JPH0677368B2 - Recording disk support and drive - Google Patents

Abstract

The support and drive mechanism includes a cylindrical rotor (20) constituting a magnetic shield and a mechanical support for multiple hard discs (31) fixed on the external face (25) of the rotor. A fixed central shaft (1) supports the emergency mechanical bearings (14,15) and the stators (61,62,71,72) of two active radial magnetic bearings (60,70) together with the stator (50,51) of an electric motor (50) placed between the two bearings. The rotor (20) has, on its internal face, laminated armatures (53,63,73) forming the rotor armatures of the electric motor and the two magnetic bearings. The bearings are servo-controlled in response to radial and axial position transducers (80,90). ADVANTAGE - Allows increase in density of date which can be stored on fixed hard disc through better position control.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention Industrial Field of the Invention The present invention relates to an apparatus for supporting and driving a storage disk in a computer.

<Prior Art> A storage hard disk in a computer is generally arranged on a mandrel supported by a central shaft by a ball bearing, and is driven by an external electric motor through a transmission means such as a belt. .

In a conventional storage disk device in a computer, the size of the device is considerably increased by using an electric drive motor separately from the disk support device, and in addition, it occurs with the rotation of a ball bearing. There is a problem that the density of the tracks for storing information on the disk cannot be sufficiently increased due to the error of the circularity of rotation.

<Problems to be Solved by the Invention> In view of such problems of the conventional technology, the main object of the present invention is to provide a small size, high reproduction fidelity, and accuracy,
It is an object of the present invention to provide a device for supporting and driving a storage disk in a computer which is compatible with various types of disks and which can increase the density of information that can be stored on a single disk. .

[Summary of the Invention] <Means for Solving the Problems> According to the present invention, such a purpose is to form a magnetic shield, and a drum type for mechanically supporting a computer storage hard disk on its cylindrical outer peripheral surface. And a fixed central shaft supporting the auxiliary mechanical bearings and the stators of the first and second active radial magnetic bearings, the stator of the electric motor having the first and second radial magnetic bearings. And a rotary armature of the first and second radial magnetic bearings is provided on the cylindrical inner circumferential surface of the drum-shaped rotor that is disposed between the stators. It is achieved by providing a device for

<Operation> As described above, by disposing the driving electric motor inside the drum-shaped rotor that supports the disk, the apparatus can be downsized. The magnetic shield effect obtained by using the drum type rotor exerts a protective function against the influence of the electric motor or the magnetic bearing on the information recorded on the storage disk. By using an active magnetic bearing device, the rotational accuracy of the disk is improved,
In particular, the deviation of the circularity of rotation of the disc can be made regular rather than random, and therefore the density of the recording tracks can be increased without causing intersections between the recording tracks of the disc.

Further, regardless of whether the storage medium of the magnetic disk is magnetic or optical, the storage density can be greatly improved.

According to an embodiment of the invention, at least one thrust bearing controlled by at least one sensor for detecting the axial displacement of the rotor and at least two sensors for detecting the radial position of the rotor. Radial magnetic bearings are provided.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The embodiment shown in FIG. 1 is intended to rotatably support and drive a computer storage disk 31, for example a magnetic hard disk, with an outer casing 13 for protecting the disk. However, only one half of the cross section of FIG. 1 is shown. The fixed outer casing 13 is itself supported on the fixed central shaft 1.

The fixed central shaft 1 includes stators 61, 62 and 71, 72 of two radial magnetic bearings 60, 70 and a stator 5 of an electric motor 50 for rotating a rotor 20 in a bell or drum shape.
Supports 1, 52 and. The central support shaft 1 further comprises two auxiliary compensatory ball bearings 1 for supporting the rotor 20 only when the magnetic bearings are not working or have failed.
Supports four and fifteen. The play of the ball bearings 14 and 15 is about half of the air gap of the magnetic bearings 60 and 70.

The bell-shaped rotor 20 has an end plate 23 that defines an end surface, and an outer peripheral wall 25 that defines a cylindrical outer peripheral surface that supports the storage disk 31. The cylindrical inner peripheral surface of the rotor 20 has rotating armatures 63, 73 of the radial magnetic bearings 60, 70.
And a rotating armature 53 of the electric motor 50 is supported. Rotating armatures 63, 73, 53 and bearings 60, 70
The cores 61, 71, 51 of the stator of the motor 50 are composed of laminated iron plates. In FIG. 1, reference numerals 62, 72, 52
Shows the magnetic bearings 60, 70 and the stator coils of the electric motor 50.

As shown in FIG. 1, active magnetic bearings 60, 70
Defines two conical surfaces, that is, the magnetic gap defined by the two magnetic bearings 60 and 70 is inclined with respect to the central axis of the rotor 20. Each of the magnetic bearings 60 and 70 has the functions of both a radial bearing and a thrust bearing, and does not require an auxiliary thrust bearing.
The structure of the device can be miniaturized.

Each active magnetic bearing 60, 70 is provided with a displacement sensor 80, 90, provided to measure the radial displacement (sensor 80, 90) or axial displacement (sensor 100) of the rotor 20 relative to the fixed central support shaft 1. It is controlled by an electronic circuit that receives a signal from 100, and always responds to the required electromagnetic force of the stator of the magnetic bearings 60 and 70 in order to keep the angular displacement of the rotor 20 stable regardless of the mechanical load applied to it. Coil 62,
Adjusts the strength of the current applied to 72. Magnetic bearing 60, 70
The circuit itself for controlling the circuit may be of a known type and is not shown in the drawing. Sensor 80,
The connecting lines between the 90, 100 and the coils of the stators 62, 72 of the magnetic bearings 60, 70 and other parts of the control circuit are the central support shaft 1
Connected to an electronic control circuit which extends inside the axial passage 11 and the sleeve 10 as an extension of the passage and which may be spaced from the device for supporting the disc. It is connected to the connection terminal 12 for. Connection lines for the electric current applied to the coils of the stator 52 of the motor 50 are also arranged inside the passage 11 and the sleeve 10.

The storage disk 31 in the computer is provided with a central opening for engaging the outer periphery of the rotor 20 and being fixed thereto. The disk 31 is fixed onto the rotor 20 by a shoulder surface 21 provided on the outer peripheral surface of the bell-shaped rotor 20 and a removable ring 22 facing the end plate 23 of the rotor 20.

As shown as head assembly 40, two read heads 41, 42 are disposed on each side of disk 31. Each head 41, 42 may be of a type known per se and the use of magnetic bearings does not cause any modification to the structure of such a read head 41, 42. However, the use of magnetic bearings not only improves the accuracy of the rotational movement of the rotor 20 with respect to the central support shaft 1, but is also a reference fixed to the rotor 20 and cooperating with the position sensors 80, 90, 100. The error in the circularity of rotation of the rotor 20, which is caused by the error in the circularity of the rings 83, 93, and 103, can be made to have an accurate regularity as the rotor 20 rotates.

Further, even if the information recording tracks of the disk 31 are not perfectly circular, even if the tracks are arranged so as to be close to each other as the rotor 20 rotates, they do not intersect with each other. Further, the magnetic field between the magnetic bearings 60, 70, the drive motor 50 and the sensors 80, 90, 100 provided inside the bell-shaped rotor 20 and the disk 31 as a storage medium provided outside thereof. Since it functions as a shield, each disk can be
It is possible to increase the density of the information recorded in 31.
Further, the rotation speed of the disk can be increased as compared with the case where the ball bearing is used, and as a result, the time required for accessing information can be significantly reduced.

FIG. 3 shows a modified embodiment of the disk supporting and driving device according to the present invention, in which parts corresponding to those in the above embodiment are designated by the same reference numerals. Since the active magnetic bearings 60 and 70 have a cylindrical shape and do not have a conical surface, they act only in the radial direction. The radial bearings 60, 70 are controlled only by signals from the radial direction sensors 80, 90. With respect to the axial direction, two active thrust magnetic bearings 65, 75 are arranged on both end faces of the rotor 20, which are based on the information obtained from the axial displacement sensor 100. Allows 31 positioning.

[Brief description of drawings]

FIG. 1 is a partial cutaway side view of a first embodiment of an apparatus for supporting and driving a storage disk in a computer according to the present invention. FIG. 2 is a plan view showing the apparatus shown in FIG. 1 in a reduced scale with the outer casing omitted. FIG. 3 is a view similar to FIG. 1 showing a second embodiment of the device according to the invention. 1 …… Fixed center support shaft 10 …… Sleeve 11 …… Axial passage 12 …… Connecting terminal 13 …… Outer casing 14,15 …… Auxiliary bearing 20 …… Rotor 21 …… Shoulder 22 …… Ring 23… … End plate 25 …… Outer peripheral wall 31 …… Disk 40 …… Assembly 41, 42 …… Head 50 …… Motor 51 …… Stator 53 …… Armature 52 …… Coil 60 …… Radial magnetic bearing 61 …… Stator 62… … Coil 63 …… Armature 70 …… Radial magnetic bearing 71 …… Stator 72 …… Coil 73 …… Armature 80 …… Radial displacement sensor 83 …… Reference ring 90 …… Radial displacement sensor 93 …… Reference ring 100 …… Thrust Displacement sensor 103 ... Reference ring

Claims (5)

[Claims] 1. A drum-shaped rotor that forms a magnetic shield and mechanically supports a computer storage hard disk on its cylindrical outer peripheral surface, an auxiliary mechanical bearing, and first and second active radial magnets. A stationary central axis for supporting the stator of the bearing, the stator of the electric motor is disposed between the stators of the first and second radial magnetic bearings, and the drum-shaped cylindrical inner circumference of the rotor A surface is provided with said electric motor and a rotating armature of said first and second radial magnetic bearings. 2. The first and second radial magnetic bearings,
The control unit is provided along at least one conical surface and is controlled by at least two sensors for detecting a radial position of the rotor and at least one sensor for detecting an axial position of the rotor. 1. The device according to 1. 3. Further comprising at least one thrust bearing controlled by at least one sensor for detecting an axial position of said rotor, wherein said first and second radial magnetic bearings are arranged in a radial direction of said rotor. Device according to claim 1, characterized in that it is controlled by at least two sensors for detecting position. 4. The apparatus according to claim 1, wherein the computer storage hard disk is an optical storage disk. 5. The apparatus according to claim 1, wherein the computer storage hard disk is a magnetic storage disk.