Bearing mechanism for spindle motor in magnetic disk drive
View Patent ↗Embodiments of the invention prevent trouble caused by an increase in viscosity of grease generated when a ball bearing operates at a low temperature, and fretting that an inner ring and/or an outer ring comes in contact with balls to produce wear when vibration is applied thereto. In one embodiment, a ball bearing is configured such that a plurality of balls are arranged between an outer ring and an inner ring. Grease is filled between the balls, the inner ring and the outer ring. A holder is provided with a spring plate, and an extreme end thereof is always in contact with the balls. The spring plate is formed of a sufficiently softer material than the balls so as not to damage the balls. The mounted direction is one along the direction in which the balls are desired to be rotated. Appropriate spring pressurization can be applied to the balls at an angle defined by the holder and the spring plate in the root at which the holder is attached to the spring plate.
1. A magnetic disk drive comprising:
an information storing magnetic disk;
a spindle motor used for supporting said magnetic disk on a rotating shaft to rotate said magnetic disk;
a magnetic head for recording or reproducing information on said magnetic disk;
a pivot hub for supporting said magnetic head through a suspension;
a rotational center shaft serving as the rotational center of said pivot hub; and
a ball bearing provided between said rotational center shaft and said pivot hub and provided with a mechanism to make balls in the ball bearing hard to rotate in a specific direction, wherein the ball bearing is operable to rotate in the specific direction during operation of the magnetic disk drive while the mechanism is engaged with the ball bearing.
2. The magnetic disk drive according to claim 1 , wherein said ball bearing has a holder that limits spaces defined by said balls, and said mechanism to make balls hard to rotate in a specific direction is provided on said holder, said mechanism being a spring plate to come into contact with said balls.
3. The magnetic disk drive according to claim 2 , wherein said spring plate is formed of a material which is softer than said balls.
4. The magnetic disk drive according to claim 2 , wherein said spring plate applies pressurization to said balls.
5. The magnetic disk drive according to claim 4 , wherein said pressurization is applied to the balls at an angle defined by the spring plate and the holder in a root at which the spring plate is attached to the holder.
6. The magnetic disk drive according to claim 1 , wherein said ball bearing has a holder that limits spaces defined by said balls, and said mechanism to make balls hard to rotate in a specific direction is provided on said holder, said mechanism being a bush having a plurality of spring plates to come into contact with said balls.
7. The magnetic disk drive according to claim 6 , wherein said spring plates are formed of a material which is softer than said balls.
8. The magnetic disk drive according to claim 6 , wherein said spring plates apply pressurization to said balls.
9. The magnetic disk drive according to claim 8 , wherein said pressurization is applied to the balls at an angle defined by each spring plate and the holder in a root at which the spring plate is attached to the holder.
10. A magnetic disk drive comprising:
an information storing magnetic disk;
a spindle motor used for supporting said magnetic disk on a rotating shaft to rotate said magnetic disk;
a magnetic head for recording or reproducing information on said magnetic disk;
a pivot hub for supporting said magnetic head through a suspension;
a rotational center shaft serving as the rotational center of said pivot hub; and
a ball bearing provided between said rotational center shaft and said pivot hub and provided with a mechanism to make balls in the ball bearing hard to rotate in a specific direction,
wherein said ball bearings are provided on both ends of said rotational center shaft, and the direction in which said balls are hard to rotate is opposite for both ends of said rotational center shaft.
11. The disk drive device according to claim 10 , wherein said ball bearing has a holder that limits spaces defined by said balls, and said mechanism to make a ball hard to rotate in a specific direction is provided on said holder, said mechanism being a spring plate to come into contact with said balls.
12. The magnetic disk drive according to claim 11 , wherein said spring plate is formed of a material which is softer than said balls.
13. The magnetic disk drive according to claim 11 , wherein said spring plate applies pressurization to said balls.
14. The magnetic disk drive according to claim 13 , wherein said pressurization is applied to the balls at an angle defined by the spring plate and the holder in a root at which the spring plate is attached to the holder.
15. The disk drive device according to claim 10 , wherein said ball bearing has a holder that limits spaces defined by said balls, and said mechanism to make balls hard to rotate in a specific direction is provided on said holder, said mechanism being a bush having a plurality of spring plates to come into contact with said balls.
16. A magnetic disk drive comprising:
an information storing magnetic disk;
a rotating shaft for supporting said magnetic disk;
a fixed shaft serving as the rotational center of said rotating shaft;
a ball bearing provided between said fixed shaft and said rotating shaft and provided with a mechanism to make balls hard to rotate in a specific direction; and
a magnetic head for recording or reproducing information on said magnetic disk,
wherein said ball bearing has a holder that limits spaces defined by said ball, and said mechanism to make balls hard to rotate in a specific direction is provided on said holder, said mechanism being a bush having a plurality of spring plates to come into contact with said balls.
17. The magnetic disk drive according to claim 16 , wherein said spring plates are formed of a material which is softer than said balls.
18. The magnetic disk drive according to claim 16 , wherein said spring plates apply pressurization to said balls.
19. The magnetic disk drive according to claim 18 , wherein said pressurization is applied to the balls at an angle defined by each spring plate and the holder in a root at which the spring plate is attached to the holder.
20. The disk drive device according to claim 16 , wherein said ball bearings are provided on both ends of said rotating shaft, and the direction in which said balls are hard to rotate is the same for both ends of said rotating shaft.