Fluid dynamic bearing system

Abstract

The invention relates to a fluid dynamic bearing system particularly for a spindle motor having a rotating component comprising a shaft and a hub connected to the shaft, and a stationary component comprising a bearing bush made of a porous material, the shaft being accommodated in the bearing bush and rotatably supported with respect to the bearing bush, and there being a bearing gap filled with a bearing fluid between the shaft and the bearing bush. According to the invention, the bearing bush is at least partly enclosed by a sleeve, a surface of the sleeve together with an adjoining surface of the rotating component forming a conical seal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a first embodiment of the fluid dynamic bearing according to the invention.

FIG. 2 shows a second embodiment of the fluid dynamic bearing according to the invention.

FIG. 3 shows a third embodiment of the fluid dynamic bearing according to the invention.

FIG. 4 shows a fourth embodiment of the fluid dynamic bearing according to the invention.

FIG. 5 shows a fifth embodiment of the fluid dynamic bearing according to the invention.

Claims

1. A fluid dynamic bearing system particularly for a spindle motor, having a rotating component comprising a shaft (1; 101; 401) and a hub (3; 103) connected to the shaft, and a stationary component comprising a bearing bush (2; 102; 202) made of a porous material, the shaft being accommodated in the bearing bush and rotatably supported with respect to the bearing bush, and there being a bearing gap (5; 105) filled with a bearing fluid between the shaft and the bearing bush, characterized in that the bearing bush (2; 102; 202) is at least partly enclosed by a sleeve (4; 104; 204; 304; 404), and that a surface (6; 106; 206; 306; 415) of the sleeve (4; 104; 204; 304; 404) together with an adjoining surface (7; 107; 407) of the rotating component forms a conical seal.

2. A fluid dynamic bearing system according to claim 1, characterized in that a circumferential surface (6; 106; 206; 306) of the sleeve (4; 104; 204; 304) together with an adjoining surface (7; 107) disposed on an inside circumference of the hub (3; 103; 203) forms the conical seal.

3. A fluid dynamic bearing system according to claim 1, characterized in that an end face (415) of the sleeve (404) and an end face (414) of the bearing bush (102) together with an adjoining surface (407) disposed on the shaft (401) forms the conical seal.

4. A fluid dynamic bearing system according to claim 1, characterized in that the conical seal comprises a seal gap (8; 108; 408) connected to the bearing gap (5; 105), the seal gap being partly filled with bearing fluid and narrowing in the direction of the bearing gap.

5. A fluid dynamic bearing system according to claim 4, characterized in that the seal gap (8; 108) extends mainly parallel to the bearing gap (5; 105).

6. A fluid dynamic bearing system according to claim 4, characterized in that the seal gap (408) extends mainly perpendicular to the bearing gap (105).

7. A fluid dynamic bearing system according to claim 1, characterized in that the sleeve (4; 104; 204; 304; 404) has at least one open end having a rim.

8. A fluid dynamic bearing system according to claim 7, characterized in that the sleeve (4; 104; 204; 304) has a first outside diameter that continuously increases in the region of the rim up to a second outside diameter.

9. A fluid dynamic bearing system according to claim 7, characterized in that the sleeve (4; 104; 204; 304; 404) is made of plastics at least in the region of the rim.

10. A fluid dynamic bearing system according to claim 7, characterized in that the sleeve (204; 304) is made of two parts, one part (204a; 304b) forming the rim.

11. A fluid dynamic bearing system according to claim 1, characterized in that the sleeve (4; 104; 204; 304; 404) takes the shape of a can and is closed at one end by a bottom piece.

12. A fluid dynamic bearing system according to claim 1, characterized in that the sleeve (4; 104; 204; 304; 404) is made of plastics.

13. A fluid dynamic bearing system according to claim 1, characterized in that the bearing bush (2; 102; 202) is made of a sintered material.