| 摘要 |
PURPOSE:To minimize an effect of a shrinkage of a resin on an inner peripheral side to prevent the deformation of the inner periphery to produce a dynamic pressure bearing having a good bearing performance. CONSTITUTION:An insert member 2 made of a small-diameter shaft part 2a having a pattern 11 for forming dynamic pressure grooves on the outer periphery thereof and a large-diameter shaft part 2b is fitted into a hole made of a small- diameter cylindrical part 1a and a large-diameter cylindrical part 1b in a mold 1. A sleeve 3 is tightly fitted into between the small-diameter cylindrical part 1a of the mold 1 and the small-diameter shaft part 2a of the insert member 2 so that the end face of the sleeve 3 is positioned beyond a stepped part 1c of the mold 1 toward the large-diameter shaft part 2b of the insert member 2. A gate member 4 is tightly fitted into between the inner periphery of the large-diameter cylindrical part 1b of the mold 1 and the outer periphery of the large-diameter shaft part 2b of the insert member 2 so that the end face thereof is positioned outside a stepped part 2c of the insert member 2. A resin melted by heating is injected into a space 10 formed by the mold 1, the insert member 2, the sleeve 3, and the gate member 4 through a path provided in the gate member 4. |
