Patent ID: 6782622
Filing Date: 2004-08-31
Classification: B60B,F16C,Y10T

Abstract:
A method for manufacturing a wheel-supporting hub unit, said hub unit comprising:a hub including a flange for supporting and fixing a wheel on an outer peripheral surface in an outside end portion, a stepped portion formed on said outer peripheral surface in an inside end portion thereof, and a cylindrical portion formed in said inside end portion; an inner ring fitted with an outer surface of said stepped portion and including at least one of a first inner raceway and a second inner raceway formed on an outer peripheral surface thereof; an unrotatable outer ring including a first outer raceway opposed to said first inner raceway and a second outer raceway opposed to said second inner raceway respectively formed on an inner peripheral surface thereof; a first group of rolling elements interposed between said first inner raceway and said first outer raceway; and a second group of rolling elements interposed between said second inner raceway and said second outer raceway, said method comprising steps of: preparing a pressing mold including a cylindrical projecting portion movable into said cylindrical portion of said hub, and including an annular-shaped recessed portion formed in a periphery of said cylindrical projecting portion to enclose an entire periphery of said cylindrical projecting portion, wherein said annular-shaped recess portion comprises an inclined surface portion that is set at a tangent angle &agr;, such that 13Â°&lE;&agr;&lE;(90Â°âˆ’an offset angle); inserting said inner ring onto said outer peripheral surface of said cylindrical portion in such a manner that the inside end portion of said cylindrical portion is projected inwardly from an inside end portion of said inner ring; pressing said pressing mold against said cylindrical portion in such a condition that said cylindrical projecting portion supports an inner peripheral surface of said cylindrical portion, where said inner ring is superimposed on said cylindrical portion in a diameter direction of said hub, so that said cylindrical portion is prevented from shifting toward an inside diameter side; and forming a caulking portion by plastic deforming said cylindrical portion outwardly in said diameter direction of said hub by using said pressing mold so that said inner ring is fixed to said hub in such a manner that said inner ring is held toward a stepped surface of said stepped portion by said caulking portion, wherein an outer peripheral surface of said cylindrical projecting portion is contacted with said inner peripheral surface of said cylindrical portion in such a manner that said annular-shaped recessed portion is butted against an end portion of said cylindrical portion to thereby plastic deform said cylindrical portion.