JPS6292270A - Drive positioning mechanism for magnetic recording medium - Google Patents

Abstract

PURPOSE:To attain the improvement of accuracy, to simplify the structure and to attain low cost by providing a recessed part to the center hub reception face of a spindle hub, a magnetic pole to obtain prescribed attractive force and providing a plane to one side of a drive roller through-hole. CONSTITUTION:A recessed part concentric to a rotary shaft 3 is provided to a part of the center hub reception face of a spindle hub 1 to reduce the contact area and to decrease friction. Further, the attractive force holding the center hub 9 on the reception face is obtained by providing a magnetic pole 8 to the face of the spindle hub 1. Further, a plane 6a is provided to one side of a through-hole 6 of a drive roller 5 to fix the drive roller by the plane 6a and one end 11a of a center hub positioning hole 11 at the end of positioning of the center hub 9 to eliminate the circumferential displacement against fluctuations as disc loading. Thus, the accuracy is improved, the structure is simplified and low cost is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a mechanism for positioning and driving a magnetic disk having a metal disk at the center of the magnetic recording medium.

2. Description of the Related Art A conventional drive positioning mechanism for this type of magnetic recording medium is
The structure was as shown in Figures (a) and (b) to Figure 9 (a) and (b).

That is, a metal spindle hub 72 is press-fitted into the rotating shaft 71, a resin sheet 73 for reducing friction is pasted on the center hub contact surface, and a center hub 74 made of gold gi is attached.
The drive roller 77 is equipped with a permanent magnet 75 for attracting the spindle hub 72 and is held by a leaf spring 76. The drive roller 77 is disposed approximately in the center of a hole 78 formed in the spindle hub 72 so as to be able to pass through the hole 78 vertically. .

Problems to be Solved by the Invention However, with such a structure, since the resin sheet 73 is attached to the contact surface of the center hub, it is difficult to achieve accuracy in controlling runout, etc., and it is unstable against environmental changes. It is.

In addition, since the drive roller 77 is supported by the elastic leaf spring 76, the circumferential position of the drive roller 77 may be displaced due to fluctuations in disk load torque, etc., and the electrical reference position for starting recording and reproduction of the magnetic disk may occur. (index signal) may occur, making recording and reproduction impossible. Further, when the center hub 74 is installed in the position shown in FIG. 8, when the center hub 74 is pressed against the contact surface by the attractive force of the permanent magnet 75 and the mounting force of the set, Since the position is higher than one end 79a of the positioning hole 79 of the center hub 74, it gets caught and cannot be properly positioned (
Become.

FIG. 9 is an enlarged view showing the mechanism by which catching occurs. In addition to the above-mentioned problems, the structure is complicated and assembly and management are extremely difficult.

In view of the above-mentioned problems, the present invention eliminates the resin sheet and permanent magnet, simplifies the structure, and displaces the circumferential position of the drive roller. Prevents catching on the end of the drive roller,
The present invention provides a stable drive positioning mechanism for a magnetic recording medium.

Means for Solving the Problems In order to solve the above problems, the drive positioning mechanism for a magnetic recording medium of the present invention uses a spindle hub molded by mixing a magnetic material into resin, and a center hub receiver of the spindle hub. It has a concave portion in the surface portion, a magnetic pole portion for obtaining a predetermined attraction force, and a flat portion on one side of the drive roller through hole.

Function The present invention provides a concave portion concentrically with the rotating shaft in a part of the center hub receiving surface of the spindle hub, thereby reducing the contact area and reducing friction, thereby eliminating the need for a resin sheet in the conventional example shown in FIG. be able to.

Further, by providing a magnetic pole section on the spindle hub surface to provide the attraction force for holding the center hub on the receiving surface section, the permanent magnet of the conventional example can be omitted. Also, by providing a flat part on one side of the drive roller through hole (thereby, when the center hub positioning is completed, the drive roller is fixed by the flat part and one end of the center hub positioning hole, and the circumference is protected against fluctuations in disk load, etc.). Directional displacement can be eliminated.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment in which a recessed portion is provided in a part of the center hub receiving surface of the present invention. In Figure 1,
Reference numeral 1 denotes a spindle hub molded by mixing a magnetic material into resin, and a center hub receiving surface 2 is provided with a recess 4 concentrically with a rotating shaft 3. A drive roller 5 passes through a roller through hole 6 provided in the spindle hub 1, and is attached to a leaf spring 7 supported at the bottom of the spindle hub 1.

By providing the recess 4 as in the above configuration, the actual contact surface roughness between the center hub and the conventional example shown in FIG. 7 can be reduced.
Friction on the receiving surface portion 2 can be reduced without applying a resin sheet. That is, it is possible to omit consideration of the accuracy of the resin sheet, thermal changes, changes over time, etc., and it is possible to ensure a receiving surface that is extremely stable both in terms of accuracy and management.

FIGS. 2 and 3 show an embodiment in which a magnetic pole is provided on the magnetic pole surface 8 of the spindle hub 1 of the present invention. FIG. 2 shows magnetic poles arranged in the radial direction with respect to the rotation axis, and FIG. 3 shows magnetic poles arranged parallel to each other. Both have a magnetic pole arrangement that allows the metal center hub to be accurately attached to the receiving surface by the attractive force of the magnetic poles, and prevents leakage of magnetic flux to the magnetic medium.

FIG. 4 shows the state of the center hub of the present invention upon completion of positioning. In FIG. 4, reference numeral 9 denotes a metal center hub, which is provided at the center of the magnetic disk 10. As shown in FIG. 11 is a center hub positioning hole, 12 is a center hole, and 13 is a magnetic head.

A configuration that eliminates displacement of the drive roller 5 in the circumferential direction due to fluctuations in disk load, etc. will be described below with reference to FIGS. 4 and 5.

First, FIG. 5 shows a cross-sectional view taken along the line xx' in FIG. By providing the flat portion 6a substantially parallel to the straight line connecting the center of the center hub 9, when the positioning of the center hub 9 is completed, the disk load and the head load cause the end 11a of the positioning hole 11 of the center hub 9 (rotation direction side) to Plane portion 6a of roller through hole 6
With this, the drive roller 5 is fixed, and displacement in the circumferential direction due to fluctuations in the disk load, etc. can be eliminated.

FIG. 6 shows one end 1 of the positioning hole 11 of the center hub 9.
This shows an embodiment in which a protrusion 14 is provided on the ash receiving surface side of the center hub 9 in order to prevent the drive roller end 5a from getting caught.

By providing the projection 14, the plate spring 7 can be
A slight inclination in the range of 0° can eliminate contact with one end 11a of the positioning hole 11 of the center hub 9 by lowering the end 5a of the drive roller 5 on the spindle hub rotation direction side. That is, even if the center hub is arranged in a position as shown in FIG. 8 and FIG. 11 of the conventional example, the drive roller end 5a is not higher than the one end 11a of the positioning hole 11, so no catching occurs.

Effects of the Invention As described above, the present invention provides a concave portion concentrically with the rotating shaft in a part of the center hub receiving surface of a spindle hub molded from a resin material containing a magnetic material, and in order to hold the center hub on the receiving surface. By providing a magnetic pole part and providing a flat part on one side of the roller through hole almost parallel to the straight line connecting the center of the drive roller and the center of the rotating shaft, the resin sheet and permanent magnet of the conventional example can be omitted. , improved accuracy and simplified structure,
Cost reduction can be realized, and displacement of the circumferential position of the drive roller can be eliminated.

[Brief explanation of drawings]

FIGS. 1(a) and 3(b) are a plan view and a sectional view taken along line z-z' of a spindle hub according to an embodiment of the present invention, and FIGS. 2 and 3 are views of a magnetic pole portion of the same spindle hub. A pattern diagram showing the magnetic pole arrangement, FIGS. 4(a) and 4(b) are a plan view and a YY' cross-sectional view showing the positioning state of the center hub of the present invention, and FIG. 5 is a pattern diagram of FIG. 4(a). Cross-sectional view seen from x-x',
FIGS. 6(a) and (b) are a plan view and a side view of another embodiment of the present invention, and FIGS. 7(a) and (b) are a plan view and a w-w' line showing a conventional example. Cross-sectional view, Fig. 8(a), (
b) is a plan view showing the catching mechanism between the end of the drive roller and one end of the center hub in the conventional example, and v
-v' line sectional view, and FIGS. 9(a) and 9(b) are sectional views showing the state before and after the center hub of the hooked portion is attracted. 1... Spindle hub, 2... Center hub receiving surface, 3... Rotating shaft, 4...
Recessed portion, 5... Drive roller, 5a... Drive roller end, 6... Roller through hole, 7...
... leaf spring, 8 ... magnetic pole surface, 9 ... old center hub, 10 ... magnetic disk, 11 ... old ...
・Center hub positioning hole, 12...Center hole. Figure 2 Figure 3 Figure 4 -Y Figure 5 X X' section Figure 6 Figure 7 Figure 8 (a)

Claims (1)

[Claims] A metal center hub provided in the center of the magnetic disk, a rotating shaft that penetrates through a center hole drilled approximately in the center of the center hub and forms the center of rotation, and a magnetic material mixed in resin. a spindle hub that supports the center hub, a leaf spring supported at the lower part of the spindle hub; Equipped with a drive roller that transmits rotational force to the magnetic disk,
The spindle hub has a concave portion concentrically with the rotating shaft on the center hub receiving surface, and has a magnetic pole portion magnetized in a radial direction or parallel to the center of the rotating shaft for supporting the center hub. and a drive positioning mechanism for a magnetic recording medium, the drive positioning mechanism having a flat portion on one side of an end in the rotational direction of the roller through hole that is substantially parallel to a straight line connecting the center of the drive roller and the center of the rotation shaft.