JPH1125585A - Recording disk device motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent malfunctioning of a motor having a balance correcting mechanism in relation to inadvertent movement of its balance body (particularly the movement in the radial direction). SOLUTION: This motor is equipped with a bearing holding member 11 and a hub member 18 which is supported freely rotatable by a slide bearing 15 as against this bearing holding member 11 and which has a mounting part to be mounted with a recording disk. The motor is further provided with a balance correcting mechanism composed of rolling bodies 24 housed freely movabe at least in the circumferential direction in a housing part 23 which is formed concentrically with the hub member 18, for the purpose of correcting unbalanced weight generated at the time of rotation. Incenter force in the radial direction of the rolling bodies 24 toward the rotary center in this balance correcting mechanism is operated by magnetic force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording disk drive motor for driving a recording disk, and more particularly to a motor required to rotate at high speed and high precision.

[0002]

2. Description of the Related Art Recording disks for recording or reproducing data include CD, FD, MO, MD, DVD, and H.
D and the like. These recording disks have different specifications such as recording / reproducing method, data capacity, rotation speed, recording density, etc., or the material and price of the disks depending on the application. Therefore, various types of motors are used to drive each disk. Exists.

[0003] In recent years, electronic information has shifted from characters to images, and with the accompanying sophistication and large capacity, recording and reproduction of such information in large amounts and quickly has been realized. There is a need for a driving device that drives this.

[0004] For example, in the case of a CD, it first appeared for music reproduction, but its advantages have been used to expand its use to a computer as a CD-ROM. As a result, the data capacity is increased, the operating time (seek time) is shortened, and the recording disk side is rotated faster, that is, the motor for driving the recording disk is sped up. As a result, a speed exceeding 20 times speed has been realized.

Now, a specific configuration of a conventional recording disk drive motor will be described with reference to FIG.

As shown in FIG. 6, a lower end of a substantially cylindrical holding member b is fitted into an opening formed in a fixing member a such as a chassis, and a bottom opening of the holding member b is closed by a closing plate c. Closed, the thrust receiver d is placed on the closing plate c and disposed at the bottom in the holding member b, and the slide bearing e is fitted inside the holding member b.

Further, a core f1 is fitted to the outside of the holding member b, and a winding f2 is wound around the core f1 and a stator f
Is composed. Further, the shaft g is fitted into the slide bearing e, the lower end of which is in contact with the thrust receiver d, and the upper end thereof is arranged to protrude above the holding member b. A hub member h made of a non-magnetic material such as aluminum is fitted to the upper end of the shaft g, and a yoke member j made of a magnetic material such as iron is attached to the hub member h.

The yoke member j is composed of a disc-shaped base and a hanging part which is integrally formed by hanging downward on the periphery of the base. Then, with the holding member b inserted through an opening formed at the center of the base of the yoke member j, the periphery of the opening is attached by crimping to the lower end of the hub member h. Further, a driving magnet body k is fitted inside the hanging portion of the yoke member j, and is disposed at a position facing the stator f.

As shown in FIG. 6, a turntable m is formed outside the hub member h, and a clamp magnet body n is formed at the center of the turntable m so as to be substantially flush with the upper surface. The recording disk pressing means (not shown) of the drive unit (not shown) is magnetically attracted by the clamp magnet n and the recording disk D is fixed.

The direction of current flow to the winding f2 of the stator f is controlled, and the stator f generates a rotating magnetic field.
By repeating the attraction and repulsion of the rotating magnetic field and the static magnetic field of the driving magnet body k, the stationary stator f
Then, the drive magnet body k, the yoke member j, the hub member h, and the shaft g rotate, whereby the turntable m and the recording disk D rotate in a certain direction.

Further, the motor is provided with a balance correcting mechanism for correcting the deviation of the weight balance generated during rotation. That is, the turntable portion m in the hub member h
And the base of the yoke member j form an accommodating portion p of an annular space, and a plurality of (for example, nine) spheres q
Are movably accommodated. When the motor rotates, these spheres q also roll in the circumferential direction. Then, when a predetermined number of revolutions is reached, the sphere q becomes the recording disk D of the motor.
Is placed symmetrically at a position where the weight balance is biased in a state where is placed. Thus, the deviation of the weight balance of the motor is offset by the sphere q, and the balance is corrected.

With this configuration, as described above, the recording disk D can be stably mounted without generating vibration, noise, vibration, and the like of the center of rotation even when high-speed rotation exceeding 20 times speed is performed. However, the motor rotates.

[0013]

However, the above motor has the following problems. That is, when the recording disk drive motor is used in a portable or movable state, for example, as in a notebook personal computer equipped with a CD-ROM drive device, regardless of whether the power supply of the drive device is on or off, The extra force acts on the spheres q and rolls at random, colliding with the spheres q or on the inner peripheral surface of the accommodating portion p. Not good.

Further, up to a predetermined number of rotations at which the balance correcting mechanism operates in the motor, the sphere q randomly rolls in the circumferential direction and the radial direction, so that the motor rotates unstablely and, in some cases, slips. Bearing e and shaft g
There is a risk that abnormal wear may be exerted on the sliding surface of the above to cause a decrease in rotational performance. One of the causes is that the accommodation part p
Is set to be larger than the diameter of the sphere q,
Since the sphere q rolls at random in the radial direction, it is considered that the shaft g easily swings due to the movement of the weight of the sphere q. However, this balance correction mechanism has a space for rolling in the radial direction even if the centrifugal force applied to the sphere q changes due to a change in the number of rotations of the motor. The configuration is such that the balance correction functions without impairing the performance. That is,
It is desirable that the width of the accommodation portion p and the width of the sphere q be such that the sphere q can roll in the radial direction, and such a conflicting problem is included.

[0015] As described above, the problem to be solved by the present invention is to solve the problem associated with careless movement (particularly in the radial direction) of a balance body in a motor having a balance correction mechanism so as not to cause a problem. It is to operate the correction function well.

[0016]

According to a first aspect of the present invention, there is provided a stationary member, and a rotary member rotatably supported by the stationary member and having a mounting portion for mounting a recording disk, A recording disk comprising a balance member housed at least in a circumferential direction movably in a housing portion formed of an annular space formed concentrically with the rotating member, and having a balance correction mechanism for correcting a deviation in weight balance generated during rotation. In the driving motor, the balance correction mechanism is characterized in that the balance body exerts a magnetic force on a radially inward force directed toward a rotation center.

According to this structure, since the centrifugal force does not act on the balance body when the motor is stopped, it is possible to limit the movement in the radial direction, and it is possible to reduce the occurrence of collision sound due to the balance body and to reduce the balance noise when the motor is rotating. The radial movement of the balance body can be controlled by the centrifugal force acting on the body and the radial inner core force.

According to the second aspect of the present invention, a stator comprising a cylindrical bearing holding member, a core fitted on the outer peripheral surface of the bearing holding member, and a winding wound around the core. A bearing member fitted to the inner peripheral surface of the bearing holding member, a shaft member rotatably supported by the bearing member, and a recording disk provided on the shaft member and located on the upper surface of the stator. A hub member to be mounted, a yoke member provided on the hub member so as to cover the stator, and a driving magnet body provided on the yoke member so as to face an outer peripheral surface of the stator; The two members form an accommodating portion composed of an annular space formed concentrically with the rotating member between the lower surface of the hub member and the upper surface of the yoke member, and are accommodated in this accommodating portion so as to be movable at least in the circumferential direction. Rose A recording disk drive motor provided with a balance correction mechanism configured to correct a deviation in weight balance generated at the time of rotation, the balance correction mechanism comprising: a magnetic force for radially inwardly moving the balance body toward the center of rotation; Characterized by the following.

With such a configuration, the centrifugal force does not act on the balance body when the motor is stopped, so that the movement in the radial direction can be restricted, and the generation of collision sound by the balance body can be reduced. The radial movement of the balance body can be controlled by the centrifugal force acting on the balance body and the radial inner core force.

At this time, when the balance body is a rolling body, the balance body moves quickly in the accommodating portion, so that the effect of correcting the balance can be quickly exhibited, and the balance can be quickly achieved. Workability at the time of assembly is good because the body is solid.

In this case, as described in claim 4, the balance body is made of a magnetic material, and a magnet portion is provided radially inward of the housing portion, and a magnetic field is provided between the balance body and the magnet portion. When the attraction force is applied, the radial inward force acting on the balance body can be easily obtained by the magnetic attraction force.

In this case, the hub member has an inner wall portion hanging down from an inner peripheral portion of a lower surface of the hub member and an outer wall portion hanging down from an outer peripheral portion of the lower surface of the hub member. Has a base on the upper surface of the hub member, the lower surface of the hub member, the inner wall and the outer wall, and the accommodation portion is configured by the base,
The inner wall portion is plastically deformed to a base portion, the yoke member is fixed to the hub member, the magnet portion is disposed on an outer peripheral surface of the inner wall portion, and a buffer is provided between the magnet portion and the base portion. The body should be interposed.

With this configuration, the pressing force generated when the yoke member is plastically deformed by the hub member does not directly act on the magnet portion, but is somewhat reduced, so that damage to the magnet portion can be prevented. it can.

According to a sixth aspect of the present invention, the balance body is made of a magnet, and a magnetic body is disposed radially inward of the housing, and a gap is provided between the balance body and the magnetic body. When the magnetic attraction force is applied, a radially inner force acting on the balance body can be easily obtained.

According to a seventh aspect of the present invention, the balance body is made of a magnet, and a magnet part is provided radially outward of the housing, and a magnetic repulsive force is provided between the balance body and the magnet part. , The radial inward force acting on the balance body can be easily obtained by the magnetic repulsive force.

Further, as described in claim 8, it is preferable that the magnet part is arranged so as not to be exposed to the balance body. The term “not exposed” means, for example, that the surface of the magnet unit is coated with a thin film, the magnet unit is depressed so as not to be on the same plane as the housing unit, or further disposed outside the housing unit. With this configuration, since the magnetically attracted balance body does not directly contact the magnet, damage to the magnet can be prevented.

Further, when the bottom surface of the housing portion is inclined downward toward the center of rotation, the radial inner force acting on the balance body can be easily obtained. it can.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the present invention will be described with reference to FIGS. 1 (a) and 1 (b).

In FIG. 1, reference numeral 10 denotes a fixing member such as a chassis, 11 denotes a bearing holding member as a substantially cylindrical stationary member having a lower end fitted into an opening 12 formed in the fixing member 10, and 13 denotes a bearing holding member. A closing plate 14 closing the bottom opening of the member 11 is mounted on the closing plate 13 to
A thrust bearing 15 disposed at the bottom of the bearing 1 is a slide bearing as bearing means, and is fitted inside the bearing holding member 11.

Further, in FIG. 1, reference numeral 16 denotes a stator comprising a core 16a fitted to the outside of the bearing holding member 11 and a winding 16b wound around the core 16a;
Reference numeral 7 denotes a shaft (shaft member) as a rotating member which is fitted into the slide bearing 15, the lower end of which contacts the thrust receiver 14, and the upper end of which protrudes above the bearing holding member 11. A hub member as a rotating member made of a non-magnetic material such as aluminum fitted, 19 is a yoke member as a fitting member constituting a rotating member made of a magnetic material such as iron, and 20 is a driving magnet as a rotating member. Body.

At this time, the yoke member 19 is substantially disk-shaped, and is constituted by a hanging portion which is integrally formed by hanging downward on the periphery of a base 19a inclined downward toward the center of rotation. In a state where the bearing holding member 11 is inserted through an opening formed at the center of the base 19 a of the base member 19, a portion around the opening is plastically deformed to an inner wall portion 18 a hanging down from an inner peripheral portion of the lower surface of the hub member 18. It is attached by tightening. Further, the driving magnet body 20 includes the yoke member 1.
9 is fitted inside the hanging portion of the motor 9 and is disposed at a position facing the stator 16. Further, a recording disk (not shown) such as a CD-ROM is placed on the upper surface of the hub member 18 via a soft material 21.

In FIG. 1, reference numeral 22 denotes a hub member 18.
Is formed by the inner wall portion 18a and the outer wall portion 18b hanging down from the outer peripheral portion of the lower surface. The open lower surface of the annular concave portion 22 is closed by the base portion 19a of the yoke member 19 to form an annular space. Accommodation section 23
Are formed. Numeral 24 denotes a plurality of rolling elements as balance bodies accommodated in the accommodation portion 23, for example, spherical bodies made of steel material. The rolling elements 24 and the accommodating portion 23 accommodating the rolling elements 24 constitute a correction mechanism for correcting the deviation of the weight balance during rotation. Here, the housing portion 23 is formed concentrically with a rotating member such as the hub member 18, and the width of the housing portion 23 in the radial direction is set to be slightly larger than the diameter of the rolling element 24.

Further, an annular concave portion 1 formed by removing a part of the inner wall portion 18a located radially inward of the housing portion 23 is formed.
The magnet body 25 corresponding to the concave portion 18c is arranged in the 8c as a magnet portion, and is embedded so as to be depressed from the surface of the inner wall portion 18a on the outer side (accommodating portion 23) side.
That is, the rolling elements 24 are set so as not to directly contact (expose) the magnet bodies 25. Thereby, even if the rolling element 24 abuts on the innermost periphery of the housing portion 23, the rolling element 24 does not directly contact the magnet body 25, so that damage to the magnet body 25 can be prevented. In addition, although the magnet body 25 is molded and fixed in advance by an adhesive member, the magnet body 25 may be integrally formed with the concave portion 18c.

The rolling elements 24 are composed of nine steel balls, and each rolling element 24 is disposed so as to occupy a central angle range of about 45 degrees of the accommodating portion 23, and the remaining approximately of the accommodating portion 23 is provided. 315
The area of the central angle of the degree is a space for moving the rolling elements 24.

Further, in FIG. 1, reference numeral 26 denotes a clamp magnet, which is buried together with the magnetic plate 27 on the upper surface of the hub member 18 so as to form substantially the same surface as the upper surface. The disk pressing means provided on the driving device side is magnetically attracted to fix the recording disk.

The direction of current flow to the stator 16b is controlled, and the stator 16 generates a rotating magnetic field. By repeating the attraction and repulsion of the rotating magnetic field and the static magnetic field of the driving magnet body 20, the stationary magnetic field is stopped. Stator 16 in state
The drive magnet 20, the yoke member 19, the hub member 18, and the shaft 17 rotate, whereby the recording disk rotates in a certain direction.

Next, the operation when a recording disk such as a CD-ROM is mounted will be described. First, when the motor is stopped, each rolling element 24 is
5 abuts against the inner wall 18a of the accommodating portion 23 by radial inner core force, which is the sum of the magnetic attractive force of No. 5 and the inward force (inward force) due to the inclination of the base 19a of the yoke member 19, and moves radially outward. No movement is possible, and circumferential movement is also limited by some resistance.

When the motor is in an unbalanced rotation state, after the motor is started, a period between the start of the motor and the resonance frequency which resonates with the natural frequency of the motor on which the recording disk is mounted is exceeded.
Each rolling element 24 moves at random in the circumferential direction while abutting on the inner wall portion 18a of the housing portion 23. At this time, the rotating part of the motor is rotated in an unstable state with a swing where the center of rotation and the center line of the shaft member 17 do not coincide with each other due to the random excessive movement of each rolling element 24.

In the rated speed range exceeding the resonance speed, the rolling element 2 in the motor mounted with the recording disk is used.
4 is set so that the centrifugal force acting simultaneously with the rotation is larger than the radial inner core force.
As shown in FIG. 1, each rolling element 24 is separated from the innermost circumference of the housing portion 23, gradually moves radially outward, and the rolling elements 24 To position. In this manner, the bias of the weight balance is corrected, and the inclination of the rotating portion of the motor is corrected, and the rotating portion stably rotates in a state where the center of rotation and the center line of the shaft 17 coincide.

On the other hand, in the case of a balanced normal rotation state, after the motor is started, the same as the above case is performed until the resonance rotation frequency that resonates with the natural frequency of the motor mounted with the recording disk is exceeded. As a result, the motor rotates in an unstable manner due to the random and excessive movement of the rolling elements 24.
At the rated speed exceeding the resonance speed, the rolling elements 2
1 are separated from the innermost circumference of the accommodating portion 23 by the centrifugal force as in the case of being balanced as shown in FIG. In this way, when the balance is originally normal, the rolling elements 24 rotate in a distributed manner so as not to disturb the rotational balance.

Therefore, according to the first embodiment, for example, even if the weight balance is deviated when the motor rotates at a high speed,
Since the rolling element 24 accommodated in the accommodating portion 23 can correct the deviation of the weight balance, the deviation of the weight balance at the time of rotation is automatically corrected without requiring extremely high dimensional accuracy, and the rotational runout is reduced. This makes it possible to stably rotate the motor on which the recording disk for performing the data recording / reproducing operation is mounted, regardless of whether the motor or the recording disk includes a dimensional error. Of course, the rolling element 24 does not lose its balance in a normal weight balance state, so that high-speed rotation can be realized with high accuracy in any case.

In addition, since the radially inward force acting on the rolling elements 24 is set so as to leave the innermost periphery of the housing portion 23 near the rated rotation range, the balance is corrected in the rotation range up to that point. At this time, the rolling element 24 is located at the innermost circumference. Therefore, when the radial center force does not act, the rolling element 24 moves to the outermost periphery of the housing portion 23 immediately after starting and acts so as to greatly disturb the balance. Since unintentional movement can be restricted, disturbance in balance can be minimized.
Along with this, the rolling element 24 does not move particularly in the radial direction of the housing portion 23 at the time of rest, so that, for example, the rolling member 24 is moved to the housing portion 23 or the like while the driving device incorporating the motor is moving or being carried. It is possible to suppress the occurrence of collision sound due to collision. When the rotation speed is changed to a low speed in the rated rotation range, the radial inner core force is set to be at an intermediate position in the radial direction of the housing portion 23, so that the rotation speed can be changed. Can respond more effectively.

As described above, since the rolling element 24 can control the movement in the radial direction by the radial inner core force, for example, the CD-
As in the ROM drive device, the rotation speed is changed depending on the reading position of the disk due to the operation method. In this type of operation, the balance correction function can be appropriately operated.

Further, in the above description, the rolling element 24 is made of a steel material. However, other magnetic substances may be used, and the shape may be an elliptical sphere or a barrel instead of a sphere. Alternatively, the rolling element 24
Since the moving member always collides with the other rolling element 24 or the housing section 23 surface when it moves, a soft material that does not easily generate a collision sound even when colliding with the surface of the rolling element 24 or the housing section 23 surface may be provided. Particularly, since the magnet body 25 is fragile, for example, the magnet body 25 or the rolling element 24 is a rubber magnet in which magnetic powder is mixed with rubber itself if it is a rubber ball.

In any of the rolling elements 24,
The movement in the housing portion 23 is smooth, and the balance can be corrected quickly. In particular, if a soft material such as a resin coating is formed on the surface of the rolling element 24, noise such as a collision noise and a frictional noise during movement can be reduced. Also, damage or rust on the rolling elements 24 themselves can be suppressed. This contributes to quietness and a longer life of the motor.

Further, the lower surface of the hub member 18 and the yoke member 1
Since the accommodating portion 23 is formed between the housing and the upper surface of the motor 9, the rolling element 24, which is a balance body, can be compactly arranged without sacrificing the structures of the driving magnet body 20 and the main part of the stator 16 in the motor. become. At this time, since the space between the lower surface of the hub member 18 and the upper surface of the yoke member 19 where the housing portion 23 is formed is close to the center of gravity of the rotating members such as the hub member 18 and the yoke member 19, the balance correction function is not provided. Easy to demonstrate.

Incidentally, the size of the central angle occupied by the rolling elements 24 is not particularly limited to the above-mentioned 45 °.
What is necessary is just to determine in consideration of the number, size, specific gravity, etc. of the rolling elements 24 to be accommodated according to the bias of the weight balance.

At this time, at least two rolling elements 24 are required to cope with various balance states.
According to experiments, it is desirable to be a multiple of 3, such as 6 or 9. This is because, in a normal rotation state where the motor on which the recording disk is mounted is balanced, the rolling elements 2
4 are evenly distributed at three places at 120 ° intervals, and are more stable than two or four places.

Further, the range in which the rolling elements 24 occupy the accommodating portion 23 is set so as not to exceed the semicircular portion (the central angle is 180 °) of the accommodating portion 23. The reason for this is to prevent the rolling elements 24 having completed the semicircle of the accommodating portion 23 from acting to disturb the balance.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS. 2 (a) and 2 (b).
However, in FIGS. 2A and 2B, the same reference numerals as those in FIG. 1 denote the same or corresponding components, and a duplicate description will be omitted below, and only the differences from FIG. explain. In the third to fifth embodiments to be described later, only points different from FIG. 1 will be described.

In this embodiment, as shown in FIG. 2A, an annular concave portion 22 is formed on the lower surface of the hub member 18,
The open lower surface side of the annular concave portion 22 is closed by the base 19a of the yoke member 19, and the accommodation portion 2 is formed of an annular space.
3 are formed. The magnet body 30 is buried by integral molding in an annular concave portion 18d that is formed by removing a part of the outer central portion of the inner wall portion 18a of the housing portion 23 and that opens in the radial direction. Therefore, between the lower end surface of the magnet body 30 and the base 19a of the yoke member 19, the lower wall 18e that forms the recess 18d is located.

Therefore, according to the second embodiment, in addition to the same effects as in the first embodiment, the yoke member 19
When caulking is fixed to the inner wall portion 18a of the hub member 18,
The pressing force acting on the caulked portion 18f does not directly act on the magnet body 30 by the lower wall portion 18e. That is, the lower wall 1
8e function as a buffer, and the magnet 30
Damage can be prevented. Therefore, compared to the first embodiment,
A motor with less defects occurring during assembly.

Further, as a modified example of the second embodiment, as shown in FIG. 2B, thin magnetic rings 31 and 32 are arranged above and below a ring-shaped magnet body 30 # so that an inner wall portion 18a is formed.
Place outside The outer diameter of the magnetic rings 31 and 32 is larger than that of the magnet body 30 #, so that the rolling elements 24 do not directly contact the magnet body 30 # (that is, are not exposed). By doing so, the magnetic ring 32 functions as a buffer, preventing damage to the magnet body 30 # in the same manner as described above, and forming a magnetic path as shown by arrows in the magnetic rings 31 and 32. A suitable rolling element 2 that can concentrate magnetic force
3 can be magnetically attracted.

(Third Embodiment) According to the present embodiment,
As shown in FIG.
Is formed, and the lower surface side of the opening of the annular concave portion 22 is closed by the base 19a of the yoke member 19 to form a housing portion 23 formed of an annular space. Magnetic rings 41 and 42 are disposed above and below a ring-shaped magnet body 40 inside the inner wall portion 18a that is radially inward of the housing portion 23. The outer peripheral edges of the magnetic rings 41 and 42 are attached to the inner wall portion 18a. It is provided with light press fit.

Therefore, according to the third embodiment, as in the modification of the second embodiment, a radial inner core force, which is the sum of the magnetic attraction force and the inward force, acts on the rolling element 23, and the magnet 23 is magnetized. Since the body 40 is not exposed to the rolling element 24 by the inner wall portion 18a, the contact between the two becomes impossible, so that the magnet body 40 is not damaged at all. In addition, the housing 23 can be simplified, which is advantageous in assembling. Although there is a gap between the outer peripheral surface of the magnet body 40 and the inner wall portion 18a, the gap may be set according to the required magnetic attraction.

(Fourth Embodiment) According to the present embodiment,
As shown in FIG.
Is formed, and the lower surface side of the opening of the annular concave portion 22 is closed by the base 19a of the yoke member 19 to form a housing portion 23 formed of an annular space. A magnetic ring 50 made of an annular iron material is fitted as a magnetic body portion outside the inner wall portion 18a that is radially inward of the housing portion 23.
The rolling element 51, which is a balance body, is a spherical body made of a magnet.

Therefore, according to the fourth embodiment, a magnetic attractive force acts between the rolling element 51 and the magnetic ring 50,
A radial inward force acts on the rolling element 51 in conjunction with the inward force due to the inclination of the bottom surface of the housing section 23 (the base 19a of the yoke member 19), and the housing section 23 has the same structure as the rolling element 24 of the first embodiment. The movement in the radial direction within 23 can be controlled. In this case, since the magnetic ring 50 can be made of a relatively hard material such as an iron material, even if a pressing force generated when the yoke member 19 is swaged and fixed to the hub member 18 acts on the magnetic ring 50, the magnetic ring 50 is not damaged. Receiving part 2 without receiving
3 can be simplified. In the same manner as described above, the magnetic ring 50 is coated with a resin surface or disposed inside the inner wall portion 18a (in this case, the inner wall portion 18a is not provided) in order to prevent damage due to contact with the rolling elements 51. (It is assumed that the magnetic ring 50 is softer than the magnetic ring 50).

(Fifth Embodiment) According to this embodiment,
As shown in FIG. 5, an annular concave portion is formed on the lower surface of the hub member 18, and the open lower surface side of the annular concave portion 22 is closed by the base 19a of the yoke member 19 to form a housing portion 23 composed of an annular space. ing. An annular magnet body 60 is fitted to the outer wall portion 18b that is radially outward of the housing portion 23. The rolling element 61, which is a balance body, is a cylindrical body made of a magnet. At this time, the magnet body 60
And the outer end face of the rolling element 61 are arranged so as to have the same polarity, and a magnetic repulsive force acts. The dimensions of the radial width and the axial width of the accommodating portion 23 are set so that the rolling elements 61 are reversed during movement or the like and the different poles are not magnetically attracted to the magnet body 60. Therefore, the rolling element 61 is not limited to a columnar body as long as the end face rolls so as not to be inverted in the housing portion 23.

Therefore, according to the fifth embodiment, a magnetic repulsive force acts between the rolling element 61 and the magnet body 60,
By applying a radial inward force to the rolling element 61 in conjunction with the inward force, the radial movement in the housing portion 23 can be controlled in the same manner as the rolling element 24 of the first embodiment. In this case, there is no problem that the pressing force generated when the yoke member 19 is crimped and fixed to the hub member 18 damages the magnet portion 25 described above. In order to prevent damage to the magnet body 60, the magnet body 60 is
For example, it may be arranged outside the outer wall portion 18b so as not to be exposed.

As described above, various embodiments of the recording disk drive motor according to the present invention have been described for a CD-ROM. However, the present invention is not limited to the above embodiment.
It may be for another recording disk, or may be a combination of different embodiments, and various modifications and changes are possible without departing from the scope of the present invention. For example, the bottom surface of the housing portion 23 in the above is inclined so that an inward force acts, but the angle may be changed in various ways and may be horizontal, and is not limited to a flat surface as described above but is a curved surface. No problem. Alternatively, the magnetic attraction force to the rolling elements 24 may be used in combination with the driving magnet body 20 and the clamp magnet body 26, and the housing 23 may be arranged near the lower end of the yoke member 19 or the like.

[0061]

According to the first and second aspects of the present invention,
When the motor is stopped, the movement of the balance body in the radial direction can be limited, so that the generation of collision sound by the balance body can be reduced and unpleasant sound does not occur. In addition, the movement of the balance body in the radial direction can be controlled by the centrifugal force acting on the balance body and the radial inner core force when the motor rotates, and the balance correction function can be exhibited with high accuracy.

According to a third aspect of the present invention, when the balance body is a rolling body, the balance body moves quickly in the accommodating portion, so that the effect of correcting the balance is quickly exhibited, and the balance body is solid. Therefore, the workability at the time of assembly is good.

According to a fourth aspect of the present invention, the balance member is made of a magnetic material, and a magnet portion is provided radially inward of the housing portion so that a magnetic attraction force acts between the balance member and the magnet portion. Then, the radial inward force acting on the balance body can be easily obtained by the magnetic attraction force.

As described in claim 5, the pressing force generated when the yoke member is plastically deformed by the hub member does not directly act on the magnet portion, but is somewhat reduced, so that damage to the magnet portion is prevented. Therefore, defective assembly can be reduced.

According to a sixth aspect of the present invention, the balance body is made of a magnet, and the magnetic body portion is disposed radially inward of the housing portion, and a magnetic attractive force acts between the balance body and the magnetic body portion. By doing so, it is possible to easily obtain the radial inner core force acting on the balance body.

According to a seventh aspect of the present invention, the balance body is made of a magnet, and a magnet portion is provided radially outward of the housing portion so that a magnetic repulsive force acts between the balance body and the magnet portion. Then, the radial inner core force acting on the balance body can be easily obtained by the magnetic repulsive force.

As described in claim 8, when the magnet portion is arranged so as not to be exposed to the balance body,
Since the magnetically attracted balance body does not directly contact the magnet, damage to the magnet can be prevented.

As described in the ninth aspect, when the bottom surface of the housing portion is inclined downward toward the center of rotation, the radial inner force acting on the balance body can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a cut-away front view showing the overall configuration of a first embodiment of the present invention.

FIG. 2A is a cut-away front view showing an overall configuration of a second embodiment of the present invention, and FIG. 2B is a half-cut front view showing a modification of the second embodiment.

FIG. 3 is a partially cut front view showing the entire configuration of a third embodiment of the present invention.

FIG. 4 is a half-cut front view showing the entire configuration of a fourth embodiment of the present invention.

FIG. 5 is a partially cut front view showing the entire configuration of a fifth embodiment of the present invention.

FIG. 6 is a cut-away front view showing the overall configuration of a conventional recording disk drive motor as the background of the present invention.

[Explanation of symbols]

 Reference Signs List 11 bearing holding member (stationary member) 15 sliding bearing (bearing means) 16 stator 17 shaft (shaft member) 18 hub member (rotating member) 18a inner wall portion 18b outer wall portion 18e lower wall portion (buffer) 19 yoke member 19a base 20 Drive magnet body 23 Housing part 24, 51, 61 Rolling body (balance body) 25, 30, 30 °, 40, 60 Magnet body 31, 32, 41, 42, 50 Magnetic ring

Claims (9)

[Claims] 1. A stationary member, and a rotating member rotatably supported by the stationary member and having a mounting portion on which a recording disk is mounted, and comprising an annular space formed concentrically with the rotating member. A recording disk drive motor comprising a balance body accommodated at least in the accommodation portion so as to be freely movable in the circumferential direction, and having a balance compensation mechanism for compensating for a deviation in weight balance generated during rotation. A recording disk drive motor characterized in that a magnetic force acts on a radially inward force in which a body is directed to a rotation center. 2. A stator comprising a cylindrical bearing holding member, a core fitted on an outer peripheral surface of the bearing holding member, and a winding wound around the core, and an inner peripheral surface of the bearing holding member. A fitted bearing means, a shaft member rotatably supported by the bearing means, a hub member provided on the shaft member and located on the upper surface of the stator, for mounting a recording disk,
A yoke member provided on the hub member so as to cover the stator; and a driving magnet body provided on the yoke member so as to face an outer peripheral surface of the stator, and a lower surface of the hub member and a yoke member This 2 between the top of
A housing formed of an annular space formed concentrically with the rotating member by the three members, and a balance body housed at least in the housing so as to be freely movable in the circumferential direction. A recording disk drive motor provided with a balance correction mechanism for correcting, wherein the balance correction mechanism applies a radial inner center force toward the rotation center of the balance body by a magnetic force. 3. The recording disk drive motor according to claim 1, wherein the balance body is a rolling body. 4. The balance body is made of a magnetic material, a magnet part is provided radially inward of the housing part, and a magnetic attractive force acts between the balance body and the magnet part. The recording disk drive motor according to claim 1. 5. The hub member has an inner wall portion hanging down from an inner peripheral portion of a lower surface of the hub member, and an outer wall portion hanging down from an outer peripheral portion of the lower surface, and has a base portion on an upper surface of the yoke member. The lower wall, the inner wall portion, the outer wall portion, and the base of the hub member constitute the housing portion, and the inner wall portion is plastically deformed to the base portion, the yoke member is fixed to the hub member, and the outer wall surface of the inner wall portion is 5. The recording disk drive motor according to claim 2, wherein a magnet is disposed, and a buffer is interposed between the magnet and the base. 6. The balance body comprises a magnet,
6. The recording disk drive according to claim 1, wherein a magnetic body portion is disposed radially inward of the housing portion, and a magnetic attractive force acts between the balance body and the magnetic body portion. For motor. 7. The balance body is made of a magnet, a magnet part is provided radially outward of the housing part, and a magnetic repulsive force acts between the balance body and the magnet part. A recording disk drive motor according to claim 1. 8. The recording disk drive motor according to claim 4, wherein the magnet portion is arranged so as not to be exposed to the balance body. 9. The recording disk drive motor according to claim 1, wherein a bottom surface of the housing portion is inclined downward toward a center of rotation.