JPH0752562B2 - Head transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head transfer device used in a disk drive device such as a floppy disk drive device, and more particularly to a recording and / or reproducing device for recording and / or reproducing an information signal on a disk. The present invention relates to a head which is operated by a stepping motor.

[0002]

2. Description of the Related Art Conventionally, in a disk drive apparatus for recording / reproducing information signals on / from a floppy disk such as a micro floppy disk, a stepping motor is used to move the magnetic head along the radial direction of the disk. I am trying to do it.

A stepping motor for moving and operating the magnetic head is mounted in the disk drive by fixing a mounting piece integrally provided on the motor housing of the stepping motor to the chassis.
A screw shaft for head transfer is connected to the motor shaft of the stepping motor using a coupling or the like. The screw shaft is rotatably supported on the chassis with the tip end and the base end supported by bearings.

Then, in the screw part of the screw shaft,
A needle attached to a carriage that is movable with respect to a guide bar on which a magnetic head is mounted is pressed and brought into contact with the carriage. The head is sequentially transferred on each recording track along the radial direction of the micro floppy disk, for example.

By the way, in such a structure in which the screw shaft is connected to the drive shaft of the stepping motor, the magnetic head and the reference track are aligned (phase alignment) by using, for example, a disc sheet for inspection.
In carrying out the above, there is a problem that it is difficult to perform an operation for finely adjusting the screw shaft. This means that, for example, when loosening the coupling to adjust the rotation of the screw shaft, or when loosening the mounting part of the motor body to the chassis to adjust the rotation of the motor body together, the screw shaft or the motor body is completely loose. This is because it becomes difficult to adjust the rotation by a small angle, and the adjustment must be performed by loosening the screw, which is not easy.

Further, unless the screw shaft and the guide bar for guiding the carriage on which the magnetic head is mounted are accurately arranged in parallel, the feed amount with respect to the rotation of the motor is slightly different, so that accurate head feed is realized. become unable. For this reason, the mounting position of the screw shaft must be adjusted, but if the amount of adjustment increases, the coupling that connects the screw shaft and the motor drive shaft will no longer be able to absorb the deviation, and the mounting part of the motor body must also be loosened. It is necessary to adjust the mounting position of the motor body.

For this reason, Japanese Utility Model Publication No. 49-13867, Japanese Utility Model Publication No. 50-110616 and Japanese Utility Model Publication No. 58-4.
As disclosed in Japanese Patent No. 8071, a motor body is attached to a unit that supports a screw shaft, and the unit is attached to a chassis of a disk drive device. With such a configuration, the position of the screw shaft is adjusted integrally with the motor main body, and it is not necessary to readjust the mounting of the motor main body.

However, according to the above-mentioned publications, it is difficult to fix the motor body to the bearing unit of the screw shaft with high accuracy and at low cost so that the screw shaft and the motor shaft are completely parallel to each other. Further, since the screw shaft and the motor shaft can be adjusted so as to be completely parallel to each other, a coupling mechanism for absorbing an error between the screw shaft and the motor shaft is required.

By the way, the above-mentioned coupling mechanism is intended to absorb an error in the parallelism between the screw shaft and the motor shaft, but has some elastic deformation. Therefore, by interposing the coupling mechanism, the responsiveness of head feed is delayed, and the feed amount varies due to the deformation of the coupling mechanism. When such a change in the feed amount occurs, when the magnetic head is operated to feed, the stop positions may be deviated when the target recording track is fed from the outer circumference side and the inner circumference side of the disk. There is.

Therefore, in order to solve the problems caused by using the coupling mechanism as described above, a structure which does not use the coupling mechanism is actually developed.
-24861. What is described in this publication is such that a motor shaft is extended by an amount corresponding to a screw shaft and a screw groove is formed in this extended portion, and one end side and an intermediate part of the motor shaft are supported by a bearing unit. At the same time, the rotor portion of the motor is attached to the other end side of the motor shaft, and the other end side of the motor shaft is in contact with the inner surface of the bottom plate of the motor body. In such a structure, the rotation center of the stator part of the motor and the rotation center of the rotor part may not necessarily coincide with each other. Since the parallel error of the axes is absorbed, the coupling mechanism can be omitted and the screw driving characteristics can be improved.

[0011]

However, in the magnetic head transfer mechanism disclosed in Japanese Utility Model Laid-Open No. 61-24861, the screw shaft is moved toward the inner surface of the bottom plate of the motor body in order to remove the play of the bearing portion. The pressing leaf spring is provided separately from the screw shaft bearing unit. Further, since the leaf spring and the bearing unit are fixed to separate chassis, the number of manufacturing steps increases, the pressing force easily varies, and if the pressing force is insufficient, backlash will occur. However, it is necessary to strictly control the pressing force at the time of manufacturing and assembling, and there is a problem that the manufacturing and assembling is difficult.

Therefore, the present invention has been proposed for the purpose of solving the above problems and providing a head transfer device which is easy to manufacture and assemble and which enables stable head transfer. Is.

[0013]

In order to achieve the above-mentioned object, the present invention provides a stepping motor having a motor shaft having a screw groove for head transfer, and the stepping motor having a mounting portion on the front surface thereof. A motor housing of the motor and a first supporting one end of the motor shaft
Bearing portion, a second bearing portion that supports the intermediate portion of the motor shaft, a motor housing support portion that supports the mounting portion of the motor housing, and a first bearing portion that supports the first and second bearing portions, respectively. A stepping motor mounting base having a second bearing support portion, and the stepping motor mounting base is positioned and fixed on the chassis of the disk drive device. The pressing portion that presses toward the first bearing portion is provided inside the bottom surface portion of the motor housing.

[0014]

In the head transfer device according to the present invention, the motor housing is supported by the motor housing supporting portion, and the first and second bearing portions for supporting the motor shaft having the screw groove are supported as the first and second bearing supporting portions. By supporting the section,
The stepping motor and the drive shaft of this stepping motor are supported on one stepping motor mounting base, and are positioned and fixed to the chassis as an integrated block via this stepping motor mounting base. Then, the motor shaft having the screw groove is placed in a state of being pressed and biased by the first bearing portion by the pressing portion provided inside the bottom surface portion of the motor housing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a head transfer device according to the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a sectional view seen from a side.

The head transfer device according to the present invention applied to a floppy disk drive will be described with reference to FIGS. 1 to 3 below. A motor mounting base for mounting a stepping motor 2 on a chassis 1 of the floppy disk drive. The base 3 is attached with screws 4. The motor mounting base 3 includes a motor housing support portion 3A,
A first support portion 3B for supporting the first bearing portion 12, and a second support portion 3B
And a second support portion 3C that supports the bearing portion 8 of FIG. The motor mounting base 3 is positioned by the positioning pins 5 that are erected from the chassis 1.

The motor housing support portion 3A of the motor mounting base 3 supports the motor housing 2A of the stepping motor 2. That is, the front surface of the motor housing 2A of the stepping motor 2 is integrally mounted with the flange portion 6 serving as a mounting portion for the motor housing supporting portion 3A. The flange portion 6 is arranged on the front side of the main body of the stepping motor 2 into which a bearing 8 that serves as a second bearing portion that pivotally supports the intermediate portion of the motor shaft 7 of the stepping motor 2 is fitted.

A second supporting portion 3C is provided at the position of the motor housing supporting portion 3A corresponding to the motor shaft 7 of the stepping motor 2. The second support portion 3C supports the bearing 8 fitted in the flange portion 6, and the motor housing support portion 3 is provided.
It is formed as a coaxial fitting hole 13 on the outer circumference of the shaft hole 11 provided in A.

Next, the first support portion 3B provided on the motor mounting base 3 supports a metal bearing 12 which is a first bearing portion which pivotally supports one end of the motor shaft 7 of the stepping motor 2. It is a thing.

On the other hand, a screw groove 9 is formed on the outer circumference of the motor shaft 7 protruding from the motor housing 2A of the stepping motor 2. As described above, in the stepping motor 2, the motor shaft 7 also serves as a screw shaft.

A pressing portion for preloading the motor shaft 7 is provided inside the bottom surface side of the motor housing 2A of the stepping motor 2. This pressing portion is located inside the motor housing 2A of the pressing member 10 arranged on the bottom surface side of the motor housing 2A.
0A is arranged, the other end of the motor shaft 7 is pressed and supported by the thrust spring 10A, and the motor shaft 7 is pressed and biased toward the first support portion 3B.

In the stepping motor 2 thus constructed, the motor shaft 7 is inserted through the shaft hole 11 provided in the motor housing supporting portion 3A of the motor mounting base 3.
Metal bearing 1 supported by the first supporting portion 3B
The tip end of the motor shaft 7 is rotatably supported via the bearing 2, and the bearing 8 rotatably supporting the intermediate portion of the motor shaft 7 fitted in the flange portion 6 of the stepping motor 2 is the second.
It is mounted on the motor mounting base 3 while being fitted in the fitting hole 13 which is the supporting portion 3C. At the time of this attachment, the flange 6 is pressed and the projection 1
This is performed by fastening the holding leaf spring 14 having 4A to the mounting base 3 with the screw 15.

A needle 18 mounted on a carriage 17 which is movable on a guide bar 16 disposed on the side of the mounting base 3 is brought into contact with a screw groove 9 of the motor shaft 7 so as to be engaged therewith. There is. As a result, the motor shaft 7 of the stepping motor 2 is driven at a predetermined angle, so that the magnetic head 19 mounted on the carriage 17 is sequentially transferred on each recording track along the radial direction of the micro floppy disk, for example. become.

In the head feeding device constructed as described above, the screw shaft also serves as the motor shaft 7 of the stepping motor, and the bearing 8 as the second bearing portion is arranged on the motor housing 2A side of the stepping motor 2. Therefore, in mounting the stepping motor 2 on the mounting base 3, the bearing 8 is mounted on the mounting base 3.
Of the stepping motor 2 against the second supporting portion 3C of the
Flange portion 6 integrated with the motor housing 2A of
The motor housing supporting portion 3A using the pressing leaf spring 14
It is fixed to.

Therefore, for example, when the reference track of the disk is aligned with the magnetic head 19 by using a disk sheet for inspection, the stepping motor 2 not directly mounted on the motor housing supporting portion 3A of the mounting base 3 is used. Even if the screw 15 is loosened in the motor part of the stepping motor, the motor housing 2A of the stepping motor 2 is operated.
Is pressed and supported by the pressing leaf spring 14 via the flange portion 6, so that displacement such as wobbling is prevented.

Further, at this time, the motor shaft 7 is provided on the first support member 3B side by the thrust spring 10A arranged inside the pressing member 10 constituting the pressing portion arranged inside the bottom surface side of the motor housing 2A of the stepping motor 2. Since it is pressed and urged by, it does not rattle.

Therefore, in this state, the stepping motor 2
It becomes easy to rotate the motor housing 2A and the motor shaft 7 by a minute angle, and the positioning with the reference track can be performed with high accuracy and easily.

[0028]

As described above, in the head transfer device according to the present invention, the motor housing supporting portion supports the motor housing, and the first and second bearing portions for supporting the motor shaft having the screw groove are provided. The stepping motor and the drive shaft of the stepping motor are supported on the stepping motor mounting base by supporting the stepping motor by the first and second bearing supporting portions, and the chassis is provided as an integral block through the stepping motor mounting base. Since it is positioned and fixed on the head, it is possible to prevent the head feed amount from varying due to the use of the coupling mechanism.

The motor shaft having the screw groove is configured to be pressed and urged against the first bearing portion by the pressing portion provided inside the bottom surface portion of the motor housing. Since the pressing mechanism can be configured in the stepping motor, manufacturing and assembling becomes extremely easy. Particularly, since the stepping motor, the drive shaft of the stepping motor, and the pressing portion for pressing the drive shaft are integrally incorporated on the common stepping motor mounting base, the pressing force of the drive shaft is applied. Since it can be mounted on the chassis in this state, it is not necessary to adjust the pressing force when mounting on the chassis, and the assembly as a head feeding device becomes extremely easy.

Further, in the above-described embodiment, the mounting member fixed to the front surface of the stepping motor body is pressed and fixed to the motor mounting base by using the pressing leaf spring.
Since the stepping motor is attached, even if the stepping motor body can be rotated by loosening the screw that tightens the holding plate spring, the stepping motor body does not wobble and the stepping motor body rotates. By performing the dynamic operation, it becomes possible to easily perform the alignment with the reference track, which is performed by rotating the motor shaft having the screw groove by a slight angle.

[Brief description of drawings]

FIG. 1 is a plan view of a stepping motor mounting device according to the present invention.

FIG. 2 is a side view of the stepping motor mounting device.

FIG. 3 is a cross-sectional view of the stepping motor mounting device seen from the side.

[Explanation of symbols]

 1 Chassis 2 Stepping Motor 3 Motor Mounting Base 6 Flange 7 Motor Shaft 8 Bearing 9 Screw Groove 10 Pressing Member 14 Holding Leaf Spring 16 Guide Bar 17 Carriage 18 Needle 19 Magnetic Head

Claims (1)

[Claims] 1. A stepping motor having a motor shaft in which a screw groove for head transfer is formed, a motor housing of the stepping motor having a mounting portion on a front surface thereof, and a first bearing for supporting one end of the motor shaft. And a second bearing portion that supports an intermediate portion of the motor shaft,
A stepping motor mounting base having a motor housing supporting portion for supporting the mounting portion of the motor housing and first and second bearing supporting portions for respectively supporting the first and second bearing portions is provided. In a head transfer device for positioning and fixing a motor-motor mounting base on a chassis of a disk drive device, a pressing portion for pressing the other end of the motor shaft toward the first bearing portion is provided inside the bottom surface portion of the motor housing. The head transfer device provided in the.