| 摘要 |
PURPOSE:To simultaneously work a ball receiving groove and a seal groove by forming a step difference on the seal groove forming corresponding peripheral surface, in an annular stock which is brought to diameter expansion and grooving by cold rolling and becomes a bearing constituting ring body. CONSTITUTION:A mandrel (d) is inserted through a stock 1 for inner wring, a receiving roll (e) is rotated so that its peripheral groove d1 comes into contact with the inside surface of the stock 1, and also, it is pressed against the outside peripheral surface of the stock 1, while rotating a main roll (f). By the shaft rotation and the pressing action of the main roll (f), and the shaft rotation of the mandrel (d) which follows them, a ball receiving groove 3 and a seal groove 4 of a projecting bar f2, etc., are imparted on the outside peripheral surface of the ring-like stock 1, and also, wall thickness of the ring-like part is thinned, and the whole is brought to diameter expansion. When the diameter expansion advances and the outside periphery of the stock 1 hits against a hitting member (g), a proximity switch (h) operates, the main roll (f) moves backward and working is ended. In such a way, the merit on the accuracy is maintained, and it is possible to contribute to manhour saving for generating a bearing.
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