JPH067500Y2 - Floppy disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a floppy disk drive (hereinafter referred to as FDD), and more particularly to a direct drive motor (hereinafter, referred to as FDD) having a rotating shaft supported by a metal bearing. An FDD that drives a floppy disk by a DD motor)
Regarding

(Prior Art) An FDD having a DD motor as a drive source is a third conventional one.
It was configured as shown. In the drawing, a housing 2 for accommodating a bearing is attached to a substrate 1, and a metal bearing 4 and a ball bearing 5 that rotatably support a rotating shaft 3 are coaxially fixed to the housing 2. A rotor 6 is concentrically fixed to the lower end of the rotary shaft 3, and a ring-shaped coil 7 and a main magnet 8 are concentrically provided on the lower surface of the substrate 1 and the upper surface of the rotor 6, respectively. The rotary shaft 3, the rotor 6, the coil 7, and the main magnet 8 constitute a DD motor. Further, the outer peripheral portion of the rotor 6 has a frequency for detecting the rotational speed of the DD motor.
A generator magnet (hereinafter referred to as FG magnet) 9 is provided, and an iron plate 10 for forming a magnetic circuit with the main magnet 8 and the FG magnet 9 is provided on the upper surface of the substrate 1.

In the conventional FDD configured as described above, the rotary shaft 3 of the DD motor that rotationally drives the floppy disk is supported by the metal bearing 4 and the ball bearing 5, and the metal shaft between the metal bearing 4 and the rotary shaft 3 is supported. Is a gap of several μm
11 had been formed. Therefore, the rotating shaft 3 may move by the distance of the gap 11 when the DD motor is rotated or when an external force such as vibration or impact is applied, which causes a problem of tracking deviation of the FDD. .

(Problems to be Solved by the Invention) As described above, in the conventional FDD, since the rotating shaft of the DD motor is supported by the metal bearing, a gap is generated between the rotating shaft and the metal bearing, and the DD motor There is a problem that the rotation axis moves by the amount of the gap when the external force such as the rotation of the device is applied or the external force such as the vibration or the shock is applied, and the tracking deviation of the FDD occurs. Therefore, the present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an FDD capable of preventing the occurrence of tracking deviation because the rotating shaft supported by the metal bearing does not move.

[Structure of the Invention] (Means for Solving Problems) The present invention is a standard for positioning a housing fixed to a substrate and a floppy disk rotatably supported in the housing through a metal bearing and a ball bearing. Of the rotating shaft, a rotor fixed to one end of the rotating shaft and having a main magnet fixed thereto, a rotation speed detecting magnet fixed to the outer periphery of the rotor, the rotation speed detecting magnet and the main magnet. A magnetic plate provided on the substrate for forming a magnetic path therebetween, and a part of the position on the substrate facing the rotation speed detection magnet,
A magnetic member for attracting the rotation speed detecting magnet is provided.

(Operation) According to such a configuration, the rotor is always attracted by the magnetic member provided on a part of the substrate through the rotation speed detecting magnet, and therefore the rotor rotates while being inclined. As a result, the rotary shaft is pressed against a certain portion of the metal bearing. Therefore, the position of the rotating shaft cannot be displaced unless a force larger than the attraction force between the rotating speed detecting magnet and the magnetic member is applied to the rotating shaft.

Embodiment An embodiment of the FDD according to the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the present invention. In the figure, parts that are the same as or equivalent to those in the conventional example shown in FIG. The feature of this embodiment is that a magnetic member 12 having a larger attraction force with the FG magnet 9 than the iron plate 10 is provided in a part of the substrate 1 at a position facing the FG magnet 9 provided on the outer circumference of the rotor 6. .

Next, the operation of this embodiment will be described. The rotor 6 is attracted to the magnetic member 12 via the FG magnet 9, and the magnetic member 12
Is tilted in the direction in which is provided. As a result, the upper portion of the rotary shaft 3 fixed to the rotor 6 in the right angle direction is pressed against a certain portion of the metal bearing 4. Therefore, the rotating shaft 3 is a metal bearing 4
It does not move in the gap 11 between the rotary shaft 3 and the rotary shaft 3, and is held at a fixed position.

According to the present embodiment, since the rotary shaft 3 is always in contact with a certain portion of the metal bearing 4 by the attractive force of the FG magnet 9, unless the rotary shaft 3 receives a force larger than this attractive force, The position does not move, and it is possible to prevent the deviation of the tracking of the FDD.

As described above, according to the present invention, the attraction force of the FG magnet provided on the rotor of the DD motor of the FDD causes the rotor to be attracted to the magnetic member provided on a part of the substrate to incline the rotor. Since the rotating shaft fixed to is pressed against a certain part of the metal bearing, the position of the rotating shaft does not move unless a force larger than the attractive force of this FG magnet is applied, and the tracking displacement of the FDD. Can be prevented.

[Brief description of drawings]

1 is a vertical sectional view showing an embodiment of an FDD according to the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a vertical sectional view showing a conventional FDD. DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Housing 3 ... Rotating shaft, 4 ... Metal bearing 5 ... Ball bearing, 6 ... Rotor 7 ... Coil, 8 ... Main magnet 9 ... FG magnet, 10 ... Iron plate (magnetic plate) 12 ... Magnetic member

Claims (2)

[Scope of utility model registration request] 1. A housing fixed to a substrate, a rotary shaft for locating a floppy disk rotatably supported in the housing through a metal bearing and a ball bearing, and fixed to one end of the rotary shaft. A rotor to which a main magnet is fixed, a rotation speed detecting magnet fixed to the outer periphery of the rotor, and a magnetic path between the rotation speed detecting magnet and the main magnet are provided on the substrate. A floppy disk drive, wherein a magnetic plate and a magnetic member for attracting the rotation speed detection magnet are provided at a part of a position facing the rotation speed detection magnet on the substrate. 2. The utility model registration claim wherein the magnetic member attracts the rotational speed detecting magnet by a force greater than the magnetic plate attracts the rotational speed detecting magnet. The floppy disk drive device according to item 1.