JP2001099142A - Motor and disk drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor having a dynamic pressure bearing of which bearing rigidity is changeable according to change in environment temperature, and provide a disk drive device using the motor. SOLUTION: There are provided: a rotating shaft 51; a first bearing member 55 that is disposed on an outer periphery of the rotating shaft 51 and can retain the rotating shaft 51 to be freely rotatable by pressure generated in fluid provided between the rotating shaft 51 and the first bearing member 55; a second bearing member 56 that is disposed on an outer periphery of the first bearing member 55 and can retain the first bearing member 55 to be freely rotatable by pressure generated in fluid provided between the first bearing member 55 and second bearing member 56; and thrust plates 52, 57 functioning as an engaging means that engages the first bearing member 55 with the second bearing member 56 to be integrally rotated with each other according to increase in environment temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor and a disk drive using the same.

[0002]

2. Description of the Related Art For example, a motor for driving a disk-shaped recording medium in a disk drive device such as a magnetic disk device is required to be downsized and thinner, and also to be restricted rotation, rotational runout accuracy and noise reduction. It is getting stronger.
In response to these demands, there has been known a type using a hydrodynamic fluid bearing having better performance than a ball bearing for holding a rotating shaft of a motor. A hydrodynamic bearing is a bearing that utilizes a phenomenon in which a rotating shaft floats on a fluid film due to dynamic pressure generated in the fluid film by sliding motion. In a motor using such a fluid bearing, it is preferable that the bearing has high rigidity, which is a magnitude of a radial load that can be tolerated by the bearing, and that the load torque acting on the rotating shaft via fluid from the bearing is small. However, the viscosity of the fluid in the bearing, particularly the liquid, decreases at high temperatures, so that the bearing stiffness and load torque become relatively small. At low temperatures, the viscosity increases, so that the bearing stiffness and load torque increase. That is, the higher the viscosity of the fluid interposed in the bearing, the higher the pressure generated in the fluid and the higher the rigidity of the bearing, but the higher the viscosity of the fluid, the greater the resistance of the fluid acting on the rotating shaft, and the higher the viscosity of the fluid. There is a trade-off between rigidity and load torque.

[0003]

By the way, the magnetic disk drive has been reduced in size, increased in recording density, and increased in capacity. For example, a data recording device of a portable AV (audiovisual) device such as a camcorder has been developed. Has begun to be used as. For example, disturbance is easily applied to a magnetic disk device used in the above-described AV equipment, and a hydrodynamic bearing is used for a motor of the magnetic disk device. Fluctuations in the number of revolutions of the motor may increase, which may affect actual use. If the specification is such that the bearing rigidity can be ensured even when the environmental temperature becomes high, the load torque becomes excessive when the environmental temperature is low, and the motor may not start or may not reach steady rotation. To prevent a decrease in bearing stiffness when the environmental temperature is high, for example, narrow the gap between the bearing and the rotating shaft, optimize the width, depth, shape, etc. of the bearing groove, or increase the overall length of the bearing However, these changes are difficult due to the physical limitations of the miniaturized magnetic disk drive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a motor having a dynamic pressure bearing whose bearing rigidity can be changed according to a change in environmental temperature, and a disk drive device using this motor. The purpose is to provide.

[0005]

A motor according to the present invention comprises a rotating shaft, driving means for rotating the rotating shaft, and a fluid disposed between the rotating shaft and the outer periphery of the rotating shaft. A first bearing member capable of rotatably holding the rotary shaft by pressure generated in the first bearing member; and a fluid interposed between the first bearing member that is arranged on the outer periphery of the first bearing member and rotates. A second bearing member capable of rotatably holding the first bearing member by the generated pressure is engaged with the first bearing member and the rotating shaft in accordance with an environmental temperature to rotate integrally. And engagement means.

The disk drive device of the present invention has a rotating mechanism for holding and rotating a disk-shaped recording medium on which information can be recorded on at least one surface, and for recording information on the recording medium and for rotating the information. A disk drive device that performs at least one of reproduction of information from a recording medium, wherein the rotation mechanism unit includes: a rotation shaft including a holding unit that holds the recording medium; and a driving unit that rotates the rotation shaft. A first bearing member disposed on an outer periphery of the rotating shaft and capable of rotatably holding the rotating shaft by pressure generated in a fluid interposed between the rotating shaft and the first bearing member;
A second bearing member disposed on the outer periphery of the bearing member and capable of rotatably holding the first bearing member by pressure generated in a fluid interposed between the first bearing member and the rotating device; Engaging means for engaging the first bearing member and the rotary shaft in accordance with the temperature in the housing to rotate integrally.

According to the present invention, when the first bearing member is not engaged with the rotating shaft, the rotating shaft rotated by the driving means rotates with respect to the first bearing member.
Pressure is generated in the fluid interposed between the first bearing member and the rotating shaft, and the rotating shaft is supported by the pressure. For this reason, at this time, the viscosity of the fluid interposed between the first bearing member and the second bearing member acts on the first bearing member. Does not make a relative movement, or even a relative movement results in a minute movement. When the environmental temperature increases, the viscosity of the fluid interposed between the first bearing member and the rotating shaft decreases, and the bearing rigidity of the first bearing member decreases. For this reason, the engagement means engages with the rotating shaft and the first bearing member in response to a rise in the environmental temperature to rotate both integrally. When the first bearing member rotates, pressure is generated in the fluid interposed between the first bearing member and the second bearing member, and the rotating first bearing member and the rotating shaft are supported by this pressure. . Since the second bearing member is disposed on the outer periphery of the first bearing member, the second bearing member and the first bearing member are not disposed at a higher speed than the relative speed between the rotating shaft and the first bearing member. The relative speed between is larger,
The pressure generated in the fluid existing between the second bearing member and the first bearing member is higher than the pressure generated in the fluid between the rotating shaft and the first bearing member. Rigidity is obtained.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the external appearance of a magnetic disk drive according to an embodiment of the disk drive of the present invention, and FIG. 2 is an exploded perspective view showing the configuration of the magnetic disk drive shown in FIG. As shown in FIG. 1, the magnetic disk device 61 according to the present embodiment is, for example, a PCMCIA (Personal Computer Memory Card In).
It is a card-type magnetic disk device that conforms to the standards of the International Association (ternational Association). In addition, the magnetic disk as a recording medium is included in a cartridge 91 that protects the magnetic disk. The cartridge 91 is inserted into the magnetic disk device 61 at a predetermined position by inserting the cartridge 91 in the direction of arrow B1. Further, the cartridge 91 can be ejected from the magnetic disk device 61 by pulling it out in the direction of arrow B2 with respect to the magnetic disk device 61. That is, the magnetic disk device 61 is a so-called removable magnetic disk device.

As shown in FIG. 2, the magnetic disk drive 61
Includes a chassis 12 and an upper cover 18 that covers the chassis 12. On this chassis 12, a head slider, on which a head (not shown) for reproducing information recorded on the magnetic disk and recording information on the magnetic disk, is mounted around a predetermined rotation axis along the surface of the magnetic disk. An actuator 13 for rotating and moving to a desired position on the surface of the magnetic disk; and a ramp member 62 for restraining the actuator 13 when the head (not shown) is moved out of the installation area of the magnetic disk.
, A chucking member 59, and a spindle motor 16 that holds and rotates the magnetic disk with the chucking member 59, and a holder member 17 that holds the cartridge 91. In the magnetic disk device shown in FIG. 2, when the rotation of the magnetic disk is stopped, the head slider held by the actuator 13 is moved out of the magnetic disk without making contact with the magnetic disk. This is a load type disk drive device.

FIG. 3 is an exploded perspective view showing the structure of the actuator 13 described above. As shown in FIG. 3, the actuator 13 includes an arm 76 rotatably held around a pivot 75, a coil 74 provided at a rear end of the arm 76, and a driving magnet arranged to face the coil 74. 71, an upper yoke 72 to which the drive magnet 71 is fixed, and a lower yoke 7 disposed opposite the upper yoke 72 with the coil 74 and the drive magnet 71 interposed therebetween.
3 and a head slider 77 provided at a tip end of the arm 76 in a direction substantially orthogonal to the arm 76 and having a head (not shown) mounted thereon, and exerts an elastic force for pressing the head slider 77 against a magnetic disk. And a suspension 78.

The suspension 78 has flexibility in a direction substantially perpendicular to the magnetic disk, so that recording and reproduction can be simultaneously performed on both surfaces of the magnetic disk with the magnetic disk interposed therebetween. Are provided substantially parallel to each other.

In the actuator 13 having the above structure, the driving magnet 71, the upper yoke 72, and the lower yoke 73
Constitutes a magnetic circuit, and includes an arm 76, a coil 74
When the coil 74 is energized, the movable portion of the actuator 13 rotates in the directions of arrows C1 and C2, and is moved and positioned at a desired position on the surface of the magnetic disk.

FIG. 4 is an exploded perspective view showing an example of the configuration of the cartridge 91. Referring to FIG.
Reference numeral 1 denotes a configuration in which a magnetic disk 94 is sandwiched between an upper cover member 92 and a lower cover member formed of, for example, a resin material. At the center of the magnetic disk 94 included in the cartridge 91, a clamp made of a ferromagnetic material is used to hold the magnetic disk 94 by the magnetic force of the chucking member 59 provided on the spindle motor 16 of the magnetic disk device. A member 95 is attached.

An upper cover member 92 and a lower cover member 93
Are fixed by, for example, welding, and at corresponding positions on the side surfaces of the upper cover member 92 and the lower cover member 93,
Notches 97 and 98 are formed respectively. When the upper cover member 92 and the lower cover member 93 are fixed, the notches 97 and 98 form an opening (hereinafter, referred to as a head opening) into which the actuator 13 is inserted. In the center of the lower cover member 93, an opening 101 for a spindle motor for inserting the rotation shaft of the spindle motor 16 is opened.

The cartridge 91 has a built-in shutter member 102 for preventing dust from entering through the opening for the head and the opening 101 for the spindle motor.
When the inside is not loaded, the shutter member 102 has a structure in which the head opening and the spindle motor opening 101 are closed by closing surfaces 102a and 102b, respectively. The shutter member 102 of the cartridge 91
The shutter member 102 is rotatably held around a rotation center 103 and is urged in a fixed direction by a coil spring 104. The shutter member 102 is turned by the urging force of the coil spring 104, and the head opening is opened. And the opening 101 for the spindle motor. When the cartridge 91 is loaded in the magnetic disk device 61, a predetermined engaging member in the magnetic disk device 61 is engaged with the arm 105 formed on the shutter member 102, and the coil spring 10
The shutter member 102 is rotated against the urging force of No. 4,
Head opening and spindle motor opening 101
Open.

Next, a basic operation of the magnetic disk device 61 having the above configuration will be described. When the cartridge 91 having the above-described configuration is inserted into the magnetic disk drive 61, the cartridge 91 pressed by the holder member 17 moves together with the holder member 17 along the arrow A shown in FIG.
The clamp member 95 is lowered in two directions (in FIG. 2, the holder member 17 is at the lowered position), and the clamping member 95 is attracted to the chucking member 59. At this time, the shutter member 102 opens the head opening and the spindle motor opening 101 in accordance with the insertion operation of the cartridge 91.
Next, when the spindle motor 16 rotates and reaches a certain number of rotations, the head slider 77 attached to the tip of the actuator 13 is positioned on the disk 94.

Here, the head slider 77 is moved by the force of air generated between the head slider 77 and the rotating magnetic disk 94.
From the surface of the magnetic disk 94, it flies at a height of, for example, several tens of nm. The head slider 7 on the magnetic disk 94
7 is loaded, a head (not shown) attached to the rear end of the head slider 77 moves the magnetic disk 94.
The reproduction of the data recorded on the disk 94 and the recording of the data on the disk 94 are performed. To end the recording / reproducing operation of the magnetic disk device 61, the head slider 77 is unloaded from the magnetic disk 94.

From the magnetic disk drive 61 to the cartridge 9
When the cartridge 1 is ejected, the chucking of the magnetic disk 94 by the magnet member 59 is forcibly released by raising the holder member 17 together with the cartridge 91. At the same time, the shutter member 102 of the cartridge 91 closes the head opening and the spindle motor opening 101, and the cartridge 91 is ejected from the magnetic disk device 71.

The illustration 5 of the motor unit is a sectional view showing the structure of a spindle motor 16. FIG. 5 shows a state where the cartridge 91 is loaded in the magnetic disk device 61. The spindle motor 16 includes a rotating shaft 51, a rotor 53 fixed to the rotating shaft 51, and a rotor magnet 5 fixed to the rotor 53.
4 and a first bearing member 5 arranged on the outer periphery of the rotating shaft 51.
5, a second bearing member 56 arranged on the outer periphery of the first bearing member 55, a winding 58 wound around the outer periphery of the second bearing member 56, and the second bearing member 56 are fixed. Support plate 4
9 is provided. A first thrust plate 52 is fixed to a lower end of the rotating shaft 51, and a second thrust plate 57 is fixed to a shaft portion of the rotating shaft 51. A chucking member 59 is fixed to the upper end of the rotating shaft 51, and a magnetic disk 94 as a recording medium is held on the chucking member 59. A chucking magnet 60 is provided on the upper end side of the rotor 53.

The spindle motor 16 corresponds to a specific example of the motor of the present invention, the rotary shaft 51 corresponds to a specific example of the rotary shaft of the present invention, and the first bearing member 55 corresponds to the first example of the present invention. The second bearing member 56 corresponds to a specific example of the bearing member of FIG.
Corresponds to a specific example of the second bearing member of the present invention, the first thrust plate 52 corresponds to a specific example of the first engagement member of the present invention, and the second thrust plate 57 corresponds to the specific example of the present invention. The support plate 49 corresponds to a specific example of the thrust bearing member of the present invention. Further, the rotor 5
3. The rotor magnet 54 and the winding 58 constitute the driving means of the present invention, and the first thrust plate 52 and the second thrust plate 57 constitute the engaging means of the present invention. 59, chucking magnet 6
0 and the clamp member 9 provided on the magnetic disk 94
5 constitutes the holding means of the present invention.

The chucking member 59 fitted and fixed to the upper end of the rotating shaft 51 has a holding surface for holding the magnetic disk 94, and this chucking member 59 is formed of a ferromagnetic material. The chucking magnet 60 provided on the upper end side of the rotor 53 is made of an annular permanent magnet.
The chucking member 59 is magnetized by the magnetic flux from. As a result, the clamp member 95 made of a ferromagnetic material fixed to the center of the magnetic disk 94 is attracted to the chucking member 59, and the magnetic disk 94 is rotated by the coupling force between the clamp member 95 and the chucking member 59. 51 and rotates with the rotating shaft 51.

The rotor 53 is made of a bottomed cylindrical member, and the rotary shaft 51 is fitted and inserted into a through hole 53a formed at the center, and the rotor 53 and the rotary shaft 51 are connected. The rotor magnet 54 fixed to the inner peripheral surface of the rotor 53 is formed of a permanent magnet formed in a cylindrical shape, and is arranged at a position facing a winding 58 wound around a second bearing member 56. I have. A driving current is supplied to the winding 58 from a motor driver (not shown), and the rotor magnet 54
, The rotor 53 is driven by the electromagnetic force generated between them, and as a result, the rotating shaft 51 rotates.

FIG. 6 shows the spindle motor 1 described above.
FIG. 6 is an enlarged sectional view showing the periphery of a first bearing member 55 and a second bearing member 56 of FIG. 6, a rotary shaft 51 has a circular cross section of a predetermined diameter, and a lower end of the rotary shaft 51 has a first thrust plate 52 made of a disk-shaped member.
A second thrust plate 57 made of an annular member is fixed to the shaft of the rotating shaft 51.

The first thrust plate 52 is disposed on a bottom surface 49b of a concave portion 49a formed in the support plate 49,
The lower side surface 52b of the first thrust plate 52 faces the bottom surface 49b of the concave portion 49a of the support plate 49. The outer diameter of the first thrust plate 52 is larger than that of the first bearing member 55,
The upper side surface 52a of the first thrust plate 52 faces the lower end surface 55d of the first bearing member 55, and also faces the end surface 56c of the step formed on the inner peripheral side of the second bearing member 56. ing. The support plate 49 is fixed to the chassis 12 of the magnetic disk device 61. The second thrust plate 57 has an outer diameter substantially equal to the outer diameter of the first bearing member 55, and the lower surface 51a of the second thrust plate 57
Is opposed to the upper end face 55c of the first bearing member 55.

The first bearing member 55 is formed of a cylindrical member, and is inserted into the rotary shaft 51 so as to be located between the first thrust plate 52 and the second thrust plate 57. The inner peripheral surface 55 a of the first bearing member 55 forms a predetermined gap of, for example, about 3 to 5 μm between the inner peripheral surface 55 a and the outer peripheral surface 51 a of the rotating shaft 51.

The second bearing member 56 includes the first bearing member 5
5 has a through hole into which is inserted a flange portion 5 at the lower end.
6b, and the flange portion 56b is fixed to the support plate 49. The inner peripheral surface 56a of the through hole of the second bearing member 56 forms a predetermined gap of, for example, about 3 to 5 μm with the outer peripheral surface 56a of the first bearing member 55.

Between the outer peripheral surface 51a of the rotating shaft 51 and the inner peripheral surface 55a of the first bearing member 55, the first bearing member 5
5 and the inner peripheral surface 56a of the second bearing member 56.
Between the first thrust plate 52, the support plate 49, the first bearing member 55 and the second bearing member 56, and
Thrust plate 57 and upper end surface 55c of first bearing member 55
An oil as a lubricating fluid is interposed between the two.

The first bearing member 55 is made of a material having a higher linear expansion coefficient than the material forming the rotating shaft 51. For example, the first bearing member 55 is formed of an aluminum alloy, and has a coefficient of linear expansion of 23 × 10 ^−6.
It is about. On the other hand, as a material for forming the rotating shaft 51, for example, a ceramic material such as silicon nitride is used. The linear expansion coefficient of silicon nitride is about 2.6 × 10 ⁻⁶ . The material for forming the first bearing member 55 and the rotating shaft 51 is not limited to the above-described materials, but the first bearing member 55
It is sufficient that there is a difference in the coefficient of linear expansion between the materials forming the rotating shaft 51. Further, as a material for forming the second bearing member 56, for example, a material similar to that of the first bearing member 55 may be used.

The upper surface 52a of the first thrust plate 52
The distance between the first bearing member 55 and the lower surface 58a of the second thrust plate 57 is longer than the entire length of the first bearing member 55 at normal temperature. The distance between the upper surface 52a of the first thrust plate 52 and the lower surface 58a of the second thrust plate 57 at the normal temperature is such that the amount of increase in the environmental temperature is a predetermined amount from the normal temperature, for example, 4
When the temperature reaches 0 ° C., the upper surface 52 a of the first thrust plate 52 and the lower surface 58 of the second thrust plate 57 due to a difference in thermal expansion generated between the rotating shaft 51 and the first bearing member 55.
a is set so as to contact the lower end face 55d and the upper end face 55c of the first bearing member 55, respectively. In particular,
For example, assuming that the total length of the first bearing member 55 is 10 mm, the difference in thermal expansion between the first bearing member 55 and the rotating shaft 51 having a length of 10 mm when the temperature rises from room temperature by about 40 ° C. When a material having the above-mentioned coefficient of linear expansion is used, the thickness is about 8 μm. Therefore, the first thrust plate 5
The distance between the upper surface 52 a of the second thrust plate 57 and the lower surface 58 a of the second thrust plate 57 is set to be about 8 μm longer than the entire length of the first bearing member 55.

Next, the operation of the spindle motor 16 having the above configuration will be described. When the rotating shaft 51 is driven at room temperature or at a temperature lower than room temperature, the rotating shaft 51 and the first
Relative to the bearing member 55, the first bearing member 5
A pressure is generated in the oil interposed between the inner peripheral surface 55a of the first bearing member 55 and the outer peripheral surface 51a of the rotating shaft 51, and the rotating shaft 51 is floated from the inner peripheral surface 55a of the first bearing member 55 by this pressure. Supported by As a result, a load acting on the rotating shaft 51 in the rotating radial direction can be supported. At this time, since the viscosity of the oil interposed between the first bearing member 55 and the second bearing member 56 acts on the first bearing member 55, the first bearing member 55 becomes the second bearing member 55. Does not make a relative movement with respect to, or a small movement even if it makes a relative movement.

The rotation of the rotary shaft 51 causes the lower surface 52b of the first thrust plate 52 and the concave portion 49a of the support plate 49 to rotate.
A pressure is also generated in the oil interposed between the first thrust plate 52 and the bottom surface 49 b of the support plate 49. by this,
An axial load acting on the rotating shaft 51 in the direction of arrow G2 in FIG. 6 can be supported. Further, the rotating shaft 51
, A pressure is also generated in the oil interposed between the lower end face 55 d of the first bearing member 55 and the end face 56 c of the second bearing member 56 and the upper side face 52 a of the first thrust plate 52, Thereby, the axial load acting on the rotating shaft 51 in the direction of the arrow G1 in FIG. 6 can be supported.

When the temperature inside the spindle motor 16 rises, the viscosity of the oil interposed between the inner peripheral surface 55a of the first bearing member 55 and the outer peripheral surface 51a of the rotating shaft 51 decreases as the temperature rises. Therefore, the load torque due to the viscosity of the oil acting on the rotating shaft 51 decreases, and the pressure generated in the oil also decreases, so that the bearing rigidity of the first bearing member 55 decreases. When the temperature rises by about 40 degrees from room temperature, the upper and lower end faces 5 of the first bearing member 55
5c and 55d are the first bearing member 55 and the rotating shaft 51.
Due to the difference in thermal expansion between the second thrust plate 57 and the first thrust plate 52, the first and second thrust plates 57 and 52 are brought into contact with each other. The thrust plate 57, the first thrust plate 52 and the first bearing member 5
5 with the upper and lower end faces 55c and 55d,
The first bearing member 55 rotates integrally with the rotating shaft 51.

When the first bearing member 55 rotates integrally with the rotating shaft 51, the oil interposed between the outer peripheral surface 55 b of the first bearing member 55 and the inner peripheral surface 56 a of the second bearing member 56 becomes oily. Generates pressure, and the outer peripheral surface 55 of the first bearing member 55
b is supported in a state of floating from the inner peripheral surface 56a of the second bearing member 56. This makes it possible to support the load on the rotating shaft in the radial direction of rotation.

At this time, the inner peripheral surface 5 of the second bearing member 56
Since the diameter of 6a is larger than the diameter of the inner peripheral surface of the first bearing member 55, it is interposed between the outer peripheral surface 55b of the first bearing member 55 and the inner peripheral surface 56a of the second bearing member 56. The working area of the pressure generated in the oil acting on the outer peripheral surface of the first bearing member 55 also increases, and the bearing rigidity of the second bearing member 56 becomes larger than the bearing rigidity of the first bearing member 55. As a result, it is possible to suppress a decrease in bearing stiffness in accordance with an increase in the environmental temperature in the spindle motor 16.

As described above, according to the present embodiment, even if the environmental temperature of the spindle motor 16 increases, the decrease in bearing rigidity can be suppressed, the environmental temperature increases, and disturbance is input to the magnetic disk device 61. Even when a radial force acts on the rotating shaft 51, the outer circumferential surface 51a of the rotating shaft 51
The problem that stable rotation of the rotating shaft 51 is hindered by contacting the inner peripheral surface 55a of the bearing member 55 is less likely to occur.

Modification As described above, if the bearing member for supporting the rotating shaft 51 is changed as the temperature rises, the load torque acting on the rotating shaft 51 when changing the bearing member is discontinuous. Changes to On the other hand, for example, as shown in FIG. 7, the spindle motor 16 is controlled by a servo control unit 202 provided in the magnetic disk device 61, and the servo control unit 202 includes a head mounted on a head slider 205. The number of rotations of the spindle motor 16 is controlled based on the information recorded on the magnetic disk 94 reproduced by the above. When the load torque acting on the rotating shaft 51 changes discontinuously, the control parameters of the servo control unit 202 change, and the control system becomes unstable,
Reliability may be reduced.

For this reason, for example, the spindle motor 1
A temperature sensor 203 as a temperature detecting means is provided in the vicinity of 6, and a detection signal 203 s of the temperature sensor 203 is fed back to the servo control unit 202. The servo control unit 202 detects the temperature rise based on the detection signal 203s of the temperature sensor 203, and the temperature rise amount is, for example,
When the temperature reaches approximately 40 ° C., that is, the bearing member supporting the rotating shaft 51 is moved from the first bearing member 55 to the second bearing member 56.
The configuration may be such that the rotation of the spindle motor 16 is automatically stopped before changing to. Further, after the driving of the spindle motor 16 is stopped, the spindle motor 16 may be driven with a control parameter prepared in advance corresponding to the changing load torque.

Alternatively, the servo control unit 202 is provided with an auto-tuning function for adjusting control parameters in real time in accordance with a change in load torque acting on the rotating shaft 51 without stopping the driving of the spindle motor 16.
A configuration capable of coping with a discontinuous change in the load torque acting on the rotating shaft 51 may be adopted.

In the above-described embodiment, the case of a magnetic disk device has been described. However, the present invention is not limited to this, and the present invention is not limited to an optical disk device or a magneto-optical disk device. Applicable.

[0040]

According to the present invention, a reduction in bearing stiffness due to an increase in environmental temperature can be suppressed, and a motor and a disk drive device in which the rotation of the rotating shaft is stabilized against a change in temperature can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a magnetic disk drive according to an embodiment of the disk drive of the present invention.

FIG. 2 is an exploded perspective view showing the configuration of the magnetic disk device shown in FIG.

FIG. 3 is an exploded perspective view showing a structure of an actuator 13.

FIG. 4 is an exploded perspective view showing an example of the configuration of the cartridge 91.

FIG. 5 is a sectional view showing the structure of a spindle motor 16;

FIG. 6 is an enlarged sectional view showing the periphery of a first bearing member 55 and a second bearing member 56 of the spindle motor 16;

FIG. 7 is a diagram for explaining a modified example of the present invention.

[Explanation of symbols]

51: rotating shaft, 52: first thrust plate, 55: first bearing member, 56: second bearing member, 49: support plate, 57
... A second thrust plate.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 19/28 G11B 19/28 B H02K 7/08 H02K 7/08 A F-term (Reference) 3J011 AA04 BA02 BA08 CA02 EA03 5D109 BA14 BA17 BA20 BA36 BB04 BB12 BB17 BB21 BB22 KB02 KB23 5H607 AA04 BB01 BB09 BB14 CC01 CC05 DD01 DD03 FF12 GG01 GG02 GG09 GG12 GG15

Claims (20)

[Claims] A rotating shaft; driving means for rotating the rotating shaft; rotating the rotating shaft by pressure generated in a fluid interposed between the rotating shaft and an outer periphery of the rotating shaft. A first bearing member that can be freely held; and a first bearing member that is disposed on an outer periphery of the first bearing member and that is generated by a pressure generated in a fluid that is interposed between the first bearing member and the rotating bearing member. A second bearing member capable of rotatably holding the first bearing member, and an engaging means for engaging the first bearing member and the rotating shaft to rotate integrally with each other in response to an increase in environmental temperature. 2. The motor according to claim 1, wherein said engagement means engages said first bearing member with said rotary shaft when a temperature rise amount becomes a predetermined amount or more. 3. The first bearing member is formed of a cylindrical member, has an inner peripheral surface forming a predetermined gap with the outer peripheral surface of the rotary shaft, and has a radial direction of rotation applied to the rotary shaft. The second bearing member has a through-hole into which the first bearing member is inserted, and the through-hole has a predetermined gap between itself and the outer peripheral surface of the first bearing member. The motor according to claim 1, wherein the motor has an inner peripheral surface to be formed, and supports a load in a rotational radial direction applied to the rotating shaft that rotates integrally with the first bearing member. 4. The first bearing member according to claim 1, wherein said engagement means engages said first bearing member by thermal expansion of said first bearing member.
A motor according to claim 1. 5. The engaging means is provided on the rotating shaft,
The first bearing member includes first and second engagement members disposed opposite to each other at both ends in the axial direction of the first bearing member, wherein the first and second engagement members are the first bearing. The motor according to claim 4, wherein the first bearing member is engaged with both end faces in the axial direction by thermal expansion of the member. 6. The motor according to claim 5, wherein a linear expansion coefficient of a material forming the first bearing member is larger than a linear expansion coefficient of a material forming the rotating shaft. 7. A thrust bearing member comprising a plate-like member provided at an axial end of said rotary shaft, said thrust bearing member having an opposing surface facing one surface of said first engaging member. The thrust bearing member according to claim 5, further comprising: the thrust bearing member supporting the shaft end of the rotating shaft by a pressure generated in a fluid interposed between the opposed surface and one surface of the first engagement member. motor. 8. The second engaging member has an opposing surface facing one end surface of the first bearing member, and the opposing surface of the second engaging member is the first surface of the rotating shaft. 1
The rotation of the first bearing member with respect to the bearing member causes
6. The motor according to claim 5, wherein an axial load applied to the rotating shaft is supported by a pressure generated in a fluid interposed between the bearing member and one end face of the bearing member. 9. The second bearing member has a facing surface facing the other surface of the first engaging member, and the second bearing member contacts the other surface of the first engaging member by rotation of the rotating shaft. The motor according to claim 5, wherein an axial load applied to the rotating shaft is supported by a pressure generated in a fluid interposed between the facing surface and the fluid. 10. A rotating mechanism for holding and rotating a disk-shaped recording medium on which information can be recorded on at least one surface, and recording information on the recording medium and transmitting information from the recording medium. A disk drive device that performs at least one of reproduction, wherein the rotation mechanism unit includes: a rotation shaft provided with a holding unit that holds the recording medium; a driving unit that rotates the rotation shaft; and an outer periphery of the rotation shaft. A first bearing member that is rotatably held by a pressure generated in a fluid interposed between the rotating shaft and the rotating shaft, and a first bearing member that is rotatably arranged on an outer periphery of the first bearing member and rotates; A second bearing member capable of rotatably holding the first bearing member by a pressure generated in a fluid interposed between the first bearing member and the second bearing member in response to a rise in temperature inside the device. One By engaging the the receiving member and the rotary shaft disc drive device having an engaging means for rotating integrally. 11. The recording medium is contained in a cartridge that protects the recording medium, and the recording medium is held by the holding means by loading the cartridge into a predetermined position in a disk drive device. 11. The disk drive according to claim 10, wherein the recording medium is released from the holding means by discharging the cartridge out of the apparatus. 12. The disk drive device according to claim 10, wherein said engagement means engages said first bearing member and said rotary shaft when a temperature rise amount becomes equal to or more than a predetermined amount. 13. The first bearing member is formed of a cylindrical member, has an inner peripheral surface forming a predetermined gap with an outer peripheral surface of the rotary shaft, and has a radial direction of rotation applied to the rotary shaft. The second bearing member has a through-hole into which the first bearing member is inserted, and the through-hole has a predetermined gap between itself and the outer peripheral surface of the first bearing member. The disk drive device according to claim 10, wherein the disk drive device has an inner peripheral surface formed and supports a load in a rotational radial direction applied to the rotating shaft that rotates integrally with the first bearing member. 14. The disk drive according to claim 10, wherein said engagement means engages said first bearing member by thermal expansion of said first bearing member. 15. The engaging means includes first and second engaging members provided on the rotating shaft and arranged opposite to both ends in the axial direction of the first bearing member. 15. The disk drive device according to claim 14, wherein the first and second engaging members engage with both axial end surfaces of the first bearing member due to thermal expansion of the first bearing member. 16. 16. The disk drive device according to claim 14, wherein a coefficient of linear expansion of a material forming the first bearing member is larger than a coefficient of linear expansion of a material forming the rotating shaft. 17. A thrust bearing member comprising a plate-like member provided at a shaft end of said rotary shaft, said thrust bearing member having a facing surface facing one surface of said first engaging member. The thrust bearing member according to claim 14, further comprising: the thrust bearing member supports the shaft end of the rotating shaft by a pressure generated in a fluid interposed between the opposed surface and one surface of the first engagement member. Disk drive device. 18. The second engaging member has an opposing surface that faces one end surface of the first bearing member, and the opposing surface of the second engaging member is the first surface of the rotating shaft. 1
The rotation of the first bearing member with respect to the bearing member causes
15. The disk drive device according to claim 14, wherein an axial load applied to the rotating shaft is supported by a pressure generated in a fluid interposed between the bearing member and one end surface of the bearing member. 19. The second bearing member has an opposing surface opposing the other surface of the first engagement member, and the second bearing member comes in contact with the other surface of the first engagement member by rotation of the rotation shaft. The disk drive device according to claim 14, wherein an axial load applied to the rotating shaft is supported by a pressure generated in a fluid interposed between the facing surface and the fluid. 20. The apparatus according to claim 10, further comprising: temperature detecting means for detecting a temperature in the apparatus; and control means for controlling said driving means based on the temperature detected by said temperature detecting means.
A disk drive device according to claim 1.