JPH0536664U - Dummy disk - Google Patents

Abstract

(57) [Summary] [Purpose] Even if the diameter of the dummy disk becomes smaller due to the miniaturization of the spindle motor, it can be easily handled and removed from the spindle motor. [Structure] A dummy disk having an inertial load substantially equivalent to that of a recording disk mounted on a spindle motor. An annular flat surface portion that extends in a radial direction substantially perpendicular to the axis of the spindle motor, and a wall portion that substantially protrudes in the axial center direction over the entire outer peripheral end of the annular flat surface portion,
Is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dummy disk for performing various characteristic tests on a spindle motor used in, for example, an optical / magnetic disk drive device under load conditions equivalent to the mounted state.

[0002]

[Prior Art]

 Conventionally, a spindle motor that rotationally drives a recording disk, such as an optical / magnetic disk device, uses a dummy disk whose characteristic check, for example, electrical characteristics and torque characteristics, is made of the same material and shape as the mounted recording disk. Was there. That is, a flat dummy disk having an annular shape was used.

[0003]

[Problems to be solved by the device]

 On the other hand, with the recent miniaturization of such recording disk drive devices, the spindle motor incorporated inside is also being made thinner and lighter. Especially for spindle motors equipped with small disks with a diameter of 2.5 inches or less, the length (height) in the axial direction becomes shorter (thinner), so the work of attaching / detaching a thin dummy disk is It required careful handling and was troublesome and troublesome.

Further, in the structure in which the bracket (fixed portion) of the spindle motor also serves as the frame of the drive device, further reduction in thickness is promoted, and the above-mentioned problem becomes more serious. In addition, when measuring the rotation accuracy (eg, NRRO: non-repetitive shake) of the spindle motor in such a state, the probe of the non-contact proximity sensor does not have a space to approach the dummy disk and is measured accurately. It was difficult to do.

The present invention has been made in view of the above problems existing in the prior art. The problem is that even if the diameter of the dummy disk is reduced as the spindle motor is downsized, It is an object of the present invention to provide a dummy disk that can be easily handled and removed from and attached to a spindle motor, and that a non-contact proximity sensor, etc. accompanying measurement can be sufficiently brought close to perform a characteristic test with high accuracy.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the dummy disk of the present invention is a dummy disk having an inertial load substantially equal to that of a recording disk mounted on a spindle motor, and is substantially perpendicular to the axis of the spindle motor. And an annular flat surface portion that extends in the radial direction, and a wall portion that substantially projects in the axial direction along the entire circumference of the peripheral end of the annular flat surface portion.

[0007]

[Action]

 According to the dummy disk having the above-described configuration, the wall portion protruding from the outer peripheral end of the annular flat surface portion extends in the axial direction. For this reason, even if the spindle motor becomes thinner, the dummy disk can have a substantial thickness space in the axial direction due to the wall portion. Therefore, by having this wall portion at the time of handling, it is possible to easily attach / detach to / from the spindle motor, while at the same time, a sufficient space can be obtained to bring a probe such as a non-contact proximity sensor close to this wall portion.

[0008]

【Example】

 An embodiment of the dummy disk according to the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a dummy disk used in, for example, a 2.5 inch magnetic disk drive spindle motor of the present invention. The dummy disk 1 is formed integrally with the outer peripheral end of the annular flat surface portion 2 by projecting the wall portion 3 substantially vertically (in the axial center x direction) over the entire circumference. The hole 5 is a mounting hole for mounting on the hub of the spindle motor.

As a material, for example, an aluminum material is used, and the material is the same as the aluminum material of an actual magnetic disk. The outer shape of the magnetic disk is smaller than that of the actual magnetic disk in order to ensure substantially the same inertial load. That is, the diameter is reduced by the amount corresponding to the mass of the wall portion 3 provided. Specifically, in contrast to an actual 2.5-inch magnetic disk having a diameter of 65 mm and a thickness of 0.9 mm, the dummy disk according to the present invention has a diameter of 48 mm, a thickness of 0.9 mm, and a wall height of 8 mm. ing.

Therefore, by having the outer peripheral surface 4 of the wall portion on the dummy disk 1 as shown in FIG. 2, it is possible to easily handle and attach and detach the spindle motor. FIG. 3 is a sectional view showing a state in which the dummy disk 1 is mounted on the spindle motor 7. In FIG. 3, a spindle motor 7 is composed of a hub 6 on which the dummy disk 1 is mounted and a bracket 8. The spindle motor 7 is connected to the hub 6 by a magnetoelectric conversion means (armature coil and rotor magnet) inside the spindle motor 7 (not shown). The bracket 8 and the bracket 8 relatively rotate relative to the axis x.

The hole 5 of the dummy disk 1 is fitted into the hub outer peripheral portion 14, and the screw 10 is screwed through the clamp member 9, whereby the dummy disk 1 is integrally fixed to the hub 6. Thus, as the hub 6 rotates, the dummy disk 1 is driven to rotate. The spindle motor bracket 8 is fixed to the frame 11.

For example, in the case of a spindle motor equipped with one 2.5-inch disk, the distance h1 from the frame 11 to the annular flat surface portion 2 of the dummy disk 1 is about 1 mm. Therefore, when handling a conventional thin disk-shaped annular disc having a thickness of 0.9 mm, it is too narrow to handle the attachment / detachment to / from the hub 6, but it is difficult to handle the dummy disc 1 of the present invention. 3, it can be easily held by hand and can be easily attached and detached.

In addition to the electrical characteristics and the torque characteristics, in order to check the rotational accuracy of the hub 6 such as NRRO (Non Repetitive run Out) measurement test, the probe size of the proximity sensor 12 (high Since the wall size h2 is set in correspondence with the wall size, the non-contact proximity sensor 12 can be sufficiently brought close to the wall outer peripheral surface 4. Thereby, the measurement test can be performed with high accuracy.

Particularly, in a spindle motor having a so-called base-integrated structure in which the bracket 8 of the spindle motor is integrated with the frame 11, the above-mentioned dimension h1 is further reduced. For this reason, the dimension h2 of the wall portion 3 works more effectively in securing a space for the probe and the like in the axial center x direction. The height dimension h2 of the wall portion 3 is arbitrarily determined depending on such handling points and the corresponding surface of the non-contact proximity sensor 12, and the inertial load is equalized based on this set dimension. The diameter of the dummy disk should be decided like this.

In addition, when the dummy disk 1 is mounted on the spindle motor 7 and a test is performed, the rotational dynamic balance may be adversely affected for some reason. Even in this case, in the dummy disk 1 of the present invention, this adverse effect can be easily avoided by adding a balance weight (not shown) to the wall inner peripheral surface 13 of the wall 3.

An embodiment of the dummy disk according to the present invention has been described above, but the present invention is not limited to this, and design changes and various modifications can be made without departing from the spirit of the present invention. For example, the material to be used does not necessarily have to be matched to the originally used material of the disc, and one that can be easily processed and easily obtained may be selected. Further, it is possible to arbitrarily design the diameter which is the shape dimension, the height of the wall portion, the thickness dimension and the like. That is, it goes without saying that these elements are premised on satisfying the values substantially equivalent to the inertial load of the original disk. In addition, in the dummy disk of this embodiment, the annular flat surface portion 2 and the wall portion 3 are integrally formed, but they are separate bodies and are integrally formed by using an adhesive or the like. It may be formed on.

[0017]

[Effect of the device]

 In the dummy disk of the present invention, since the outer peripheral end of the annular flat surface portion 2 is formed over the entire circumference and the wall portion 3 is provided so as to project in the axis x direction, various restrictions due to miniaturization of the spindle motor 7 are provided. Also, the dummy disk 1 can be easily handled and attached / detached to / from the hub 6, and a dummy disk can be obtained in which the characteristic test can be performed with high accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view of a dummy disk according to an embodiment of the present invention.

FIG. 2 is a perspective view of a dummy disk according to an embodiment of the present invention.

FIG. 3 is a sectional view showing an example of mounting a dummy disk according to an embodiment of the present invention.

[Explanation of symbols]

 1 Dummy disc 2 Annular plan view 3 Wall part 6 Hub 7 Spindle motor 8 Bracket 9 Clamping member

Claims (1)

[Scope of utility model registration request] 1. A dummy disk having an inertial load substantially equal to that of a recording disk mounted on a spindle motor, the annular flat surface extending in a radial direction substantially perpendicular to an axis of the spindle motor, A dummy disk, characterized in that a wall portion that substantially projects in the axial direction is provided over the entire outer peripheral edge of the annular flat surface portion.