To inexpensively provide a hydrodynamic bearing device provided with high durability and reliability.
A step 17 is formed on an inner circumferential face of a bearing member 8. A dynamic pressure groove pattern is printed on an outer circumferential face 2a1 of a shaft member 2 facing a large diameter inner circumferential face 8a1 by an ink jet method to form a first bearing part 14 comprised of a hydrodynamic bearing. A radial bearing clearance is formed between a small diameter inner circumferential face 8a2 and the outer circumferential face 2a1 of the shaft member 2 facing it to form a second bearing member 15 comprised of a perfect circle bearing. The shaft member 2, and a portion forming the small diameter inner circumferential face 8a2 of the bearing member 8 are both formed by a metal material.
| JPH06178487 | FLUID BEARING SPINDLE MOTOR |
| JP2500731 | SPINDLE MOTOR FOR MAGNETIC DISK DEVICE |
| WO/2001/033083 | A TANK AND A CENTRIFUGAL PUMP FOR EMPTYING THE TANK |
Hideka Tanaka
Yoshiyuki Shiraishi
Kunihiko Shiromura
Tsuyoshi Kumano
Hiroaki Yamane