1. A spindle motor, comprising:
a turntable coupled to a rotating shaft, and supporting the rotating shaft and a disc;
a centering unit fitted over the rotating shaft, and supporting an inner circumference of the disc; and
a coil spring interposed between the turntable and the centering unit to elastically support the centering unit,
wherein a first end of the coil spring is brought into contact with a spring hanging portion protruding from a side surface of the centering unit, and a second end opposite to the first end of the coil spring is supported by a spring support portion formed in the turntable.
2. The spindle motor as set forth in claim 1, wherein the first end of the coil spring has a first diameter, and the second end has a second diameter that is greater than the first diameter.
3. The spindle motor as set forth in claim 2, wherein an angle between an imaginary line extending along an outer surface of the coil spring and a vertical line parallel to an axial direction of the rotating shaft ranges from 2\xb0 to 12%.
4. The spindle motor as set forth in claim 3, wherein the angle between the imaginary line and the vertical line is T.
5. The spindle motor as set forth in claim 1, wherein the spring hanging portion protrudes from the side surface of the centering unit in a shape of an annular protrusion.
6. The spindle motor as set forth in claim 1, wherein the spring hanging portion comprises a plurality of hanging protrusions that protrude from the side surface of the centering unit.
7. The spindle motor as set forth in claim 1, wherein the spring support portion has a shape of an annular trench when viewed on a plane.
8. The spindle motor as set forth in claim 1, further comprising:
a base plate;
a stator including a bearing housing coupled to the base plate, a bearing inserted into the bearing housing and rotatably supporting the rotating shaft, a core coupled to an outer circumference of the bearing housing, and a coil coupled to the core; and
a rotor including a yoke coupled to the rotating shaft and supporting the turntable, and a magnet coupled to an inner surface of the yoke and facing the core.
9. The spindle motor as set forth in claim 1, wherein the centering unit includes a body having a shape of a container that is open at a top thereof and forming the side surface, and a centering portion inclined from an upper end of the body to a lower end opposite to the upper end of the body.
10. The spindle motor as set forth in claim 1, wherein the coil spring is formed by winding a wire in a shape of a truncated cone.
11. A spindle motor, comprising:
a rotating shaft;
a turntable coupled to a rotating shaft to be rotated along therewith, and supporting a disc;
a centering unit fitted over the rotating shaft, and elastically coupled to an inner circumference of the disc; and
a coil spring interposed between the turntable and the centering unit,
wherein an angle between an imaginary line extending along an outer surface of the coil spring and a vertical line parallel to an axial direction of the rotating shaft ranges from 2\xb0 to 12\xb0.
12. The spindle motor as set forth in claim 11, wherein the coil spring includes a first end making contact with the turntable and having a first diameter, and a second end making contact with the centering unit and having a second diameter that is smaller than the first diameter.
13. The spindle motor as set forth in claim 12, wherein the coil spring has a shape of a truncated cone.
14. The spindle motor as set forth in claim 11, wherein the turntable includes a spring support portion to receive an end of the coil spring.
15. The spindle motor as set forth in claim 14, wherein the spring support portion has a shape of an annular recess.
16. The spindle motor as set forth in claim 11, wherein an end of the coil spring making contact with the centering unit is in contact with a spring hanging protrusion that protrudes from a side surface of the centering unit.
17. The spindle motor as set forth in claim 16, wherein the spring hanging protrusion protrudes along the side surface of the centering unit in a ring shape.
18. The spindle motor as set forth in claim 16, wherein the spring hanging protrusion comprises a plurality of spring hanging protrusions protruding from the side surface of the centering unit.
19. The spindle motor as set forth in claim 11, wherein the angle between the imaginary line and the vertical line is 7\xb0.
20. The spindle motor as set forth in claim 11, further comprising:
a base plate;
a stator including a bearing housing coupled to the base plate, a bearing inserted into the bearing housing and rotatably supporting the rotating shaft, a core coupled to an outer circumference of the bearing housing, and a coil coupled to the core; and
a rotor including a yoke coupled to the rotating shaft and supporting the turntable, and a magnet coupled to an inner surface of the yoke and facing the core.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A bioreactor comprising a chamber (100) capable of receiving a liquid media, and a filter assembly (200) comprising a perfusion filter (210; 212; 214), wherein the filter assembly (200) is disposed in the chamber (100) and the filter assembly (200) is free to move within the chamber (100), wherein the filter assembly (200) comprises means for coupling a harvesting flow through said filter (210; 212; 214) and means for coupling a feed flow through said filter in an opposite direction compared to the harvesting flow, wherein the feed flow is pumped to the bioreactor by means of a feed pump (330) and the harvest flow is pumped from the bioreactor by means of a harvest pump (340).
2. The bioreactor assembly of claim 1, wherein the means for coupling the flows comprises a flexible tube attached to the filter assembly.
3. The bioreactor assembly of claim 1, wherein the filter assembly (200) comprises means for coupling the feed flow and the harvesting flow, respectively.
4. The bioreactor assembly of claim 1, wherein the filter assembly (200) comprises means for coupling the feed flow and harvesting flow in a coaxial manner.
5. The bioreactor assembly of claim 4, wherein the feed flow is arranged coaxially around the harvesting flow.
6. The bioreactor assembly of claim 1, wherein the filter assembly comprises at least two filters (211, 212; 213, 214).
7. The bioreactor assembly of claim 6, wherein the feed flow is directed to flow between the at least two filters (211, 212; 213, 214).
8. A method of operating a bioreactor comprising a chamber (100) capable of receiving a liquid media, and a filter assembly (200) comprising a perfusion filter (210; 212; 214), wherein the filter assembly (200) is disposed in the chamber (100) and the filter assembly (200) is free to move within the chamber (100), wherein the method comprises:
removing a harvesting flow through said perfusion filter (210; 212; 214) from the bioreactor by means of a harvest pump (340);
feeding a feed flow through said perfusion filter (210; 212; 214) to the bioreactor by means of a feed pump (330);
wherein the harvesting flow is removed through said perfusion filter (210; 212; 214) in an opposite direction compared to the feed flow.
9. The method of claim 7, wherein the method is carried out in a mode in which a specific volume of the harvesting flow is first removed from the bioreactor (100) and then a substantially equal volume of the feed flow is fed to the bioreactor (100).
10. The method of claim 8, wherein the removal of the harvesting flow and the feeding of the feed flow are performed in periodic intervals.