JPS63274351A - Flat type motor - Google Patents

Abstract

PURPOSE:To shorten a motor in the axial direction, and to decrease the number of parts by arranging a chucking magnet to one part of a rotor yoke and using the plane section of the rotor yoke as a turntable. CONSTITUTION:When the position of a multipolar magnet 1 is detected by a phase changeover sensor 9 and currents are applied to a driving coil 8 by a driver circuit, force in the fixed direction is generated in the multipolar magnet 1, and a rotor section is turned in the fixed direction. The phase changeover sensor 9 detects the position of the multipolar magnet 1 in succession at that time, and currents are applied to the driving coil 8 from the driver circuit so as to continue revolution in the fixed direction. Consequently, when the rotor section continues revolution in the specified direction, the rotor section is pulled by a chucking magnet 2, and a disk 11 fixed to the plane section 4 of a rotor yoke 3 is also rotated. Accordingly, the plane section 4 of the rotor yoke 3 is employed as a turntable on which the disk 11 is loaded, thus shortening length in the axial direction of a motor, then largely decreasing manhours for assembling.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flat electric motor that has a planar facing multi-pole magnet and a drive coil and rotates a disk of audiovisual equipment or information equipment.

Conventional technology In recent years, tape recorders and video tape recorders.

2. Description of the Related Art In the field of audiovisual equipment such as compact display players, and information equipment such as floppy disk drives and optical recording devices, flat motors are often used as drive sources. With the miniaturization of these devices, there is a strong desire for flat electric motors to be lighter, thinner, and smaller.

An example of a conventional flat electric motor used in the above-mentioned □ equipment will be described below with reference to FIGS. 4 and 6.

FIG. 4 shows a cross section of a conventional flat type electric motor.

In FIG. 4, 31 is a multi-pole magnet, 32 is a rotor yoke, 33 is a shaft, 34 is a turntable, and 35 is a chucking magnet, which is magnetized in the thrust direction. The above multipolar magnet 31. Rotor yoke 32° shaft 33. Turntable 34.
The chucking magnet 35 constitutes a rotor section.

36.37 is a bearing. 38 is a drive coil fixed at a position facing the multipolar magnet 31 and formed of self-fused wire or the like in accordance with the magnetic pole shape of the multipolar magnet 31; 39;
is a phase switching sensor such as a Hall element. 40 is a stator section. Further, in order to drive the electric motor, a drive circuit is required in addition to this, but it is omitted because it is not directly related to the present invention.

FIG. 6 is a cross-sectional view showing a state in which a disk 41 is mounted on the flat electric motor of the conventional example. 42 is a hub made of a magnetic material, which is pulled by a chucking magnet 36 and fixed to the turntable 34. 43 is a recording section in which information is recorded. 44 records and reproduces information in the recording section 43;

This is the erasing head.

The operation of the flat electric motor configured as described above will be explained below.

The position of the multipolar magnet 31 is detected by the phase switching sensor 39, and a current is applied to the drive coil 38 by the drive circuit. When a current is applied to the drive coil 38, a rotation force is generated in the multipolar magnet 31 in a fixed direction according to Fleming's left-hand rule, and the rotor portion rotates in a fixed direction. At this time, the phase switching sensor 39 sequentially detects the position of the multipolar magnet 31, and a current is applied to the drive coil 38 from the drive circuit so that the drive coil 38 continues to rotate in a constant direction. When the rotor continues to rotate in a certain direction in this way, the turntable 34
The disk 41 fixed to the disk 41 also rotates, and information is recorded, reproduced, and erased in the recording section 43 by the head 44.

Problems to be Solved by the Invention However, in the above configuration, the turntable 34 is required to mount the disk 41, the electric motor is long in the axial direction, and the number of parts increases. Further, there is a problem in that the number of man-hours required for fitting the turntable 34 to the shaft 33 increases.

In view of the above problems, the present invention shortens the electric motor in the axial direction,
Furthermore, the present invention provides a flat electric motor with a simple structure that reduces the number of parts and production man-hours.

Means for Solving the Problems In order to solve the above-mentioned problems, a flat type electric motor according to a first aspect of the invention described in claim 1 is provided with A recessed portion for attaching a chucking magnet is formed in the rotor yoke, and the chucking magnet is disposed within the recessed portion, and the flat portion of the rotor yoke serves as a turntable.

On the other hand, in the flat electric motor of the second invention described in claim 2, a recess for mounting a chucking magnet is formed on the inner peripheral side of the rotor yoke, and the chucking magnet is disposed within this recess. A flat part serving as a turntable is formed around the recessed part, and the rotor yoke has a slope that increases from the inner circumferential side to the outer circumferential side of the stator part.

Operation In both the first invention and the second invention, with the above-described configuration, the rotor yoke also serves as a turntable on which the disk is mounted, so a separate part called a turntable is not required, the electric motor can be shortened in the axial direction, and furthermore, the number of parts is reduced. The number of points and the number of man-hours for assembling the flat electric motor, which involves fitting the turntable to the shaft, can be significantly reduced, resulting in lower costs and superior mass productivity.

Furthermore, in the second invention, the information signal is recorded by tilting the rotor yoke from the flat part of the rotor yoke, which becomes the turntable, to the outer circumferential part of the rotor yoke with a slope toward the stator part.
This makes it possible to reduce the axial length of the flat electric motor while dealing with the case where there are two heads for reproducing and erasing the disk.

EXAMPLES Hereinafter, examples of the first invention will be described with reference to the drawings. FIG. 1 shows a cross section of a flat electric motor in an embodiment of the first invention.

In Fig. 1, 1 is a multipolar magnet with multipolar magnetization, 2
is the chucking magnet, 3 is the rotor yoke,
A recess 3a is formed on the inner circumferential side for attaching the chucking magnet 2.

Reference numeral 4 designates an upper flat portion of the rotor yoke 3, and this portion serves as a turntable on which a disk is mounted.

6 is a shaft. The above multipolar magnet 1. Chucking McNett 2. Rotor yoke 3. The shaft 5 constitutes a rotor section. 6.7 is a bearing. Reference numeral 8 denotes a drive coil formed of a self-fused electric wire in accordance with the magnetic pole shape of the multipolar magnet 1 fixed at a position facing the multipolar magnet 1, and 9 a phase switching sensor using a Hall element. 1° is the stator portion. FIG. 2 is a sectional view showing a state in which the disk 11 is mounted on the flat motor of this embodiment. A hub 12 is made of magnetic stainless steel, and is pulled by the chucking magnet 2 and fixed to the flat part 4 of the rotor yoke 3. 13 is a recording section in which information is recorded. 14 records and reproduces information in the recording unit 13;

This is the erasing head.

The operation of the flat electric motor configured as described above will be described below.

The position of the multipolar magnet 1 is detected by the phase switching sensor 9, and a current is applied to the drive coil 8 by the drive circuit.

When a current is applied to the drive coil 8, a rotation force is generated in the multipolar magnet 1 in a fixed direction according to Fleming's left-hand rule, and the rotor portion rotates in a fixed direction. At this time, the phase switching sensor 9 sequentially detects the position of the multipolar magnet 1, and a stain current is applied to the drive circuit so that the drive coil 8 continues to rotate in a constant direction. When the rotor section continues to rotate in a certain direction in this manner, the disk 11, which is pulled by the chucking magnet 2 and fixed to the flat surface section 4 of the rotor yoke 3, also rotates, and the recording section 1 is transferred to the head 14.
Information is recorded and played back in 3.

will be deleted.

As described above, according to this embodiment, the recess 3a is formed on the inner peripheral side of the rotor yoke 3, the chucking magnet 2 is attached to the recess 3a, and the flat part 4 serves as a turntable on which the disk 11 is mounted. The axial length of can be shortened. Furthermore, by simply fitting the rotor yoke 3 to the shaft, the number of man-hours for assembling the electric motor can be significantly reduced.

Next, an embodiment of the second invention will be described with reference to the drawings. FIG. 3 is a sectional view showing a state in which a disk is mounted on a flat electric motor according to an embodiment of the second invention.

In FIG. 3, 16 is a multipolar magnet, 16 is a chucking magnet, and 17 is a rotor yoke.
7a is formed. Reference numeral 18 designates an upper flat portion of the rotor yoke 17, and this portion serves as a turntable on which the disk 26 is mounted. 19 is an inclined portion. 2° is the shaft. The above multipolar magnet 16. Chucking magnet 16. The rotor yoke 17° shaft 20 constitutes a rotor portion. 21° and 22 are bearings. 23 is a drive coil fixed at a position facing the multipolar magnet 16 and formed of a self-fused wire to match the magnetic pole shape of the multipolar magnet 15; 24 is a phase switching sensor using a Hall element. 26 is a stator section. 26 is a disk. A hub 27 is made of magnetic stainless steel, and is pulled by the chucking magnet 16 and fixed to the flat part 18 of the rotor yoke 17. 28
is a recording section in which information is recorded. Numerals 29 and 30 are heads for recording, reproducing, and erasing information in the recording section 28, and two heads 29 and 30 are attached to sandwich the disk 26.

These are used to separately record, reproduce, and erase information on the top and bottom surfaces of the recording section 28 of the disk 26.

The operation of the flat electric motor configured as described above is described in this first article.
Since this is the same as the embodiment of the invention, the description will be omitted.

As described above, according to this embodiment, by providing the rotor yoke 17 with the inclined portion 19, even if there are two heads 29 and 28, the same effect as in the first embodiment can be obtained.

In the embodiment of the first invention, the concave portion of the rotor yoke 3 is formed on the inner circumferential side, but it may be formed on the outer circumferential side or the middle circumferential side.

Further, in the embodiments of the first and second inventions, the disks 11.26 are directly attached to the flat parts 4, 18 of the rotor yokes 3, 17.
However, thin rubber or the like may be attached to the flat parts 4, 18 to prevent the flat parts 4, 18 and the hub 12, 27 from slipping when the rotation of the electric motor is accelerated or decelerated. In addition, although the disks 11.26 are aligned with the motor rotor yokes 3, 17 using the shirts 5, 20, the flat portions 4° 1 of the rotor yokes 3, 17
In order to position the hubs 12, 27, the hubs 12, 27 may be provided with a spigot process.

Effects of the Invention As described above, since the first invention has the above configuration, it has the following effects.

(1) There is no need for a turntable for mounting the disk as in the past, and the axial length of the motor can be shortened by the length of the turntable.

(2) The turntable can be omitted and the number of parts can be reduced.

(3) The number of steps needed to assemble the turntable and shaft can be reduced, reducing costs and improving mass productivity.

Since the second invention has the above configuration, it has the unique effect that it can be applied even when there are two heads for recording, reproducing, and erasing information signals sandwiching a disk, and it also has the same effect as the first invention (1). , (2>, (3)).

[Brief explanation of drawings]

FIG. 1 is a sectional view of a flat motor according to an embodiment of the first invention, FIG. 2 is a sectional view showing a disk mounted on the flat motor according to an embodiment of the first invention, and FIG. 3 is a sectional view of the flat motor according to an embodiment of the first invention. A sectional view showing a disk mounted on a flat motor according to an embodiment of the second invention, FIG. 4 is a sectional view of a conventional flat motor, and FIG. 6 is a sectional view showing a disk mounted on a conventional flat motor. FIG. 3 is a sectional view showing a mounted state. 1.15...Multi-polar magnet, 2,16...
...Chucking magnet, 3,17...
Rotor yoke, 3a, 17a... recess, 4, 1
8... Flat part, 8.23... Drive coil, 19... Inclined part.

Claims (2)

[Claims] (1) In a flat electric motor consisting of a rotor part having a multipolar magnet, a chucking magnet, and a rotor yoke, and a stator part having a drive coil, a recessed part for attaching the chucking magnet is formed in a part of the rotor yoke. A flat electric motor characterized in that a chucking magnet is disposed within the recess, and the flat surface of the rotor yoke is configured to function as a turntable. (2) In a flat electric motor consisting of a rotor portion having a multipolar magnet, a chucking magnet, and a rotor yoke, and a stator portion having a drive coil, a recessed portion for attaching the chucking magnet is formed on the inner circumferential side of the rotor yoke. The chucking magnets are arranged in the concave part of the lever, a flat part serving as a turntable is formed around this concave part, and the rotor yoke is configured to have a slope from the inner circumferential side to the outer circumferential side toward the stator part. A flat electric motor characterized by: