JPH05161327A - Disk driving motor - Google Patents

Abstract

PURPOSE:To make it possible to miniaturize and thin a motor by arranging a structure in which the metal hub of a disk is directly chucked to the rotor yolk of a rotor by the magnetic attraction of the rotor magnets which drives the rotor to rotate. CONSTITUTION:The magnetic flux of rotor magnets 4 leaks from the holes 2 punched on the chucking surface of a rotor yolk 1. The metal hub 11 of a floppy disk 12 is attracted by this leaking magnetic flux to the chucking surface 1a and mounted. At this juncture, a shaft 9 is coupled to the central aperture of the metal hub 11, but a chucking pin 3 is biased downward. Then, when the motor is rotated in this state to bring the chucking pin to the aperture for positioning, the pin is extruded upward by the resiliency of a flat spring 3a to be inserted in a chucking pin coupling hole 11a for coupling. When further rotated, the chucking pin 3 is positioned in the part on the outer diameter side where no cutting it is biased in the direction is then in a state that it is biased in the direction opposite to the coupling hole 11a.

Description

Detailed Description of the Invention

 [Object of the Invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive motor having a chucking mechanism for directly attracting a metal hub of a disk to a chucking surface by utilizing a magnetic attraction force of a rotor magnet.

[0002]

2. Description of the Related Art A conventional disk drive motor has a structure in which an exclusive chucking magnet for attracting a metal hub of a disk is provided on an upper portion of a rotor yoke. Hereinafter, a conventional disk drive motor having a chucking magnet is
A case where the invention is applied to a 3.5-inch floppy disk drive will be described with reference to FIG.

Reference numeral 29 in the drawing denotes a shaft which engages with the metal hub 11 of the floppy disk 12 and is driven to rotate integrally with the floppy disk 12 at a predetermined rotational speed.
A chucking magnet 28 made of a ring-shaped permanent magnet is fitted to the upper end side position of the shaft 29 so that the upper end of the shaft 29 is slightly projected. The chucking magnet 28 has a metal hub 11 for the floppy disk 12.
Chucking pin engaging hole 11 for positioning provided in
The chucking pin 23 for engaging with a (see FIG. 3) for positioning the floppy disk 12 has a chucking pin insertion hole 28a penetrating in the axial direction so that one end thereof can be slightly projected from the chucking magnet 28. Perforated. On the other end side of the chucking pin 23, a leaf spring 23a which is a spring member for fixing one end projecting from the chucking magnet 28 in a projecting and retractable state is provided. Below the chucking magnet 28, a bottomed cylindrical rotor yoke 21 has a shaft 29 with its opening facing downward.
It is fitted and fixed to. On the lower surface of the rotor yoke 21, a ring-shaped rotor magnet 2 is divided and magnetized at equal intervals so as to alternate with N poles and S poles along the circumferential direction.
4 is provided by adhesion.

Below the rotor magnet 24, a plurality of stator coils 25 for driving a motor are circumferentially arranged at a position facing each other with a predetermined gap. 26 is installed. 27
Is a housing in which the printed wiring board 26 is engaged with a flange portion 27a which is cylindrical and is formed at a substantially central position, and the shaft 29 described above is inserted into the cylindrical inner diameter side of the housing 27. Reference numeral 30 is a bearing for engaging the shaft 29 on the inner diameter side and engaging the housing 27 on the outer diameter side for rotatably holding the shaft 29.
When a current is applied to the stator coil 25, the stator coil 25 is divided and magnetized at equal intervals along the circumferential direction, and torque is generated between the stator coil 25 and the rotor magnet 24 that is generating the field magnetic flux. It is configured to rotationally drive the mechanism.

In the conventional 3.5-inch floppy disk drive, the disk drive motor having the above-described structure is used to attract the metal hub 11 of the floppy disk 12 onto the upper surface of the chucking magnet 28, and the shaft 29 and The chucking pin 23 was used to position and rotate the floppy disk 12.

[0006]

In the conventional disk drive motor as described above, since the chucking magnet dedicated to chucking the metal hub of the disk is provided above the rotor yoke, the motor becomes thick in the axial direction. Sisters,
Nowadays, motors are required to be smaller and thinner, which causes problems.

Further, since the structure is provided with the chucking magnet, the number of parts is increased at the time of assembling the motor, and the assembling process is further increased. As a result, the manufacturing cost and the unit price of the product are increased. Become. [Constitution of Invention]

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above technical problems, and a metal hub of a disk is magnetically attracted to a rotor to be attracted thereto and driven to rotate. In a disk drive motor having a chucking mechanism, the metal hub of the disk is directly chucked on a rotor yoke of the rotor by a magnetic attraction force of a rotor magnet that drives the rotor to rotate. Is provided. Further, the present invention provides a disk drive motor characterized in that a hole is bored in a chucking surface of the rotor yoke, which is in contact with the metal hub of the disk.

[0009]

According to the present invention, the magnetic attraction force for chucking the metal hub of the disk is configured to utilize the leakage magnetic flux of the rotor magnet for rotationally driving the motor. Since the chucking magnet is not required, the motor can be thinned accordingly, and the number of parts and the number of steps can be reduced.

[0010]

EXAMPLE A disk drive motor according to the present invention will be described below.
An embodiment applied to an inch floppy disk drive will be described with reference to the drawings of FIGS. Reference numeral 9 in the drawing denotes a shaft which engages with the central hole 11b of the metal hub 11 of the floppy disk 12 and is integrally driven with the floppy disk 12 to rotate at a predetermined rotational speed. 1
Is a rotor yoke having a bottomed cylindrical shape and fitted and fixed at a central position in the vicinity of one end side (upper side) of the shaft 9. The rotor yoke 1 is formed separately into a disk-shaped portion having a predetermined distance in the radial direction from the center position and a ring-shaped step portion that is one step outward in the radial direction, and is one step close to the shaft 9. The high portion is used as a chucking surface 1a for chucking the metal hub 11 of the floppy disk 12 (see FIG. 2). As shown in FIG. 2, the chucking surface 1a has a plurality of holes 2
… Perforated concentrically, one of which is
A chucking pin 3 for positioning the floppy disk 12 is inserted by engaging a chucking pin engaging hole 2a (see FIG. 2) for positioning provided on the metal hub 11 of the floppy disk 12. The chucking pin 3 has one end side (upper side in the drawing) protruding from the rotor yoke 1, and the other end side (lower side in the drawing) is capable of protruding and retracting one end protruding from the rotor yoke 1. A leaf spring 3a is provided for maintaining the above. The leaf spring 3a is stretched on the back surface of the chucking surface 1a of the rotor yoke 1. The back surface of a portion of the rotor yoke 1 which is formed one step lower than the chucking surface 1a is divided and magnetized at equal intervals along the circumferential direction so as to alternate with N poles and S poles. A ring-shaped rotor magnet 4 for generating a magnetic flux is provided by adhesion. A part of the inner peripheral side of the rotor magnet 4 is formed so as to reach below the chucking surface 1a. And this rotor magnet 4
A part of the magnetic flux generated further leaks from the holes 2 formed in the chucking surface 1a.

A printed wiring board 6 having a plurality of rotationally driven stator coils 5 arranged in a circle is installed at a position below the rotor magnet 4 with a predetermined gap. The printed wiring board 6 is engaged with a flange portion 7a formed in an outer diameter direction at a substantially central position of a cylindrical housing 7, and a shaft 9 is inserted inside the cylindrical shape of the housing 7. .. Reference numeral 10 is a bearing that holds the shaft 9 rotatably by engaging the inner diameter side with the shaft 9 and the outer diameter side with the inner peripheral surface of the housing 7. Then, when a current is passed through the stator coil 5, the rotor coil 4 is divided and magnetized at equal intervals along the circumferential direction, and torque is generated between the rotor magnet 4 and the field magnetic flux. Is configured to drive the rotor yoke 1 provided with.

The operation of the disk drive motor of this embodiment will be described below. The magnetic flux of the rotor magnet 4 arranged inside the rotor yoke 1 leaks through the hole 2 formed in the portion of the rotor yoke 1 forming the chucking surface 1a. Due to this leakage magnetic flux, the metal hub 11 of the floppy disk 12 placed on the chucking surface 1a of the rotor yoke 1 is attracted and placed on the chucking surface 1a. At this time, the shaft 9 is engaged with the central opening formed at the central position of the metal hub 11. However, normally, the central opening portion is engaged with the shaft 9 as described above, the metal hub is sucked and mounted on the chucking surface 1a, and at the same time, the chucking pin 3 is engaged with the opening portion for positioning the metal hub. The chucking pins 3 are urged downward. Then, when the chucking pin 3 is moved to the positioning opening by rotating the motor in this state, the chucking pin 3 is projected upward by the elastic force of the leaf spring 3a, and the positioning is perforated in the metal hub 11. Is inserted into and engaged with the chucking pin engagement hole 11a. When the rotation progresses further,
As shown in FIG. 3, the chucking pin 3 is located on the outer diameter side of the chucking pin engaging hole 11a and in a portion having no notch. At this time, the shaft 9 inserted through the central hole 11b is in a state of being urged in the direction opposite to the chucking pin engagement hole 11a. In this way, the chucking pin 3 has the chucking pin engaging hole 11a for positioning.
, And the shaft 9 is urged toward the predetermined side of the central hole 11b to position the chucked floppy disk 12, and at the same time, the chucking pin 3 is rotated to move the floppy disk 12 together. The rotation drive of is started.

In the above embodiment, the leakage flux is obtained by forming the holes 2 concentrically in the portion where the chucking surface 1a of the rotor yoke 1 is formed, but it is limited to such a shape. However, by utilizing the magnetic attraction force of the rotor magnet 4 of the present invention, such as forming the rotor yoke 1 thin, forming the chucking surface 1a with a mesh member, and providing slits, If the disk drive motor has a structure in which the metal hub 11 of the floppy disk 12 is directly attached to the chucking surface 1a by suction, by implementing this, the same effect as that of the embodiment in which the holes 2 are concentrically provided is obtained. It is possible to get.

In the above embodiment, as shown in FIG.
Although the rotor magnet 4 is described as a flat ring-shaped one, it is not limited to this, and a step portion is formed along the shape of the rotor yoke 1 as shown in FIG. 4, and the back surface of the chucking surface 1a is formed. By using the rotor magnet 8 having a shape that reaches the above, it is possible to add a magnetic attraction force greater than the magnetic attraction force in the above-described embodiment to the metal hub 11 of the disk 12, and thus, similar to the above-described embodiment. The above effects can be achieved. However, the portion of the rotor magnet 8 located within the range of movement of the leaf spring 3a and the chucking pin 3 at this time needs to be provided with a notch so as not to hinder the movement.

Further, in the above embodiment, the spring member that allows the chucking pin 3 to project and retract is implemented by using the leaf spring 3a. However, the present invention is not limited to this, and, for example, the upper side of the rotor magnet 4 is used. The chucking pin 3 may be provided by fixing a spring or the like at a predetermined position, so that the chucking pin 3 may be pushed and retracted.

Further, in the above embodiment, the holes 2 perforated in the chucking surface 1a are arranged circumferentially, but the size, the perforation position, etc. are randomly set except for the chucking pin insertion hole 2a. It is also possible to carry out.

The present invention is not a disk drive motor that can be implemented only in the 3.5-inch floppy disk drive as in the above embodiment, but a method of chucking with a magnet such as a drive device for driving a magneto-optical disk. It is also possible to apply the chucking mechanism of the present invention as long as the disk is rotationally driven by utilizing.

[0018]

According to the disk drive motor of the present invention,
By providing a hole in the chucking surface of the rotor yoke, the leakage magnetic flux of the rotor magnet provided inside is used to attach the metal hub of the disk directly to the chucking surface provided on the rotor yoke. Since the disk drive motor itself can be thinned, it is easy to contribute to the size reduction and thinning of the applicable floppy disk drive.

Further, since the number of parts and the number of manufacturing steps in manufacturing the disk drive motor can be reduced,
It is possible to reduce the manufacturing cost and the like, and thus reduce the unit price of the applied disk drive device.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment.

FIG. 2 is a plan view of FIG.

FIG. 3 is a plan view of a metal hub of a floppy disk.

FIG. 4 is a vertical sectional view of another embodiment.

FIG. 5 is a vertical cross-sectional view of a conventional technique.

[Explanation of symbols]

 1 rotor yoke 1a chucking surface 2 hole 3 chucking pin 4 rotor magnet 11 metal hub 12 floppy disk

Claims (2)

[Claims] 1. A disk drive motor having a chucking mechanism for magnetically attracting and mounting a metal hub of a disk on a rotor to drive the rotor, wherein the magnetic attraction force of a rotor magnet for driving the rotor causes the magnetic hub to rotate. A disk drive motor, wherein the metal hub of the disk is directly chucked on a rotor yoke of a rotor. 2. A disk drive motor according to claim 1, wherein a hole is bored in a chucking surface of the rotor yoke which comes into contact with a metal hub of the disk.