Manufacturing method of half-split bearings

Abstract

This invention pertains to a method of manufacturing a half-split bearing, comprising the steps of: providing a blank having a width corresponding to a width of a final said half split bearing: first bending opposite ends of the blank by a first punch and die set while restraining a central portion of the blank in a wall-thickness wise direction, the restraining produced by clamping the blank between a restrainer located centrally on the punch of the first punch and die set and the die of said set, thereby forming a partially processed bent blank having first bending; further, bending in a second stage said partially processed bent blank by a second punch and die set beginning at points between the first bendings and said restrained a central portion while continuing to restrain restraining the central portion of the partially processed bent blank in the wall-thickness wise direction, the restraining produced by clamping the partially processed bent blank between a restrainer located centrally on the punch of the second punch and die set and the die of the set, said bending in a second stage forming to form a substantially half-circular blank; reducing a circumferential length of the substantially half-circular blank while restraining the substantially half circular blank in the wall-thickness wise, widthwise and circumferential directions between a third punch and die set, thereby forming a half-split bearing of a predetermined size.