JPS6247896A - Disk driver for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce the quantity of off-tracks due to temperature/humidity expansion and contraction by providing cooling holes to a protection cover which covers the outside of the rotor of a disk driving motor. CONSTITUTION:A protection cover 51 contains a hole 55 for cooling air path at the outer edge and a hole 56 in the vicinity of rotary shaft respectively. Open air is supplied through the hole 56 by the rotation of the cover 51 to cool a heat generating part. Then the open air is discharged to the outside through the hole 55. Furthermore, a plate 60 is attached onto the surface of the cover 51 by means of a rib 61. While a blade 62 is attached at the position of the hole 55 at the side of a substrate 50 and supported by the plate 60. Then ventilation is carried out forcibly with the rotation of the cover 51. In such a way, the cooling efficiency is further improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic recording and reproducing apparatus that performs recording and reproducing by rotationally driving a circular magnetic disk.

[Background of the invention]

As the density of magnetic recording and reproducing devices becomes higher, higher precision is required for the positioning of the magnetic head.

For this reason, the margin for deviation of the static position of the magnetic head from the normal position (hereinafter referred to as off-track) also becomes stricter. The biggest cause of off-track is the temperature/humidity expansion/contraction difference within the magnetic recording/reproducing device, but the factors that cause temperature/humidity changes in the device include (1) changes in environmental conditions, (2) heat generation from peripheral devices, ( 3) The magnetic recording/reproducing device itself generated heat.

In conventional devices, the stator coil section of the disk drive motor is covered with a rotor protection cover, so the heat generated from the chain section has no place to escape and is transferred to the disk side via the chassis. This heat accounts for most of the above-mentioned factor (3), and off-track always occurs due to temperature rise depending on the time after the power is turned on.

[Purpose of the invention]

An object of the present invention is to provide a more reliable magnetic recording and reproducing device by reducing the influence of the above factor (3) and reducing the amount of off-track due to differences in expansion and contraction due to temperature and humidity.

[Summary of the invention]

The present invention utilizes the fact that the rotor protection cover of the disk drive motor rotates together with the rotating shaft,
By providing cooling holes in the protective cover and forcibly cooling the heat generating portion during rotation, the temperature rise in the motor was reduced. Furthermore, by attaching blades to the holes provided in the protective cover, the cooling effect can be further improved.

[Embodiments of the invention]

An example of a magnetic recording/reproducing apparatus using the present invention will be described below.

The chassis 1 has a substantially box-like shape with only the operation section side 18 open, which is formed by a side wall 2 connected to the mounting wall 5 of the stepping motor 20, a side wall 3 provided over the entire opposite side, a rear wall 4, and a bottom surface 6. It has become. On the opposite side of the bottom surface 6 of the chassis, there are guide shafts 25, 25 that slidably hold a carriage 100 on which a magnetic head is mounted.
a is placed and fixed by holding plates 26 and 28, respectively. On the other hand, a disk drive motor 40 is attached to the bottom surface 6 of the chassis 1, and a hub shaft 43 of the motor 40 is attached.
penetrates a mounting hole 11 provided in the bottom surface 6 and protrudes inside the chassis 1.

The disk drive motor 40 will be described in detail below. The hub shaft 43 is provided with a hub receiver 42 . A leaf spring 45 to which a drive pin 44 is fixed is attached to the hub receiver 42.
is fixed by a set screw 46, and the cassette 23
0 is attached, the drive pin 44 is inserted into the drive pin hole 234 of the disk 235 as the drive motor 4o rotates.
are mated. Then, the rotational force of the drive motor 40 is transmitted to the disk 235, and the relative position between the rotating shaft 43 of the drive motor 40 and the disk 235 is determined on a one-to-one basis. A hub attracting magnet 47 is also fixed to the hub receiver 42, which attracts the metal hub 232 of the disk 235 when the cassette is attached to ensure that the disk 235 is attached to the hub receiver 43, and also reduces vibration after attachment. The structure is such that the disk 235 is difficult to separate from the hub receiver 43 due to impact or the like.

The hub axle 43 is attached to the mounting step 5 by bearings 48 and 49.
It is fixed to the inner edge of 7. A control board 50 for the drive motor 40 is fixed to the outer edge of the mounting step 57, and when the drive motor 40 is mounted to the chassis 1, the hub receiver 42 side of the control board 50 is attached to the chassis 1. It comes into contact with the bottom surface 6. Further, the portion of the mounting step portion 57 that protrudes from the substrate 5o fits into the mounting hole 11 of the bottom surface 6.

A protective cover 51 is attached to the tip of the rotating shaft 43 with a female screw 52.
A permanent magnet 53 is attached to the inside of the protective cover 51.

On the other hand, a coil 54 is provided on the side opposite to the hub receiver 43 of the control board 50.
is provided, and faces the permanent magnet 53 with a slight gap therebetween.

When the power is turned on, a magnetic field that changes over time is generated in the coil 54 by the control board 50, and by repeating repulsion and attraction with the permanent magnet 53, the disk drive motor 40
obtains rotational force. At this time, the coil 54 becomes a stator and the permanent magnet 53 becomes a rotor.

An index pulse generating element 58 is provided on the outside of the protective cover 51, and one index pulse sensing element 59 is provided on the control board 50. When the disk 235 rotates, the index pulse generating element 58 is connected to the sensing element 59. Generates an electrical pulse signal at the moment of closest approach to
It is sent to the control circuit of the magnetic recording/reproducing device. This pulse signal becomes a signal indicating the reference position on the disk 235 in the rotational direction. The reason why the reference position signal in the rotational direction of the disk 235 can be taken out from the drive motor 40 rather than directly from the disk 235 is that the hub drive pin 44 and the hub 2
By fitting the drive pin holes 234 of 32, the disk 23
This is because the positional relationship in the rotational direction between the drive motor 40 and the drive motor 40 is always determined to be one-to-one when both are rotating.

Next, the holes provided for cooling according to the present invention will be explained below. FIG. 2 is a view of one embodiment of the present invention viewed from the side opposite to the hub receiver 43. The protective cover 51 is provided with a hole 55 at its outer edge and a hole 56 near the rotating shaft 43 as a cooling air passage. As the protective cover 51 rotates,
As shown in FIG. 1, outside air flows in through the hole 56, cools the heat generating portion, and then exits through the hole 55. According to this embodiment, by providing the outside air inflow hole and outflow hole in the protective cover 51, the heat generating portion can be efficiently cooled.

FIG. 3 shows another embodiment in which a blade is further attached to the hole provided for cooling to further improve the cooling efficiency. The protective cover 51 has ribs 61 on its surface.
A blade support plate 60 is attached to which the blade support plate 60 is fixed. A blade 62 is attached to the control board 50 side of the blade support plate 60 at a portion corresponding to the position of the hole 55 of the protective cover 51,
Wind is forcibly generated as the protective cover 51 rotates.

In yet another embodiment, the protective cover 51 shown in FIG. 3 is eliminated, and the permanent magnet 53 and coil 54 are covered only with the skeletal rib 61 and the blade support plate 6o. In this example, it is preferable to attach the blades 62 to the blade support plate 60, but it is also conceivable that the blades 62 are not attached.

〔Effect of the invention〕

According to the present invention, by sending cooling air to the coil 54, which is the heat generation source of the magnetic disk drive motor 4o, it is possible to dissipate the heat that has conventionally been trapped in the core. and,
The amount of heat that was conventionally conducted to the bottom surface 6 of the chassis 1 via the control board 50 of the disk drive motor 40 can be reduced. As a result, off-track caused by thermal expansion of the chassis 1 or the disk 235 can be reduced, contributing to the provision of a more reliable magnetic recording/reproducing device.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the effects of the present invention, FIGS. 2 and 3 are views showing an embodiment of the present invention, and FIG. 4 is a perspective view of the entire disk drive motor as seen from the side opposite to the hub. 5 is a sectional view showing an embodiment of the entire magnetic recording/reproducing device, and FIG. 5 is a plan view showing the main parts of the entire device. 50... Control board, 51... Protective cover, 53...
・Permanent magnet, 54...coil, 55.56...hole,
60...feathers. Plate support plate, 61... rib, 62... feather.

Claims (1)

[Scope of Claims] 1. A disk drive device for a magnetic recording and reproducing device, characterized in that, in a flat type motor that rotationally drives a magnetic disk, cooling holes are provided in a protective cover that covers the outside of the rotor. 2. A disk drive device for a magnetic recording and reproducing device according to claim 1, characterized in that a blade is attached to a hole provided in a protective cover.