| 摘要 |
A cylindrical bearing member which can hold a lubricating oil charged into blind grooves serving as oil reservoirs for a long period of time and thereby exhibit a lubricating function sufficiently and which can be mass-produced at low cost. The cylindrical bearing member is made with a plurality of blind grooves serving as oil reservoirs swaged on the inner circumferential surface of a pipe-shaped seamless cylindrical member by using a hollow die pin including a plurality of grooving protrusions on end portions of the outer circumferential surface of the die pin and provided with a plurality of diameter=expanding slits therein along the longitudinal direction of the die pin, and a diameter-expanding center pin EP, which is retractable in said hollow die pin HP. The hollow die pin is inserted into a hollow cylindrical part, and the center pin is inserted into the die pin to cause the protrusions to penetrate the interior cylindrical surface of the part. The assembly is displaced for a limited distance, and the center pin is extracted from the die pin and the assembly is removed to leave swaged blind grooves in the hollow cylindrical part. |
