WO2001008149A1 - Rotor balancing mechanism - Google Patents

Abstract

A rotor balancing mechanism (1) has a rotor attaching member (4) and an adjusting mechanism (36). The rotor attaching member (4) has a rotary shaft portion (6) fixed to the rotary shaft (3) of a motor (2) that is a driver, and an elastic connecting portion (8) that elastically connects a rotor attaching portion (7) attaching and supporting a rotor (5) such as a disk in such a manner that the rotor attaching portion (7) is radially movable with respect to the rotary shaft portion (6). The adjusting mechanism (36) has an inside annular portion (27) directly or indirectly attached to the rotary shaft (3), an outside annular portion (28) directly or indirectly attached to the rotor attaching portion (7), and a plurality of rotary members (29) disposed between the inside and outside annular portions (27, 28) and capable of rotary motion on a circumference along the edge of either of the annular portions (27, 28). Further, one of the three parts, the inside annular portion (27), rotary member (29), and outside annular portion (28) is made of magnet, and one of the remainder is made of magnet or magnetic material.

Description

 Specification

 Rotating body balance mechanism

 Technical field

 The present invention relates to a mechanism for suppressing eccentric vibration when rotating a rotating body such as a disk or a turbine at a high speed. More specifically, the present invention relates to a rotating body balance mechanism suitable for a disk drive device for rotating a disk such as a CD (compact disk) and a DVD (digital video disk).

 Background art

 With the spread of disk memories such as CD-ROM, CD-R / W, and DVD-ROM, it is desired to improve the access speed to disks. For example, it has been considered to increase the rotation speed of a disk memory to 24 times or 32 times the rotation speed of a normal CD, but in these cases, the disk rotation speed reaches 5000 to 7000 rpm. . In the future, it is required to increase the rotation speed of the disk, and it may be necessary to increase the rotation speed to about 1000 rpm.

 However, when the disk is rotated at a high speed as described above, a large eccentric vibration occurs when the disk is eccentric, or when the disk is not eccentric and the installation on the turntable is uneven. In particular, discs such as DVDs and CD-ROMs, which are bonded together, are often eccentric and unbalanced, and, for example, current industrial standards in Japan allow eccentricities of up to 1 gcm. Therefore, when the disk is rotated at high speed, eccentric vibration may occur. Furthermore, a label for classification may be attached to CD-R / W, etc., and in this case, eccentric vibration may occur.

When such eccentric vibration occurs, the optical pickup cannot smoothly pick up the reproduced signal, and the read / write accuracy of the signal is reduced. Acoustic noise may occur. In particular, the generation of noise and vibration may shorten the life of the bearing of the disk drive device. On the other hand, if an attempt is made to provide a disk vibration isolator separately from the disk drive device, the entire device becomes large, and it is difficult to install a large vibration isolator. On the other hand, in order to prevent the eccentric vibration of the disk rotating at high speed, an annular magnet 101 is attached to the rotating shaft 100 of the motor, as shown in Fig. 21. An anti-vibration device 104 in which an annular outer wall 102 is provided on the outer periphery and a plurality of steel balls 103 are accommodated between the magnet 101 and the outer wall 102 has been developed. In this vibration isolator 104, the steel ball 103 is separated from the magnet 101 by centrifugal force and is moved to the outer wall 102 by centrifugal force as the motor rotation speed increases, and the motor rotation speed is reduced. When the resonance frequency becomes higher than the resonance frequency of the vibration isolator 104, the steel ball 103 is biased and stabilized in the direction opposite to the direction of the eccentricity F as shown by the two-dot chain line in the figure. As a result, the eccentricity F and the centrifugal force of the steel ball 103 cancel each other out, so that the disk is prevented from being vibrated.

 However, in this anti-vibration device 104, when the high-speed rotation exceeding 500 rpm described above is performed, the steel balls 103 come into close proximity to each other and magnetically interact with each other. In some cases, the anti-vibration effect may be insufficient due to the influence of rolling resistance or the like, and the reproduced signal may not be reliably picked up, and the read / write accuracy of the signal may be reduced. In addition, when a disk having no eccentricity is used, the eccentricity is promoted by friction or deviation of the steel balls 103 in the vibration isolator 104, and eccentric vibration is caused on the contrary.

 Some discs have a disc positioning mechanism so as not to bias the disc on the turntable. However, even with this positioning mechanism, eccentric vibration cannot be prevented if the disk itself is eccentric. In addition, the provision of the positioning mechanism increases the size of the entire apparatus and increases the cost. Here, the problem of the eccentric vibration as described above is not a problem peculiar to the disk, but applies to a rotating body rotating at a high speed, for example, a turbine or a wheel in general.

 Therefore, an object of the present invention is to provide a rotating body balance mechanism capable of minimizing eccentric vibration even when the eccentric rotating body is rotated at high speed.

 Disclosure of the invention

In order to achieve the above object, the present invention provides a rotating body balance mechanism including a rotating body mounting member and an adjusting mechanism, wherein the rotating body mounting member includes a rotating shaft fixed to a rotating shaft of a driving body; A rotating body mounting portion for mounting and supporting the rotating shaft, and a spring so that the rotating body mounting portion can move in the radial direction with respect to the rotating shaft portion. The adjusting mechanism includes an inner annular portion directly or indirectly attached to the rotating shaft, and an directly or indirectly attached to the rotating body attaching portion. An outer annular portion, and a plurality of rotating members rotatable circumferentially along an edge of any of the annular portions provided between the inner annular portion and the outer annular portion. One of the annular portion, the rotating member, and the outer annular portion is constituted by a magnet, and the other is constituted by a magnet or a magnetic material.

 Therefore, when the driving body is not driven, since the plurality of rotating members repel each other due to the magnetic repulsion, they are positioned at equal intervals in a balance in the annular space between the inner annular portion and the outer annular portion. I do.

 When the rotating shaft is rotated by the driving body, the rotating body such as a disk is rotated via the rotating body mounting member. At this time, when the center of rotation of the rotating body and the entire rotating body and the rotating body mounting member coincide with each other, the rotating members are positioned at equal intervals and are balanced, and the elastic connecting portion is deformed. The rotating body rotates smoothly without generating any unnecessary eccentric vibration.

 On the other hand, when the rotating body and the rotating body mounting member are eccentric with respect to the rotation axis, the centrifugal force due to the eccentricity is generated by driving the driving body. As the rotation speed of the rotating shaft increases, the centrifugal force of the rotating body and the rotating body mounting member gradually increases. Then, in the rotating body mounting member, the centrifugal force acts as an external force on the elastic connecting portion via the rotating body mounting portion. As a result, the elastic connecting portion is elastically deformed, and the rotating body attaching portion and the rotating body swing around in the outer circumferential direction. When the rotation speed increases to some extent, the complex vibration of the entire system triggers the rotating body mounting part and the rotating body, which had been swinging around the rotation axis, now rotate around the center of gravity. Try to. In other words, in general, the rotating body behaves like rotating around its own center of gravity, but the rotating body mounting part and the rotating body are also set to the rotation mode that automatically tries to rotate around the center of gravity. Change. Since the rotating body mounting portion is supported by the elastic connecting portion so as to be movable only in the radial direction and is restricted from moving in the axial direction, the rotating body does not swing in the axial direction.

Here, since the elastically deformed elastic connecting portion has a restoring force, the rotating body mounting portion and And the center of rotation of the rotating body is drawn toward the rotating shaft. For this reason, the rotating body mounting part and the rotating body do not necessarily rotate at the position of the center of gravity, and the centrifugal force due to the eccentricity toward the center of gravity of the rotating body mounting part and the rotating body and the rotating shaft side due to the elastic connecting part. It rotates at the equilibrium point with the restoring force. The rotating body mounting part and the rotating body can smoothly rotate at high speed with no eccentric vibration at the equilibrium point without swinging.c On the other hand, in the adjusting mechanism, the rotating speed of the rotating shaft is controlled by the resonance of the entire device. When the frequency is lower than the frequency, the rotating member is swung to the side having the eccentricity. When the rotation frequency of the rotating shaft increases and becomes higher than the resonance frequency of the entire device, a force is applied to the rotating member in a direction opposite to the eccentricity to move in the direction. Since the direction of movement of the rotating member at this time is a direction for canceling the center of gravity, the movement of each rotating member acts as a counterweight and gradually reduces the center of gravity. Eventually, the rotation speed of the rotating shaft stabilizes, the position of the rotating member stabilizes, and the eccentricity is minimized. As a result, eccentric vibration can be minimized even when the eccentric rotating body is rotated at high speed.

 Therefore, the two functions of minimizing the eccentricity using the elastic deformation of the elastic connecting part of the rotating body mounting member and minimizing the eccentricity by moving the rotating member in the adjusting mechanism enable stable and wide eccentricity. Can be minimized.

 Thus, the rotator can be rotated at a high speed while suppressing the eccentric vibration, so that various adverse effects caused by the eccentric vibration can be suppressed. Moreover, since the occurrence of eccentric vibration can be suppressed, vibration fatigue can be suppressed and the life of each member can be prolonged. In addition, since a conventional mechanism for positioning the rotating body is not required, the size and cost of the apparatus can be reduced.

Furthermore, eccentric vibration can be prevented by providing an elastic connecting part in a part of the rotating body mounting member and providing the rotating member and each annular part in the adjusting mechanism, so that complicated equipment like the conventional eccentric vibration suppressing mechanism can be prevented. Thus, the balance mechanism can be provided at low cost without the need for the balance mechanism. In addition, when the rotating body is eccentric, or when the rotating body is eccentrically mounted on the rotating body mounting portion, the rotation center of the rotating body moves and the rotating member moves, so even when there is no eccentricity, The driving body can be rotated at high speed. Therefore, it is possible to rotate all the normally used rotating bodies at high speed without whirling. You.

 Further, by changing the weight of the rotating member, it is possible to cope with various amounts of eccentricity.

 In the present invention, it is preferable that the rotating body mounting member and the adjusting mechanism are arranged side by side in the axial direction. In this case, since the axial length between the rotating body mounting member and the adjusting mechanism can be shortened, the whirling of the balance mechanism due to the rotation of the rotating shaft can be suppressed. In particular, it is preferable that the outer annular portion of the adjusting mechanism is attached to the rotating body mounting portion of the rotating body mounting member. According to this, even when the rotating body mounting portion moves in the radial direction, the outer annular portion can reliably follow.

 In the present invention, when the rotating shaft rotates, the elastic connecting portion is deformed by the eccentricity acting on the rotating body mounting portion, and the rotating body mounting portion moves in the radial direction, and the inner annular portion and the outer annular portion It is preferable that the rotation member moves by changing the distance between the rotating member and the rotating member. According to this, when the rotation of the rotating shaft exceeds the resonance frequency of the balance mechanism, the rotating member moves in a direction in which the interval between the inner annular portion and the outer annular portion becomes narrower and stays at a magnetically stable position. Become like Therefore, since the rotating member moves in the direction of canceling the eccentricity, each rotating member acts as a counterweight so that the eccentricity can be gradually reduced.

 Further, in the present invention, the rotating body mounting portion is a turntable on which a disc is mounted, the rotating shaft is a rotating shaft of the motor, and a holding portion for holding the outer annular portion of the adjusting mechanism is formed on the turntable. You may be.

 In this case, the eccentric vibration can be minimized even when the eccentric disk is rotated at high speed, so that it is possible to suppress the deterioration of the accuracy of reading / writing a signal to / from the disk and the occurrence of various problems due to the vibration.

 Moreover, even if the disk is rotated at a high speed in the future and the rotational speed of the motor is set to, for example, about 100,000 rpm, according to the rotating body balance mechanism of the present invention, the rotating member can be rotated. It is possible to respond sufficiently by changing the weight or adjusting the elastic connecting portion.

In the present invention, two of the outer annular portion, the rotating member, and the inner annular portion are configured by magnets, and the other is configured by a magnetic material. You may. Specifically, three types of configurations are possible.The outer annular portion is an annular magnetic material, the rotating member is a magnet, the inner annular portion is an annular magnet, or the outer annular portion is a circular magnet. An annular magnet, a rotating member made of a magnet, an inner annular portion made of an annular magnetic material, or an outer annular portion made of an annular magnet, a rotating member made of a magnetic material, and an inner annular portion made of an annular magnet Can be

 In any of these cases, it is possible to magnetize both the outer annular portion and the rotating member and between the inner annular portion and the rotating member so as to attract, so the distance between the annular portions changes due to the eccentricity. Then, the rotating member moves in a direction in which the interval between the annular portions is reduced, that is, in a direction in which the magnetic attraction force is strong, and can smoothly move in a direction in which the eccentricity is canceled.

 In particular, when the outer annular portion is made of an annular magnet, the rotating member is made of a magnet, and the inner annular portion is made of an annular magnetic material, the outer annular portion and the rotating member are repelled and the inner annular portion and the rotating member are repelled. Since the rotating members can be magnetized so as to be attracted, when the distance between the annular portions changes due to the eccentricity, the rotating members are moved between the rotating member and the outer annular portion by the magnetic repulsive force with the outer annular portion. The contact pressure due to the acting centrifugal force can be reduced. Therefore, the rotating member can move very smoothly in the direction to cancel the eccentricity.

 When the outer annular portion is an annular magnetic material, the rotating member is a magnet, and the inner annular portion is an annular magnet, suction is performed between the outer annular portion and the rotating member, and between the inner annular portion and the rotating member. In this case, the rotating member can move in a direction in which the interval between the annular portions becomes smaller. Further, in the present invention, the outer annular portion and the inner annular portion may be annular magnets, and the rotating member may be a magnet. In this case, the magnetization direction can be set so as to repel or attract both between the outer annular portion and the rotating member and between the inner annular portion and the rotating member, respectively, so that various operations can be performed. it can.

For example, if the magnet is magnetized so as to attract both the outer annular portion and the rotating member and between the inner annular portion and the rotating member, the rotating member becomes a magnetic member in which the interval between the annular portions becomes narrower. As a result, the eccentricity can be smoothly moved in the direction of canceling.

 In addition, if the outer annular portion and the rotating member are magnetized so as to repel and the inner annular portion and the rotating member are attracted, the rotating member is in contact with the outer annular portion due to the magnetic repulsive force with the outer annular portion. It can move extremely smoothly in the direction to cancel the eccentricity by reducing the contact pressure between them.

 Further, if the outer ring and the rotating member are magnetized so as to repel both the inner ring and the rotating member, a centrifugal force is applied to the rotating member to reduce the distance between the annular members. It can be moved in the narrowing direction. At this time, the rotating member can reduce the contact pressure due to the centrifugal force by the magnetic repulsive force with the outer annular portion, so that the rotating member can move very smoothly in the direction of canceling the eccentricity.

 Alternatively, if the outer annular portion and the rotating member are magnetized so as to be attracted while the inner annular portion and the rotating member are repelled, the rotating member is rotated when the interval between the annular portions changes due to the eccentricity. It is possible to move in a direction in which the interval between the parts becomes smaller. Further, in the present invention, one of the outer annular portion, the rotating member, and the inner annular portion may be configured by a magnet, and the other two may be configured by a magnetic material. Specifically, three types of configurations are possible, with the outer annular portion being an annular magnetic material, the rotating member being a magnetic material, the inner annular portion being an annular magnet, or the outer annular portion being a circular magnet. An annular magnet, a rotating member made of a magnetic material and an inner annular portion made of an annular magnetic material, or an outer annular portion made of an annular magnetic material, a rotating member made of a magnet, and an inner annular portion made of a circle It can be an annular magnetic material.

 In any of these cases, suction is performed between both the outer annular portion and the rotating member and between the inner annular portion and the rotating member. Since it moves in the direction of strong suction force, it can move smoothly in the direction to cancel the eccentricity.

 In these cases, the number of components can be minimized without using a yoke by using an inner annular portion or an outer annular portion made of an annular magnet.

In addition, use an inner annular portion or an outer annular portion made of an annular magnetic material. Accordingly, each annular portion forms a magnetic path, and the rotating members can repel each other with magnetic force from the rotating member so as to be balanced. At this time, if one of the annular portions is made of a magnet, the rotating members can be repelled by only one annular magnet. On the other hand, in the present invention, the outer annular portion may be made of an annular non-magnetic material, and at least one of the rotating member and the inner annular portion may be made of a magnet. Specifically, there are three possible configurations: the rotating member is a magnet, the inner annular portion is an annular magnet, or the rotating member is a magnet, and the inner annular portion is an annular magnetic material. Alternatively, the rotating member may be a magnetic material and the inner annular portion may be an annular magnet. In these cases as well, when the elastic connecting portion radially changes due to the eccentricity and the interval between the outer annular portion and the inner annular portion changes, the rotating member is moved toward the outer annular portion of the non-magnetic material by centrifugal force during high-speed rotation.

 The case where both the rotating member and the inner annular portion are made of a magnet and magnetized so that they are attracted, and the case where the rotating member and the inner annular portion are configured by a combination of a magnet and a magnetic material are as follows. However, since neither suction nor repulsion occurs between the outer annular portion and the rotating member, and suction occurs between the inner annular portion and the rotating member, when the interval between the annular portions changes due to the eccentricity, the rotating member is moved to the outer annular portion. The contact pressure due to the centrifugal force acting between the rotating member and the outer annular portion without being sucked can be reduced. Therefore, the rotating member can smoothly move in the direction to cancel the eccentricity by the balance between the centrifugal force and the suction force by the inner annular portion.

 When both the rotating member and the inner annular portion are made of magnet and magnetized so that they are repelled, a centrifugal force is applied to the rotating member to reduce the distance between the annular portions. Can be moved in any direction. At this time, since the rotating member can reduce the contact pressure with the outer annular portion without being sucked by the outer annular portion, the rotating member can move smoothly in the direction of canceling the eccentricity.

On the other hand, in the present invention, it is preferable that the magnet is magnetized in the axial direction. In this case, the magnet can be arranged with one end in the axial direction as the N pole and the other end as the S pole, so that the attraction and repulsion of the magnets can be easily set. Further, in the present invention, the magnet may be provided with a yoke made of a magnetic material on at least one side in the axial direction. In this case, since the magnetic flux from each magnet can be concentrated at both axial ends of the rotating member via the yoke, N and S poles of strong magnetic force are formed at both axial ends of each rotating member. Can be. For this reason, the repulsive force between adjacent rotating members increases, so that even if each magnet is miniaturized, the center of rotation of the rotating shaft and the entire rotating body and the rotating body mounting member coincide with each other. In this case, the rotating members can be positioned at equal intervals to achieve balance.

 In the present invention, the rotating member may be formed of a roller having a substantially cylindrical outer peripheral surface, and the roller may be formed to have a longer axial dimension than a diameter. In this case, the distance between the magnetic poles of each roller, that is, the axial dimension can be made relatively large, so that the influence ratio of the repulsive force between adjacent rollers can be increased. Here, the fact that the outer peripheral surface of the rotating member has a substantially cylindrical shape means that not only an accurate cylindrical shape but also a shape in which the central portion in the longitudinal direction is depressed, a shape in which the central portion in the longitudinal direction protrudes, and a shaft. It is intended to include a cylindrical shape having a hole along the direction, and the point is that the shape may be such that it can smoothly move in contact with the annular portion.

 In the present invention, the rotating member may be formed of a roller having a substantially cylindrical outer peripheral surface, and the roller may be formed to have a smaller axial dimension than a diameter. For this reason, since the roller can be formed in a flat disk shape, the balance mechanism can be made thinner.

 In the present invention, it is preferable that a regulating member that regulates the movement of the rotating body mounting portion in the radial direction to a predetermined amount is provided. According to this, when the rotating body mounting portion rotates at high speed while being eccentric, it rotates while contacting the regulating member. Therefore, complicated vibration can be easily generated in the rotating body mounting portion, and the complicated vibration is a trigger, and the rotating body mounting portion and the rotating body are automatically integrated as a unit and centered on the center of gravity. The mode changes to a rotation mode that rotates.

 BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a central longitudinal sectional side view showing an embodiment of a disk drive device equipped with a rotating body balance mechanism of the present invention. Fig. 2 is a plan view showing the rotating member when it is not rotating. Fig. 3 is a plan view showing the rotating member during high-speed rotation. Fig. FIG. 4 is an exploded view showing the disk drive device. Fig. 5 is a perspective view showing the evening table. Fig. 6 is a side view showing the state cut along the line VI-VI in Fig. 5. Fig. 7 is a plan view showing a state before and after the elastic connection portion is deformed. Fig. 8 is a vertical cross-sectional side view showing the disk drive unit with the bracket open. Fig. 9 is a plan view showing the disk drive device. Fig. 10 is a plan view showing the positional relationship of the rotation center with respect to the rotation axis. Fig. 11 is a longitudinal sectional side view showing another embodiment of the balance mechanism. Fig. 12 is a perspective view showing another embodiment of the balance mechanism. Fig. 13 is a vertical cross-sectional side view showing a balance mechanism in which the outer annular portion is a magnet, the rotating member is a magnet, and the inner annular portion is a magnetic material. Fig. 14 is a vertical cross-sectional side view showing another balance mechanism in which the outer annular portion is a magnet, the rotating member is a magnet, and the inner annular portion is a magnetic material. Fig. 15 is a vertical cross-sectional side view showing a balance mechanism in which the outer annular portion is a magnetic material, the rotating member is a magnet, and the inner annular portion is a magnet. Fig. 16 is a vertical cross-sectional side view showing a balance mechanism in which the outer annular portion is a magnet, the rotating member is a magnetic material, and the inner annular portion is a magnetic material. FIG. 17 is a longitudinal sectional side view showing a balance mechanism in which the outer annular portion is a magnet, the rotating member is a magnet, and the inner annular portion is a magnet. Fig. 18 is a perspective view showing another embodiment of the balance mechanism. Fig. 19A and Fig. 19B both show an embodiment of a rotating member whose central portion in the axial direction protrudes to the outer peripheral side. Fig. 20 is a plan view showing another embodiment of the turntable. Fig. 21 is a plan view showing a vibration isolator of a conventional disk drive.

 BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the configuration of the present invention will be described in detail based on an embodiment shown in the drawings.

1 to 10 show an embodiment in which the balance mechanism 26 of the rotating body 5 of the present invention is mounted on the disk drive device 1 for CD. The balance mechanism 26 of the rotating body 5 includes a rotating body mounting member 4 that supports the rotating body 5 and an adjusting mechanism 36 that suppresses eccentric vibration of the rotating body 5.

The rotating body mounting member 4 includes a rotating shaft portion 6 fixed to the rotating shaft 3 of the driving body 2, a rotating body mounting portion 7 for mounting and supporting the rotating body 5, a rotating shaft portion 6, and a rotating body mounting portion 7. The rotating body mounting part 7 has elasticity so that it can move in the radial direction with respect to the rotating shaft part 6. And an elastic connecting portion 8 for connecting the two. The adjusting mechanism 36 includes an inner annular portion 27 directly or indirectly attached to the rotating shaft 3, an outer annular portion 28 directly or indirectly attached to the rotating body attaching portion 7, and an inner annular portion. A plurality of rotating members 29 disposed between the outer ring 27 and the outer annular part 28 and rotatable on the circumference along the edge of one of the annular parts 27 and 28. . One of the inner annular portion 27, the rotating member 29, and the outer annular portion 28 is formed of a magnet, and the other is formed of a magnet or a magnetic material. . In the present embodiment, each of the annular portions 27 and 28 is made of a magnet, and the rotating member 29 is made of a magnetic material.

 When the rotating body 5 and the rotating body mounting member 4 are eccentric with respect to the rotating shaft 3, as shown in FIG. 10, the rotating body mounting portion 7 and the rotating body 5 are oriented toward their centers of gravity 23. Rotating at the equilibrium point 2 4 between the centrifugal force F 2 due to the eccentricity to be covered and the restoring force F 1 on the rotating shaft 3 side by the elastic connecting portion 8, the rotating member 29 as shown in FIG. The force acts in the opposite direction to the center of gravity and moves in that direction, acting as a counterweight. Therefore, the two functions of minimizing the eccentricity using the elastic deformation of the elastic connecting portion 8 of the rotating body mounting member 4 and minimizing the eccentricity by moving the rotating member 29 correspond to a stable and wide eccentricity. As a result, the center of gravity can be minimized.

 The disk drive 1 equipped with the balance mechanism 26 of the rotating body 5 mounts the disk 5 as a rotating body on a turntable 4 as a rotating body mounting member attached to a rotating shaft 3 of a motor 2 as a driving body. Then, by rotating the rotating shaft 3, the disk 5 is rotated via the evening table 4. In the present embodiment, the rotating body mounting portion is the mounting portion 7 and the holding portion is the flange portion 13.

The balance mechanism 26 is provided with a regulating member 9 for regulating the movement of the mounting portion 7 in the radial direction to a predetermined amount. The restricting member 9 is attached to the rotating shaft 3 of the motor 2 and abuts against the flange portion 13 formed on the mounting portion 7 of the turntable 4 so that the disc 5 and the mounting portion 7 have a certain size. The displacement is regulated. Then, the outer annular portion 28 is attached to the turntable 4, and the inner annular portion 27 is attached to the rotating shaft 3 via the regulating member 9. In the present embodiment, the inner annular portion 27 and the outer annular portion 28 are formed of annular magnets 30, 31, and yoke 3 made of magnetic material disposed at both axial ends of the magnets 30, 31. 2, 3 3, 3 4, 3 5 are provided. Further, the rotating member 29 is made of a magnetic roller. For this reason, the magnetic flux from each magnet 30, 31 can be concentrated at both axial ends of the rotating member 29 via the yokes 32, 33, 34, 35. N poles and S poles with strong magnetic force can be formed at both axial ends.

 Further, two rotating members 29 are provided. Each rotating member 29 has a so-called rod shape having an axial dimension longer than its diameter. For this reason, the interval between the magnetic poles of the rotating members 29 can be made larger than the diameter, so that the influence ratio of the repulsive force between the adjacent rotating members 29 can be increased.

 The rotating member 29 has a substantially cylindrical shape. That is, the rotating member 29 has not only an accurate columnar shape, but also a concave shape at the center in the longitudinal direction, a shape protruding at the center in the longitudinal direction, and a cylindrical shape having a hole along the axial direction. Includes. The contact between the rotating member 29 and each of the annular portions 27 and 28 may be line contact or point contact. The point is that the shape should be such that it can smoothly move in contact with the annular portion.

 The relationship between the diameter and the axial dimension of each rotating member 29 is set in accordance with the overall size and weight of the balance mechanism 26, and the size of the eccentricity that can be minimized. For example, by making the axial dimension shorter than the diameter of the rotating member 29 and forming it into a flat disk shape as shown in FIG. 18, the balance mechanism 26 can be made thinner. As a result, the size and weight of the disk drive device equipped with the balance mechanism 26 can be reduced. Alternatively, the diameter and the axial dimension of the rotating member 29 may be substantially the same length.

As shown in FIGS. 5 and 6, the turntable 4 is made of plastic, and the rotating shaft 6, the mounting part 7, and the elastic connecting part 8 are integrally formed by injection molding or the like. Therefore, the turntable 4 can be manufactured easily and inexpensively. In particular, since the elastic connecting portion 8 is formed of three leaf springs having a simple shape, the mold for forming the unit table 4 as a plastic molded product can be simplified and easily formed. Can be For this reason, the evening table 4 can be manufactured at low cost. The rotating shaft 6 of the turntable 4 is cylindrical and fitted to the rotating shaft 3 of the motor 2 and is fixed by press-fitting. The mounting portion 7 of the turntable 4 has a substantially disk shape, and includes a cylindrical boss portion 10 formed around the elastic connecting portion 8. For example, a metal cap 11 is attached to the boss 10. The disc 5 can be positioned by fitting the center hole of the disc 5 into the cap 11. The mounting section 7 supports the center of the disk 5. Here, a rubber sheet 12 is provided on a surface of the mounting portion 7 on which the disk 5 is mounted. For this reason, it is possible to prevent the disk 5 from slipping with respect to the evening table 4 and to suppress the transmission of the vibration from the mounting portion 7 to the disk 5.

 An elastic connecting part 8 is formed between the rotating shaft part 6 and the boss part 10 of the placing part 7. The elastic connecting portion 8 is composed of a leaf spring having three arms as shown in FIGS. The arm portion of each leaf spring has three straight portions, and is substantially N-shaped so that the straight portions at both ends are parallel to the radial direction and the central straight portion is parallel to the circumferential direction (or turned over). ) Is formed. For this reason, each arm is likely to bend in the radial direction. The movement of one arm is such that when an external force is applied in the radial direction, the central straight part is radially charged and when an external force is applied in the circumferential direction, the straight parts at both ends are bent and stored. Is done. Thus, when centrifugal force acts on the mounting portion 7 due to the eccentricity of the disk 5 when the turntable 4 rotates, the leaf spring is deformed and the mounting portion 7 and the disk 5 move in the radial direction or the circumferential direction. . For example, as shown in Fig. 7, when rotating without eccentricity or when it has not yet rotated, the rotating shaft 3 is located at the center of the boss 10 (shown by a two-dot chain line in the figure). ). On the other hand, when rotating with an eccentricity, the rotating shaft 3 deforms the elastic connecting portion 8 and is eccentric with respect to the boss portion 10 (shown by a solid line in the figure).

Further, the elastic connecting portion 8 is formed to be long in the axial direction so as to prevent the mounting portion 7 from being displaced in the axial direction. That is, the elastic connecting portion 8 has a thickness (height) that provides sufficient strength in the axial direction. Accordingly, the displacement of the mounting portion 7 in the axial direction can be prevented, so that vibration along the surface direction of the disk 5, that is, surface runout can be prevented. An outer annular portion 28 is provided inside the flange portion 13 of the mounting portion 7. Outside The annular portion 28 and the flange portion 13 are fixed to each other by press-fitting or bonding the upper yoke 34, the magnet 31, and the lower yoke 35 in order. The magnet 31 of the outer annular portion 28 is magnetized in the axial direction so that the upper portion becomes the N pole and the lower portion becomes the S pole.

 The restricting member 9 is fitted to the rotating shaft 3 to restrict the displacement of the mounting portion 7 beyond a certain level. The restricting member 9 has a substantially disk shape having a fixed portion 14 which is a boss at the center, and is arranged closer to the motor 2 than the turntable 4 and press-fits the fixed portion 14 to the rotating shaft 3. A gap of about 0.3 to 0.5 mm should be provided between the fixed part 14 and the body of the motor 2 to avoid contact.

 The outer peripheral surface of the regulating member 9 is located inside the flange portion 13 of the mounting portion 7. Then, the gap G between the outer peripheral surface of these regulating members 9 and the inner peripheral surface of the flange portion 13 is set to, for example, about 0.4 mm. For this reason, when the mounting portion 7 is displaced radially by the gap G due to centrifugal force during the rotation of the evening table 4, the flange portion 13 contacts the regulating member 9 and cannot be further displaced.

 Here, the distance between the regulating member 9 and the flange portion 13 can be set based on the magnitude of the amount of eccentricity of the disk 5 and the rotation speed at which the flange portion 13 comes into contact with the regulating member 9. For example, the amount of eccentricity of the disk is 1 cm, which is the maximum allowable value of the current Japanese industrial standard, and when the disk rotation speed reaches approximately 200 rpm, the flange portion 13 becomes a regulating member. In order to come into contact with 9, the distance between the regulating member 9 and the flange 13 is preferably about 0.4 mm.

 An inner annular portion 27 is provided outside the fixing portion 14 of the regulating member 9. The fixing between the inner annular portion 27 and the fixing portion 14 is performed by the lower yoke 33 and the magnet 30. And the upper yoke 32 are press-fitted or bonded in order. The magnets 30 and 31 of the inner annular portion 27 are magnetized in the axial direction so that the upper portion becomes the S pole and the lower portion becomes the N pole.

For this reason, between the outer annular portion 28, the inner annular portion 27, and the rotating member 29, the upper yoke 34 of the outer annular portion 28 above the rotating member 29 as shown in FIG. A magnetic path toward the upper yoke 32 of the inner annular portion 27 is formed, and a lower yoke 33 of the inner annular portion 27 and a lower portion of the rotating member 29 from the outer annular portion 28 are formed. Lower A magnetic path toward the yoke 35 is formed (each indicated by an arrow in the figure). As a result, the upper and lower portions of each rotating member 29 are equivalent to being magnetized to the same polarity, and the two rotating members 29 are magnetically repelled.

 Furthermore, the radial distance between the outer annular portion 28 and the inner annular portion 27 is set so that each rotating member 29 can move in the circumferential direction even when the mounting portion 7 moves to the maximum in the radial direction. I do. Further, the outer annular portion 28, the inner annular portion 27, and the rotating members 29 have substantially the same height. A gap is provided between the yoke 35 below the outer annular portion 28 and the regulating member 9 and between the yoke 32 above the inner annular portion 27 and the elastic connecting portion 8. Have been. The height of each rotating member 29 is smaller than the distance between the regulating member 9 and the mounting portion 7. Therefore, the outer annular portion 28, the inner annular portion 27, and the rotating members 29 do not hinder the relative movement between the regulating member 9 and the mounting portion 7.

 Further, since each rotating member 29 is sucked from both the outer annular portion 28 and the inner annular portion 27, it may be sucked into either annular portion. When the rotation is stopped because it is sucked by the part 28, the state is held by the outer annular part 28 as it is.

 On the other hand, the motor 2 is installed on the disk drive 1 by the bracket 15. A holder 16 for fixing the disk 5 to the turntable 4 is provided at a position facing the center of the turntable 4. The holder 16 includes a magnet hole 18 for accommodating a magnet 17 to be attracted to face the cap 11, an annular fixed protrusion 19 for pressing the disk 5 against the evening table 4, and a holder 1. 6 has a flange portion 20 which is locked to a bracket 21 supporting the flange portion 20 to prevent it from falling off. When the disk 5 is fixed to the table 4, the magnet 17 is brought close to the cap 11 so as to have a slight gap. Press 5 against turntable 4.

The bracket 21 supporting the holder 16 can swing about the rotation axis C with respect to the disk drive device 1 as shown in FIG. Then, as shown in FIG. 1, when the bracket 21 is brought close to the turntable 4, the holder 16 and the evening table 4 hold the disc 5 therebetween. On the other hand, as shown in Fig. 8, When the bracket 21 is separated from the turntable 4, the entire unit including the dinner table 4 supporting the disk 5 is moved horizontally, and the disk 5 is removed from below the bracket 21. I do. Further, a stop plate 22 located on the opposite side of the holder 16 from the evening table 4 is screwed to the bracket 21 to prevent the holder 16 from dropping off.

 The operation when the disk 5 is rotated at a high speed by the disk drive device 1 described above will be described below.

 As shown in Fig. 8, the loading of the disc 5 is performed by opening the bracket 21 and placing the disc 5 on the evening table 4 and closing the bracket 21. As a result, the magnet 17 of the holder 16 and the cap 11 of the turntable 4 attract each other, and the disk 5 is fixed to the turntable 4 by the holder 16. Then, the motor 2 is driven to rotate the rotating shaft 3.

 If the disk 5 is eccentric due to the eccentricity of the disk 5 or the disk 5 is not properly installed on the evening table 4, etc., the rotation speed of the rotating shaft 3 is reduced. The centrifugal force of the disk 5 gradually increases with the rise. At a low speed of, for example, 200 rpm or less, the centrifugal force becomes an external force to the elastic connecting portion 8 via the mounting portion 7, and the elastic connecting portion 8 is elastically deformed, and the mounting portion 7 and the disk 5 are rotated. The rotating member such as the holder 16 swings in the outer peripheral direction. In the present embodiment, the clearance G between the flange portion 13 and the regulating member 9 is set to 0.4 mm, so that the whirling of the mounting portion 7 in the outer peripheral direction is also restricted to 0.4 mm. Here, since the elastic connecting portion 8 has a thickness having sufficient strength in the axial direction, the displacement of the mounting portion 7 in the axial direction is prevented, and the surface runout of the disk 5 is suppressed.

When the rotation speed of the motor 2 reaches about 2000 rpm, the flange portion 13 of the mounting portion 7 rotates while contacting the regulating member 9. When the rotation speed further increases, the mounting portion 7 generates vibration due to contact with the restricting member 9, and the flange portion 13 rotates while hitting the restricting member 9, generating vibration. Evening 2 and bracket 15 will also vibrate. For this reason, complicated vibrations occur in the mounting section 7. Here, since the regulating member 9 is annular, the mounting portion 7 always comes into contact with the regulating member 9 while whirling at high speed. Yo Thus, complicated vibration can be easily generated in the mounting section 7.

 The mounting part 7 and the disk 5, which had been oscillating around the rotation axis 3 until then due to the complex vibration of the whole system, became the mounting part 7 as shown in Fig. 10. And about the center of gravity 23 of the disk 5. In other words, a complicated vibration of the mounting part 7 is used as a trigger to set the rotation mode such that the mounting part 7 and the disk 5 automatically rotate about the center of gravity 23 as in a general rotating body. Try to change.

 In the present embodiment, in order to rotate the disk 5 around the center of gravity 23, the position of the center of gravity 23 and the position of the rotation axis 3 are substantially matched by the elastic connecting portion 8 being radiused. As a result, the eccentricity is canceled, and a smooth transition to high-speed rotation without eccentric vibration is enabled. However, actually, the elastically deformed elastic connecting portion 8 has a restoring force F 1, so that the center of rotation of the mounting portion 7 and the disk 5 is drawn to the rotating shaft 3. For this reason, the mounting portion 7 and the disk 5 do not necessarily rotate at the center of gravity position 2 3, and the centrifugal force F 2 due to the eccentricity toward the center of gravity 23 of the mounting portion 7 and the disk 5 and the elastic connecting portion 8 Then, it rotates at the equilibrium point 2 4 with the restoring force F 1 on the rotating shaft 3 side. In other words, the restoring force F1 and the centrifugal force F2 act in opposite directions, so that the two forces F1 and F2 are balanced on the line connecting the rotation axis 3 and the position of the center of gravity 23, minimizing eccentric vibration. High speed rotation of the disk 5 is realized as the rotation center.

 Further, the flange portion 13 of the mounting portion 7 does not come into contact with the regulating member 9 due to a change in the rotation center position of the mounting portion 7 and the disk 5. The mounting portion 7 and the disk 5 can rotate at the equilibrium point 2 close to the center of gravity 23 without eccentric vibration, and can rotate stably at high speed without contacting the regulating member 9. it can. In addition, it is possible to smoothly change the position of the rotation center of the mounting unit 7 and the disk 5. Furthermore, even if the rotation speed of the motor 2 is increased from 2000 rpm to, for example, about 1000 rpm, the mounting portion 7 and the disk 5 can be rotated stably.

On the other hand, when the eccentricity occurs in the rotation of the disk 5, the eccentricity is minimized by the movement of the rotating member 29 at the same time as the eccentricity is reduced by the deformation of the elastic connecting portion 8 described above. First, when the disk 5 is not rotating, as shown in Figs. 1 and 2, the rotating members 29 face 180 ° due to magnetic repulsion. Is assumed to remain in a magnetically balanced position.

 Then, when the rotation shaft 3 starts rotating and the rotation speed is lower than the resonance frequency of the entire device, the rotation member 29 is swung to the side with the eccentricity. When the rotation speed further increases and becomes higher than the resonance frequency of the entire device, a force in the direction opposite to the eccentricity acts on the rotating member 29 to move the rotating member 29 in that direction. Since the direction of canceling the eccentricity, which is the moving direction of the rotating member 29, is on the side where the interval between the inner annular portion 27 and the outer annular portion 28 becomes narrower, the plurality of rotating members 2 9 (two in this embodiment) can move quickly using the magnetic action, and can cancel the eccentricity. That is, since the magnetically attracting force is stronger in the portion where the interval between the annular portions 27 and 28 is narrower than in the portion where it is wide, the rotating members 29 are arranged in the direction in which the interval between the annular portions 27 and 28 is narrower. That is, it can move smoothly in the direction to cancel the eccentricity.

 As shown in Fig. 3, in the final stable state, the rotating member 29 stops rotating and rotates at a fixed position, and the eccentricity is minimized. As described above, the stable and wide eccentricity is achieved by the two actions of minimizing the eccentricity using the elastic deformation of the elastic connecting portion 8 of the turntable 4 and minimizing the eccentricity by moving the rotating member 29. Accordingly, it is possible to minimize the eccentricity.

 On the other hand, if the disk 5 is not eccentric and the installation of the disk 5 on the evening table 4 is balanced and the disk 5 and the turntable 4 are not eccentric, each rotating member 29 is Even when the motor 2 is rotated at high speed, the disc 5 and the evening table 4 do not swing and rotate smoothly around the rotating shaft 3 of the motor 2 because the motor 2 is rotated at high speed. can do.

As described above, according to the balance mechanism 26 of the present embodiment, the disk 5 can be rotated at high speed without causing eccentric vibration, so that the accuracy of reading and writing data to the disk due to the eccentric vibration is reduced, and other devices are used. High-speed rotation of the disk 5 can be realized while preventing adverse effects due to vibration on the disk, generation of acoustic noise, and the like. In addition, since the occurrence of eccentric vibration can be suppressed, vibration fatigue can be prevented, and the life of members such as the motor 2 can be extended. In addition, since a conventional mechanism for positioning the disk 5 is not required, the size and cost of the apparatus can be reduced. Furthermore, eccentric vibration can be prevented by providing the elastic connecting portion 8 on a part of the turntable 4 and providing the rotating member 29 and each of the annular portions 27, 28. The balance mechanism can be provided at low cost without requiring complicated equipment.

 In addition, when the disk 5 is eccentric, or when the disk 5 is mounted eccentrically on the mounting portion 7, the rotation center of the disk 5 moves and the rotating member 29 moves, so even when there is no eccentricity, Motor 2 can be rotated at high speed. Therefore, all the disks 5 normally used can be rotated at high speed without whirling. Further, by changing the weight of the rotating member 29, it is possible to cope with various amounts of eccentricity.

 In addition, if the rotation speed of the disk 5 is increased in the future and the rotation speed of the motor 2 is set to about 1000 rpm, for example, the weight of the rotating member 29 is changed or the elastic connection is performed. It is possible to respond sufficiently by adjusting the part 8.

 The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the inner annular portion 27 and the outer annular portion 28 are provided with two strokes 32, 33, 34, 35, respectively. As shown in FIG. 11, it may be possible to form only a magnet without a yoke. According to this, the number of parts can be minimized. Also in this case, it is possible to minimize the eccentricity due to the movement of the rotating member 29.

Further, in the present embodiment, the magnets 30 and 31 are provided on the inner annular portion 27 and the outer annular portion 28 and the rotating member 29 is made of a magnetic material. As shown, the inner annular portion 27 and the outer annular portion 28 may be made of an annular magnetic material, and each rotating member 29 may be made of a magnet roller. In this case, each rotating member 29 is magnetized in the axial direction so that each rotating member 29 repels, and the polarity of the upper side of each rotating member 29 and the polarity of the lower side are the same. To According to this, the rotating members 29 can be repelled without using an annular magnet. Also in this case, it is possible to minimize the eccentricity by moving the rotating member 29. Further, in the present embodiment, both the inner annular portion 27 and the outer annular portion 28 are formed of an annular magnetic material or an annular magnet, but the present invention is not limited to this. If at least one of the three members of the inner rectangular portion 27, the outer annular portion 28, and the rotating member 29 is a magnet, the rotating members 29 can be repelled from each other. The effect can be achieved.

 For example, two of the outer annular portion 28, the rotating member 29, and the inner annular portion 27 may be made of a magnet, and the other one may be made of a magnetic material. In this case, specifically, three configurations are possible. For example, as shown in Fig. 13 and Fig. 14, the outer annular part 28 is an annular magnet, the rotating member 29 is a magnet, and the inner part is a magnet. The annular portion 27 is an annular magnetic material, or the outer annular portion 28 is an annular magnetic material, the rotating member is a magnet 29, and the inner annular portion 27 is an annular magnet. Alternatively, the outer annular portion 28 may be an annular magnet, the rotating member 29 may be a magnetic material, and the inner annular portion 27 may be an annular magnet.

 In any of these cases, it is possible to set so that both the space between the outer annular portion 28 and the rotating member 29 and the space between the inner annular portion 27 and the rotating member 29 can be sucked. When the interval between the annular portions 27 and 28 changes, the rotating member 29 moves in the direction in which the interval between the annular portions 27 and 28 becomes narrow, that is, the direction in which the magnetic attraction force is strong. The eccentricity can be smoothly moved in the direction to cancel. For example, as shown in Figs. 13 and 14, the inner annular portion 27 is made of an annular magnetic material and the outer annular portion 28 is made of an annular magnet or a magnet with a yoke. The rotating member 29 may be a magnet roller. At this time, the magnet of the outer annular portion 28 and the magnet of the rotating member 29 are respectively magnetized in the axial direction, but the outer annular portion 28 and the rotating member 29 are attracted (Fig. 13) or the outer annular portion 28 and the rotating member 29 may be repelled (Fig. 14).

As shown in Fig. 13, when the outer ring 28 and the rotating member 29 are magnetized, the outer ring 28 and the rotating member 29 and the inner ring 27 And both rotating members 29 are in the suction state, so that it is smooth in the direction to cancel the eccentricity. It can move smoothly.

 As shown in Fig. 14, when the outer annular portion 28 and the rotating member 29 are magnetized so as to repel, the outer annular portion 28 and the rotating member 29 repel, and the inner annular portion Since the rotating member 29 and the rotating member 29 are in a suction state, when the distance between the outer annular portion 28 and the inner annular portion 27 changes due to the eccentricity, the rotating member 29 The contact pressure due to the centrifugal force acting between the rotating member 29 and the outer annular portion 28 due to the magnetic repulsion can be reduced, and the center of gravity can be moved very smoothly to the position where it can be canceled.

 Further, the outer annular portion 28 may be an annular magnetic material, the inner annular portion 27 may be an annular magnet or a magnet with a yoke, and the rotating member 29 may be a magnet roller. In this case, the outer annular portion 28 and the rotating member 29 are always in a suction state. The magnet of the inner annular portion 27 and the magnet of the rotating member 29 are each magnetized in the axial direction, but the inner annular portion 27 and the rotating member 29 are attracted (Fig. 1 5) The inner annular portion 27 and the rotating member 29 may be repelled (not shown). In particular, as shown in Fig. 15, if the outer annular part 28 and the rotating member 29 and the inner annular part 27 and the rotating member 29 are both in the suction state, the eccentricity is canceled. It can move smoothly in the direction you do. Also, even if the inner annular portion 27 and the rotating member 29 are repelled, the outer annular portion 28 and the rotating member 29 are always in a suction state. It is possible to move in a direction in which the gap becomes narrower.

 Alternatively, one of the outer annular portion 28, the rotating member 29, and the inner annular portion 27 may be formed of a magnet and the other two may be formed of a magnetic material. Specifically, three configurations are possible. As shown in Fig. 16, the outer annular part 28 is an annular magnet, the rotating member 29 is a magnetic material, and the inner annular part 27 is an annular magnetic property. Or the outer annular portion 28 is an annular magnetic material, the rotating member 29 is a magnetic material, and the inner annular portion 27 is an annular magnet, or The outer annular portion 28 may be an annular magnetic material, the rotating member 29 may be a magnet, and the inner annular portion 27 may be an annular magnetic material.

In each case, between the outer annular part 28 and the rotating member 29 and the inner annular part Since both the rotating member 27 and the rotating member 29 suck, the rotating member 29 moves in the direction of strong magnetic attraction where the interval between the annular portions 27 and 28 becomes narrow. It is possible to move smoothly in the direction to cancel the eccentricity. In particular, if the rotating member 29 is a roller made of a magnetic material as shown in Fig. 16, the rotating members 29 can be repelled by using only one annular magnet.

 Alternatively, as shown in Fig. 17, all of the inner annular portion 27, the outer annular portion 28, and the rotating member 29 may be magnetized. In Fig. 17, the magnetization in the axial direction was set so that both the outer annular portion 28 and the rotating member 29 and the inner annular portion 27 and the rotating member 29 were in the attracted state. However, by changing the magnetization direction, the interval between them can be changed as repulsion-suction, repulsion-repulsion, and suction-repulsion.

 For example, as shown in Fig. 17, if it is set so that both the space between the outer annular portion 28 and the rotating member 29 and the space between the inner annular portion 27 and the rotating member 29 suck, the rotating member 2 9 moves in the direction of strong magnetic attraction where the interval between the annular portions 27 and 28 becomes narrow, and can move smoothly in the direction of canceling the eccentricity. In addition, if it is set so as to repel between the outer annular portion 28 and the rotating member 29 and suction between the inner annular portion 27 and the rotating member 29, the rotating member 29 will be in contact with the outer annular portion 28. Due to the magnetic repulsion, the contact pressure between the outer annular portion 28 and the outer annular portion 28 can be reduced, and the eccentricity can be moved very smoothly in the canceling direction.

 Furthermore, if both the outer annular portion 28 and the rotating member 29 are repelled between the inner annular portion 27 and the rotating member 29, centrifugal force can be applied to the rotating member 29. Thereby, it can be moved in the direction in which the interval between the annular portions 27 and 28 becomes smaller. At this time, since the rotating member 29 can reduce the contact pressure due to the centrifugal force by the magnetic repulsive force with the outer annular portion 28, the rotating member 29 can move extremely smoothly in the direction of canceling the eccentricity. Alternatively, if the space between the outer annular portion 28 and the rotating member 29 is set to be sucked while the space between the inner annular portion 27 and the rotating member 29 is repelled, the respective annular portions 27, 28 by the eccentricity When the distance between the annular portions 27 changes, the rotating member 29 can move in the direction in which the distance between the annular portions 27 and 28 becomes smaller.

The outer annular portion 28 is made of an annular non-magnetic material and has a rotating member. At least one of the inner ring portion 29 and the inner annular portion 27 may be formed of a magnet. As the non-magnetic material forming the outer annular portion 28, for example, plastic can be used. Specifically, three configurations are possible. The outer annular portion 28 shown in Fig. 15 is made of non-magnetic material, the rotating member 29 is a magnet, and the inner annular portion 27 is an annular magnet. Or the rotating member 29 is a magnet and the inner annular portion 27 is an annular magnetic material, or the rotating member 29 is a magnetic material and the inner annular portion 27 is a circle. It can be a ring-shaped magnet.

 Then, as shown in Fig. 15, when the rotating member 29 and the inner annular portion 27 are magnetized so as to be attracted, or when the rotating member 29 and the inner annular portion 27 are magnetized and magnetized. In the case of a combination (not shown), since there is no suction or repulsion between the outer annular portion 28 and the rotating member 29 and suction is performed between the inner annular portion 27 and the rotating member 29, the weight is unbalanced. When the distance between the annular portions changes due to the center, the rotating member 29 is not attracted to the outer annular portion 28 and the contact pressure due to the centrifugal force acting between the rotating member 29 and the outer annular portion 28 is reduced. it can. Therefore, the rotating member 29 can move smoothly in the direction to cancel the eccentricity by the balance between the centrifugal force and the suction force by the inner annular portion 27.

 When both the rotating member 29 and the inner annular portion 27 are made of magnets and are magnetized so that they repel, the centrifugal force is applied to the rotating member 29 so that the rotating It can be moved in the direction in which the interval between 27 and 28 becomes smaller. At this time, since the rotating member 29 is not sucked by the outer annular portion 28 and the contact pressure with the outer annular portion 28 can be reduced, the rotating member 29 can move smoothly in the direction to cancel the eccentricity. it can.

In short, at least one of the inner annular portion 27, the outer annular portion 28, and the rotating member 29 may be formed as a magnet. In this way, the rotating members 29 can repel each other. Further, in the present embodiment, the rotating member 29 has a cylindrical shape. However, the present invention is not limited to this. Any shape may be used as long as the rotating member 29 can smoothly move in contact with the annular portions 27, 28. The central part in the direction is concave, the central part in the longitudinal direction protrudes in a circular arc shape as shown in Fig. 19A, and the central part in the longitudinal direction as shown in Fig. 19B. The portion may have a shape protruding linearly in cross section, a cylindrical shape having a hole along the axial direction, or a spherical shape. When the yokes 32, 33, 34, 35 are attached to the annular portions 27, 28, the rotating member 29 can contact the yoke at at least two points at both ends in the axial direction. However, even if the rotating member 29 is shaped as described above, for example, the shape in which the center in the longitudinal direction is depressed, or the shape in which the center in the longitudinal direction is protruded as shown in FIGS. It can rotate well.

 In the present embodiment, two rotating members 29 are provided. However, the present invention is not limited to this, and three or more rotating members 29 may be provided. Also in this case, the rotating members 29 can be magnetically repelled and positioned at equal intervals when there is no eccentricity, and can be moved and balanced when there is an eccentricity.

 In this embodiment, the inner annular portion 27 and the outer annular portion 28 and the rotating member 29 are arranged on the base end side of the rotating shaft 3 and the elastic connecting portion 8 is arranged on the distal end side of the rotating shaft 3. However, the present invention is not limited to this. The inner annular portion 27 and the outer annular portion 28 and the rotating member 29 are arranged on the distal end side of the rotating shaft 3 and the elastic connecting portion 8 is arranged on the proximal end side of the rotating shaft 3. Alternatively, the elastic connecting portion 8 may be disposed on the upper side and the lower side, and the intermediate portion may be disposed so as to sandwich the inner annular portion 27 and the outer annular portion 28 and the rotating member 29.

Further, in the present embodiment, the turntable 4 is made of plastic, but is not limited to this.For example, the turntable 4 may be made of metal or resin, an elastomer such as rubber, sponge, paper, or the like. be able to. Therefore, a suitable material can be selected according to the strength / cost required for the turntable 4. For example, an embodiment in which the evening table 4 is made of rubber is shown in FIG. The turntable 4 includes a rotating shaft 6, a mounting portion 7, and an elastic connecting portion 8 as shown in FIGS. 1 to 10, and three elastic connecting portions 8 are provided. Radial ribs. In this case, since the elastic connecting portion 8 is made of rubber and can be deformed in the radial direction and the circumferential direction, the elastic connecting portion 8 is elastically deformed by the centrifugal force when the disk 5 rotates, and the mounting portion 7, the disk 5 and the holder The rotating member 29 such as 16 is swung in the outer peripheral direction. In addition, since the elastically deformed elastic connecting portion 8 has a restoring force F1, the rotation center of the mounting portion 7 and the disk 5 can be drawn to the rotating shaft 3 and moved. In this case, the elastic connecting portion 8 is sandwiched from both sides in the axial direction to prevent displacement. Attach the axial restriction member. As a result, surface runout of the disk 5 can be prevented.

 Further, in each of the above-described embodiments, the evening table 4 is formed as an integrally molded product.However, the present invention is not limited to this.For example, the rotating shaft portion 6, the elastic connecting portion 8, and the mounting portion 7 of the turntable 4 are formed as separate members. It may be integrated later. In this case, each part can be made of, for example, plastic, metal, resin, rubber or other elastomer, sponge, paper, etc., so that each part of the turntable 4 is required. A suitable material can be selected according to strength / cost.

 Further, in each of the above-described embodiments, the elastic connecting portion 8 is formed of three leaf springs or ribs. However, the present invention is not limited to this, and may be one, two, or four or more. The shape of the elastic connecting portion 8 is not limited to a leaf spring or a rib. In short, the mounting portion 7 can move in the radial direction with respect to the rotating shaft portion 6 between the rotating shaft portion 6 and the mounting portion 7. Any other shape may be used as long as it has elasticity for connecting as described above.

 In each of the embodiments described above, the disk drive device 1 is mounted on the CD-ROM drive device. However, the present invention is not limited to this, and the disk drive device 1 can be used for other devices that rotate the disk at high speed. In this embodiment, the disk 5 is used as the rotating body. However, the present invention is not limited to this, and the present invention can be applied to all kinds of high-speed rotating members such as wheels and evening bins. Also in this case, the occurrence of eccentric vibration can be suppressed by minimizing the eccentricity of the member rotating at a high speed with respect to the engine or the like.

Claims

The scope of the claims  1. In a rotating body balance mechanism including a rotating body mounting member and an adjusting mechanism, the rotating body mounting member includes a rotating shaft fixed to a rotating shaft of a driving body, and the rotating body mounted and supported. Resiliently connecting the rotating body mounting portion to the rotating shaft portion and the rotating body mounting portion so that the rotating body mounting portion can move in the radial direction with respect to the rotating shaft portion. A connection portion, and the adjusting mechanism includes: an inner annular portion directly or indirectly attached to the rotating shaft; an outer annular portion directly or indirectly attached to the rotating body attaching portion. A plurality of rotating members disposed between the inner annular portion and the outer annular portion and rotatable on a circumference along an edge of any of the annular portions; and Attach one of the rotating member and the outer annular A rotating body balance mechanism comprising a net and one of the other being a magnet or a magnetic material. 2. The rotating body balance mechanism according to claim 1, wherein the rotating body mounting member and the adjustment mechanism are arranged side by side in the axial direction.  3. The rotating body balance mechanism according to claim 2, wherein the outer annular portion of the adjusting mechanism is attached to the rotating body mounting portion of the rotating body mounting member. 4. When the rotating shaft rotates, the elastic connecting portion is deformed by the eccentricity acting on the rotating body mounting portion, and the rotating body mounting portion moves in the radial direction, and the inner annular portion is formed. 4. The rotating body balance mechanism according to claim 3, wherein a distance between the rotating member and the outer annular portion changes to move the rotating member.  5. The rotating body mounting portion is a turntable on which a disk is mounted, the rotating shaft is a rotating shaft of a motor, and a holding portion for holding the outer annular portion of the adjusting mechanism on the evening table. 4. The rotating body balance mechanism according to claim 3, wherein the balance mechanism is formed.  6. The rotating body according to claim 1, wherein at least two of the inner annular portion, the rotating member, and the outer annular portion are made of a magnet, and the rest is made of a magnetic material. Balance mechanism. 7. The rotating body according to claim 6, wherein the outer annular portion is an annular magnetic material, the rotating member is a magnet, and the inner annular portion is an annular magnet. Lance mechanism.  7. The rotating body balance mechanism according to claim 6, wherein the outer annular portion is an annular magnet, the rotating member is a magnet, and the inner annular portion is an annular magnetic material.  9. The balance mechanism according to claim 6, wherein the outer annular portion is an annular magnet, the rotating member is a magnetic material, and the inner annular portion is an annular magnet.  10. The rotating body balance mechanism according to claim 1, wherein the outer annular portion and the inner annular portion are annular magnets, and the rotating member is a magnet.  11. The method according to claim 1, wherein two of the inner annular portion, the rotating member, and the outer annular portion are made of a magnetic material, and one is made of a magnet. Rotating body balance mechanism.  12. The balance of a rotating body according to claim 11, wherein the outer annular portion is an annular magnetic material, the rotating member is a magnetic material, and the inner annular portion is an annular magnet. mechanism.  13. The rotating body balance mechanism according to claim 11, wherein the outer annular portion is an annular magnet, the rotating member is a magnetic material, and the inner annular portion is an annular magnetic material. .  14. The rotating body according to claim 11, wherein the outer annular portion is an annular magnetic material, the rotating member is a magnet, and the inner annular portion is an annular magnetic material. mechanism.  15. The outer annular portion is made of an annular non-magnetic material, and at least one of the rotating member and the inner annular portion is made of a magnet. Rotating body balance mechanism.  16. The rotating body balance mechanism according to claim 15, wherein the rotating member is a magnet, and the inner annular portion is an annular magnet. 17. The rotating body balance mechanism according to claim 15, wherein the rotating member is a magnet, and the inner annular portion is an annular magnetic material. 18. The rotating body balance mechanism according to claim 15, wherein the rotating member is a magnetic material, and the inner annular portion is an annular magnet.  19. The rotating body balance mechanism according to claim 1, wherein the magnet is magnetized in an axial direction.  20. The rotating body balance mechanism according to claim 19, wherein a yoke made of a magnetic material is disposed on at least one of the magnets in the axial direction.  21. The rotating body according to claim 1, wherein the rotating member is formed of a roller having a substantially cylindrical outer peripheral surface, and the roller is formed to have an axial dimension longer than a diameter. Balance mechanism.  22. The rotating body according to claim 1, wherein the rotating member comprises a roller having a substantially cylindrical outer peripheral surface, and the roller is formed to have an axial dimension shorter than a diameter. Balance mechanism.  23. The rotating body balance mechanism according to claim 1, further comprising a regulating member that regulates a radial movement of the rotating body mounting portion to a predetermined amount.