| 摘要 |
PROBLEM TO BE SOLVED: To reduce the number of parts items. SOLUTION: A housing 7 is formed by a porous member composed of sintered metal and includes an inner peripheral surface 7a into which a shaft part 2a is inserted, a seal part 7c provided in an opening part of an upper end and a step 7b provided in a lower end part. In the inner peripheral surface 7a, the bearing surface 7a1 of a first radial bearing part R<SB>1</SB>and a bearing surface 7a2 of a second radial bearing part R<SB>2</SB>are axially separated. In the end face of the step part 7b, the bearing surface 7b1 of a first thrust bearing part S<SB>1</SB>is provided. On these bearing surfaces 7a1, 7a2 and 7b1 respectively, herringbone shaped or spiral shaped dynamic pressure grooves are formed. The inner peripheral surface of the seal part 7c is opposed to the outer peripheral surface 2a1 of the shaft part 2a through a prescribed seal space. COPYRIGHT: (C)2004,JPO
|
