JP2001307402A - Leveling mechanism for turntable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive turntable which eliminates the need to specially use an expensive material and need not be machined with precision. SOLUTION: A disk mount surface (24) is fitted loosely to the turntable (21) movably in the direction of a shaft (6) and stopped by claws (21d, e, f) from falling, and the disk mount surface (24) is automatically leveled by gyro effect generated as a spindle motor rotates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turntable for a spindle motor, and more particularly to a turntable leveling mechanism capable of holding the turntable horizontally.

[0002]

2. Description of the Related Art Conventionally, when a medium such as a CDROM is mounted on a disk mounting surface of a turntable fixed to a spindle motor to read / write information, the runout of the turntable has been a problem. .

FIG. 4 is a sectional view showing a turntable fixed to a conventional spindle motor. In the figure,
1 is a base plate, 2 is a bearing housing implanted in the center of the base plate 1, 3 is a thrust bearing provided at the bottom of the bearing housing 2, 4 and 5 are press-fitted inside the bearing housing 2 or the like. It is a held bearing. 6 is the bearings 4 and 5 and the thrust bearing 3
Reference numeral 7 denotes a stator core fixed to the outer periphery of the bearing housing 2, and reference numeral 8 denotes a stator coil wound around the stator core 7. Reference numeral 9 denotes a case fixed to the shaft, and a ring magnet 1
0 is fixed. The ring magnet 10 faces the stator core 7 with a radial gap. Reference numeral 11 denotes a turntable fixed to the output end of the shaft. The lower surface of the turntable is fixed to the case 9. The outer periphery of the upper surface has a ball storage groove 11a. A groove 11b is provided. A ball 13 is housed in the ball housing groove 11a and moves freely in the ball housing groove 11a to maintain the balance of the turntable 11. 14 is
The ball 1 is provided so as to cover the ball storage groove 11a.
Reference numeral 3 denotes a disk mounting surface on which the recording disk 15 is mounted while preventing the ball 3 from coming out of the ball storage groove 11a. Reference numeral 16 denotes an elastic material adhered to the outer peripheral portion of the disk mounting surface 14. In the spindle motor turntable configured as described above, if the recording disk or the like is warped or decentered, surface runout occurs,
In recent years, in a large-capacity recording disk in which data is written at a high density, an error easily occurs on the drive side during writing and reading.

Therefore, conventionally, in order to improve the accuracy of the disk mounting surface 14, it is necessary to coat the mounting surface or to cut the disk mounting surface with a material such as brass and to process it with high accuracy. Was.

[0005]

However, in the turntable constructed as described above, since the accuracy of the disk mounting surface 14 is required, an expensive material such as brass is used, and further high-precision processing is required. Of course,
There was a problem that it took a lot of processing time and resulted in an expensive turntable.

The present invention can provide an inexpensive turntable which does not require the use of a particularly expensive material and does not require any precision in processing.

[0007]

According to a first aspect of the present invention, there is provided a turntable which is fixed to a shaft of a spindle motor and has a recording disk mounted on a disk mounting surface. This can be achieved by holding the disk mounting surface loosely on the turntable and movably in the axial direction. Further, as in the second aspect of the present invention, the movably holding means can be achieved by holding by at least three flexible claws.

[0008]

FIG. 1 is a sectional view of a turntable according to a first embodiment of the present invention. FIG. 2 is a plan view as viewed from the turntable side, and FIG. 3 is a schematic view showing a state in which the turntable is shifted horizontally. 1 to 3, 1 is a base plate, 2 is a bearing housing implanted in the center of the base plate 1, 3 is a thrust bearing provided at the bottom of the bearing housing 2, and 4 and 5 are the bearing housings described above. 2 is a bearing held by press-fitting or the like in the interior of the housing 2. Reference numeral 6 denotes a shaft supported by the bearings 4 and 5 and the thrust bearing 3, reference numeral 7 denotes a stator core fixed to the outer periphery of the bearing housing 2, and reference numeral 8 denotes a stator coil wound around the stator core 7. Reference numeral 9 denotes a case fixed to the shaft 6, and a ring magnet 10 is fixed to the inner periphery. The ring magnet 1
0 is opposed to the stator core 7 with a radial gap. Reference numeral 21 denotes a turntable fixed to the output end of the shaft 6, a lower surface of which is fixed to the case 9, a ball storage groove 21a at an outer peripheral portion of the upper surface, and a magnet for accommodating the annular magnet 12 at an inner periphery thereof. Holding groove 21b
It has. Further, 21c is a tapered portion, 21d
(E, f) are flexible claws, and it is preferable that three or more nails are provided at substantially equal intervals on at least one circumference. 13 is
The ball is housed in the ball storage groove 21a and moves freely in the ball storage groove 21a to keep the balance of the turntable 21. Reference numeral 24 has a through hole in the center and is provided so as to slidably cover the ball storage groove 21a so that the ball 13 does not protrude from the ball storage groove 11a and a disk mount on which the recording disk 15 is mounted. It is a table. The diameter of the central through hole of the disc mounting surface 24 is smaller than the circumference connecting the outer circumferences of the claws 21d, 21e, and 21f. , 21e, 2
1f bends inward and stops against the support surface 21g. When the disk mounting surface 24 passes through the claws 21d, 21e, and 21f, the claws 21d, 21e, and 21f return to their original positions due to the restoring force. For this reason, even if the disk mounting surface 24 tries to escape again, the tips of the claws 21d, 21e, and 21f do not come off due to contact. Reference numeral 16 denotes an elastic material adhered to the outer peripheral portion of the disk mounting surface 24 to improve the seating of the recording disk 15. Reference numeral 26 denotes a gap between the outer periphery of the turntable 21 and the disk mounting surface 15.

In the turntable of the spindle motor constructed as described above, the disk mounting surface 24 is only mounted on the support surface 21g, so that the claws 21d, 2d
It is possible to move until it comes into contact with 1e or 21f. Hereinafter, how the turntable 21 is leveled independently when the recording disk 15 is warped, the center of gravity is displaced, or the turntable itself is deflected will be described with reference to FIG. FIG. 3 shows a state where the disk mounting surface 24 is inclined by θ with respect to the vertical shaft 6. In this state, the turntable 21
Starts rotating with the shaft 6 inclined by θ as indicated by the arrow R, a gyro moment J (gyro moment) is generated by the gyro effect. That is, J (gyro moment) = Acos θ, and rotational moments in the B and b directions are generated until θ = 0. As described above, since the disk mounting surface 24 is only mounted on the support surface 21g, the disk mounting surface 24 can move in the axial direction until it comes into contact with the claws 21d, 21e or 21f. Therefore, due to the gyro effect, a force indicated by an arrow b is generated on the left side of the disk mounting surface 24, and a force indicated by an arrow B is generated on the right side, so that the disk mounting surface 24 itself moves horizontally.

[0010]

As described above, according to the present invention, in a turntable in which a recording disk is mounted on a disk mounting surface which is fixed to a shaft of a spindle motor, the disk mounting surface is loosely fitted and movably held. By using a leveling mechanism to level the disk mounting surface by the gyro effect with the rotation of the spindle motor, specially expensive materials such as brass are used to pursue the accuracy of the disk mounting surface. It is possible to provide an inexpensive turntable that does not require the use of a precision and does not require any precision in the processing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a turntable according to a first embodiment of the present invention.

FIG. 2 is a plan view seen from a turntable side.

FIG. 3 is a schematic diagram showing a state in which the turntable is shifted horizontally.

FIG. 4 is a sectional view showing a turntable fixed to a conventional spindle motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base plate 2 Bearing housing 3 Thrust bearing 4,5 Bearing 6 Shaft 7 Stator core 8 Stator coil 9 Case 10 Ring magnet 11,21 Turntable 12 Annular magnet 13 Ball 14,24 Disk mounting surface 15 Recording disk 16 Elastic material

Claims (2)

[Claims] 1. A turntable fixed to a shaft of a spindle motor and mounting a recording disk on a disk mounting surface, wherein the disk mounting surface is loosely fitted to the turntable and held movably in the axial direction. Turntable leveling mechanism. 2. The turntable leveling mechanism according to claim 1, wherein said movably holding means is held by at least three flexible claws.