JPS6348102B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a spindle for a magnetic disk device, and particularly to a spindle for a magnetic disk suitable for a large-sized magnetic disk device.

[Prior art]

FIG. 1 shows a schematic diagram of a general magnetic disk device. The magnetic disk device includes a spindle 2 on which magnetic disks 1 are stacked, a head positioning mechanism 4 that positions the head 3 at a predetermined position by electromagnetic attraction, a base 5 that fastens and holds them, and a dustproof cover 6. A drive pulley 7 is attached to the spindle 2 and is driven by a drive motor 9 via a belt 8.

In recent years, with the increase in the storage capacity of magnetic disk drives, it has become necessary to improve the accuracy of preventing rotational runout of spindles for magnetic disk drives. Self-rotation processing of the disk positioning surface 10A of the hub 10 (see FIG. 2) that holds the disk is now performed.

2 and 3 show prior art spindle structures. A hub 10 holding a magnetic disk 1 (see FIG. 1) is coupled to a shaft 11 by a method such as shrink fitting, and is connected to a housing 13 by an upper bearing (not shown) and a lower bearing 14.
is rotatably supported. Also, shaft 1
A self-rotating pulley 15 is fixed to the lower part of the bearing 1 by a washer 16 and a bolt 17, and a collar 12 is inserted between the upper bearing and the lower bearing 14. Further, a preload is applied to the outer ring of the lower bearing 14 by a spring 20, so that stable rotation is achieved.

In the structure shown in FIG. 2, self-rotation processing is performed on the disk positioning surface 10A while applying belt tension similar to that during mounting to the self-rotation processing pulley 15 and rotating it, and then removing the self-rotation processing pulley 15. , as shown in FIG.
It is fixed to the shaft 11 by. Note that the pulley 15 for self-rotation processing is an essential component that cannot be replaced by the drive pulley 7 due to processing technology problems during self-rotation processing such as the size of the diameter and the number of revolutions of the spindle.

As mentioned above, in the conventional spindle, the self-rotation processing pulley 15 is rotated during self-rotation processing.
Because it is structured to be attached and removed, it has the following drawbacks.

(1) Since the pulley 15 for self-rotation processing is removable, it cannot be firmly connected. {During self-rotation processing (state shown in Figure 2), the key 18 to ensure rotational strength cannot be press-fitted, resulting in a gap connection. } Therefore, vibration during machining has a negative effect on the accuracy and vibration characteristics of the spindle after machining.

(2) When installing and removing the self-rotating pulley 15, impact force is applied to the upper bearing (not shown) and lower bearing 14, which often damages the bearings and shortens spindle life.
Adversely affects vibration characteristics.

(3) Installation and removal are time-consuming and increase man-hours.

[Purpose of the invention]

An object of the present invention is to improve the drawbacks of the prior art as described above, to reduce vibrations during self-rotation processing of a spindle for a magnetic disk device, and to obtain a highly accurate spindle.

[Summary of the invention]

In order to achieve the above object, the present invention provides a spindle for driving magnetic disk rotation, by incorporating a pulley for self-rotation processing for final finishing of the spindle inside the pulley for driving magnetic disk. It is characterized by achieving low vibration during operation and realizing a high-precision spindle.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. The spindle components include a hub 10 on which magnetic disks are stacked, a shaft 11 coupled to the hub 10 by a method such as shrink fit, an upper bearing (not shown) and a lower bearing 14 that support the shaft 11, and the bearing. Housing 1 that supports
3, a collar 12, a spring 20, etc. After assembling these, the magnetic disk positioning surface 10A
A pulley 15 for self-rotation processing is firmly fastened to the shaft 11 with a bolt 17, a washer 16, and a key 18 to correct rotational runout (self-rotation processing), and after self-rotation processing, a plurality of pulleys 7 for driving the magnetic disk are connected. It has a structure in which it is fastened to the self-rotating processing pulley 15 with screws 19.

During self-rotation processing, only the self-rotation processing pulley 15 is installed among the self-rotation processing pulley 15 and the magnetic disk drive pulley 7, and the hub 10 is rotated using the self-rotation processing pulley 15. , disk positioning surface 10A
Process. After that, the spindle 2 and the base 5 (the first
(see figure), the magnetic disk drive pulley 7 is attached on top of the self-rotating pulley 15 without removing it.

In this way, by omitting the process of attaching and detaching the self-rotating pulley 15, it is possible to prevent the negative impact on the bearing 14 due to the impact during attaching and detaching, thereby extending the life of the spindle and improving vibration characteristics. .

Since the self-rotating processing pulley 15 is firmly connected with the key 18, washer 16, and bolt 17, the vibration generated at the disk positioning surface 10A is small, and processing with small runout is possible. Therefore, a highly accurate spindle can be provided.

In addition, in order to ensure spindle driving force,
A large-diameter magnetic disk drive pulley 7 is required, but in order to reduce vibrations, it is advantageous to use a magnetic disk drive pulley 7 with small inertia and to strengthen the coupling force between it and the shaft 11. .
Therefore, in order to increase the axial force that connects the magnetic disk drive pulley 7 and the shaft 11, the material strength of the magnetic disk drive pulley 7 itself is required. In this embodiment, the self-rotation processing pulley 15 is made of highly rigid iron to ensure the axial force for connection with the shaft 11, and the magnetic disk drive pulley 7
By making the magnetic disc drive pulley 7 made of aluminum and fastening it to the self-rotating pulley 15, it is possible to reduce the inertia of the magnetic disk drive pulley 7.

〔Effect of the invention〕

As explained above, according to the present invention, the pulley for self-rotating machining is built into the spindle, and the pulley for self-rotating machining can be firmly connected to the shaft, thereby reducing vibration during self-rotating machining and achieving high precision. You can get a spindle.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a general magnetic disk device.
Figure 2 is a sectional view of a spindle with a self-rotating pulley attached in the prior art;
The figure is a partial sectional view of a spindle with a magnetic disk drive pulley attached in the prior art.
FIG. 4 is a sectional view showing an embodiment of the present invention. 2: spindle, 7: pulley for magnetic disk drive, 10: hub, 10A: disk positioning surface, 11: shaft, 15: pulley for self-rotating processing, 18: key.

Claims (1)

[Claims] 1. A magnetic disk rotation drive spindle having a magnetic disk drive pulley, characterized in that a self-rotation processing pulley for final finishing of the spindle is built inside the magnetic disk drive pulley. Spindle for disk devices.