JP2001211627A - Balance compensator and rotary machine including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balance compensator and a rotary machine including the same which assures good reproducibility of balance compensation and can perform delicate compensation for unbalance. SOLUTION: An upper surface of the base portion of a yoke member corresponding to at least lower surface of a moving path 16 is formed of a metal material among the lower surface of a turn table and the upper surface of base portion of yoke member forming a moving path 16 and a mound type projection 31 is also formed at the lower surface of this moving path 16. Thereby, even when a spherical body 17 cannot follow the rotation of the moving path 16, the spherical body 17 is accelerated with a moving resistance (friction) by the projection 31 each time when it rides over the projection 31, the spherical body 17 finally moves following the rotation of the moving path 16 and stops at the unbalance compensating position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balance correcting device which is attached to a rotating device such as a motor and automatically corrects imbalance during rotation, and a rotating device provided with the same.

[0002]

2. Description of the Related Art In general, there are various types of rotating devices such as motors, and one of them is a driving device for a recording disk for recording and reproducing data. There are various types of recording disks, such as CDs, FDs, MOs, MDs, and DVDs, and these recording disks have specifications such as recording / reproducing method, data capacity, rotation speed, recording density, etc., disk material, and price. Therefore, there are various motors for driving each disk.

[0003] In recent years, electronic information has shifted from characters to images, and with the accompanying advancement and capacity of information, a large amount of information can be recorded and reproduced quickly, that is, high-speed operation is possible. Is required for a recording disk and a drive device for driving the recording disk, for example, because of its low cost. On the other hand, the recording density of data is increasing, and a high rotational accuracy without rotational vibration is required to accurately record and reproduce the data.

[0004] In a conventional recording disk drive motor, for example, a motor for driving a CD-ROM is configured as shown in FIG. That is, a fixing member 1 such as a chassis
The lower end of the holding member 2 as a stationary member having a substantially cylindrical shape is fitted into the opening formed in the opening, the bottom opening of the holding member 2 is closed by the closing plate 3, and the thrust receiver 4 is closed by the closing plate 3.
The slide bearing 5 is mounted on the bottom of the holding member 2 and is fitted inside the holding member 2.

Further, a core 7a is fitted to the outside of the holding member 2, and a winding 7b is wound around the core 7a to form a stator 7 as a stationary member. Further, a shaft 8 which is a rotating member is fitted into the slide bearing 5, a lower end of the shaft 8 is in contact with the thrust receiver 4, and an upper end thereof is arranged to protrude above the holding member 2. A hub member 9 as an interlocking member made of a non-magnetic material such as aluminum is fitted to an upper end portion of the shaft 8, and a yoke member 10 as an interlocking member made of a magnetic material such as iron is attached to the inner cylindrical portion of the hub member 9. 9a.

The yoke member 10 is composed of a substantially disk-shaped base 10a and a hanging part 10b which is integrally formed by hanging downward on the periphery of the base 10a.
a portion around the opening formed at the center of the hub member 9
Is attached to the inner cylindrical portion 9a by caulking. Further, the driving magnet 11 is attached to the hanging portion 1 of the yoke member 10.
0b, and is disposed at a position facing the stator 7.

As shown in FIG. 6, a turntable portion 13 is formed outside the hub member 9, and a clamp magnet 14 is buried in the center of the hub member 9 so as to be substantially flush with the upper surface. This clamp magnet 1
By 4, the disk pressing means (not shown) of the drive unit is magnetically attracted, and the recording disk D is fixed. Then, the direction of current flow to the winding 7b of the stator 7 is controlled, and the stator 7 generates a rotating magnetic field. By repeating the attraction and repulsion of the rotating magnetic field and the static magnetic field with the driving magnet 11, the stationary magnetic field is stopped. The driving magnet 11, the yoke member 10, the hub member 9 and the shaft 8 rotate with respect to the stator 7 in the state, whereby the turntable portion 13 and the recording disk D rotate in a certain direction.

Incidentally, an increase in the speed of the motor may cause an imbalance in weight balance (imbalance) due to a minute dimensional error of each part which has not been a problem until then. As means for correcting such imbalance, a balance correction device is known. Conventionally, as shown in FIG. 6, for example, as shown in FIG. 6, a base portion 13a of a turntable portion 13 of a hub member 9, an inner cylindrical portion 9a on a lower surface thereof, and an outer cylindrical portion concentric with the inner cylindrical portion 9a. A moving path 16 composed of an annular space is formed by the portion 9b and the base 10a of the yoke member 10, and a spherical body 17 composed of a plurality of steel balls is accommodated in the moving path 16 as a balance body so as to be movable in the circumferential direction. A recording disk drive motor 19 incorporating this is proposed. However, the vertical distance of the moving path 16 is the sphere 1
It is desirable to set the diameter so as not to be more than twice as large as the diameter of 7.

Specifically, as described in JP-A-10-92094 and JP-A-10-188465,
2. Description of the Related Art A balance correcting device has been considered for a motor for driving a disk such as a CD-ROM.

[0010]

However, CD-ROMs
In such a recording disk D, various printings are performed on the surface opposite to the recording surface, and a slight imbalance may occur in the recording disk D due to the weight of the ink used for printing. However, if the unbalance is extremely small, the balance correction device 18 cannot completely correct the unbalance, and the recording disk D with extremely small unbalance is not available.
In the case of the motor 19 which is mounted and rotated, there is a case where a problem occurs in which the rotational vibration becomes larger when the balance correction device 18 is provided than when the balance correction device 18 is not provided.

The motor 19 having the unbalanced recording disk D or the like and rotated and provided with the above-described balance correcting device 18 has the same structure as the motor 1 having the same configuration.
Even with 9, there is a problem with reproducibility that the vibration value of the rotational shake changes every time it is started.

The cause of these problems is that the frictional force acting on the sphere 17 in the balance correction device 18 is closely involved during rotation of the motor, and this frictional force causes the sphere 17 to move to the balance correction point. Cannot be moved accurately to a certain area including this point,
It will stop at an unbalanced position. Also,
An eccentric arrangement of the movement path 16 with respect to the shaft 8 may also be involved.

Therefore, in order to reduce the frictional force, the moving path 16 is processed smoothly and the roundness is improved, and
In order to make the contact area with the sphere 17 as small as possible, it is conceivable to use a hard material, for example, a metal such as stainless steel as the material forming the moving path 16. In addition, in order to prevent the eccentricity of the moving path 16 with respect to the shaft 8, it is conceivable to make the concentricity of the shaft 8 and the moving path 16 as small as possible.

However, when metal is used as the material of the moving path 16, a hula hoop phenomenon occurs in which the frictional force is too small and the sphere 18 cannot follow the rotational speed of the moving path 16, and as a result, the balance correction function is exhibited. A new problem arises in that both vibration and noise increase.

Therefore, as a constituent material of the moving path 16,
It is conceivable to use a resin material such as polycarbonate, but in the case of resin, it is difficult to solve the above-mentioned problems of frictional force and workability.

Accordingly, the present invention provides a balance correction device which has good reproducibility of balance correction and is capable of correcting minute imbalances even when the moving path is made of metal, and a rotating device having the same. The purpose is to do.

[0017]

In order to solve the above-mentioned problems, a balance correction device according to the present invention has a configuration in which the side surface of the moving path is made of metal and the lower surface thereof has a vertically projected portion. It is characterized by:

According to such a configuration, when the moving path is rotated by the interlocking member rotating in conjunction with the rotating member, the moving speed of the balance body is slower than the rotating speed of the moving path. When the balancer cannot follow the convex portion formed on the moving path when the balancer cannot follow the balance, the convex portion acts as a movement resistance to the balancer.

In other words, the movement resistance becomes friction, and the balance body is accelerated by the movement resistance so as to follow the rotation of the moving path. The balance body is stationary with respect to the moving path at a balance position that follows the rotation of the road and corrects imbalance.

When the balancer is stationary, the balancer receives centrifugal force and drag from the side of the moving path, but the side is made of metal and has very little friction. for that reason,
Since the circumferential component of the centrifugal force (acting in the direction in which the balance body is moved), which is the driving force for performing the balance correction, is not impaired, the minute imbalance can be effectively corrected.

At this time, even if the side surface of the moving path is made of metal and the friction is extremely small, the balance body can be accelerated by the movement resistance of the convex portion to follow the rotation of the moving path as described above. it can. Further, since the convex portion is in the vertical direction, the roundness of the moving path is not impaired, and the concentricity of the axis of the rotating member and the moving path can be ensured with high accuracy.

Therefore, according to the above-described configuration, when rotating a rotating device such as a motor on which a disk with a small unbalance is mounted, the balance body moves quickly in the moving path, and the minute unbalance is caused. The balance can be corrected reliably and with good reproducibility.

The projection in this case can be easily formed by pressing the lower surface of the moving path made of metal, or by sticking, cutting, injection molding or spray coating of another member. it can.

Further, the balance correcting device according to the present invention is characterized in that a plurality of the convex portions are formed. According to such a configuration, the balance body can be effectively accelerated by the plurality of protrusions, and the balance body can quickly follow the rotation of the moving path as compared with the case where only one protrusion is provided. Become.

Further, the balance correcting device according to the present invention is characterized in that the balance body is made of a rolling element. According to such a configuration, there is an advantage that, when the rolling element is used, the friction when moving in the moving path is small, and the handling when the rolling element is accommodated in the moving path becomes easy.

The rotating device according to the present invention comprises a stationary member and a rotating member rotatably provided on the stationary member, wherein the interlocking member rotates in conjunction with the rotating member, and the interlocking member rotates in conjunction with the rotating member. In a rotating device provided with a balance correcting device including a moving path formed of an annular space formed in a member and a balance body movably accommodated in the moving path, a side surface of the moving path is formed of metal. A vertical projection is formed on the lower surface.

According to this configuration, when the moving path is rotated by the rotation of the interlocking member in conjunction with the rotating member, the moving speed of the balance body is slower than the rotating speed of the moving path. When the balance body cannot follow the convex portion formed on the moving path when the balance body cannot follow, the convex portion acts as a movement resistance to the balance body, and every time the balance body passes over the convex portion. After being accelerated, the balance body follows the rotation of the moving path, and at a balance position where imbalance is corrected, the balance body stands still with respect to the moving path.

At this time, even if the side surface of the moving path is made of metal and the friction is extremely small, the balance body can be accelerated by the movement resistance of the convex portion to follow the rotation of the moving path as described above. it can. Further, since the convex portion is in the vertical direction, the roundness of the moving path is not impaired, and the concentricity of the axis of the rotating member and the moving path can be ensured with high accuracy. Therefore, when rotating a rotating device such as a motor on which a disk with a small unbalance is mounted, the balance body moves quickly in the moving path, and the minute unbalance can be corrected reliably and with good reproducibility.

Further, the rotating device according to the present invention is characterized in that a plurality of the convex portions are formed. According to such a configuration, the balance body can be effectively accelerated by the plurality of protrusions, and the balance body can quickly follow the rotation of the moving path as compared with the case where only one protrusion is provided. Become.

Further, the rotating device according to the present invention is characterized in that the balance body comprises a rolling element. According to such a configuration, there is an advantage that, when the rolling element is used, the friction when moving in the moving path is small, and the handling when the rolling element is accommodated in the moving path becomes easy.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. This embodiment is an example of a CD-ROM drive motor as a rotating device provided with a balance correction device. FIG. 1 is a perspective view showing a schematic configuration of the balance correction device, and FIGS. is there. However, FIG. 6 is also referred to in the following description.

In the present embodiment, the basic structure of the motor is substantially the same as that of the conventional motor described above, and only the following points are greatly different. That is, in the present embodiment, as shown in FIG. 1, the moving path 16 of the balance correction device incorporated in the motor 19 shown in FIG. 6 includes the base 13 a of the turntable 13, the inner cylinder 9 a, and the outer cylinder 9. The moving path 16 is formed on the lower surface (the base 10a of the yoke member 10) with a single mountain-shaped convex portion 31 formed by the portion 9b and the base 10a of the yoke member 10.

At this time, the turntable section 13 itself is formed of stainless steel (hereinafter referred to as SUS), or the side of the turntable section 13 is made of SU.
By fixing the ring plate made of S, the moving path 16
Can be made of metal. However,
The metal in this case is not limited to SUS,
It is preferable to select at least a metal material which can be easily mirror-finished.

As shown in FIG. 1, the base 13a of the turntable portion 13 corresponding to the upper surface of the moving path 16 is provided so that the sphere 17 does not come into contact with the upper surface of the moving path 16 when climbing over the convex portion 31. Also, a mountain-shaped concave portion 32 corresponding to the convex portion 31 is formed. These convex portions 31 and concave portions 32
For example, it can be easily formed by pressing a metal.

Further, since the convex portion 31 and the concave portion 32 are formed in the vertical direction of the moving path 16, there is no eccentricity of the center axis of the moving path 16 with respect to the shaft 8 as shown in FIG. The concentricity with the shaft 8 is maintained with high accuracy. Therefore, vibration due to minute imbalance can be completely removed.

By the way, when the shaft 8 rotates, the hub member 9 and the yoke member 10 rotate in conjunction therewith, and when the moving path 16 rotates in the direction indicated by the white arrow in FIG.
At the beginning of the rotation, the sphere 17 hardly moves and its moving speed V
b is equal to zero, and the moving speed Vb of the sphere 17 is much slower than the rotation speed Vd of the moving path 16 (0 ≒ Vb≪V
d) Since the sphere 17 cannot follow the rotation of the moving path 16, the sphere 17 moves relative to the moving path 16 in the direction of the solid arrow in FIG. 3. However, FIG. 3 shows a state where the moving path 16 is developed.

When the sphere 17 tries to climb over the convex portion 31 formed on the moving path 16, the convex portion 31 acts as a movement resistance to the sphere 17, in other words, as a friction. That is, the manner in which the sphere 17 climbs over the convex portion 31 is as shown in FIG. 4, but the angle between the inclined surface of the convex portion 31 that the sphere 17 is going to climb and the horizontal plane is θ, and the mass of the sphere 17 is M Assuming that the radius of the moving path 16 is r and the velocity component in the parallel direction on the inclined surface of the sphere 17 is V ′, the velocity V of the sphere 17 in the horizontal direction is V = (Vd−V
b), V ′ = (Vd−Vb) cos θ, and the centripetal force acting on the sphere 17 is MV ′ ² / r, so that the direction of the normal drag N of the inclined surface of the projection 31 is opposite to this centripetal force. Therefore, N = MV ′ ² / r = M (Vd−Vb) ² cos ² θ /
r.

Further, assuming that the friction coefficient of the lower surface of the moving path 16 is μ, the friction force acting on the sphere is represented by μN. At this time, since N is MV ′ ² / r, the friction force μN is μN = ΜMV ′ ² / r = μM (Vd−Vb) ² cos
² theta / r becomes, every time the sphere 17 climbs the convexity 31, will undergo friction force μN of this formula.

The sphere 17 is accelerated by this frictional force so as to follow the rotation of the moving path 16, and is gradually accelerated each time the sphere 17 passes over the convex portion 31, and the sphere 17 follows the rotation of the moving path 16. And the sphere 17 stops at the balance position where the imbalance is corrected.

As described above, when the moving speed Vb of the sphere 17 is slower than the rotation speed Vd of the moving path 16 and the sphere 17 cannot follow the rotation of the moving path 16, the sphere 17
When trying to get over the convex portion 31, the convex portion 31 is moved by the moving resistance 1 (friction) with respect to the sphere 17.
6 is accelerated so as to follow the rotation of the sphere 6, so that the sphere 17 is accelerated each time it passes over the convex portion 31 and eventually the sphere 17
Moves at the same speed as the rotation of the moving path 16.

Therefore, in the above embodiment, the moving path 1
Even if 6 is formed of a metal material, the above-mentioned hula hoop phenomenon can be avoided because of the presence of the projections 31. And
Since the side surface of the moving path 16 can be mirror-finished, the sphere 1
The roller 7 can be easily rolled even if it is weak (in this case, the circumferential component of the centrifugal force), so that a minute imbalance can be corrected.

Since the convex portion 31 is vertically oriented, the roundness of the moving path 16 is not impaired, and
It is possible to ensure the concentricity between the robot and the moving path 16 with high accuracy, and it is possible to completely eliminate the vibration due to minute imbalance.

As a result, even when the disk D having little unbalance is mounted on the balance correcting device using metal as the material of the moving path 16, the sphere 17 is moved to the moving path 16.
It is possible to move the inside quickly and to correct minute imbalances reliably and with good reproducibility with a simple configuration.

As another embodiment of the present invention, a plurality of convex portions 31 and concave portions 32 may be formed on the lower surface and the upper surface of the moving path 16 as shown in FIG. The portion 31 allows the sphere 17 to be effectively accelerated, and allows the sphere 17 to quickly follow the rotation of the moving path 16 as compared with the case where only one projection 31 is provided. However, FIG. 5 shows a state in which the moving path 16 is developed, similarly to FIG.

Further, in each of the above-described embodiments, the protrusion 31
Is described by forming a metal by pressing, but a mountain-shaped protrusion made of resin or metal is prepared,
The protrusion may be fixed to the lower surface of the moving path 16 with an adhesive or the like, solidified by spray coating with a liquid, or formed by a method such as cutting or injection molding. The convex portion 31 is not limited to a mountain shape as long as the convex portion 31 has the same function.

Further, in each of the embodiments described above, the case where the present invention is applied to the motor 19 in which the shaft 8 rotates is described. However, the present invention is also applicable to an inner rotor type motor and a motor in which the shaft is fixed. Of course, the present invention can also be applied.

The present invention can be applied not only to the motor as in the above-described embodiments but also to all rotating devices which have a rotating member and can cause imbalance during rotation. It is possible.

The present invention is not limited to the above embodiments, and various changes other than those described above can be made without departing from the spirit of the present invention.

[0049]

As described above, according to the first aspect of the present invention, when the moving path rotates due to the rotation of the interlocking member in conjunction with the rotating member, the rotational speed of the moving path is more balanced than that of the moving path. Even if the movement speed of the body is slow and the balance body cannot follow the rotation of the movement path, the balance body can accelerate the balance body when trying to get over the convex part formed on the movement path, The body can follow the rotation of the moving path.

Therefore, when rotating a rotating device such as a motor on which a disk with a small unbalance is mounted, the balance body moves quickly in the moving path, and the minute unbalance is surely achieved by a simple structure. It can be corrected with good reproducibility, and with accurate balance correction,
The rotation of the rotating device can be further stabilized.

According to the second aspect of the present invention, the balance body can be effectively accelerated by the plurality of protrusions, and the balance body can be rotated on the moving path as compared with the case where only one protrusion is provided. Can be quickly followed, and minute imbalance can be reliably corrected.

According to the third aspect of the present invention, if the rolling element is used, the friction when moving in the moving path is small, and the handling when accommodating in the moving path becomes easy.

According to the fourth aspect of the present invention, when the moving path is rotated by the rotation of the interlocking member in conjunction with the rotating member, the moving speed of the balance body is made smaller than the rotating speed of the moving path. Even if the balancer cannot follow the rotation of the moving path lately, the balancer accelerates the balancer and causes the balancer to follow the rotation of the moving path when the balancer tries to get over the convex portion formed on the moving path. It becomes possible.

Therefore, when rotating a rotating device such as a motor on which a disk with a small unbalance is mounted, the balance body moves quickly in the moving path, and the minute unbalance is surely corrected with good reproducibility. Therefore, it is possible to reliably correct a minute imbalance, and to provide a rotating device such as a motor having a stable rotating performance.

According to the fifth aspect of the present invention, the balance body can be effectively accelerated by the plurality of protrusions, and the balance body can be rotated on the moving path as compared with the case where only one protrusion is provided. , It is possible to provide a rotating device such as a motor having a stable rotating performance, which can reliably correct a slight imbalance.

According to the sixth aspect of the present invention, if the rolling element is used, the friction when moving in the moving path can be reduced, and the handling when accommodating in the moving path can be facilitated. We can correct minute imbalance surely,
It is possible to provide a rotation device such as a motor having stable rotation performance.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of one embodiment of the present invention.

FIG. 3 is an operation explanatory diagram of one embodiment of the present invention.

FIG. 4 is an operation explanatory diagram of one embodiment of the present invention.

FIG. 5 is an operation explanatory view of another embodiment of the present invention.

FIG. 6 is a cut-away front view of a conventional example.

[Explanation of symbols]

 2 Holding member (stationary member) 7 Stator (stationary member) 8 Shaft (rotating member) 9 Hub member (interlocking member) 10 Yoke member (interlocking member) 17 Spherical body (balance body) 18 Balance correction device 19 Motor (rotating device) 31 Convex part

Claims (6)

[Claims] An interlocking member that rotates in conjunction with a rotating member, a moving path including an annular space formed in the interlocking member, and a balance body movably accommodated in the moving path. In the balance correction device, a side surface of the moving path is formed of metal, and a vertical protrusion is formed on a lower surface thereof. 2. The balance correction device according to claim 1, wherein a plurality of the protrusions are formed. 3. The balance correction device according to claim 1, wherein the balance body is made of a rolling element. 4. An interlocking member comprising a stationary member and a rotating member rotatably provided with respect to the stationary member, wherein the interlocking member rotates in conjunction with the rotating member, and an annular space formed in the interlocking member. A rotation device provided with a balance correction device including a moving path formed by a moving path and a balance body movably accommodated in the moving path, wherein a side surface of the moving path is formed of metal, and a vertical projection is formed on a lower surface thereof. A rotating device characterized by being formed. 5. The rotating device according to claim 4, wherein a plurality of the protrusions are formed. 6. The rotating device according to claim 4, wherein the balance body is made of a rolling element.