Rotopeening Apparatus Having a Flexible Spindle

Author:  Phillip J. Hawkins
Source:  US Patent 4,616,496
Doc ID:  1986164
Year of Publication:  1986
Abstract:  
A rotopeening apparatus utilizing a flexible spindle for rotopeening the inside wall of tubes of limited access is disclosed herein. The spindle is formed from a flexible, rotatable housing and includes a mandrel having eighteen peening flappers connected thereto along its axis of rotation. The mandrel is rotatably mounted within the housing in an off-center orientation relative to the longitudinal axis of the spindle in order that the peening flapper may rotate and orbit within the tube when the mandrel and the housing are rotated. The apparatus includes a frame plate for detachably mounting the flexible spindle within the open end of the tube to be rotopeened. The spindle is mounted in cantilever off the side of the frame plate to maximize its manipulability in areas of limited access. Additionally, the drive motors of the apparatus are remotely coupled to the peening spindle by means of flexible shafts in order to maximize portability. The apparatus is particularly useful for rotopeening heat exchange tubes mounted in the peripheral regions of the tubesheets of nuclear steam generators.