To provide a cylindrical bearing member having a sufficiently lubricating function while holding lubricating oil filled into an oil reservoir blind groove for a long period, and to provide a method for manufacturing the low cost cylindrical bearing member in a mass-productive manner by efficiently forming the oil reservoir blind groove in the inner face of a cylindrical member.
The cylindrical bearing member 100 comprises the plurality of oil reservoir blind grooves 112 formed in the inner peripheral face of the cylindrical member 110 having no bus line joint. The oil reservoir blind groove 112 is formed by pushing a blind groove forming die pin DP6 into a bottomed cylindrical member 106 having a tapered inner peripheral face portion 106a whose diameter is shrunk as tending from the opening end to the inward direction and grooving the tapered inner peripheral face portion 106a as a starting end portion 112a concurrently with bottom removal to form a blind groove 107a. The starting end portion 112a of the blind groove is sealed by a restoring and correcting portion 113 which cylindrically restores and corrects the tapered inner peripheral face portion 106a.
Masayuki Miyake
Atsuo Kawai