Roller burnishing tool for effecting diminishing stress reversal on annular workpieces

An apparatus for deforming metal surfaces, comprising:

• a first plurality of roller means disposed in a generally circular arrangement having a first diameter;
• a second plurality of roller means disposed in a generally circular arrangement concentric with said first plurality of roller means, said generally circular arrangement of said second plurality of rollers having a second diameter, said second diameter being slightly larger than said first diameter to thereby allow a metallic material having inner and outer surfaces to be inserted therebetween;
• means for controllably urging at least one of said first and second pluralities of roller means towards the other to thereby cause said first and second pluralities of roller means to forcibly contact said inner and outer surfaces respectively of said metallic material when said metallic material is inserted between said pluralities of roller means;
• and
• means for axially rotating at least one of said first and second pluralities of roller means whereby said pluralities of roller means operate to controllably deform said surfaces of said metallic material while in contact with said surfaces.

An apparatus for deforming simultaneously inner and outer surfaces of an annular metallic workpiece, said apparatus comprising:

• an inner plurality of roller means disposed in a generally circular arrangement having a first diameter;
• an outer plurality of roller means disposed in a generally circular arrangement concentric with said inner plurality of roller means and having a second diameter, said second diameter being slightly larger than said first diameter to thereby allow a portion of said workpiece to be inserted therebetween;
• means for simultaneously rotating said inner and outer pluralities of roller means in a planetary fashion about a common axis;
• and
• mandrel means for controllably urging said inner roller means outwardly against a portion of said inner surface when said workpiece is inserted between said inner and outer roller means, thereby urging said portion of said workpiece outwardly, whereby said outer surface of said workpiece is forcibly urged into contact with said outer roller means, said inner and outer roller means operating simultaneously to deform said inner and outer surfaces of said portion of said workpiece.

An apparatus for simultaneously deforming inner and outer surfaces of an annular metallic workpiece, said apparatus comprising:

• an inner plurality of rolls disposed in a generally circular arrangement, said circular arrangement having a first diameter;
• an outer plurality of rolls disposed in a generally circular arrangement concentric with said inner plurality of rolls, said outer plurality of rolls further having a second diameter, said second diameter being slightly larger than said first diameter to thereby allow a portion of said annular metallic workpiece to be inserted therebetween;
• a cage for housing said inner and outer pluralities of rolls, said cage being operable to allow independent, axially rotational movement of said inner and outer pluralities of rolls;
• an outer housing for housing said cage;
• a pilot assembly for enabling said inner and outer pluralities of rolls to be concentrically aligned with said annular metallic workpiece;
• and
• a mandrel for controllably urging said inner rolls outwardly against a portion of said inner surface when said annular metallic workpiece is inserted between said inner and outer rolls, thereby urging said portion of said annular metallic workpiece outwardly, whereby said outer surface of said annular metallic workpiece is forcibly urged into contact with said outer rolls, said inner and outer rolls operating simultaneously and cooperatively to deform said inner and outer surfaces of said portion of said annular metallic workpiece.