Apparatus and method for manufacturing hollow shafts
AssigneeIUSRD (Ireland) Limited
InventorsRobert G. J. Jack, Geoffrey Brook
Life of this patent
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Abstract
An apparatus and method for welding a shaft having an open seam defined between opposed longitudinal edges. The method comprising passing the shaft along its longitudinal axis through an array of pressure rollers which contact the surface of the shaft at a plurality of discrete points and compress the shaft by applying inwardly directed radial forces to the shaft. An electrical resistance welding assembly welds the seam while closed by the pressure rollers.
Claims30
A method for welding a tapered shaft having an open seam defined between opposed longitudinal edges, said method comprising;
- moving a tapered shaft along its longitudinal axis relative to a plurality of rollers arranged substantially symmetrically around a common fixed axis and each inclined at an acute angle relative to its next adjacent neighbors on each side, each of said plurality of rollers being movable by hydraulic pressure radially of the fixed axis for applying inwardly directed radial forces to the shaft at a plurality of discrete points spaced circumferentially around the shaft surface;
- controlling the movement of said rollers radially of the fixed axis to account for the taper and progressively close the seam as it passes said rollers;
- and
- progressively welding the seam after it is closed by said rollers;
- wherein the step of controlling the movement of the rollers includes using a control computer to vary the hydraulic pressure applied to the rollers by open loop control according to a predetermined voltage ramp.
An apparatus for welding a tapered shaft having an open seam defined between opposed longitudinal edges, said apparatus comprising:
- a plurality of rollers arranged substantially symmetrically around a common fixed axis and each inclined at an acute angle relative to its next adjacent neighbors on each side, each of said plurality of rollers being movable by hydraulic pressure radially of the fixed axis for applying inwardly directed radial forces to the shaft at a plurality of discrete points spaced circumferentially around the shaft surface;
- means for moving the shaft along its longitudinal axis relative to said rollers;
- control means for moving said rollers radially of the fixed axis to account for the taper and progressively closing the seam as it passes said rollers;
- and
- means for progressively welding the seam after it is closed by said rollers;
- wherein said control means includes a control computer for varying the hydraulic pressure applied to said rollers by open loop control according to a predetermined voltage ramp.
Dependencies are inferred from the claim text.