JPH02193559A - Magnetic disc device - Google Patents

Abstract

PURPOSE:To thin a motor by a method wherein a magnetic disc is attached to the upper end of the rotary shaft of a rotor in a housing, the lower end of the rotary shaft is projected out of the housing and magnets are opposed to the coils of a control base plate outside of the housing. CONSTITUTION:A flange 1 is engaged with a base 2 forming a housing and supports a rotary shaft 9 rotatably through a bearing 8 attached to the central part of the flange. A disc 12 is turned by a hub 10 and a clamp 11 at the upper end of the rotary shaft 9 to read and write a record by a head DH. The lower end of the rotary shaft 9 is projected from the flange 1, forming the housing, and is connected to a rotor 14a equipped with magnets 15. The magnets 15 are opposed to coils 4, provided on a control base plate 16a outside of the housing. A magnetic sensor 5 is also attached to the control base plate 16a. According to this method, wiring for the coil 4 is facilitated and a spindle motor can be thinned.

Description

Detailed Description of the Invention "Field of Industrial Application" This invention relates to magnetic disk drives, and in particular to magnetic disk drives that improve the electrical characteristics of a spindle motor and also reduce the thickness and cost of the motor. Regarding equipment.

"Prior Art" FIG. 3 is a sectional view showing a spindle motor, which is a component of a conventional magnetic disk device. In this figure, 1
is a flange, the peripheral edge of which is fixed to a housing (not shown) via the base 2. A substrate 3 is attached to the lower surface of the flange 1. A coil 4 and a magnetic sensor 5 for detecting rotation are attached to the lower surface of the substrate 3. Further, the board 3 is equipped with FPC (Flexible P
A cable 6 is attached, through which power is supplied from the outside and the output of the magnetic sensor 5 is supplied to the outside. A connector 7 is attached to the tip of the cable 6. Next, the above-mentioned flange 1
A shaft 9 is rotatably attached via a bearing 8 to a through hole formed in the center of the shaft. A hub 10 is attached to the upper end of the shaft 9, and a magnetic disk 12 is held between the hub 10 and a clamp 11, and is tightened with a screw 13. On the other hand, a rotor 14 is attached to the lower end portion of the shaft 9. A magnet 15 is attached to the upper surface of the rotor I4. The above-mentioned flange 11 substrate 3, coil 4
, the magnetic sensor 5, the FPC cable 6, the connector 7, the bearing 8, the shaft 9, the hub 10, the clamp II, the magnetic disk I2, the screw 13, the rotor 14, and the magnet 15 constitute a spindle motor. Next, the code DH,
DH is a disk head, which is disposed opposite to each other with the magnetic disk 12 interposed therebetween. In this figure, the head mechanism for reading and writing information to and from the magnetic disk I2 by the disk heads DH and DH is omitted. A control board 16 controls the spindle motor, head mechanism, etc., and is arranged below the spindle motor as shown. A connector 17 is provided on the top surface of this control board 16.
is installed. In this case, the connector 7 of the nine FPC cables 6 pulled out from the above-mentioned board 3 is connected to the connector 17.

In the spindle motor configured in this way, when the power switch (not shown) is turned on, the control board 1
Power is supplied to the spindle motor from 6. As a result, current flows through the coil 4 of the motor, causing the rotor 14 to rotate, and the magnetic disk 12 to rotate accordingly.

"Problem to be Solved by the Invention" By the way, in the conventional spindle motor described above, since the substrate 3 is provided between the flange 1 and the magnet 15, it is difficult to form the motor itself thin and small. was difficult. In addition, a connection means such as an FPC cable 6 is provided between the board 3 and the control board 16 in order to supply power to the coil 4 and the magnetic sensor 5 via the board 3, but this may break. It is easy to cause poor contact, and it is also difficult to reduce costs due to the necessity of these.

This invention has been made in view of the above-mentioned circumstances, so that it is possible to reduce the thickness and size of the spindle motor.
Furthermore, it is an object of the present invention to provide a magnetic disk device that can reduce disconnections and contact failures and also reduce costs.

"Means for Solving the Problems" The present invention includes a magnetic disk provided in a housing, a head mechanism provided in the housing for reading and writing information on the magnetic disk, and a head mechanism located outside the housing and configured to read and write information on the magnetic disk. a control board provided to control the head mechanism; a rotating shaft having one end attached to the magnetic disk so as to rotate the magnetic disk and the other end protruding outside the housing; and the rotating shaft. A magnet provided on the control board, and a coil provided on the control board so as to face the magnet and apply rotational force to the magnet.

"Operation" According to the above configuration, a magnet is provided at the other end of the rotating shaft,
A coil is provided on a surface of the control board located outside the housing that faces the magnet. This eliminates the need to provide a coil or the like in the spindle motor itself, making the motor thinner and smaller.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing a spindle motor constituting a magnetic disk device according to an embodiment of the present invention. In addition,
In this figure, parts common to those in FIG. 3 described above are given the same reference numerals and their explanations will be omitted.

In this figure, 14a is a rotor, and a magnet 15 is attached to the lower surface of the rotor. Reference numeral 16a denotes a control board, and a coil 4 and a magnetic sensor 5 are respectively attached to the upper surface of the control board so as to face the magnet 15. Further, the control board 16a is provided with a drive circuit having a function of supplying power to the coil 4 and the magnetic sensor 5, a function of processing an output signal of the magnetic sensor 5, and a function of controlling the head mechanism. Here, FIG. 2 is a perspective view showing the control board 16a and the housing 18 in which all the components of the spindle motor except for the control board 16a are housed.As shown in this figure, the control board 16a is It is arranged outside the housing 18, and a coil 4 and a magnetic sensor 5 are attached to the upper surface thereof. Note that the reference numeral 19 shown in this figure is a cable for connecting the disk heads DH, DH and the control board 16a.

In this way, by separating the coil 4, magnetic sensor 5, and board 3 for supplying power, etc. to these of the conventional spindle motor (see FIG. 3) and providing them on the control board 16a, the flange I can be There is no need to form it according to the size of the rotor 14a. Therefore, since the flange l can be made small, the rigidity of the bearing 8 and the shaft 9 can be increased. Furthermore, by removing the substrate 3 from the flange 1, it becomes unnecessary to adjust the flange 1 to the size of the rotor 14a, and the rotor 14a itself can be increased in size. In this case, by enlarging the rotor 14a, a high torque spindle motor can be designed. Also, coil 4
Since the magnets 15 and 15 are exposed above the surface, maintenance thereof becomes easier. Also, the magnet 15 is connected to the rotor 1.
Since it is provided on the lower surface of the magnet 4a, the influence of the magnetic flux generated from the magnet 15 on the magnetic disk 12 is reduced.
Measures against leakage magnetic flux become unnecessary.

"Effects of the Invention" As explained above, according to the present invention, there is a magnetic disk provided in a housing, a head mechanism provided in the housing for reading and writing information on the magnetic disk, and a head mechanism located outside the housing. a control board provided to control the head mechanism; a rotating shaft having one end attached to the magnetic disk and the other end protruding outside the housing to rotate the magnetic disk; Since it includes a magnet provided on the rotating shaft and a coil provided on the control board to face the magnet and apply rotational force to the magnet, the spindle motor itself can be made thin and small. Become.

Further, there is no need for a cable or the like that connects the board provided on the spindle motor itself and the control board of the motor as in the past, so that disconnections and poor connections do not occur.

Furthermore, since this connecting means is not required, costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a perspective view of the same embodiment, and FIG. 3 is a cross-sectional view showing a portion of a conventional magnetic disk. l...flange, 3...board, 4...
...Coil, 5...Magnetic sensor, 6...
...FPC cable, 7.17...Connector, 9...Shaft (rotating axis), 14a...
...Rotor, 15... Magnet, 16a...
...Control board, 18...Housing.

Claims (1)

[Claims] A magnetic disk provided in a housing, a head mechanism provided in the housing to read and write information on the magnetic disk, and a control board provided outside the housing to control the head mechanism. , a rotating shaft having one end attached to the magnetic disk so as to rotate the magnetic disk and the other end protruding outside the housing; a magnet provided on the rotating shaft; and a rotating shaft provided on the control board. , and a coil provided to face the magnet and apply rotational force to the magnet.