JP2003130044A - Dynamic pressure bearing device, motor, and disc device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a dynamic pressure bearing device from playing at the time of rotary stop in the relatively simple constitution. SOLUTION: The dynamic pressure bearing device is provided with a shaft 3 and a sleeve 4b. The shaft 3 has a shaft body and a thrust plate 16 installed to the shaft body. The sleeve 4b is formed of a cylindrical member arranged to be relatively rotatable at the outer periphery of the shaft 3 and has a radial inner peripheral face 4g forming a radial dynamic pressure bearing 14 formed of radial fine clearance in which a lubricant fluid is retained between the sleeve and the outer peripheral face 3a of the shaft body and a thrust face 4f confronting through the thrust clearance 30 to the thrust face 16d of the plate 16. A thrust bearing 13 formed of thrust fine clearances in which the lubricant fluid 8 is retained is formed in the thrust clearance 30. The dynamic pressure bearing device is arranged in the thrust bearing 30 to prevent the idle motion of both members at the time of relative rotary stop of the shaft 3 and the sleeve 4b and an idle preventive mechanism 17 to release restriction at the time of relative rotation is further provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic pressure bearing device, and more particularly, to a dynamic pressure bearing device having a thrust dynamic pressure bearing having a minute thrust gap for holding a lubricating fluid, a motor and a disk device using the same. Regarding

[0002]

2. Description of the Related Art A recording disk device such as a hard disk has a rotation driving motor arranged concentrically with the disk in the device. This motor is mainly composed of a stator having an armature coil, a rotor having a rotor magnet facing the stator, and a dynamic pressure bearing mechanism that rotatably supports the rotor on the stator. For example, a plurality of recording disks are fixed to the outer peripheral surface of the rotor. The dynamic pressure bearing mechanism is composed of a shaft, a cylindrical sleeve rotatably arranged on the outer periphery of the shaft, and a lubricating fluid held in a minute gap between both members. And dynamic pressure thrust bearings. In the dynamic pressure radial bearing and the dynamic pressure thrust bearing, a large number of grooves are formed on at least one surface of the facing members with a minute gap therebetween, and when the facing members rotate relative to each other, the grooves generate fluid pressure. . As a result, the rotor is rotatably supported with respect to the stator.

[0003]

The minute gap of the dynamic pressure bearing device has a size of, for example, about 2 to 50 μm, and non-contact rotation is realized between the shaft and the rotor, but the relative rotation is stopped. In the above, since the dynamic pressure is not generated, there is a portion contacting the minute gap in the bearing portion. Therefore, for example, due to external vibration or shock during transportation,
The bearing surface may slide while contacting with each other, resulting in wear. Further, when the minute gap moves, the retained lubricating fluid may flow and leak toward the outside of the gap.

Therefore, in order to solve such a problem, in the hydrodynamic bearing motor disclosed in Japanese Unexamined Patent Publication No. 2001-78387, the center of the stator and the center of the rotor magnet fixed to the rotor are displaced so that relative rotation occurs. At the time of stop, due to the urging force greater than the weight of the rotor and shaft,
The thrust surfaces forming the dynamic pressure thrust bearing are in contact with each other. As a specific urging force generating means, for example, a ring-shaped suction ring 23 for generating a thrust direction attraction force between the armature coil 13 and the rotary magnet 11 is fixed to the outer periphery of the armature coil 13.

However, in the solution described above, since the center of the stator and the center of the rotor magnet are displaced,
When the stator is excited and the rotor rotates, electromagnetic vibration and noise are generated more than the stator. An object of the present invention is to suppress the floating motion of the hydrodynamic bearing device when the rotation of the hydrodynamic bearing device is stopped, with a relatively simple structure.

[0006]

A hydrodynamic bearing device according to a first aspect of the present invention includes a shaft and a sleeve. The shaft has a shaft body and a flange provided on the shaft body. The sleeve is a cylindrical member that is rotatably arranged on the outer periphery of the shaft, and forms a radial dynamic bearing with a radial minute gap in which lubricating fluid is retained between the outer peripheral surface of the shaft body and the radial inner periphery. And a thrust surface opposed to the one axial side surface of the flange with a thrust gap therebetween. In the thrust gap, a thrust dynamic pressure bearing formed of a thrust minute gap holding a lubricating fluid is formed. The hydrodynamic bearing device further includes a floating suppression mechanism that is disposed in the thrust gap and that suppresses the floating of both members when the relative rotation of the shaft and the sleeve is stopped, and releases the suppression when the relative rotation of the shaft and the sleeve is stopped.

In this dynamic pressure bearing device, when the shaft and the sleeve rotate relative to each other, dynamic pressure is generated in the radial dynamic pressure bearing and the thrust dynamic pressure bearing, and a minute gap in which a lubricating fluid is retained is maintained between both members. . Since the motion suppression mechanism suppresses the motion of both members when the relative rotation of the shaft and the sleeve is stopped, the bearing surface of the dynamic pressure bearing is less likely to wear even if vibration or shock is applied from the outside. In addition, the lubricating fluid in the minute gap does not promote the leakage and leakage to the outside of the gap.
Furthermore, since the floating suppression mechanism releases the suppression when the shaft and the sleeve rotate, the rotational performance of the hydrodynamic bearing device does not deteriorate.

In particular, since the floating suppression mechanism is arranged between the axial one side surface of the shaft flange and the thrust surface of the sleeve, a simple structure is realized. Claim 2
In the hydrodynamic bearing device according to the first aspect of the present invention, in the first aspect, the floating suppression mechanism suppresses the members by forming the thrust minute gaps into contact with each other. In this dynamic pressure bearing device, the members forming the thrust minute gap contact each other,
When the relative rotation of the shaft and the sleeve is stopped, the movement of both members is suppressed. Therefore, the play of both members can be suppressed more reliably.

According to a third aspect of the present invention, there is provided the dynamic pressure bearing device according to the first or second aspect, wherein the free movement suppressing mechanism applies an elastic force between the axially one side surface of the flange and the thrust surface of the sleeve. have. In this hydrodynamic bearing device, since the shaft and the rotor are prevented from moving due to the urging force of the elastic member when the shaft and the sleeve stop rotating, the both members can be more reliably suppressed from moving.

According to a fourth aspect of the present invention, there is provided the dynamic pressure bearing device according to any one of the first to third aspects, in which the floating motion suppressing mechanism is provided with a shaft by a dynamic pressure generated in the thrust dynamic pressure bearing when the shaft and the sleeve are relatively rotated. Release the restriction of relative rotation of the sleeve. In this dynamic pressure bearing device, the dynamic suppression generated by the thrust dynamic pressure bearing is used to release the suppression of relative rotation between the shaft and the sleeve, so that a simple structure is maintained.

According to a fifth aspect of the dynamic pressure bearing device of the present invention, in the first aspect, the movement suppressing mechanism has a thrust member and an elastic member. The thrust member is arranged so as to be movable in the axial direction with respect to the shaft and the sleeve, and has a thrust surface for generating a dynamic pressure that axially faces one of the axial side surface and the thrust surface and that forms a thrust dynamic pressure bearing. Have.
The elastic member is arranged between the thrust member and the other one of the axial direction side surface and the other thrust surface, and biases the thrust member toward one side. During relative rotation between the shaft and the sleeve, the thrust member overcomes the urging force of the elastic member from one side due to the dynamic pressure generated in the thrust dynamic pressure bearing, and separates the thrust member from one side and the thrust surface for dynamic pressure generation. Secure. When the relative rotation of the shaft and the sleeve is stopped, the thrust member is biased by the elastic member and is in contact with one side.

In this dynamic pressure bearing device, when the relative rotation of the shaft and the sleeve is stopped, the thrust member is urged by the elastic member and abuts on one side. That is, the movement of the shaft and the sleeve is restricted by the friction generated at the contact portion between the thrust member and one side. Therefore, the bearing surface of the dynamic pressure bearing is less likely to suffer wear and leakage of the lubricating fluid. When the shaft and the sleeve rotate relative to each other, the dynamic pressure generated between the thrust member and the one acts against the elastic force of the elastic member, and the thrust member separates from the one. As a result, the thrust dynamic pressure bearing is brought into a non-contact state, and the movement restriction of the rotation-side member is released.

In this dynamic pressure bearing device, the play suppressing mechanism is composed of an elastic member and a thrust member, and realizes a simple structure. In particular, since the elastic member and the thrust member are arranged in the thrust gap, the space is saved. Further, since the dynamic pressure of the thrust dynamic pressure bearing is used as the drive source of the floating suppression mechanism, the structure is simple. In the dynamic bearing device according to claim 6, in claim 5, the elastic member is
An O-ring, the lubricating fluids held in the radial minute gap and the thrust minute gap are continuous with each other, and the lubricating fluid is held in the gap between one axial side surface and the other thrust surface, One end is continuous with both minute gaps, and the other end of the gap acts so that the elastic member regulates the flow of the lubricating fluid at least when dynamic pressure is generated in the lubricating fluid. In this dynamic pressure bearing device, the dynamic pressure of the dynamic pressure bearing can be appropriately generated even if the floating suppression mechanism is provided, and it is possible to realize bearing characteristics almost equivalent to those of the dynamic pressure bearing device without the floating suppression mechanism.

According to a seventh aspect of the present invention, there is provided a motor according to the first to sixth aspects.
Any one of the dynamic pressure bearing device, a stator having a coil fixed to one of a shaft and a sleeve, and a rotating member having a magnet fixed to the other of the shaft and the sleeve and facing the coil. . With this motor, it is possible to suppress the floating motion of the dynamic pressure bearing device when the rotation is stopped, with a relatively simple structure. Further, since the bearing device of the motor can suppress the floating motion, it is not necessary to dispose the center of the stator and the center of the magnet, which deteriorate the magnetic characteristics of the motor, to realize a motor having excellent magnetic characteristics. it can.

A disk device according to an eighth aspect comprises the motor according to the seventh aspect and a recording disk fixed to a rotating member. With this disk device, it is possible to suppress the floating motion of the hydrodynamic bearing device when the rotation of the hydrodynamic bearing device is stopped, with a relatively simple structure.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION 1. First Embodiment (1) Overall Motor Structure FIG. 1 is a vertical cross-sectional view schematically showing a schematic configuration of a motor 1 as an embodiment of the present invention. The motor 1 is a spindle motor for driving a recording disk and constitutes a part of a disk device such as a hard disk.

In FIG. 1, the recording disk drive motor 1 mainly comprises a fixed member 41, a rotating member 42, and a dynamic pressure bearing mechanism 5 for rotatably supporting the rotating member 42 on the fixed member 41. Is equipped with. The motor 1 is
Stator 7 composed of a coil fixed to a fixing member 41
And a rotor magnet 6 fixed to the rotating member 42, and both members constitute a magnetic circuit unit for applying a rotating force to the rotating member 42.

The fixing member 41 comprises the bracket 2 and the shaft 3 whose lower end is fitted and fixed in the central opening 2a of the bracket 2. The stator 7 is fixed to the bracket 2. The rotating member 42 includes a rotor 4 that is rotatable with respect to the shaft 3. The rotor 4 is positioned on the inner peripheral side of the rotor hub 4a on which a recording disk (not shown) is placed on the outer peripheral portion, and the rotor hub 4a.
And a sleeve portion 4b axially supported by the shaft 3 via a dynamic pressure bearing mechanism 5. A rotor magnet 6 is fixed to the inner peripheral portion of the rotor hub 4a by means such as adhesion, and the rotor magnet 6 faces the stator 7 with a small gap in the radial direction.

OO shown in FIG. 1 is the center line of the motor 1, that is, the rotation axis of the rotating member 42. Further, in the description of the present embodiment, the vertical direction of FIG. 1 is referred to as the “axial vertical direction” for convenience, but the direction in the actual mounting state of the motor 1 is not limited. (2) Structure of Dynamic Pressure Bearing Mechanism In the dynamic pressure bearing mechanism 5, the rotating member 42 is rotatable with respect to the fixed member 41, more specifically, the rotor 4 is rotatable with respect to the shaft 3 via the lubricating fluid 8. It is a mechanism for supporting, and is composed of an upper bearing portion 11 and a lower bearing portion 12 provided on the shaft 3 so as to be separated from each other in the axial direction. Further, each of the bearing portions 11 and 12 is composed of a thrust bearing portion 13 and a radial bearing portion 14.

Position of the hydrodynamic bearing device The sleeve portion 4b is formed substantially at the center of the sleeve portion 4b so that the inner peripheral surface forms a minute gap for retaining the lubricating fluid 8 with the outer peripheral surface 3a of the shaft 3. A through hole 4c is formed so as to pass through in the axial direction. An annular recess 3b is formed in a substantially central portion of the outer peripheral surface 3a of the shaft 3 so as to increase a gap between the outer peripheral surface 3a and the inner peripheral surface of the through hole 4c. A communication hole 27 communicating with the outside air formed in the shaft 3 is opened in the recess 3b, and the outside air taken into the minute gap from the opening is substantially in the center of the inner peripheral surface of the recess 3b and the through hole 4c. An annular gas intervening portion 15 is formed between the and. The lubricating fluid 8 held in the minute gap between the outer peripheral surface 3a of the shaft 3 and the inner peripheral surface of the through hole 4c by the gas interposed portion 15 is
It is divided into upper and lower parts in the axial direction and is located in an upper bearing part 11 and a lower bearing part 12, which will be described later.

The communication hole 27 is continuous with the vertical hole 27a penetrating the shaft 3 in the axial direction, the first opening 27b opening in the recess 3b extending in the radial direction from the vertical hole 27a, and the lower bearing portion 12. The lower counter plate 21 and the outer peripheral surface of the shaft 3 are constituted by a second opening 27c that opens into a space communicating with the outside air through a minute gap defined. It should be noted that the vertical hole 27a is sealed by sealing members 28 and 29 made of an elastic member such as rubber after the shaft 3 has been processed and cleaned so that the openings at both ends of the shaft 3 are sealed. That is, the communication hole 27 communicates with the outside air only through a minute gap defined between the second opening 27c and the inner peripheral surface of the lower counter plate 21 and the outer peripheral surface 3a of the shaft 3.

At both ends of the through hole 4c, openings 4d are formed in which thrust plates 16 to be described later are respectively arranged. As shown in FIG. 2, each opening 4d has a shaft 3
The outer peripheral surface 3a has an inner peripheral surface 4e that is spaced apart in the radial direction, and a thrust surface 4f that faces outward in the axial direction. The thrust surface 4f extends from a radial inner peripheral surface 4g (described later) of the through hole 4c to an inner peripheral surface 4e of the opening 4d. The inner peripheral surface 4e is
The inner side in the axial direction forms an inner peripheral surface 4e1 having a small diameter, and the outer side in the axial direction forms an inner peripheral surface 4e2 having a large diameter, and a step is formed at the boundary between the two. In addition, each opening 4d
The ring-shaped counter plate 21 having an opening 21a through which the shaft 3 is inserted is fitted into the large-diameter inner peripheral surface 4e2 and is closed.

Hereinafter, the structure of the upper bearing portion 11 will be mainly described, and the lower bearing portion 12 is almost the same as the upper bearing portion 11, and therefore only different points will be described. Further, the following description of the structure is for explaining the relationship and position of each member in a stationary state where the rotor 4 stops rotating. Structure of Radial Bearing Part FIG. 2 is a partially enlarged view of FIG. 1, and is a vertical cross-sectional view schematically showing the schematic configuration of the upper bearing part 11. The radial bearing portion 14 includes a radial inner peripheral surface 4 g formed on an upper portion of the inner peripheral surface of the through hole 4 c of the rotor 4 and an outer peripheral surface 3 of the shaft 3.
It is formed between a and. The radial inner peripheral surface 4g faces the outer peripheral surface 3a of the corresponding shaft 3 so as to secure a radial minute gap in which the lubricating fluid 8 is retained. A vertical asymmetrical herringbone-shaped groove 24 is formed on the radial inner peripheral surface 4g to generate a dynamic pressure in the lubricating fluid 8 by causing the lubricating fluid 8 to flow outward in the axial direction. In this way, the radial inner peripheral surface 4g of the rotor 4
The outer peripheral surface 3a of the shaft 3 and the lubricating fluid 8 between them form a radial bearing portion 14.

Structure of Thrust Bearing Section The thrust bearing section 13 of the upper bearing section 11 is mainly composed of a thrust plate 16 and a floating suppression mechanism 17. The thrust bearing portion 13 of the lower bearing portion 12 is mainly
It is composed of the thrust plate 16. The thrust plate 16 is a member that is fixed to the shaft 3 and forms a flange of the shaft 3. Floating suppression mechanism 17
Is a mechanism for preventing the rotor 4 from floating (rattle) when the rotor 4 stops rotating, thereby preventing damage to each bearing surface and leakage of the lubricating fluid.

The thrust plate 16 is an annular or disc-shaped member having a central hole formed therein, and is fixed to the outer peripheral surface 3a of the shaft 3 by press fitting and bonding in the opening 4d. More specifically, the thrust plate 1
Reference numeral 6 denotes a cylindrical portion 16a having a hole portion 16c in which the outer peripheral surface 3a of the shaft 3 is fixed to the inner peripheral surface, and a disk shape extending from the lower end portion (inner end in the axial direction) outward in the radial direction. The part 16b.

The disk-shaped portion 16b of the thrust plate 16 has a thrust surface 16d facing inward in the axial direction, and the thrust surface 16d has a thrust gap 30 in which the lubricating fluid 8 intervenes with respect to the thrust surface 4f of the sleeve portion 4b. Oppose to ensure. Further, the outer peripheral surface 16f of the thrust plate 16 secures a predetermined gap between the small-diameter inner peripheral surface 4e1 of the opening 4d and the inner peripheral surface of the counter plate 21. One end of this gap communicates with the thrust gap 30 and the other end communicates with the outside air to function as a holding portion for the lubricating fluid of the upper and lower bearing portions 11 and 12, and
It also functions as a seal that suppresses the lubricating fluid from flowing to the outside by capillary force.

The floating restraint mechanism 17 is arranged in the thrust gap 30 of the upper bearing portion 11, and mainly comprises the thrust member 18.
And an O-ring 19. The thrust member 18 is an annular and disk-shaped member, and is disposed on the outer peripheral side of the shaft 3 so as to be fitted in the shaft 3 movably in the axial direction.
Further, the axial thickness of the thrust member 18 is slightly smaller than the thrust gap 30, its inner diameter is somewhat larger than the shaft outer diameter, and its outer diameter is somewhat smaller than the small diameter inner peripheral surface 4e1. As a result, the thrust member 18 can be moved in the axial direction within the small axial distance (gap length of the thrust gap 30), and can be moved in the radial direction to some extent in order to smooth the axial movement. Has become.

In the thrust member 18, the thrust surface 4f
A thrust surface 18a for generating dynamic pressure is formed on the side. On the thrust surface 4f side of the sleeve portion 4b, the rotor 4
Along with the rotation, the spiral groove 22 for generating a dynamic pressure is formed in the lubricating fluid 8 so that the lubricating fluid 8 flows radially inward. As described above, the thrust bearing portion 13 is configured by the dynamic pressure generating thrust surface 18a of the thrust member 18, the thrust surface 4f of the sleeve portion 4b, and the lubricating fluid 8 therebetween. Furthermore, the thrust plate 16
Thrust surface 16d and thrust member 18 facing it
The lubricating fluid is also held in the thrust gap formed by the opposing surfaces of the above and the radial gap formed by the inner peripheral surface of the thrust plate 16 and the outer peripheral surface of the shaft 3.

Thrust surface 16d of thrust plate 16
An annular groove 16e is formed in the groove 16e, and an O-ring 19 is arranged in the groove 16e. O-ring 19 has its groove 1
6e is compressed in the axial direction between the thrust plate 16 and the thrust member 18 in such a size that a part thereof is exposed, and urges both members away from each other. Therefore, the thrust member 18 is separated from the thrust surface 16d of the thrust plate 16 and is separated from the thrust surface 4f of the sleeve portion 4b.
Being pressed against. Further, although not shown, in the lower bearing portion 12, the thrust surface 16d of the thrust plate 16 is composed of the thrust surface 4f of the rotor 4 and the lubricating fluid 8 therebetween to form the thrust bearing portion 13.

In this way, the upper and lower bearing parts 11, 1
2, the bearing surfaces of the thrust bearing portion 13 are both in contact with each other through the lubricating fluid 8, whereby the rotor 4 is
The movement of the shaft 3 is restricted by the frictional force of both bearing surfaces. As a result, damage such as wear is less likely to occur in each bearing. In addition, there is no local change in bearing clearance,
Lubrication fluid leakage is less likely to occur.

In this case, since the elastic force of the O-ring 19 is used, a sufficient biasing force and thus a frictional force can be obtained, and the movement of the rotor 4 is sufficiently restricted with respect to an external force. Since oil is used as the lubricating fluid in this embodiment, there is a small amount of oil between the bearing surfaces that are in contact with each other when stationary. (3) Operation With the above configuration, the operation will be described below. First,
When the coil of the stator 7 is energized, the rotor 4 is supported by the bearing portions 11 and 12 of the hydrodynamic bearing mechanism 5, more specifically, the thrust bearing portion 13 and the radial bearing portion 14, and the rotor 4 is rotated around the shaft 3. To rotate.

More specifically, in each radial bearing portion 14, the lubricating fluid 8 in the gap between the outer peripheral surface 3a of the shaft 3 and the radial inner peripheral surface 4g of the rotor 4 forms a herringbone-shaped groove 24 as the rotor 4 rotates. By the action, the radial load supporting pressure is generated while causing the lubricating fluid 8 to flow outward in the axial direction. Similarly, in each thrust bearing portion 13, the lubricating fluid 8 in the minute gap is rotated by the rotor 4 to rotate in the spiral groove 22.
By this action, the thrust fluid supporting pressure (thrust dynamic pressure) is generated while causing the lubricating fluid 8 to flow radially inward.
Thereby, in the vicinity of the intersection of the radial bearing portion 14 and the thrust bearing 13, a maximum pressure portion where the maximum pressure acts on the lubricating fluid 8 is formed. This maximum pressure portion is formed in each of the upper and lower bearing portions 11 and 12, so that the rotor 4 is stably supported around the pair of maximum pressure portions.

The operation of generating the thrust dynamic pressure will be described in detail below. In the thrust bearing portion 13 of the upper bearing portion 11, the thrust surface 4f and the dynamic pressure generating thrust surface 18 are formed.
The thrust member 18 resists the urging force of the O-ring 19 due to the dynamic pressure generated between the thrust plate 18 and the thrust plate 16.
Move to the side. In the thrust bearing portion 13 of the lower bearing portion 12, the thrust plate 16 separates from the thrust surface 4f of the sleeve portion 4b due to the dynamic pressure generated between the thrust surface 4f and the thrust surface 16d. As a result, the dynamic pressures of the thrust bearing portions 13, the elastic force of the O-ring 19, and the own weight of the rotating member 42 are balanced, and as shown in FIG. 3, in the thrust bearing portion 13 of the upper bearing portion 11,
Until then, the rotor 4 was in contact with itself due to the weight of the rotor 4 and the urging force of the O-ring 19, etc., but the thrust member 18 comes into contact with the thrust surface 16d of the thrust plate 16 and becomes integral with the thrust surface 4f. A desired thrust minute gap 31 is secured between the thrust surface 18a for generation. Also,
In the thrust bearing portion 13 of the lower bearing portion 12, a desired thrust minute gap (not shown) is secured between the thrust surface 4f and the thrust surface 16d.

At this time, since the O-ring 19 in the gap between the thrust plate 16 and the thrust member 18 is arranged in a compressed state, the gap is sealed by the O-ring 19 and the lubricating fluid 8 held therein flows. Regulated. As a result, the lubricating fluid 8 in the thrust minute gap 31 does not pass through the gap on the upper surface side of the thrust member 18 to reduce the dynamic pressure. That is, in the present embodiment, the thrust minute gap 3
In order to increase the volume of the thrust gap 30 including 1 as compared with that of a conventional dynamic bearing device that does not have a floating suppression mechanism and to generate an equivalent dynamic pressure,
Although it is necessary to make the configuration such that the dynamic pressure is further increased, in the present embodiment, the lubricating fluid 8 does not flow remarkably due to the O-ring 19 in the above-mentioned gap that communicates with the thrust minute gap 31, so that it is possible to prevent It is possible to generate a dynamic pressure equivalent to that of the configuration (when there is no play suppression mechanism, the thrust minute gap and the thrust gap are the same).

Since oil, which is a lubricating fluid, is present between the members even when stationary, a dynamic pressure due to the oil is generated relatively early at the start of rotation, and the contact state between the members is quickly released. Further, since the rotating rotor 4 is stopped, the dynamic pressure gradually decreases as the decrease in the rotation speed decreases. As a result, when the dynamic pressure becomes smaller than the elastic force of the O-ring 19 and the biasing force of the rotor 4 such as its own weight, the thrust member 18 separates from the thrust plate 16, approaches the thrust surface 4f of the sleeve member 4b again, and stops at the same time. The movement of the rotor 4 is restricted.

In the above embodiment, the thrust member 18 is in contact with the thrust plate 16 during rotation,
The thrust members 18 do not necessarily have to be in contact with each other, and when the contraction amount of the O-ring 19 is small, they may contact with each other via the O-ring 19 (that is, both members do not directly contact each other). And the thrust plate 16 need to be integrated.

Further, the O-ring 19 may be another elastic member as long as it has the same elastic force, and the floating suppressing mechanism 17 can be used.
However, if the elastic member cannot regulate the flow of the lubricating fluid 8 between the thrust plate 16 and the thrust member 18 like the O-ring 19, the maximum pressure of the upper bearing portion 11 cannot be controlled. Part is thrust bearing part 1
3 and the radial bearing portion 14 may deviate from the intersection.
In such a configuration, the stability of the rotor 4 may be impaired, so that means for restricting the flow of the lubricating fluid 8 is provided in the gap, or the pattern of the dynamic pressure groove in the bearing portion is changed. Set the position of the maximum pressure part.

(4) Effects of the invention a) Improvement of the motion suppression function Since the motion suppression mechanism 17 suppresses the motion of both members when the relative rotation of the shaft 3 and the sleeve portion 4b is stopped, the bearing surface of each bearing is abraded. Is less likely to occur. In addition, the floating suppression mechanism 17
Since the restriction is released when the shaft 3 and the sleeve portion 4b rotate, the rotation performance of the motor 1 does not deteriorate.

The members forming the minute thrust gap (the thrust member 18 and the sleeve portion 4b in the upper portion, and the thrust plate 16 and the sleeve portion 4b in the lower portion) are in contact with each other, so that the shaft 3 and the sleeve portion 4b are prevented from rotating relative to each other. The movement of the member is suppressed. Therefore, the play of both members can be suppressed more reliably. When the rotation of the shaft 3 and the sleeve portion 4b is stopped, the free movement of the shaft 3 and the sleeve portion 4b is suppressed by the urging force of the O-ring 19, so that the free movement of both members can be suppressed more reliably.

Further, in order to allow the motor bearing device to suppress the floating motion, the conventional structure is designed such that the center of the stator 7 and the center of the rotor magnet 7, which deteriorate the magnetic characteristics of the motor, are offset from each other. A motor having excellent magnetic characteristics can be realized without the need. Furthermore, by using the O-ring 19 for the movement suppressing mechanism 17, the mechanism 17
Does not interfere with the dynamic pressure action of the upper bearing portion 11. In addition, when an external impact is applied to the rotor 4, the O-ring 1
9 does not have a damping action and the bearing surface is not easily damaged.

As a result of the above, when the motor 1 is used in a recording disk device such as a hard disk, the rotating member 42 does not move even when an external shock is applied, so that a high-performance hard disk capable of high-density recording and having excellent shock resistance. The device can be realized. b) Simple structure Especially, since the floating suppression mechanism 17 is arranged between the thrust surface 16d of the thrust plate 16 which is the flange of the shaft 3 and the thrust surface 4f of the sleeve portion 4b,
It has a space-saving and simple structure.

In particular, the floating suppression mechanism 17 has a simple structure composed of the thrust member 18 and the O-ring 19, and is inexpensive as compared with the case where a magnet or the like is used. Moreover, the thrust member 18 is controlled by utilizing the dynamic pressure of the O-ring 19 and the bearing portion, so that a drive source for the floating suppression mechanism 17 other than the O-ring 19 is not required, which contributes to simplification of the structure. There is.

Further, since the floating suppression mechanism 17 releases the suppression of the relative rotation of the shaft 3 and the sleeve portion 4b by utilizing the dynamic pressure generated in the thrust bearing portion 13, a simple structure is maintained. c) Others The minute thrust clearance is automatically adjusted by the thrust dynamic pressure. That is, when the viscosity of the oil decreases due to the high temperature and the thrust dynamic pressure decreases, the thrust minute gap decreases accordingly. Therefore, a temperature compensating effect is obtained in which the dynamic pressure is kept constant regardless of the temperature change.

2. Second Embodiment (1) Overall Motor Structure FIG. 4 is a vertical cross-sectional view schematically showing a schematic configuration of a motor 50 as an embodiment of the present invention. The motor 50 is a recording disk driving motor and constitutes a part of the recording disk device.

In FIG. 4, the recording disk drive motor 50 mainly includes a fixed member 51, a rotating member 52, and
And a dynamic pressure bearing mechanism 54 for rotatably supporting the rotating member 52 on the fixed member 51. The motor 1 further includes a stator 57 composed of a coil fixed to a fixed member 51, and a rotor magnet 6 fixed to the rotating member 52.
2, and a magnetic circuit unit for applying a rotational force to the rotating member 52 is configured by both of them.

The fixing member 51 is composed of a sleeve 55, a bracket 56, and a stator 57 composed of an armature coil. The sleeve 55 is a cylindrical member and has a through hole 55a. The bracket 56 is a disc-shaped member fixed to the lower end of the sleeve 55. The stator 57 is fixed to the inner peripheral side tubular portion of the bracket 56.

The rotating member 52 mainly comprises a shaft 59,
It is composed of a rotor hub 60. Shaft 59
Are arranged in the through hole 55a of the sleeve 55.
The rotor hub 60 has a center portion fixed to the upper end of the shaft 59, and a rotor magnet 62 fixed to the outer peripheral portion. The rotor magnet 62 faces the stator 57 in the radial direction with a small gap.

OO shown in FIG. 1 is the center line of the motor 50, that is, the rotation axis of the rotating member 52. Further, in the description of the present embodiment, the vertical direction of FIG. 1 is referred to as the “axial vertical direction” for convenience, but the direction in which the motor 50 is actually mounted is not limited. (2) Structure of Dynamic Pressure Bearing Mechanism In the dynamic pressure bearing mechanism 54, the rotating member 52 is rotatable with respect to the fixed member 51, more specifically, the shaft 59 is rotatable with respect to the sleeve 55 via the lubricating fluid 80. It is a mechanism for supporting the radial bearing portion 71 and the thrust bearing portion 7.
2 and.

In the approximately central portion of the position sleeve 55 of the hydrodynamic bearing mechanism , the inner peripheral surface is axially formed with the outer peripheral surface 59a of the shaft 59 so as to form a radial minute gap in which the lubricating fluid 80 is retained. A through hole 55a penetrating therethrough is formed. Through hole 55a of sleeve 55
At the lower end of the opening 55, the inner diameter of which is larger than that of the upper portion
c is formed.

As shown in FIG. 5, the opening 55c has a thrust surface 55d that faces downward in the axial direction around the through hole 55a.
And an inner peripheral surface 55e. The sleeve 55
A thrust cover 58 is fixed to the lower end of the through hole 55a, so that the opening 55c is a closed space. The following description of the dynamic pressure bearing mechanism 54 is for explaining the relationship and position of each member in a stationary state where the shaft 59 stops rotating.

Structure of Radial Bearing Section FIG. 5 is a partially enlarged view of FIG. 4, and is a vertical sectional view showing a schematic configuration of the dynamic pressure bearing mechanism 54. Radial bearing part 71
Are formed between a pair of axially upper and lower radial inner peripheral surfaces 55 b formed on the inner peripheral surface of the through hole 55 a of the sleeve 55 and the outer peripheral surface 59 a of the shaft 59. The radial inner peripheral surface 55b corresponds to the outer peripheral surface 59a of the corresponding shaft 59.
Between them and so as to secure a radial minute gap in which the lubricating fluid 80 is held. A herringbone-shaped groove 64 for generating a dynamic pressure in the lubricating fluid 80 is formed on the radial inner peripheral surface 55b. In this way, the radial inner peripheral surface 55b of the sleeve 55, the outer peripheral surface 59a of the shaft 59, and the lubricating fluid 80 between them form a pair of radial bearing portions 71.

Structure of Thrust Bearing Section The thrust bearing section 72 is composed of a thrust flange 61 integrally formed at the lower end of the shaft 59, and a floating suppression mechanism 68. The thrust flange 61 is a portion for forming the flange of the shaft 3. The floating suppression mechanism 68 is configured to prevent the shaft 59 from rotating when the shaft 59 stops rotating.
This is a mechanism for preventing the bearing surface from being damaged and the lubricating fluid from leaking by preventing the sleeve 55 from moving.

The flange 61 of the shaft 3 is
Is a disk-shaped portion extending from the lower end to the outer peripheral side, and is arranged in the opening 55c in proximity to the thrust surface 55d. The flange 61 has a first thrust surface 61a facing the thrust surface 4f of the sleeve portion 4b and a second thrust surface 61b facing the opposite side, that is, the thrust cover 58 side.

The floating restraint mechanism 68 is provided on the second side of the flange 61.
Thrust surface 61b and thrust cover 58 of sleeve 55
Of the thrust surface 58a. The floating restraint mechanism 68 mainly includes a thrust member 69 and a plate spring 70. The thrust member 69 is a disk-shaped member, and is provided with the opening 5 of the sleeve 55.
It is arranged movably in the axial direction within 5c. In the thrust member 69, a dynamic pressure generating thrust surface 69a is formed on the second thrust surface 61b side, and a thrust surface 69b is formed on the opposite side.

First thrust surface 6 of thrust flange 61
Spiral grooves 65 and 66 for generating dynamic pressure in the lubricating fluid due to the rotation of the shaft 59 are formed on the 1a and the second thrust surface 61b, respectively. As described above, the thrust surface 55d of the sleeve 55, the first thrust surface 61a of the thrust flange 61, and the lubricating fluid 80 between the thrust surface 55d, the second thrust surface 61b of the thrust flange 61, and the thrust surface 69a for generating the dynamic pressure of the thrust member 69 are used. A pair of thrust bearing portions 72 is formed by the lubricating fluid 80 between them. The lubricating fluid is a pair of radial bearing portions 71 and a pair of thrust bearing portions 72.
Is continuously held, and is also continuously held in the thrust bearing portion 72 in the gap formed by the thrust member 69 and the thrust cover 58.

The plate spring 70 is arranged between the thrust member 69 and the thrust cover 58. The plate spring 70 is a thin disk-shaped spring, and an outer peripheral portion thereof abuts on the thrust cover 58, and a central portion thereof has a conical shape and abuts on the thrust member 69. The plate spring 70 is axially compressed between the two members and urges the two members away from each other. Therefore, the thrust member 69 is pressed against the second thrust surface 61b of the flange 61 of the shaft 59. The first thrust surface 61 a of the thrust member 69 is pressed against the thrust surface 55 d of the sleeve 55. In this way, the two bearing surfaces that make up the thrust bearing portion 72 are in contact with each other, and thus the movement of the shaft 59 with respect to the sleeve 55 is restricted by the frictional force of the bearing surface.

In this case, since the elastic force of the plate spring 70 is used, a sufficient biasing force and thus a frictional force can be obtained, and the movement of the shaft 59 against the external force is sufficiently restricted. By the way, when there is a risk that the thrust member 69 will rotate together with the rotation of the shaft 59,
The plate spring 70 may be fixed to the thrust surface 69b of the thrust member 69, or the plate spring 70 and the thrust cover 58 may be further fixed. Further, as another means, the fitting surface between the thrust member 69 and the sleeve 55 may be formed with unevenness extending in the axial direction so that the thrust member 69 moves only in the axial direction.

Since oil is used as the lubricating fluid in this embodiment, there is a slight amount of oil between the bearing surfaces that are in contact with each other when stationary. (3) Operation The operation of the above configuration will be described. First, the stator 57
When the coil is energized, the rotating member 52 is supported by the bearing portions 71 and 72 of the dynamic pressure bearing mechanism 54 and rotates around the fixed member 51.

The operation of the dynamic pressure bearing mechanism 54 will be described in detail. In the radial bearing 71, the lubricating fluid 80 in the gap between the outer peripheral surface 59a of the shaft 59 and the radial inner peripheral surface 55b of the sleeve 55 is rotated by the shaft 59, and acts on the radial load supporting pressure (thrust) by the action of the herringbone-shaped groove 64. Dynamic pressure) is generated.

In the thrust bearing portion 72, the lubricating fluid 80 in the minute gap generates thrust load supporting pressure by the action of the spiral grooves 65 and 66 by the rotation of the shaft 59. Hereinafter, the operation of generating the thrust dynamic pressure will be described in detail. In the thrust bearing portion 72, the thrust surface 55
The shaft 59 moves in a direction away from the thrust surface 55d by the dynamic pressure generated between d and the first thrust surface 61a. Further, the thrust member 18 moves in a direction away from the second thrust surface 61b by the dynamic pressure generated between the second thrust surface 61b and the dynamic pressure generating thrust surface 69a. The above-described movement of each member is performed by the generated dynamic pressure overcoming the urging force of the plate spring 70, and the dynamic pressure of the thrust bearing portion 72, the urging force of the spring 70, and the weight of the rotating member 52 are balanced. Movement stops. As a result, as shown in FIG. 6, the plate spring 70 contracts somewhat, and a desired thrust minute gap 75 is secured between the thrust surface 55d and the first thrust surface 61a, and further, the second thrust surface 61b and the dynamic pressure. A desired thrust minute gap 76 is secured between the thrust surface 69a for generation, and the frictional force on the bearing surface disappears to allow the rotation member 52 to move. In addition, the operation from the rotating state to the stopped state is
This is similar to the case of the first embodiment described above.

Since oil, which is a lubricating fluid, exists between the respective members even in a stationary state, a dynamic pressure due to the oil is generated relatively early at the start of rotation, and the contact state between the respective members is quickly released. (4) Effects of the Invention a) Improvement of Floating Suppression Function Since the swaying suppressing mechanism 68 suppresses the swaying of both members when the relative rotation of the shaft 59 and the sleeve 55 is stopped, the bearing surface of each bearing is less likely to wear. In addition, the floating suppression mechanism 68
Since the restriction is released when the shaft 59 and the sleeve 55 rotate, the rotation performance of the motor 50 does not deteriorate.

The members forming the thrust minute gap (the sleeve 55 and the thrust flange 61 on the upper side, and the thrust flange 61 and the thrust member 69 on the lower side) contact each other, so that when the relative rotation of the shaft 59 and the sleeve 55 is stopped, both members are stopped. Suppresses the wandering of. Therefore,
The movement of both members can be suppressed more reliably. When the shaft 59 and the sleeve 55 stop rotating, the plate spring 70
Since the shaft 59 and the sleeve 55 are suppressed from moving due to the urging force of, the moving of both members can be suppressed more reliably.

Further, since it is possible to suppress the motion of the bearing device of the motor, the structure of the motion is suppressed by shifting the center of the stator 57 and the center of the rotor magnet 62 which deteriorate the magnetic characteristics of the motor as in the conventional case. A motor having excellent magnetic characteristics can be realized without the need. As a result, when the motor 50 is used in a recording disk device such as a hard disk, the rotating member 52 is not affected by an external impact.
Since it does not move, it is possible to realize a high-performance hard disk device that has excellent shock resistance and enables high-density recording.

B) Simple structure In particular, since the floating suppression mechanism 68 is arranged between the second thrust surface 61b of the thrust flange 61 of the shaft 59 and the thrust surface 58a of the thrust cover 58 of the sleeve 55, the structure is saved. A simple structure is realized in space.
In particular, the floating suppression mechanism 68 has a simple structure including the thrust member 69 and the plate spring 70, and is cheaper than the case where a magnet or the like is used. Moreover, the thrust member 69 is controlled by utilizing the dynamic pressure of the plate spring 70 and the bearing portion, so that a drive source for the floating suppression mechanism 68 other than the plate spring 70 is not required, which contributes to simplification of the structure. There is.

Further, since the floating restraint mechanism 68 releases the restraint of the relative rotation between the shaft 59 and the sleeve 55 by utilizing the dynamic pressure generated in the thrust bearing portion 72, the simple structure is maintained. c) Others The minute thrust clearance is automatically adjusted by the thrust dynamic pressure. That is, when the viscosity of the oil decreases due to the high temperature and the thrust dynamic pressure decreases, the thrust minute gap decreases accordingly. Therefore, a temperature compensating effect is obtained in which the dynamic pressure is kept constant regardless of the temperature change.

3. Other Embodiments One embodiment of the recording disk drive motor according to the present invention has been described above, but a disk device equipped with this motor according to the present invention will be described by taking a hard disk device as an example. FIG. 7 is a schematic diagram showing the internal configuration of a general hard disk device 80. The inside of the housing 81 forms a clean space in which dust and the like are extremely small, and a motor 82 having a disk-shaped recording disk 83 for storing information is installed therein. In addition, a magnetic head moving mechanism 87 for reading / writing information from / to the recording disk 83 is arranged inside the housing. The magnetic head moving mechanism includes a head 86 for reading / writing information on the recording disk and an arm 85 for supporting the head. , And an actuator section 84 for moving the head and the arm to a desired position on the disk plate. The hard disk device 80 is suitable for applications that are susceptible to shock, for example, portable electronic devices, because the motor 82 has excellent shock resistance.

As described above, the present invention is not limited to such an embodiment, and various changes and modifications can be made without departing from the scope of the present invention. Specifically, the present invention is not limited to the motor or dynamic pressure bearing device and the disk device shown in the above embodiment. Furthermore, the movement suppression mechanism according to the present invention is not limited to the above embodiment. For example, as the elastic member, a member other than an O-ring or a leaf spring may be used.

Further, in the above-mentioned embodiment, the member constituting the floating suppression mechanism is arranged in only one of the two thrust dynamic pressure bearings, but it may be arranged in both. Furthermore, in the above-described embodiment, contact is made on both bearing surfaces of the two thrust dynamic pressure bearings when rotation is stopped. However, for example, one part may be in contact with portions different from the bearing surface.

[0069]

In the dynamic pressure bearing device according to the first aspect of the present invention, when the shaft and the sleeve rotate relative to each other, dynamic pressure is generated in the radial dynamic pressure bearing and the thrust dynamic pressure bearing, and the lubricating fluid is held between both members. A small gap is maintained. Since the motion suppression mechanism suppresses the motion of both members when the relative rotation of the shaft and the sleeve is stopped, the bearing surface of the dynamic pressure bearing is less likely to wear. Further, since the floating suppression mechanism releases the suppression when the shaft and the sleeve rotate, the rotational performance of the dynamic pressure bearing device does not deteriorate.

In particular, since the floating suppression mechanism is arranged between the one axial side surface of the shaft flange and the thrust surface of the sleeve, a simple structure is realized. Claim 2
In the dynamic pressure bearing device described in (1), the members forming the thrust minute gap contact each other, thereby suppressing the floating motion of both members when the relative rotation of the shaft and the sleeve is stopped. Therefore, the play of both members can be suppressed more reliably.

In the hydrodynamic bearing device according to the third aspect of the present invention, when the rotation of the shaft and the sleeve is stopped, the urging force of the elastic member suppresses the free movement of the shaft and the rotor. . In the dynamic pressure bearing device according to the fourth aspect, the simple structure is maintained because the floating suppression mechanism releases the suppression of the relative rotation of the shaft and the sleeve by utilizing the dynamic pressure generated in the thrust dynamic pressure bearing. It

In the dynamic pressure bearing device according to the fifth aspect, when the relative rotation of the shaft and the sleeve is stopped, the thrust member is biased by the elastic member and is in contact with one side. That is, the movement of the shaft and the sleeve is restricted by the friction generated at the contact portion between the thrust member and one side. Therefore, the bearing surface of the dynamic pressure bearing is less likely to wear. When the shaft and the sleeve rotate relative to each other, the dynamic pressure generated between the thrust member and the one acts against the elastic force of the elastic member, and the thrust member separates from the one. As a result, the thrust bearing is brought into a non-contact state, and the movement restriction of the rotating member is released.

In this dynamic pressure bearing device, the play suppressing mechanism is composed of an elastic member and a thrust member, and realizes a simple structure. In particular, since the elastic member and the thrust member are arranged in the thrust gap, the space is saved. In the dynamic pressure bearing device according to the sixth aspect, the dynamic pressure of the dynamic pressure bearing can be appropriately generated even if the floating suppression mechanism is provided.

In the motor according to the seventh aspect, it is possible to suppress the free movement of the dynamic pressure bearing device when the rotation is stopped, with a relatively simple structure. Further, since it is possible to suppress the motion of the bearing of the motor, it is not necessary to shift the center of the stator and the center of the rotor magnet, which deteriorate the magnetic property of the motor, to suppress the motion. It is possible to realize a motor that has.

In the disk device according to the eighth aspect, it is possible to suppress the floating motion of the hydrodynamic bearing device when the rotation of the hydrodynamic bearing device is stopped and to improve the shock resistance with a relatively simple structure.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view schematically showing a schematic configuration of a motor according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view schematically showing a schematic configuration of an upper thrust bearing portion and an upper radial bearing portion of the motor shown in FIG. 1, and a diagram for explaining a rotation stopped state.

FIG. 3 is a diagram corresponding to FIG. 2, and is a diagram for explaining a rotating state.

FIG. 4 is a vertical sectional view schematically showing a schematic configuration of a motor according to a second embodiment of the present invention.

5 is a partial cross-sectional view schematically showing a schematic configuration of a thrust bearing portion and a radial bearing portion of the motor shown in FIG. 4, and a diagram for explaining a rotation stopped state.

FIG. 6 is a diagram corresponding to FIG. 5, and is a diagram for explaining a rotating state.

[Explanation of symbols]

1 motor 3 shafts 4 rotor 5 Dynamic bearing mechanism 16 Thrust plate 17 Floating suppression mechanism 18 Thrust member 19 O-ring

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[Procedure amendment]

[Submission date] December 17, 2001 (2001.12.
17)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view schematically showing a schematic configuration of a motor according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view schematically showing a schematic configuration of an upper thrust bearing portion and an upper radial bearing portion of the motor shown in FIG. 1, and a diagram for explaining a rotation stopped state.

FIG. 3 is a diagram corresponding to FIG. 2, and is a diagram for explaining a rotating state.

FIG. 4 is a vertical sectional view schematically showing a schematic configuration of a motor according to a second embodiment of the present invention.

5 is a partial cross-sectional view schematically showing a schematic configuration of a thrust bearing portion and a radial bearing portion of the motor shown in FIG. 4, and a diagram for explaining a rotation stopped state.

FIG. 6 is a diagram corresponding to FIG. 5, and is a diagram for explaining a rotating state.

[Fig. 7] Schematic internal structure of a general hard disk device
Fig.

[Explanation of symbols] 1 motor 3 shafts 4 rotor 5 Dynamic bearing mechanism 16 Thrust plate 17 Floating suppression mechanism 18 Thrust member 19 O-ring

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02K 21/22 H02K 21/22 M 5H621 29/00 29/00 ZF term (reference) 3J011 AA01 AA20 BA02 BA08 CA02 JA02 KA02 KA03 MA12 5D109 BB13 BB18 BB21 BB22 5H019 AA09 CC04 DD01 FF03 5H605 AA07 BB05 BB10 BB14 BB19 CC04 DD09 EB02 EB06 EB38 5H607 BB07 KK08 KK07 BB07 BB07 BB07 BB07 DD15 GG01 GG15 GG01 GG15 GG01 GG01 GG15 GG01 GG15 GG01 GG15 GG01 GG15 GG01 GG15 GG15 GG15 GG01 GG15 GG01 GG15 GG15 GG05 GG01 GG15 GG01 GG01 GG01

Claims (8)

[Claims] 1. A shaft having a shaft main body and a flange provided on the shaft main body; a cylindrical member rotatably arranged on the outer periphery of the shaft, the outer peripheral surface of the shaft main body. A sleeve having a radial inner peripheral surface forming a radial dynamic pressure bearing having a minute radial gap in which a lubricating fluid is retained, and a thrust surface facing the axial one side surface of the flange via a thrust gap. And a thrust dynamic pressure bearing formed of a thrust minute gap in which a lubricating fluid is retained. A dynamic pressure bearing device, further comprising a floating suppression mechanism for suppressing the above-mentioned fluctuation and canceling the restriction during relative rotation. 2. The dynamic pressure bearing device according to claim 1, wherein the floating suppression mechanism performs the suppression by bringing members forming the thrust minute gap into contact with each other. 3. The floating suppression mechanism has an elastic member that applies an elastic force to both of the axial direction one side surface of the flange and the thrust surface of the sleeve.
Alternatively, the dynamic pressure bearing device according to item 2. 4. The floating suppression mechanism releases the suppression of relative rotation of the shaft and the sleeve by the dynamic pressure generated in the thrust dynamic pressure bearing when the shaft and the sleeve rotate relative to each other. 5. The dynamic pressure bearing device according to any one of 3 above. 5. The thrust suppression mechanism is arranged so as to be movable in the axial direction with respect to the shaft and the sleeve, and axially faces one of the one axial side surface and the thrust surface in the thrust dynamic pressure bearing. A thrust member having a thrust surface for generating dynamic pressure for forming a thrust member, and the thrust member is disposed between the thrust member and the other one of the axial direction side surface and the thrust surface, and urges the thrust member toward the one side. When the shaft and the sleeve rotate relative to each other, the thrust member separates from the one side by overcoming the urging force of the elastic member by the dynamic pressure generated in the thrust dynamic pressure bearing. , The minute thrust gap is secured between the one side and the thrust surface for generating dynamic pressure, and when the relative rotation of the shaft and the sleeve is stopped, the thrust Strike member, said have been urged in elastic member abutting said one dynamic pressure bearing device according to claim 1. 6. The elastic member is an O-ring, and the lubricating fluids held in the radial minute gap and the thrust minute gap are continuous with each other, and are formed on the other side of the one axial side surface and the other thrust surface. A lubricating fluid is retained in the gap between the two, the one end of the gap is continuous with both of the minute gaps, and the other end of the gap is at least when the dynamic pressure is generated in the lubricating fluid. The dynamic pressure bearing device according to claim 5, wherein the dynamic pressure bearing device acts to regulate 7. The hydrodynamic bearing device according to claim 1, a stator having a coil fixed to one of the shaft and the sleeve, and a stator fixed to the other of the shaft and the sleeve. A rotating member having a magnet facing the coil. 8. A disk device comprising: the motor according to claim 7; and a recording disk fixed to the rotating member.