

摘要

The assembly consists of a roll body with longitudinal slots contg. three or more rolls, which can be driven radially outwards, against the bore of the tube being anchored in the tube plate, by the conical outer dia. of a mandrel moved axially inside the body. On the end of the conical mandrel is a cylindrical shank fitted with a centering bush which is free to rotate but is in contact with the bore of the tubular body without play. The centering- or guide- tolerance is max. 75% of the difference between the bore dia. of the tube and the outer dia. of the body. Bush pref. of polytebrafluorocarbon, is located between a shoulder on the mandrel and a threaded nut, possibly using a spring washer. Abrasion of the roll assembly is avoided.