JPS61218344A - Disc-drive motor - Google Patents

Abstract

PURPOSE:To prevent torque loss and dust from being generated on the earthing section of a magnetic disc, by fitting a brush on the rotational center of a disc clamper to make the brush come in electrical contact with the end face of a shaft, and by arranging a flexible seal ring on the periphery. CONSTITUTION:On a disc drive motor providing a stator 16 and a rotor 15 between a disc clamper 7 for retaining a magnetic disc 6 and a shaft 2, and being rotatably and pivotally supported by two or more bearings 3, 4, a brush 12 is provided for the rotational central section of the disc clamper 7 via a brush suspension 11. An earth ball 13 is buried into the end face of the shaft 2, and is made to come in electrical contact with the brush 12. On the periphery of the contact section, a flexible seal ring 10 is arranged between a hub 5 and the disc clamper 7. As the result, torque loss is reduce, and the abrasion chip or the like on the brush 12 is not generated on the disc 6 side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disk drive motor, and more particularly to a disk drive motor having a characteristic motor structure for rotating a magnetic disk of a fixed magnetic disk device.

[Summary of the invention]

The present invention provides a disk drive motor with a built-in hub.
By electrically shorting the brush installed on the disk clamper and the shaft and arranging a seal ring between the disk clamper and the hub, the magnetic disk is electrically grounded and dust is removed from the magnetic disk. This prevents contamination and improves the reliability of the disk drive motor.

[Conventional technology]

A conventional disk drive motor with a built-in hub has a shaft 2 that is fitted and fixed to a motor frame 21, as shown in the cross-sectional view of the main part of a conventional disk drive motor in FIG.
2 is provided with at least two bearings, a first bearing 25 and a second bearing 24, and one or more magnetic disks 26.
The hub 25 to which the magnetic disk is mounted is rotatably supported around the shaft 220 by a first bearing 25 and a second bearing 24, and the magnetic disk 26 is mounted to the hub 25 at a predetermined interval by a disk spacer 28, and a disk damper 27 is mounted on the hub 25. At the same time that the magnetic disk 26 is fixed to the hub 25 using screws 29, a rotor yoke 50 is fixed to the inside of the hub 25, and a plurality of poles are arranged in the radial direction inside the rotor yoke 50. A separately magnetized rotor magnet 51 is fixed, and a stator core 52 fixed to the shaft 22 is disposed inside the rotor magnet 31 with an air gap in between.
A stator coil 55 is wound around the stator coil 5.
6 generates an electromagnetic torque between it and the rotor magnet 51, giving rotational driving force to the hub 25, and the second bearing 24 is connected to the hub 25 via the fixing ring 54.
A brush 55 fixed to the fixing ring 54 is electrically short-circuited to the commistator 36 fixed to the shaft 22, and the space between the hub 25 and the motor frame 21 is sealed by a magnetic fluid seal 57.

[Problems and Objectives to be Solved by the Invention] However, in the prior art as described above, static electricity generated due to friction between a magnetic disk and a magnetic head is removed by a commutator and a hub disposed near the shaft. By electrically short-circuiting and grounding the brushes installed on the sides, a decrease in reliability due to static electricity is prevented.A magnetic fluid seal is installed between the hub and the motor frame, and the disk clamper is connected to the magnetic disk. By bringing them into close contact, dust generated from the bearings, brushes, etc. is prevented from entering the magnetic disk side, but in this configuration, the torque loss due to contact between the brushes and the commistator is large. If the disks are not densely layered, there is a problem in that dust enters the magnetic disk side, significantly reducing the reliability of the magnetic disk device.

The present invention has been made in view of these problems, and includes:
The purpose is to provide a highly reliable disk drive motor that has a ground terminal for the magnetic disk with small torque loss, has a structure that prevents dust from entering the magnetic disk side.

[Failure to solve the problem]

The disk drive motor of the present invention is a disk drive motor in which a rotational driving force generating means for rotating the magnetic disk at a predetermined speed is disposed inside the hub to which one or more magnetic disks are attached. A shaft supported by at least two bearings and a brush supported by a brush suspension disposed approximately at the center of rotation of a disk clamper that fixes the magnetic disk to the hub are electrically short-circuited, and the hub is The disc clamper is characterized in that a flexible seal ring is disposed between the disc clamper and the disc clamper.

[Effect]

According to the above configuration of the present invention, the brush disposed approximately at the center of rotation of the disk clamper grounds static electricity generated between the magnetic disk and the magnetic head with an electric resistance so large that it can be almost ignored. The ground terminal can also be taken out from non-rotating parts such as the shaft or motor frame. In addition to a dust-proof seal using a magnetic fluid seal, a flexible seal ring is installed between the hub and the disc clamper, and when the disc clamper is screwed to the hub, the seal ring is pressed and the knob and disc clamper are pressed together. By bringing the discs into close contact with each other, dust generated from the bearings, brushes, etc. is prevented from entering from the disk clamper side to the magnetic disk side.

〔Example〕

FIG. 1 is a sectional view of a main part of a disk drive motor according to an embodiment of the present invention, in which a shaft 2 fitted and fixed to a motor frame 1 has a first bearing 6 and a second bearing 4. A hub 5, which is provided with at least two bearings and has one or more magnetic disks 6 mounted thereon, is rotatably supported around the shaft 2 by a first bearing 3 and a second bearing 4,
The magnetic disk 6 is attached to the knob 5 by the disk spacer 8.
By fixing the disk clamper 7 to the knob 5 using the screws 9, the magnetic disk 6 is simultaneously clamped and fixed to the hub 5, and at the same time, the first bearing 5 clamps its outer ring. A flexible ring-shaped seal ring 10 made of rubber or the like, which is disposed between the disk clamper 7 and the hub 5 on the outer periphery of the part fixed to the hub 5, becomes elastic-plastic due to the pressing force of the disk clamper 7. The disk clamper 7 and the hub are deformed into a tight seal over the entire circumference, and at the same time, a conductive brush suspension 11 such as a thin plate spring is installed approximately at the center of rotation of the disk clamper 7.
A brush 12 supported by the hub 5 is electrically grounded to the magnetic disk 6 and the shaft 2 by pressingly contacting the ground pole 15 fitted and fixed to the shaft 2 with an appropriate preload force. A rotor yoke 14 that constitutes a part of the magnetic circuit is fixed inside the rotor yoke 14 made of magnetic metal such as a yoke, and a rotor magnet 15 that is divided and magnetized into a plurality of poles in the radial direction is fixed inside the rotor yoke 14. A stator core 16 is disposed inside the rotor magnet 15 and has a plurality of slots fixed to the shaft 22 with a gap in the radial direction from the rotor magnet 15 and constitutes a part of the magnetic circuit. The coil is wound a plurality of times to form a multi-phase stator coil 17 according to the number of slots, and when the stator coil 17 is energized, an electromagnetic torque is generated between the rotor magnet 15 and the hub 25. The dust-proof seal in the lower part of the knob 5 constitutes a rotational driving force generation means for causing the knob 5 to rotate. 19 and the shaft 2 to prevent dust from entering the magnetic disk 6 side.

According to the configuration of the above embodiment, the brush 12 supported by the brush suspension 11 approximately at the center of rotation of the disk clamper 7 can be suppressed by the ground ball 15 with an appropriate preload force, and the magnetic disk 6 can be stably moved. Ground contact is possible, and since contact occurs near the center of rotation, there is almost no torque loss, vibration and noise due to contact can be reduced, and dust generation due to brush wear can be reduced. In addition, in order to prevent dust generated from brushes and bearings from entering the magnetic disk side, a flexible seal ring 10 is disposed between the disk clamper 7 and the knob 5, and is pressed into tight contact with the disk clamper 7. screw 9
The dust generating section is blocked from a nearby minute gap or a minute gap in the part of the disk clamper 7 that suppresses the magnetic disk 6, thereby preventing a decrease in the reliability of the magnetic disk device due to dust.

Furthermore, it is now possible to install the magnetic fluid seal 19 in the same position as the conventional brush, with the same allowable dimensions as before, and the torque loss due to the viscosity of the magnetic fluid can be significantly reduced. This simplifies the structure of the magnetic fluid seal part.

Note that FIG. 1 does not limit the present invention, and the present invention can be widely applied to disk drive motors that have a built-in hub and a non-rotating shaft.

〔Effect of the invention〕

As described above, according to the present invention, the torque loss due to the brush is reduced, vibration and noise are also reduced, the dust-proof seal by the seal ring prevents dust from entering the magnetic disk side, and the brush is attached to the upper surface of the hub. It is possible to improve space utilization efficiency and simplify the structure by arranging a seal ring and a magnetic fluid seal, which also reduces torque loss due to the magnetic fluid seal, and improves the reliability and power consumption of a disk drive motor with a built-in hub. It has the effect that it can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a disk drive motor showing an embodiment of the disk drive motor of the present invention. FIG. 2 is a sectional view of the main parts of a conventional disk drive motor. The names of the main parts in Figure 1 are as follows. 2... Shaft 5... First bearing 4... Second bearing 5 ■I Meno Pro... Magnetic disk 7... Disk clamper 10... Seal ring 11... Brush suspension 12.・Brush or more

Claims (1)

[Claims] In a disk drive motor in which a rotational driving force generating means for rotating the magnetic disk at a predetermined speed is disposed inside a hub to which one or more magnetic disks are mounted, the hub is supported by at least two bearings. A shaft that fixes the magnetic disk to the hub and a brush supported by a brush suspension disposed approximately at the center of rotation of a disk clamper that fixes the magnetic disk to the hub are electrically short-circuited to create a gap between the hub and the disk clamper. A disk drive motor characterized by a flexible seal ring.