Bearing device for disk drive device, and disk drive device

Abstract

A bearing device (bearing device 40) for a disk drive device comprises: a bearing 43 having an inner race 43a and an outer race 43b; a first member (shaft 41) to which the inner race 43a is attached; a second member (sleeve 42) to which the outer race 43b is attached; and an annular first seal (seal 44) that is separated from the bearing 43 in the axial direction of the bearing 43, extends in the circumferential direction of the bearing 43, and is provided on the first member or the second member. The first seal has a first extension part 44a extending away from the bearing 43 in the axial direction.

Description

Bearing device for disk drive and disk drive

[0001] The present invention relates to a bearing device for a disk drive and a disk drive. This application claims the benefit of priority based on Japanese Patent Application No. 2025-023988 filed on February 18, 2025, the content of which is incorporated herein by reference.

[0002] As a storage device for storing various data, a disk drive is used. In a disk drive, data is read and written by moving a magnetic head relative to a rotating disk. Such a disk drive is also called a hard disk drive.

[0003] A disk drive includes a bearing device that rotatably supports a swing arm to which a magnetic head is attached. Also, inside the disk drive, an air flow is generated as the disk rotates. If this air flow enters the bearing device, the grease of the bearing inside the bearing device may be discharged outside the bearing device, which may reduce the cleanliness inside the disk drive. A decrease in cleanliness can be a factor such as an error in data reading and writing. Here, as disclosed in Patent Document 1, various techniques for suppressing a decrease in cleanliness due to the intrusion of air flow into the bearing device have been proposed.

[0004] Japanese Unexamined Patent Application Publication No. 2013-048005

[0005] As described above, some techniques for suppressing a decrease in cleanliness due to the intrusion of air flow into the bearing device have been proposed. However, new proposals for suppressing a decrease in cleanliness are desired.

[0006] Therefore, an object of the present invention is to provide a bearing device for a disk drive and a disk drive that can suppress a decrease in cleanliness inside the disk drive.

[0007] To solve the above problems, the present invention provides a bearing device for a disk drive device comprising: a bearing having an inner ring and an outer ring; a first member to which the inner ring is attached; a second member to which the outer ring is attached; and an annular first seal arranged in the axial direction of the bearing with respect to the bearing, extending in the circumferential direction of the bearing, and provided on the first member or the second member, wherein the first seal has a first extending portion that extends in a direction away from the bearing in the axial direction.

[0008] The first seal is provided on the second member, and the first seal has a second extending portion that extends radially from the second member toward the first member toward the bearing, and the first extending portion may extend along the outer circumferential surface of the first member from the radially inner end of the second extending portion.

[0009] The radial length of the first extension may be longer than the maximum radial length of the inner ring.

[0010] The radial length of the first extension may be longer than the axial length of the second extension.

[0011] The axial length of the second extension may be longer than the radial length of the first extension.

[0012] The first seal may include an annular second seal provided on the first member, positioned between the bearing and the first seal, extending in the circumferential direction of the bearing.

[0013] The second seal may have a third extending portion that extends in a direction away from the bearing in the axial direction.

[0014] The second seal has a fourth extending portion that extends radially from the first member toward the second member of the bearing, and the third extending portion may extend toward the second member from the radially outer end of the fourth extending portion.

[0015] The first seal is provided on the second member, and the end of the first member on the side of the first seal relative to the bearing may be further from the bearing than the end of the first seal on the side of the bearing.

[0016] The end of the second member that is on the side of the first seal with respect to the bearing may be further from the bearing than the end of the first member that is on the side of the first seal with respect to the bearing.

[0017] The first seal is provided on the first member, and the first seal has a second extending portion that extends radially from the first member toward the second member toward the second member, and the first extending portion may extend along the inner circumferential surface of the second member from the radially outer end of the second extending portion.

[0018] The first seal is provided on the first member, and the first extended portion may face the side opposite to the bearing and have an inclined surface that is inclined in a direction that moves away from the bearing in the axial direction as it extends radially outward from the bearing.

[0019] To solve the above problems, the disk drive device of the present invention includes the bearing device for the disk drive device described above.

[0020] The device comprises a base plate and a cover attached to the base plate, wherein the first member is sandwiched in the axial direction by the base plate and the cover, the cover is provided with a projection that protrudes toward the first member relative to the surrounding portion, and the first seal is provided on the second member, and a gap may be formed between the projection and the first seal.

[0021] The device comprises a base plate and a cover attached to the base plate, wherein the first member is sandwiched in the axial direction by the base plate and the cover, and the cover is provided with a projection that protrudes toward the first member relative to the surrounding portion, and the end of the second member on the first seal side with respect to the bearing may be located on the opposite side from the first member with respect to the surface of the projection that faces the first member.

[0022] According to the present invention, it is possible to suppress the decrease in the cleanliness of the inside of the disk drive.

[0023] Figure 1 is a front view showing a disk drive device according to an embodiment of the present invention. Figure 2 is a cross-sectional view showing a disk drive device according to an embodiment of the present invention. Figure 3 is a cross-sectional view showing a bearing device according to an embodiment of the present invention. Figure 4 is an enlarged cross-sectional view showing a bearing device according to a comparative example. Figure 5 is an enlarged cross-sectional view showing a bearing device according to an embodiment of the present invention. Figure 6 is an enlarged cross-sectional view showing a bearing device according to a first modified example. Figure 7 is an enlarged cross-sectional view showing a bearing device according to a second modified example. Figure 8 is an enlarged cross-sectional view showing a bearing device according to a third modified example. Figure 9 is an enlarged cross-sectional view showing a bearing device according to a fourth modified example. Figure 10 is an enlarged cross-sectional view showing a bearing device according to a fifth modified example. Figure 11 is an enlarged cross-sectional view showing a bearing device according to a sixth modified example. Figure 12 is an enlarged cross-sectional view showing a bearing device according to a seventh modified example. Figure 13 is an enlarged cross-sectional view showing a bearing device according to an eighth modified example. Figure 14 is an enlarged cross-sectional view showing a bearing device according to a ninth modified example. Figure 15 is an enlarged cross-sectional view showing a bearing device according to a tenth modified example. Figure 16 is an enlarged cross-sectional view showing a bearing device according to an eleventh modified example. Figure 17 is an enlarged cross-sectional view showing a bearing device according to a twelfth modified example.

[0024] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in these embodiments are merely examples to facilitate understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to the present invention are omitted from the illustrations.

[0025] Figure 1 is a front view showing a disk drive device 1 according to this embodiment. As shown in Figure 1, the disk drive device 1 has a substantially rectangular parallelepiped shape. In the drawings referred to below, the width direction D1, the longitudinal direction D2, and the thickness direction D3 (see Figure 2) of the disk drive device 1 are shown as appropriate. Figure 1 is a view of the disk drive device 1 from the front side. That is, the front side of the paper in Figure 1 corresponds to the front side of the disk drive device 1, and the back side of the paper in Figure 1 corresponds to the back side of the disk drive device 1. The length of the width direction D1 of the disk drive device 1 is shorter than the length of the longitudinal direction D2 of the disk drive device 1.

[0026] As shown in Figure 1, the disk drive unit 1 comprises a base plate 10, a spindle motor 20, a disk 30, a bearing device 40, a swing arm 50, a magnetic head 60, and a voice coil motor 70. The bearing device 40 is an example of a bearing device for a disk drive unit according to the present invention. In Figure 1, the base plate 10 is shown by a solid line, and components other than the base plate 10 are shown by dashed lines.

[0027] The disk drive unit 1 is a storage device that stores various types of data. In the disk drive unit 1, data is read and written by moving a magnetic head 60 relative to a rotating disk 30. The disk drive unit 1 is also called a hard disk drive.

[0028] The base plate 10 houses the various components of the disk drive unit 1. The base plate 10 forms the general shape of the disk drive unit 1. The base plate 10 has a substantially rectangular parallelepiped shape. The base plate 10 is equipped with a metal base 11.

[0029] The base 11 is formed from, for example, an aluminum alloy. The general shape of the base 11 is formed by casting. After casting, various processes are performed on the base 11. This is how the base plate 10 is manufactured. The base 11 is provided with a housing space 12, an arcuate surface 13, a bottom surface 14, a shaft 15, screw holes 16, screw holes 17, screw holes 18, and a through hole 19.

[0030] The storage space 12 is a space for housing the disk 30. The storage space 12 is located on the base 11 at a position offset from the center in the longitudinal direction D2. The storage space 12 is a roughly cylindrical space. The axial direction of the storage space 12 coincides with the thickness direction D3 of the disk drive unit 1. The axial direction of the disk 30 also coincides with the thickness direction D3 of the disk drive unit 1.

[0031] The arcuate surface 13 faces the disk 30 in the radial direction of the disk 30. The arcuate surface 13 divides the housing space 12 in the radial direction of the disk 30. The arcuate surface 13 extends along the outer edge of the disk 30, with a distance from the outer edge of the disk 30 in the radial direction. The arcuate surface 13 has an arc shape that extends in the circumferential direction of the disk 30. In the example of Figure 1, the arcuate surface 13 extends clockwise from point P1 to point P2.

[0032] The bottom surface 14 faces the disk 30 in the axial direction of the disk 30. The bottom surface 14 divides the storage space 12 in the axial direction of the disk 30. The bottom surface 14 extends approximately parallel to the disk 30, with a gap between it and the disk 30 in the axial direction. The bottom surface 14 has a substantially circular shape.

[0033] The bottom surface 14 includes a through hole 14a, a first surface 14b, a second surface 14c, a third surface 14d, and a fourth surface 14e. The first surface 14b, the second surface 14c, the third surface 14d, and the fourth surface 14e have a substantially annular shape. The through hole 14a, the first surface 14b, the second surface 14c, the third surface 14d, and the fourth surface 14e are arranged coaxially. The through hole 14a, the first surface 14b, the second surface 14c, the third surface 14d, and the fourth surface 14e are arranged in this order from the center of the bottom surface 14 outward in the radial direction of the bottom surface 14.

[0034] The through hole 14a opens at the center of the bottom surface 14. Specifically, the through hole 14a opens at the center of the first surface 14b. The through hole 14a penetrates the base 11 in the thickness direction D3. As will be described later, the shaft 21 of the spindle motor 20 (see Figure 2) is fitted into the inner circumferential surface 14a1 of the through hole 14a. In this way, the spindle motor 20 is attached to the base plate 10.

[0035] An annular projection 14b1 is provided on the outer edge of the first surface 14b. The annular projection 14b1 has a ring shape. The annular projection 14b1 extends along the circumferential direction of the first surface 14b. The annular projection 14b1 protrudes from the first surface 14b toward the front side of the disk drive device 1 relative to the surrounding portion.

[0036] The second surface 14c is positioned radially outward from the bottom surface 14 relative to the first surface 14b. The second surface 14c is recessed on the back side of the disk drive unit 1 relative to the first surface 14b.

[0037] The third surface 14d is positioned radially outward from the bottom surface 14 relative to the second surface 14c. The third surface 14d protrudes toward the front side of the disk drive unit 1 relative to the second surface 14c.

[0038] The fourth surface 14e is positioned radially outward from the bottom surface 14 relative to the third surface 14d. The fourth surface 14e is recessed on the back side of the disk drive unit 1 relative to the third surface 14d. The fourth surface 14e corresponds to the outer edge of the bottom surface 14.

[0039] The shaft 15 has a cylindrical shape extending in the thickness direction D3. The shaft 15 is positioned in a recess formed in the base 11 where no housing space 12 is provided. The shaft 15 protrudes from the surrounding portion toward the front side of the disk drive device 1. As will be described later, a swing arm 50 is attached to the shaft 15 via a bearing device 40.

[0040] Screw holes 16, 17, and 18 are holes with internal threads formed therein and are used to attach various components to the base 11 by screwing them. For example, screw hole 16 is used to attach the voice coil motor 70. For example, screw hole 17 is used to attach a lamp (not shown) on which the magnetic head 60 is mounted. For example, screw hole 18 is used to attach the cover 80 (see Figure 2), which will be described later.

[0041] The through-holes 19 are through which windings forming the coils of the stator 25 of the spindle motor 20, which will be described later, are inserted. These windings are connected to a flexible substrate (not shown) provided on the back surface of the base 11. In Figure 1, three through-holes 19 are shown, through which the U-phase, V-phase, and W-phase windings are inserted, respectively.

[0042] The spindle motor 20 is a motor for rotating the disk 30. The spindle motor 20 is disposed at the center of the accommodation space 12. The axial direction of the spindle motor 20 coincides with the thickness direction D3 of the disk drive device 1. Details of the spindle motor 20 will be described later.

[0043] The disk 30 is a storage medium for storing data. The disk 30 has a disk shape. A magnetic material is coated on the surface of the disk 30. The disk 30 is also called a magnetic disk. The surface of the disk 30 has a huge number of regions divided in the radial direction and circumferential direction of the disk 30. This region is also called a sector. As will be described later, the disk drive device 1 is provided with a plurality of disks 30. However, the number of disks 30 may be at least one or more.

[0044] The bearing device 40 rotatably supports the swing arm 50. The bearing device 40 has a substantially cylindrical shape. The inner peripheral surface of the bearing device 40 is fitted to the outer peripheral surface of a shaft 15 provided on the base 11. The swing arm 50 is attached to the outer peripheral surface of the bearing device 40. Details of the bearing device 40 will be described later.

[0045] The swing arm 50 moves the magnetic head 60. The magnetic head 60 is attached to the tip of the swing arm 50. The swing arm 50 is rotatable about the central axis of the bearing device 40. When the swing arm 50 rotates, the magnetic head 60 moves integrally with the swing arm 50.

[0046] The magnetic head 60 reads and writes data to and from the disk 30. Specifically, the magnetic head 60 can write data to the disk 30 by rewriting the magnetization direction of the magnetic material of each sector of the rotating disk 30. Also, the magnetic head 60 can read data from the disk 30 by reading the magnetization direction of the magnetic material of each sector of the rotating disk 30.

[0047] The voice coil motor 70 is a motor that drives the swing arm 50. Specifically, the voice coil motor 70 can move the proximal end of the swing arm 50 (that is, the end on the side opposite to the magnetic head 60 side with respect to the bearing device 40). Thereby, the voice coil motor 70 can rotate the swing arm 50 around the central axis of the bearing device 40. Note that the voice coil motor 70 is connected to a control board (not shown) and is controlled by the control board.

[0048] Here, referring to FIG. 2, the details of the spindle motor 20 will be described. FIG. 2 is a cross-sectional view showing the disk drive device 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the disk drive device 1 seen in the width direction D1. In FIG. 2, the disk 30, the bearing device 40, the swing arm 50, and the magnetic head 60 are shown by two-dot chain lines.

[0049] In FIG. 2, a cover 80 not shown in FIG. 1 is shown. The cover 80 has a substantially rectangular shape. The length of the cover 80 in the width direction D1 substantially coincides with the length of the base plate 10 in the width direction D1. The length of the cover 80 in the longitudinal direction D2 substantially coincides with the length of the base plate 10 in the longitudinal direction D2. The cover 80 is attached to the front side of the base plate 10. Thereby, each component of the disk drive device 1 is housed between the base plate 10 and the cover 80.

[0050] As shown in FIG. 2, the spindle motor 20 includes a shaft 21, a bearing 22, a hub 23, a cap 24, a stator 25, and a magnet 26. In the spindle motor 20, the hub 23 to which a plurality of disks 30 are attached rotates around the shaft 21. Thereby, the spindle motor 20 can rotate a plurality of disks 30.

[0051] The shaft 21 has a cylindrical shape extending in the thickness direction D3. The shaft 21 is fitted to the inner peripheral surface 14a1 of the through hole 14a. The shaft 21 is fixed to the base plate 10.

[0052] The bearing 22 rotatably supports the hub 23. The bearing 22 is fixed to the outer circumferential surface of the shaft 21. In the example shown in Figure 2, the bearing 22 is a conical bearing. Two bearings 22 are arranged spaced apart in the axial direction of the shaft 21. The hub 23 has a substantially cylindrical shape. Each bearing 22 is interposed between the outer circumferential surface of the shaft 21 and the inner circumferential surface of the hub 23. This allows the hub 23 to rotate relative to the shaft 21.

[0053] Multiple discs 30 are mounted on the hub 23. In the example shown in Figure 2, 10 discs 30 are mounted on the hub 23. However, the number of discs 30 is not particularly limited. Multiple discs 30 are fitted into the outer circumferential surface of the hub 23. The central axis of each disc 30 coincides with the central axis of the shaft 21. That is, the central axis of each disc 30 coincides with the central axis of the through hole 14a. Each disc 30 is spaced apart from each other in the thickness direction D3. Spacers 31 are interposed between adjacent discs 30. Each spacer 31 has an annular shape. Each spacer 31 is fitted into the outer circumferential surface of the hub 23.

[0054] The cap 24 has a roughly disc shape. The cap 24 is attached to the hub 23 from the front side of the disk drive unit 1. By attaching the cap 24 to the hub 23, the multiple disks 30 are fixed to the hub 23.

[0055] The stator 25 is an electromagnet having multiple magnetic poles. The number of magnetic poles of the stator 25 is not particularly limited. The stator 25 is fixed to the base plate 10. The stator 25 has, for example, an annular stator core and a plurality of coils wound around the stator core. The central axis of the stator core coincides with the central axis of the shaft 21. The plurality of coils are arranged spaced apart from each other in the circumferential direction of the stator core. The stator 25 is fixed to the base plate 10 while being supported, for example, by an annular projection 14b1 on the first surface 14b.

[0056] The magnets 26 are fixed to the hub 23. Specifically, multiple magnets 26 are arranged spaced apart from each other in the circumferential direction of the hub 23. Each magnet 26 is positioned radially outward of the hub 23 relative to the stator 25. Each magnet 26 faces the stator 25 radially in the hub 23.

[0057] In the spindle motor 20, the direction of the magnetic flux generated by the stator 25 is regularly switched by controlling the current applied to the coil of the stator 25. As a result, the magnetic force between the stator 25 and the magnet 26 is regularly switched, causing the hub 23 to rotate. The stator 25 is connected to a control board (not shown) and controlled by the control board.

[0058] As described above, in the example shown in Figure 2, ten disks 30 are mounted on the hub 23. Two magnetic heads 60 are provided for each disk 30. Specifically, the two magnetic heads 60 are positioned to face both the front and back surfaces of each disk 30. The magnetic head 60 facing the front surface of the disk 30 reads and writes data to the front surface of the disk 30. The magnetic head 60 facing the back surface of the disk 30 reads and writes data to the back surface of the disk 30. In the example shown in Figure 2, a total of 20 magnetic heads 60 are mounted on the tip of the swing arm 50.

[0059] Figure 3 is a cross-sectional view showing a bearing device 40 according to this embodiment. As shown in Figure 3, the bearing device 40 comprises a shaft 41, a sleeve 42, two bearings 43, and a seal 44. The shaft 41 corresponds to an example of a first member according to the present invention. The sleeve 42 corresponds to an example of a second member according to the present invention. The seal 44 corresponds to an example of a first seal according to the present invention.

[0060] As described above, the bearing device 40 is fitted onto the shaft 15 of the base plate 10. Therefore, the bearing device 40 and the shaft 15 have a common central axis A1. The direction of the central axis A1 coincides with the thickness direction D3. Hereafter, the axial direction of the bearing device 40 (i.e., the direction of the central axis A1), the radial direction of the bearing device 40, and the circumferential direction of the bearing device 40 will also be referred to simply as the axial direction, radial direction, and circumferential direction, respectively.

[0061] In the following, the upper side of Figure 3 (i.e., the front side of the disk drive unit 1) will be simply referred to as the upper side, and the lower side of Figure 3 (i.e., the back side of the disk drive unit 1) will be simply referred to as the lower side.

[0062] The shaft 41 has a substantially cylindrical shape. The inner circumferential surface 41a of the shaft 41 fits into the outer circumferential surface of the shaft 15. Therefore, the shaft 41 is arranged coaxially with the central axis A1. The shaft 41 is fixed to the shaft 15. For example, the shaft 41 is held axially between the base 11 and the cover 80. In the example of Figure 3, a projection 81 is provided on the part of the cover 80 that abuts the upper end of the shaft 15. The projection 81 is a part of the cover 80 that protrudes downward relative to the surrounding part. That is, the projection 81 protrudes in a direction toward the shaft 41 relative to the surrounding part of the cover 80. For example, the projection 81 has a substantially annular shape arranged coaxially with the central axis A1. The outer diameter of the lower surface 81a of the projection 81 is larger than the outer diameter of the shaft 41. The lower surface 81a of the projection 81 is, for example, a surface perpendicular to the central axis A1. For example, the shaft 41 is pressed downward by such a protrusion 81.

[0063] The sleeve 42 has a substantially cylindrical shape. The sleeve 42 is positioned coaxially with the shaft 41 and radially outward relative to the shaft 41. As will be described later, the sleeve 42 is attached to the shaft 41 via a bearing 43. For example, in the axial direction, the upper end of the sleeve 42 is located below the upper end of the shaft 41. For example, in the axial direction, the lower end of the sleeve 42 is located approximately at the same time as the lower end of the shaft 41.

[0064] The bearing 43 has an inner ring 43a, an outer ring 43b, and a plurality of rolling elements 43c. For example, the bearing 43 is a rolling ball bearing. In this case, the rolling elements 43c have a spherical shape. However, the bearing 43 may be a bearing other than a rolling ball bearing. The plurality of rolling elements 43c are held by a cage (not shown).

[0065] The inner ring 43a of the bearing 43 is attached to the shaft 41. Specifically, the inner circumferential surface of the inner ring 43a engages with the outer circumferential surface 41b of the shaft 41. The inner ring 43a is fixed to the shaft 41. For example, the inner ring 43a is bonded to the shaft 41. The outer ring 43b of the bearing 43 is attached to the sleeve 42. Specifically, the outer circumferential surface of the outer ring 43b engages with the inner circumferential surface 42a of the sleeve 42. The outer ring 43b is fixed to the sleeve 42. For example, the outer ring 43b is bonded to the sleeve 42.

[0066] The shaft 41 and the sleeve 42 are connected via the bearing 43 as described above, allowing the sleeve 42 to rotate relative to the shaft 41. For example, the swing arm 50 described above is attached to the outer circumferential surface 42b of the sleeve 42. This allows the swing arm 50 to rotate around the central axis A1 of the bearing device 40.

[0067] The two bearings 43 are positioned axially separated from each other. In the example shown in Figure 3, the inner circumferential surface 42a of the sleeve 42 includes a first inner circumferential surface 42a1, a second inner circumferential surface 42a2, and a third inner circumferential surface 42a3. The first inner circumferential surface 42a1, the second inner circumferential surface 42a2, and the third inner circumferential surface 42a3 are arranged in this order from top to bottom. For example, the inner diameter of the first inner circumferential surface 42a1 and the inner diameter of the third inner circumferential surface 42a3 are the same. The inner diameter of the second inner circumferential surface 42a2 is smaller than the inner diameter of the first inner circumferential surface 42a1 and the inner diameter of the third inner circumferential surface 42a3. The upper of the two bearings 43 is positioned between the outer circumferential surface 41b of the shaft 41 and the first inner circumferential surface 42a1 of the sleeve 42. The lower of the two bearings 43 is positioned between the outer circumferential surface 41b of the shaft 41 and the third inner circumferential surface 42a3 of the sleeve 42.

[0068] The internal space S1 of the bearing device 40 is formed by the outer circumferential surface 41b of the shaft 41 and the inner circumferential surface 42a of the sleeve 42. The internal space S1 is a substantially cylindrical space partitioned by the outer circumferential surface 41b of the shaft 41 and the inner circumferential surface 42a of the sleeve 42. The bearing 43 is housed in this internal space S1. The inside of the bearing 43 is filled with grease to maintain the smooth rotation of the rolling elements 43c. If the grease from the bearing 43 is discharged outside the bearing device 40, the cleanliness of the inside of the disk drive device 1 may decrease. Therefore, it is necessary to block the flow of fluid between the internal space S1 and the space outside the bearing device 40.

[0069] A flange 41c is formed on the lower side of the shaft 41, extending radially outward. The flange 41c has an annular shape that extends along the circumferential direction of the shaft 41. The flange 41c is positioned coaxially with the central axis A1. The outer edge of the flange 41c is in close proximity to the third inner surface 42a3 of the sleeve 42. The flange 41c is positioned below the lower bearing 43. As a result, the fluid flow between the lower part of the internal space S1 and the space outside the bearing device 40 is obstructed to some extent by the flange 41c.

[0070] The seal 44 is provided to block the flow of fluid between the upper part of the internal space S1 and the space outside the bearing device 40. The seal 44 is formed in an annular shape that extends in the circumferential direction. The seal 44 is positioned coaxially with the central axis A1. The seal 44 is positioned axially parallel to the bearing 43. For example, the seal 44 is spaced axially apart from the bearing 43. The seal 44 may also be in contact with the bearing 43 in the axial direction. Specifically, the seal 44 is positioned above the upper bearing 43 in the internal space S1. The seal 44 is provided on the sleeve 42. In the example of Figure 3, the seal 44 is fixed to the first inner circumferential surface 42a1 of the sleeve 42. The seal 44 extends from the first inner circumferential surface 42a1 of the sleeve 42 toward the outer circumferential surface 41b of the shaft 41. Details of the seal 44 will be described later.

[0071] As described above, the disk drive unit 1 includes a bearing device 40. Inside the disk drive unit 1, airflow is generated as the disk 30 rotates. If this airflow enters the internal space S1 of the bearing device 40, the grease from the bearing 43 may be discharged to the outside of the bearing device 40, potentially reducing the cleanliness of the inside of the disk drive unit 1. This reduction in cleanliness can lead to errors in data reading and writing. Therefore, in this embodiment, as will be described later, the reduction in the cleanliness of the inside of the disk drive unit 1 is suppressed mainly by modifying the shape of the seal 44. After describing a bearing device according to a comparative example, the details of the bearing device 40 according to this embodiment will be described below.

[0072] Figure 4 is an enlarged cross-sectional view showing a bearing device 400 according to a comparative example. As shown in Figure 4, the bearing device 400 corresponds to an example in which the seal 44 is replaced with a seal 440 compared to the bearing device 40 described above.

[0073] The seal 440 has an annular plate shape that extends in the circumferential direction. The seal 440 is positioned coaxially with the central axis A1. The seal 440 is positioned above the upper bearing 43 in the internal space S1. The seal 440 extends radially from the sleeve 42 toward the shaft 41. Specifically, the seal 440 is fixed to the first inner circumferential surface 42a1 of the sleeve 42. The seal 440 extends radially inward from the first inner circumferential surface 42a1 of the sleeve 42. The inner circumferential end of the seal 440 is spaced apart from the outer circumferential surface 41b of the shaft 41.

[0074] As described above, airflow is generated inside the disk drive unit 1 as the disk 30 rotates. In the bearing device 400 according to the comparative example, a seal 440 is provided to suppress fluid flow between the upper part of the internal space S1 and the space outside the bearing device 40. Therefore, the intrusion of airflow from above the bearing device 400 into the internal space S1 is suppressed to some extent by the seal 440. However, as shown by the dashed arrow in Figure 4, some of the airflow may enter the internal space S1 from above the bearing device 400, passing between the inner circumferential end of the seal 440 and the outer circumferential surface 41b of the shaft 41. Therefore, it is desirable to suppress such intrusion of airflow.

[0075] Figure 5 is an enlarged cross-sectional view showing a bearing device 40 according to this embodiment. As described above, the bearing device 40 includes a seal 44. As shown in Figure 5, the seal 44 has a first extended portion 44a and a second extended portion 44b. In the seal 44, the second extended portion 44b is attached to the sleeve 42, and the first extended portion 44a extends from the second extended portion 44b.

[0076] The second extending portion 44b has, for example, an annular plate shape extending in the circumferential direction. The second extending portion 44b is, for example, arranged coaxially with the central axis A1. The second extending portion 44b extends radially from the sleeve 42 toward the shaft 41. Specifically, the second extending portion 44b is fixed to the first inner circumferential surface 42a1 of the sleeve 42. The second extending portion 44b extends radially inward from the first inner circumferential surface 42a1 of the sleeve 42. The inner circumferential end of the second extending portion 44b is spaced apart from the outer circumferential surface 41b of the shaft 41. In this example, the entire portion of the seal 44 that extends in an annular plate shape within the same plane corresponds to the second extending portion 44b. That is, in Figure 5, the bent portion on the lower left side of the seal 44 is included in the second extending portion 44b. However, in Figure 5, the bent portion on the lower left side of the seal 44 may be included in the first extending portion 44a.

[0077] The first extending portion 44a has, for example, a cylindrical shape that extends in the circumferential direction. The first extending portion 44a is, for example, arranged coaxially with the central axis A1. The first extending portion 44a extends in a direction that moves away from the bearing 43 in the axial direction. In the example of Figure 5, the first extending portion 44a extends along the outer circumferential surface 41b of the shaft 41. That is, the first extending portion 44a extends in the axial direction. The first extending portion 44a extends from the inner circumferential end of the second extending portion 44b. Specifically, the first extending portion 44a extends upward from the inner circumferential end of the second extending portion 44b. The first extending portion 44a is spaced away from the outer circumferential surface 41b of the shaft 41.

[0078] As described above, the bearing device 40 according to this embodiment comprises a bearing 43 having an inner ring 43a and an outer ring 43b, a shaft 41 corresponding to a first member to which the inner ring 43a is attached, a sleeve 42 corresponding to a second member to which the outer ring 43b is attached, and a seal 44 corresponding to an annular first seal provided on the sleeve 42, which is arranged in the axial direction of the bearing 43 and extends in the circumferential direction of the bearing 43. The seal 44 has a first extending portion 44a that extends in a direction away from the bearing 43 in the axial direction.

[0079] Therefore, as shown by the dashed arrow in Figure 5, the first extended portion 44a can block the airflow attempting to enter the internal space S1 from above the bearing device 40. Specifically, the airflow attempting to enter the internal space S1 from above the bearing device 40 flows radially inward of the bearing device 40. The first extended portion 44a extends in a direction intersecting this airflow direction. Therefore, since this airflow can be blocked by the first extended portion 44a, the intrusion of airflow into the internal space S1 can be suppressed. As a result, the discharge of grease from the bearing 43 to the outside of the bearing device 40 can be suppressed, and thus the decrease in the cleanliness of the inside of the disk drive device 1 can be suppressed.

[0080] In particular, in the example shown in Figure 5, the seal 44 has a second extended portion 44b that extends radially from the sleeve 42 toward the shaft 41 toward the bearing 43, and the first extended portion 44a extends from the radially inner end of the second extended portion 44b along the outer circumferential surface 41b of the shaft 41. Therefore, the seal 44 can be brought close to the shaft 41 over a sufficiently long axial length in the first extended portion 44a. This allows a narrow passage to be formed between the first extended portion 44a and the shaft 41. This passage provides resistance to fluid flow. Therefore, even if an airflow is generated that attempts to enter the internal space S1 by passing over the first extended portion 44a without being blocked by the first extended portion 44a, it is possible to suppress such airflow from entering the internal space S1.

[0081] Here, the outer diameter of the lower surface 81a of the protrusion 81 of the cover 80 is larger than the outer diameter of the first extension 44a. Therefore, the protrusion 81 of the cover 80 faces the first extension 44a in the axial direction. In the example of Figure 5, the upper end 41d of the shaft 41 is located above the upper end 44a1 of the first extension 44a. In other words, the end of the shaft 41 on the side of the seal 44 relative to the bearing 43 (specifically, the upper end 41d) is further from the bearing 43 than the end of the seal 44 on the side of the bearing 43 opposite to the bearing 43 (specifically, the upper end 44a1). As a result, a gap G1 is formed between the protrusion 81 of the cover 80 and the seal 44. Therefore, contact between the seal 44 and the cover 80 can be suppressed, and the sleeve 42 can rotate smoothly.

[0082] In the above description, the bearing device 40 according to this embodiment was explained with reference to Figure 5. However, various modifications may be made to the bearing device 40 described above. Hereinafter, various modifications will be explained with reference to Figures 6 to 17.

[0083] Figure 6 is an enlarged cross-sectional view showing a bearing device 40A according to the first modified example. The bearing device 40A corresponds to an example in which a seal 45 is added to the bearing device 40 described above. The seal 45 corresponds to an example of the second seal according to the present invention.

[0084] The seal 45 is positioned between the upper bearing 43 and the seal 44. For example, the seal 45 is axially separated from the upper bearing 43 and the seal 44. The seal 45 is formed in an annular shape that extends in the circumferential direction. The seal 45 is positioned coaxially with the central axis A1. The seal 45 is provided on the shaft 41. Specifically, the seal 45 is fixed to the outer circumferential surface 41b of the shaft 41. The seal 45 extends from the outer circumferential surface 41b of the shaft 41 toward the first inner circumferential surface 42a1 of the sleeve 42.

[0085] Specifically, the seal 45 has a third extending portion 45a and a fourth extending portion 45b. In the seal 45, the fourth extending portion 45b is attached to the shaft 41, and the third extending portion 45a extends from the fourth extending portion 45b.

[0086] The fourth extending portion 45b has, for example, an annular plate shape that extends in the circumferential direction. The fourth extending portion 45b is, for example, arranged coaxially with the central axis A1. The fourth extending portion 45b extends radially from the shaft 41 toward the sleeve 42. Specifically, the fourth extending portion 45b is fixed to the outer circumferential surface 41b of the shaft 41. The fourth extending portion 45b extends radially outward from the outer circumferential surface 41b of the shaft 41. The outer circumferential end of the fourth extending portion 45b is spaced apart from the first inner circumferential surface 42a1 of the sleeve 42.

[0087] The third extending portion 45a has, for example, a substantially frustoconical shape that extends in the circumferential direction. The third extending portion 45a is, for example, arranged coaxially with the central axis A1. The third extending portion 45a extends in a direction that moves away from the bearing 43 in the axial direction. For example, the third extending portion 45a extends in a direction that moves away from the bearing 43 in the axial direction as it moves radially outward. In the example of Figure 6, the third extending portion 45a inclins upward as it moves radially outward. The third extending portion 45a extends from the outer peripheral end of the fourth extending portion 45b. The third extending portion 45a may also extend axially upward from the outer peripheral end of the fourth extending portion 45b. The outer peripheral end of the third extending portion 45a is spaced away from the first inner circumferential surface 42a1 of the sleeve 42.

[0088] The bearing device 40A, like the bearing device 40 described above, is equipped with a seal 44. Therefore, as shown by the dashed arrow in Figure 6, the first extended portion 44a can block airflow attempting to enter the internal space S1 from above the bearing device 40A. However, it is conceivable that some airflow may pass above the first extended portion 44a and proceed towards the internal space S1.

[0089] Here, as described above, the bearing device 40A is positioned between the bearing 43 and the seal 44, extends in the circumferential direction of the bearing 43, and includes a seal 45 that corresponds to an annular second seal provided on the shaft 41. Therefore, in addition to the passage formed between the seal 44 and the shaft 41, a narrow passage can also be formed between the seal 44 and the seal 45. Thus, the passage formed by the seal 44 and the seal 45 at the top of the bearing device 40A is narrow and curved. Such a passage provides significant resistance to fluid flow. A structure having such a passage is also called a labyrinth structure. In the bearing device 40A, when some airflow passes over the first extending portion 44a and heads towards the internal space S1, the labyrinth structure formed by the seal 44 and the seal 45 can suppress the entry of the airflow into the internal space S1. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40A can be more effectively suppressed, and the decrease in the cleanliness of the inside of the disk drive device 1 can be more effectively suppressed.

[0090] In particular, in the example shown in Figure 6, the seal 45 has a third extended portion 45a that extends in a direction away from the bearing 43 in the axial direction. This makes it possible to locally narrow the width of a part of the passage formed between the seal 44 and the seal 45 (specifically, the radially outer portion). Therefore, it is possible to suppress the entry of airflow into the internal space S1 by passing between the seal 44 and the seal 45.

[0091] Furthermore, in the example shown in Figure 6, the seal 45 has a fourth extension portion 45b that extends radially from the shaft 41 toward the sleeve 42 toward the bearing 43, and the third extension portion 45a extends toward the sleeve 42 from the radially outer end of the fourth extension portion 45b. This appropriately realizes the formation of the labyrinth structure described above by the seals 44 and 45.

[0092] In the above description, an example was given in which the seal 45 has a third extension portion 45a in the bearing device 40A. However, the third extension portion 45a may be omitted from the seal 45 in the bearing device 40A. For example, the seal 45 may have an annular plate shape that extends radially from the shaft 41 toward the sleeve 42.

[0093] In the above description, an example was given in which the seal 45 has a fourth extension portion 45b in the bearing device 40A. However, the fourth extension portion 45b may be omitted from the seal 45 in the bearing device 40A. For example, the entire seal 45 may correspond to the third extension portion 45a.

[0094] Figure 7 is an enlarged cross-sectional view showing a bearing device 40B according to a second modified example. The bearing device 40B corresponds to an example in which the shape of the seal 44 is changed compared to the bearing device 40A described above.

[0095] In the bearing device 40B, compared to the bearing device 40A described above, the seal 44 further has a fifth extended portion 44c in addition to the first extended portion 44a and the second extended portion 44b. In other respects, the bearing device 40B is the same as the bearing device 40A described above.

[0096] The fifth extending portion 44c has, for example, an annular plate shape that extends in the circumferential direction. The fifth extending portion 44c is, for example, arranged coaxially with the central axis A1. The fifth extending portion 44c extends radially outward from the upper end of the first extending portion 44a. The fifth extending portion 44c is axially separated from the lower surface 81a of the protruding portion 81 of the cover 80.

[0097] In the bearing device 40B, as shown by the dashed arrow in Figure 7, the first extended portion 44a can block the airflow attempting to enter the internal space S1 from above the bearing device 40B, similar to the bearing device 40 described above. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40B can be suppressed, thereby suppressing a decrease in the cleanliness of the inside of the disk drive device 1. Furthermore, in the bearing device 40B, the third extended portion 45a extends from the upper end of the first extended portion 44a, so the airflow attempting to enter the internal space S1 from above the bearing device 40B can also be blocked by the third extended portion 45a. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40B can be suppressed more effectively.

[0098] The above describes an example in which the bearing device 40B is equipped with a seal 45. However, the seal 45 may be omitted from the bearing device 40B. Furthermore, the seal 45 may also be omitted from the bearing devices 40C, 40D, 40E, 40F, 40G, and 40H described later.

[0099] Figure 8 is an enlarged cross-sectional view showing a bearing device 40C according to the third modified example. The bearing device 40C corresponds to an example in which the shape of the seal 44 is changed compared to the bearing device 40A described above.

[0100] In the bearing device 40C, the radial length L1 of the first extension portion 44a is longer compared to the bearing device 40A described above. In other respects, the bearing device 40C is the same as the bearing device 40A described above.

[0101] Specifically, in the bearing device 40C, the radial length L1 of the first extension portion 44a is longer than the maximum radial length L2 of the inner ring 43a. The maximum length L2 corresponds to the maximum radial length of the inner ring 43a. As a result, the radial length L1 of the first extension portion 44a is made longer to a certain extent, which allows a narrow passage to be formed between the upper surface of the first extension portion 44a and the protruding portion 81 of the cover 80. This passage provides resistance to fluid flow. Therefore, it is possible to suppress the airflow from passing over the first extension portion 44a. Thus, the discharge of grease from the bearing 43 to the outside of the bearing device 40C can be more effectively suppressed, and the decrease in the cleanliness of the inside of the disk drive device 1 can be more effectively suppressed.

[0102] Furthermore, in the bearing device 40C, the radial length L1 of the first extension portion 44a is longer than the axial length L3 of the second extension portion 44b. As a result, the radial length L1 of the first extension portion 44a is made somewhat longer, which allows a narrow passage to be formed between the upper surface of the first extension portion 44a and the protruding portion 81 of the cover 80. This passage provides resistance to fluid flow. Therefore, it is possible to suppress the airflow from passing over the first extension portion 44a. Thus, the discharge of grease from the bearing 43 to the outside of the bearing device 40C can be suppressed more effectively, and the decrease in the cleanliness of the inside of the disk drive device 1 can be suppressed more effectively.

[0103] As described above, the narrow passage formed between the first extended portion 44a and the shaft 41 provides resistance to fluid flow. This passage corresponds to a part of the labyrinth structure. From the viewpoint of increasing the resistance to fluid flow due to the labyrinth structure, it is preferable that the radial distance between the first extended portion 44a and the shaft 41 is shorter than the maximum radial length L2 of the inner ring 43a. From a similar viewpoint, it is even more preferable that the radial distance between the first extended portion 44a and the shaft 41 is shorter than the minimum radial length L4 of the inner ring 43a. The minimum length L4 corresponds to the minimum radial length of the inner ring 43a. The above points also apply to the bearing devices 40, 40A, 40B described above, and the bearing device 40H described later.

[0104] In the above, an example was described in which the length L1 of the bearing device 40C is longer than the maximum length L2 and also longer than the length L3. However, in the bearing device 40C, the length L1 may be longer than the maximum length L2 but not longer than the length L3. Also, in the bearing device 40C, the length L1 may be longer than the length L3 but not longer than the maximum length L2.

[0105] Figure 9 is an enlarged cross-sectional view showing a bearing device 40D according to the fourth modified example. The bearing device 40D corresponds to an example in which the shape of the seal 44 is changed compared to the bearing device 40A described above.

[0106] In the bearing device 40D, the extension direction of the first extension portion 44a is changed compared to the bearing device 40A described above. In other respects, the bearing device 40D is the same as the bearing device 40A described above.

[0107] Specifically, in the bearing device 40D, the first extending portion 44a extends in a direction that moves axially away from the bearing 43 as it proceeds radially inward. In the example of Figure 9, the first extending portion 44a extends from the inner circumferential end of the second extending portion 44b and inclins upward as it proceeds radially inward. The first extending portion 44a has, for example, a substantially frustoconical shape that extends in the circumferential direction. The first extending portion 44a is arranged, for example, coaxially with the central axis A1. In a cross-section including the central axis A1, the first extending portion 44a extends, for example, in a straight line. However, in a cross-section including the central axis A1, the first extending portion 44a may be bent overall or partially.

[0108] In the bearing device 40D, as shown by the dashed arrow in Figure 9, the first extended portion 44a can block the airflow attempting to enter the internal space S1 from above the bearing device 40D, similar to the bearing device 40 described above. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40D can be suppressed, thereby suppressing a decrease in the cleanliness of the inside of the disk drive device 1.

[0109] Figure 10 is an enlarged cross-sectional view showing a bearing device 40E according to the fifth modified example. The bearing device 40E corresponds to an example in which the shape of the seal 44 is changed compared to the bearing device 40A described above.

[0110] In the bearing device 40E, the extension direction of the first extension portion 44a is changed compared to the bearing device 40A described above. In other respects, the bearing device 40E is the same as the bearing device 40A described above.

[0111] Specifically, in the bearing device 40E, the first extending portion 44a extends in a direction that moves axially away from the bearing 43 as it extends radially outward. In the example of Figure 10, the first extending portion 44a extends from the inner circumferential end of the second extending portion 44b and inclins upward as it extends radially outward. The first extending portion 44a has, for example, a substantially frustoconical shape that extends in the circumferential direction. The first extending portion 44a is, for example, arranged coaxially with the central axis A1. In a cross-section including the central axis A1, the first extending portion 44a extends, for example, in a straight line. However, in a cross-section including the central axis A1, the first extending portion 44a may be bent overall or partially.

[0112] In the bearing device 40E, as shown by the dashed arrow in Figure 10, the first extended portion 44a can block the airflow attempting to enter the internal space S1 from above the bearing device 40E, similar to the bearing device 40 described above. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40E can be suppressed, thereby suppressing a decrease in the cleanliness of the inside of the disk drive device 1.

[0113] Figure 11 is an enlarged cross-sectional view showing a bearing device 40F according to the sixth modified example. The bearing device 40F corresponds to an example in which the shape of the seal 44 is changed compared to the bearing device 40A described above.

[0114] In the bearing device 40F, the positional relationship between the first extension portion 44a and the second extension portion 44b has been changed compared to the bearing device 40A described above. In other respects, the bearing device 40F is the same as the bearing device 40A described above.

[0115] Specifically, in the bearing device 40F, similar to the bearing device 40A described above, the first extended portion 44a extends in the axial direction. However, unlike the bearing device 40A described above, in the bearing device 40F, the first extended portion 44a extends upward from the radially outer side of the inner circumferential end of the second extended portion 44b. The first extended portion 44a has, for example, a cylindrical shape that extends in the circumferential direction. The first extended portion 44a is, for example, arranged coaxially with the central axis A1.

[0116] In the bearing device 40F, as shown by the dashed arrow in Figure 11, the first extended portion 44a can block the airflow attempting to enter the internal space S1 from above the bearing device 40F, similar to the bearing device 40 described above. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40F can be suppressed, thereby suppressing a decrease in the cleanliness of the inside of the disk drive device 1.

[0117] In the above, an example was described in which the first extended portion 44a in the bearing device 40F extends in the axial direction. However, in the bearing device 40F, the first extended portion 44a may extend in a direction inclined with respect to the axial direction. Furthermore, in the bearing device 40F, the first extended portion 44a may be bent in whole or in part in a cross-section including the central axis A1.

[0118] Figure 12 is an enlarged cross-sectional view showing a bearing device 40G according to the seventh modified example. The bearing device 40G corresponds to an example in which the shape of the seal 44 is changed compared to the bearing device 40A described above.

[0119] In the bearing device 40G, compared to the bearing device 40A described above, the extension direction of the first extension portion 44a is changed, and the second extension portion 44b is omitted from the seal 44. In other respects, the bearing device 40G is the same as the bearing device 40A described above.

[0120] Specifically, in the bearing device 40G, the entire seal 44 corresponds to the first extended portion 44a. The first extended portion 44a extends in a direction that moves axially away from the bearing 43 as it proceeds radially inward. In the example of Figure 12, the first extended portion 44a is fixed to the first inner circumferential surface 42a1 of the sleeve 42. The first extended portion 44a extends from the first inner circumferential surface 42a1 of the sleeve 42 and inclins upward as it proceeds radially inward. The first extended portion 44a has, for example, a substantially frustoconical shape that extends in the circumferential direction. The first extended portion 44a is, for example, arranged coaxially with the central axis A1. In a cross-section including the central axis A1, the first extended portion 44a extends linearly, for example. However, in a cross-section including the central axis A1, the first extended portion 44a may be bent overall or partially.

[0121] In the bearing device 40G, as shown by the dashed arrow in Figure 12, the first extended portion 44a can block the airflow attempting to enter the internal space S1 from above the bearing device 40G, similar to the bearing device 40 described above. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40G can be suppressed, thereby suppressing a decrease in the cleanliness of the inside of the disk drive device 1.

[0122] Figure 13 is an enlarged cross-sectional view showing a bearing device 40H according to the eighth modified example. The bearing device 40H corresponds to an example in which the dimensions of the sleeve 42 are changed compared to the bearing device 40A described above.

[0123] In the bearing device 40H, the axial position of the upper end portion 42c of the sleeve 42 is changed compared to the bearing device 40A described above. In other respects, the bearing device 40H is the same as the bearing device 40A described above.

[0124] Specifically, in the bearing device 40H, the upper end 42c of the sleeve 42 is located above the upper end 41d of the shaft 41. In other words, the end of the sleeve 42 on the side of the seal 44 relative to the bearing 43 (specifically, the upper end 42c) is further from the bearing 43 than the end of the shaft 41 on the side of the seal 44 relative to the bearing 43 (specifically, the upper end 41d). Therefore, the upper end 42c of the sleeve 42 is located on the opposite side (specifically, above) of the shaft 41 relative to the surface of the protruding portion 81 of the cover 80 on the shaft 41 side (specifically, the lower surface 81a). This makes it possible to reduce the gap between the sleeve 42 and the cover 80. Therefore, as shown by the dashed arrow in Figure 13, the airflow generated with the rotation of the disk 30 can be blocked by the sleeve 42. Thus, it is possible to suppress such airflow from passing over the sleeve 42 and entering the upper part of the bearing device 40H. Therefore, it is possible to more effectively suppress the entry of airflow into the internal space S1. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40H can be more effectively suppressed, and thus the decrease in the cleanliness of the inside of the disk drive device 1 can be more effectively suppressed.

[0125] Furthermore, even if the airflow were to pass over the sleeve 42 and enter the area above the bearing device 40H, such airflow could be blocked by the first extended portion 44a, as indicated by the dashed arrow in Figure 13.

[0126] As described above, the bearing device 40H is an example in which the upper end portion 42c of the sleeve 42 is positioned above the upper end portion 41d of the shaft 41, compared to the bearing device 40A described above. However, in the bearing devices 40, 40B, 40C, 40D, 40E, 40F, and 40G described above, the upper end portion 42c of the sleeve 42 may be positioned above the upper end portion 41d of the shaft 41.

[0127] Figure 14 is an enlarged cross-sectional view showing a bearing device 40I according to the ninth modified example. The bearing device 40I corresponds to an example in which the shape of the seal 44 is changed compared to the bearing device 40 described above.

[0128] In the bearing device 40I, the axial length L3 of the second extension portion 44b is longer compared to the bearing device 40 described above. In addition, in the bearing device 40I, the axial position of the upper end portion 42c of the sleeve 42 is also changed compared to the bearing device 40 described above. In other respects, the bearing device 40I is the same as the bearing device 40 described above.

[0129] Specifically, in the bearing device 40I, the axial length L3 of the second extension portion 44b is longer than the radial length L1 of the first extension portion 44a. By increasing the axial length L3 of the second extension portion 44b in this way, the seal 44 can be brought closer to the shaft 41 over a sufficiently long axial range. This makes it possible to increase the axial length of the narrow passage formed between the seal 44 and the shaft 41 (specifically, the passage formed between the inner circumferential surface of the seal 44 and the outer circumferential surface 41b of the shaft 41). As described above, the narrow passage formed between the seal 44 and the shaft 41 provides resistance to fluid flow. Therefore, even if an airflow is generated that attempts to enter the internal space S1 by passing over the first extension portion 44a without being blocked by the first extension portion 44a, it is possible to suppress such airflow from entering the internal space S1.

[0130] In the bearing device 40I, as with the bearing device 40C described above, it is preferable that the radial distance between the seal 44 and the shaft 41 be shorter than the maximum radial length L2 of the inner ring 43a, in order to increase the resistance to fluid flow in the passage formed between the seal 44 and the shaft 41. Furthermore, from the same viewpoint, it is even more preferable that the radial distance between the seal 44 and the shaft 41 be shorter than the minimum radial length L4 of the inner ring 43a.

[0131] In the bearing device 40I, as shown by the dashed arrow in Figure 14, the first extended portion 44a can block the airflow attempting to enter the internal space S1 from above the bearing device 40I, similar to the bearing device 40 described above. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40I can be suppressed, thereby suppressing a decrease in the cleanliness of the inside of the disk drive device 1.

[0132] Furthermore, in the bearing device 40I, similar to the bearing device 40H described above, the upper end portion 42c of the sleeve 42 is located above the upper end portion 41d of the shaft 41. Therefore, the upper end portion 42c of the sleeve 42 is located above the lower surface 81a of the protrusion 81 of the cover 80. This reduces the gap between the sleeve 42 and the cover 80. Therefore, as shown by the dashed arrow in Figure 14, the airflow generated by the rotation of the disk 30 can be blocked by the sleeve 42. Thus, it is possible to suppress such airflow from passing over the sleeve 42 and entering the upper part of the bearing device 40I. Therefore, the entry of airflow into the internal space S1 can be suppressed more effectively. Thus, it is possible to more effectively suppress the discharge of grease from the bearing 43 to the outside of the bearing device 40I, and therefore, the decrease in the cleanliness of the inside of the disk drive device 1 can be suppressed more effectively. Furthermore, the fact that the upper end portion 42c of the sleeve 42 is located above the upper end portion 41d of the shaft 41 is also the same for the bearing devices 40J, 40K, and 40L, which will be described later.

[0133] Figure 15 is an enlarged cross-sectional view showing a bearing device 40J according to the tenth modified example. The bearing device 40J corresponds to an example in which the seal 44 is provided on the shaft 41 instead of the sleeve 42, compared to the bearing device 40I described above.

[0134] As shown in Figure 15, in the bearing device 40J, the seal 44 has a first extended portion 44a and a second extended portion 44b. Unlike the bearing devices 40, 40A, 40B, 40C, 40D, 40E, 40F, 40G, 40H, and 40I described above, in the bearing device 40J, the second extended portion 44b of the seal 44 is attached to the shaft 41, and the first extended portion 44a extends from the second extended portion 44b.

[0135] The second extending portion 44b has, for example, an annular plate shape that extends in the circumferential direction. The second extending portion 44b is, for example, arranged coaxially with the central axis A1. The second extending portion 44b extends radially from the shaft 41 toward the sleeve 42. Specifically, the second extending portion 44b is fixed to the outer circumferential surface 41b of the shaft 41. The second extending portion 44b extends radially outward from the outer circumferential surface 41b of the shaft 41. The outer circumferential end of the second extending portion 44b is spaced apart from the first inner circumferential surface 42a1 of the sleeve 42.

[0136] The first extending portion 44a has, for example, a cylindrical shape that extends in the circumferential direction. The first extending portion 44a is, for example, arranged coaxially with the central axis A1. The first extending portion 44a extends in a direction that moves away from the bearing 43 in the axial direction. In the example of Figure 15, the first extending portion 44a extends along the first inner circumferential surface 42a1 of the sleeve 42. That is, the first extending portion 44a extends in the axial direction. The first extending portion 44a extends from the outer circumferential end of the second extending portion 44b. Specifically, the first extending portion 44a extends upward from the outer circumferential end of the second extending portion 44b. The first extending portion 44a is spaced away from the first inner circumferential surface 42a1 of the sleeve 42.

[0137] As described above, the bearing device 40J according to the 10th modified example comprises a bearing 43 having an inner ring 43a and an outer ring 43b, a shaft 41 corresponding to a first member to which the inner ring 43a is attached, a sleeve 42 corresponding to a second member to which the outer ring 43b is attached, and a seal 44 that is arranged in the axial direction of the bearing 43, extends in the circumferential direction of the bearing 43, and corresponds to an annular first seal provided on the shaft 41. The seal 44 has a first extending portion 44a that extends in a direction away from the bearing 43 in the axial direction.

[0138] Here, the airflow generated as the disk 30 rotates may pass over the sleeve 42 and enter above the seal 44. In Figure 15, the dashed arrow indicates the airflow that enters above the seal 44 from the left side of the drawing, passing over the sleeve 42, and flowing to the right side of the drawing. In the bearing device 40J according to the 10th modified example, as indicated by the dashed arrow in Figure 15, the airflow that has entered above the seal 44 by passing over the sleeve 42 can be blocked by the first extended portion 44a. Specifically, the airflow that has entered above the seal 44 by passing over the sleeve 42 mainly flows in a direction perpendicular to the central axis A1 of the bearing device 40. The first extended portion 44a extends in a direction intersecting this airflow direction. Therefore, since this airflow can be blocked by the first extended portion 44a, it is possible to suppress the airflow from entering the gap between the seal 44 and the sleeve 42, and thus suppress the entry of airflow into the internal space S1. Therefore, since the grease from the bearing 43 is prevented from being discharged outside the bearing device 40J, a decrease in the cleanliness of the inside of the disk drive device 1 can be suppressed.

[0139] Furthermore, in the bearing device 40J, the axial length L3 of the second extension portion 44b is longer than the radial length L1 of the first extension portion 44a. By increasing the axial length L3 of the second extension portion 44b in this way, the seal 44 can be brought closer to the sleeve 42 over a sufficiently long axial range. This makes it possible to increase the axial length of the narrow passage formed between the seal 44 and the sleeve 42 (specifically, the passage formed between the outer circumferential surface of the seal 44 and the first inner circumferential surface 42a1 of the sleeve 42). The narrow passage formed between the seal 44 and the sleeve 42 provides resistance to fluid flow. Therefore, even if an airflow attempts to enter the gap between the seal 44 and the sleeve 42, it is possible to suppress such airflow from entering the internal space S1.

[0140] In the bearing device 40J, from the viewpoint of increasing resistance to fluid flow in the passage formed between the seal 44 and the sleeve 42, it is preferable that the radial distance between the seal 44 and the sleeve 42 is shorter than the maximum radial length L5 of the outer ring 43b. The maximum length L5 corresponds to the maximum value of the radial length of the outer ring 43b. Furthermore, from a similar viewpoint, it is even more preferable that the radial distance between the seal 44 and the sleeve 42 is shorter than the minimum radial length L6 of the outer ring 43b. The minimum length L6 corresponds to the minimum value of the radial length of the outer ring 43b. The above points regarding preferred values ​​for the radial distance between the seal 44 and the sleeve 42 are also the same in the bearing device 40K described later.

[0141] In addition, in bearing device 40J and bearing device 40K described later, the diameter of the protrusion 81 of the cover 80 is smaller compared to bearing devices 40, 40A, 40B, 40C, 40D, 40E, 40F, 40G, 40H, and 40I described above. Thus, the dimensions of the protrusion 81 of the cover 80 are not particularly limited. Also, in bearing device 40J, bearing device 40K described later, and bearing device 40L described later, the upper end portion 44a1 of the first extension portion 44a is located above the lower surface 81a of the protrusion 81 of the cover 80. However, in the axial direction, the position of the upper end portion 44a1 of the first extension portion 44a may substantially coincide with the position of the lower surface 81a of the protrusion 81 of the cover 80. Alternatively, the upper end portion 44a1 of the first extension portion 44a may be located below the lower surface 81a of the protrusion 81 of the cover 80.

[0142] Figure 16 is an enlarged cross-sectional view showing a bearing device 40K according to the 11th modified example. The bearing device 40K corresponds to an example in which the shape of the seal 44 is changed compared to the bearing device 40J described above. In the bearing device 40K as well as the bearing device 40J described above, the seal 44 is provided on the shaft 41 instead of the sleeve 42.

[0143] As shown in Figure 16, in the bearing device 40K, the seal 44 has a first extended portion 44a and a second extended portion 44b. In the bearing device 40K, similar to the bearing device 40J described above, the second extended portion 44b of the seal 44 is attached to the shaft 41, and the first extended portion 44a extends from the second extended portion 44b. In Figure 16, for ease of understanding, the boundary between the first extended portion 44a and the second extended portion 44b of the seal 44 is shown by a dashed line.

[0144] The second extending portion 44b has, for example, an annular plate shape that extends in the circumferential direction. The second extending portion 44b is, for example, arranged coaxially with the central axis A1. The second extending portion 44b extends radially from the shaft 41 toward the sleeve 42. Specifically, the second extending portion 44b is fixed to the outer circumferential surface 41b of the shaft 41. The second extending portion 44b extends radially outward from the outer circumferential surface 41b of the shaft 41. The outer circumferential end of the second extending portion 44b is spaced apart from the first inner circumferential surface 42a1 of the sleeve 42.

[0145] The first extending portion 44a has, for example, a ring shape that extends in the circumferential direction. The first extending portion 44a is, for example, arranged coaxially with the central axis A1. Specifically, the first extending portion 44a has a triangular shape in a cross-section including the central axis A1. The first extending portion 44a protrudes upward from the upper surface of the second extending portion 44b. The first extending portion 44a tapers down so that its radial length decreases as it extends upward.

[0146] The first extension portion 44a has a cylindrical surface F1 and an inclined surface F2 as its outer surface. The cylindrical surface F1 is continuous with the outer circumferential surface of the second extension portion 44b. The inclined surface F2 is continuous with the inner circumferential surface of the second extension portion 44b and is also continuous with the cylindrical surface F1.

[0147] The cylindrical surface F1 is, for example, positioned coaxially with the central axis A1 and has a cylindrical shape. The cylindrical surface F1 faces radially outward and is opposite to the first inner circumferential surface 42a1 of the sleeve 42. The outer diameter of the cylindrical surface F1 is the same as the outer diameter of the second extended portion 44b.

[0148] The inclined surface F2 is, for example, positioned coaxially with the central axis A1 and has a tapered shape. The inclined surface F2 faces away from the bearing 43 and opposite the cover 80. The inclined surface F2 extends from the outer circumferential surface 41b of the shaft 41 and inclins upward (i.e., in the direction away from the bearing 43 in the axial direction) as it extends radially outward. In the example of Figure 16, the inclined surface F2 extends linearly in the cross-section including the central axis A1. However, in the cross-section including the central axis A1, the inclined surface F2 may be bent overall or partially.

[0149] In the axial direction, the position of the upper end 44a1 of the first extension portion 44a substantially coincides with the position of the upper end 42c of the sleeve 42. In the bearing device 40K, the connection portion between the cylindrical surface F1 and the inclined surface F2 corresponds to the upper end 44a1 of the first extension portion 44a. However, the upper end 44a1 of the first extension portion 44a may be located above or below the upper end 42c of the sleeve 42.

[0150] Similar to Figure 15, Figure 16 shows, indicated by dashed arrows, an airflow that enters above the seal 44, over the sleeve 42, from the left side of the drawing, and flows to the right. In the bearing device 40K according to the 11th modified example, as indicated by the dashed arrows in Figure 16, the airflow that enters above the seal 44, over the sleeve 42, can be smoothly sent to the outside of the sleeve 42 by the first extended portion 44a. Specifically, the airflow that enters above the seal 44, over the sleeve 42, mainly flows in a direction perpendicular to the central axis A1 of the bearing device 40. In the bearing device 40K, such airflow can be directed along the inclined surface F2 of the first extended portion 44a. The airflow flowing along the inclined surface F2 is then sent to the outside of the sleeve 42, over the sleeve 42. This prevents the airflow from entering the gap between the seal 44 and the sleeve 42, thus preventing the airflow from entering the internal space S1. Therefore, since the grease from the bearing 43 is prevented from being discharged outside the bearing device 40K, the decrease in the cleanliness of the inside of the disk drive device 1 can be suppressed.

[0151] Here, from the viewpoint of effectively suppressing the intrusion of airflow into the internal space S1, it is preferable that the distance L8 between the outer peripheral edge of the lower surface 81a of the protruding portion 81 of the cover 80 and the inclined surface F2 is shorter than the distance L7 between the upper end 44a1 of the first extending portion 44a and the cover 80. A shorter distance L8 prevents airflow that has entered above the seal 44 beyond the sleeve 42 from entering radially inward through the gap between the outer peripheral edge of the lower surface 81a of the protruding portion 81 of the cover 80 and the inclined surface F2. This makes it easier to return airflow that has entered above the seal 44 beyond the sleeve 42 to the outside of the sleeve 42. Therefore, the possibility of airflow entering the internal space S1 can be reduced, and thus the intrusion of airflow into the internal space S1 can be effectively suppressed.

[0152] Furthermore, from a similar viewpoint, it is preferable that the distance L9 between the outer circumferential surface of the seal 44 and the first inner circumferential surface 42a1 of the sleeve 42 is shorter than the distance L7 between the upper end portion 44a1 of the first extension portion 44a and the cover 80. As described above, the narrow passage formed between the seal 44 and the sleeve 42 provides resistance to fluid flow. Therefore, by shortening the distance L9, the resistance to fluid flow in the passage formed between the seal 44 and the sleeve 42 can be increased. Thus, even if an airflow is generated that attempts to enter the gap between the seal 44 and the sleeve 42, it is possible to suppress such airflow from entering the internal space S1. The preference for a distance L9 to be shorter than the distance L7 is also true for the bearing device 40J described above.

[0153] However, distance L8 may be the same as distance L7, or it may be longer than distance L7. Similarly, distance L9 may be the same as distance L7, or it may be longer than distance L7. Furthermore, distance L8 may be the same as distance L9, or it may be shorter than distance L9, or it may be longer than distance L9.

[0154] Figure 17 is an enlarged cross-sectional view showing a bearing device 40L according to the twelfth modified example. The bearing device 40L is an example in which the inclined surface F2 of the first extending portion 44a is modified so that it extends from the upper surface of the second extending portion 44b rather than from the outer circumferential surface 41b of the shaft 41, compared to the bearing device 40K described above. In other respects, the bearing device 40L is the same as the bearing device 40K described above.

[0155] In the bearing device 40L, similar to the bearing device 40K described above, the first extending portion 44a has, for example, an annular shape extending in the circumferential direction. The first extending portion 44a is arranged, for example, coaxially with the central axis A1. Specifically, the first extending portion 44a has a triangular shape in a cross-section including the central axis A1. The first extending portion 44a protrudes upward from the upper surface of the second extending portion 44b. The first extending portion 44a tapers as it extends upward, with its radial length decreasing.

[0156] In the bearing device 40L, similar to the bearing device 40K described above, the first extended portion 44a has a cylindrical surface F1 and an inclined surface F2 as its outer surface. The cylindrical surface F1 is continuous with the outer circumferential surface of the second extended portion 44b. The inclined surface F2 is continuous with the cylindrical surface F1.

[0157] In the bearing device 40L, similar to the bearing device 40K described above, the cylindrical surface F1 is, for example, arranged coaxially with the central axis A1 and has a cylindrical shape. The cylindrical surface F1 faces radially outward and is opposite to the first inner circumferential surface 42a1 of the sleeve 42. The outer diameter of the cylindrical surface F1 is the same as the outer diameter of the second extended portion 44b.

[0158] In the bearing device 40L, similar to the bearing device 40K described above, the inclined surface F2 is, for example, arranged coaxially with the central axis A1 and has a tapered shape. The inclined surface F2 faces the side opposite to the bearing 43 and faces the cover 80. Here, in the bearing device 40L, unlike the bearing device 40K described above, the inclined surface F2 is spaced apart from the outer circumferential surface 41b of the shaft 41, extends from a position on the upper surface of the second extending portion 44b that is spaced apart from the outer circumferential surface 41b of the shaft 41, and inclins upward (i.e., in a direction that moves away from the bearing 43 in the axial direction) as it extends radially outward. Therefore, the first extending portion 44a protrudes upward from the radially outer portion of the upper surface of the second extending portion 44b. Thus, the inclined surface F2 does not have to extend from the outer circumferential surface 41b of the shaft 41. In the example of Figure 17, in a cross-section including the central axis A1, the inclined surface F2 extends in a straight line. However, in the cross-section including the central axis A1, the inclined surface F2 may be bent entirely or partially.

[0159] In the bearing device 40L, similar to the bearing device 40K described above, the position of the upper end 44a1 of the first extension portion 44a in the axial direction is approximately the same as the position of the upper end 42c of the sleeve 42. In the bearing device 40L, similar to the bearing device 40K described above, the connection portion between the cylindrical surface F1 and the inclined surface F2 corresponds to the upper end 44a1 of the first extension portion 44a. However, the upper end 44a1 of the first extension portion 44a may be located above or below the upper end 42c of the sleeve 42. Also, in the axial direction, the upper end 44a1 of the first extension portion 44a may be located below the lower surface 81a of the protruding portion 81 of the cover 80.

[0160] Similar to Figure 16, Figure 17 shows, indicated by a dashed arrow, an airflow that enters from the left side of the drawing, over the sleeve 42, and above the seal 44, and flows to the right in the drawing. In the bearing device 40L according to the 12th modification, similar to the bearing device 40K according to the 11th modification, the airflow that enters over the sleeve 42 and above the seal 44 can be directed along the inclined surface F2 of the first extended portion 44a. The airflow flowing along the inclined surface F2 is then sent over the sleeve 42 and to the outside of the sleeve 42. This prevents the airflow from entering the gap between the seal 44 and the sleeve 42, thus preventing the airflow from entering the internal space S1. Therefore, the discharge of grease from the bearing 43 to the outside of the bearing device 40L is prevented, thus preventing a decrease in the cleanliness of the inside of the disk drive device 1.

[0161] Furthermore, in the bearing device 40L, similar to the bearing device 40K described above, from the viewpoint of effectively suppressing the intrusion of airflow into the internal space S1, it is preferable that the distance L8 between the outer peripheral edge of the lower surface 81a of the protruding portion 81 of the cover 80 and the inclined surface F2 is shorter than the distance L7 between the upper end portion 44a1 of the first extended portion 44a and the cover 80. Also, from a similar viewpoint, it is preferable that the distance L9 between the outer peripheral surface of the seal 44 and the first inner peripheral surface 42a1 of the sleeve 42 is shorter than the distance L7 between the upper end portion 44a1 of the first extended portion 44a and the cover 80.

[0162] However, in the bearing device 40L as described above, distance L8 may coincide with distance L7, or it may be longer than distance L7. Also, distance L9 may coincide with distance L7, or it may be longer than distance L7. Furthermore, distance L8 may coincide with distance L9, or it may be shorter than distance L9, or it may be longer than distance L9.

[0163] In addition, even in examples where the seal 44 is provided on the shaft 41, such as in bearing devices 40J, 40K, or 40L, the first extended portion 44a only needs to extend in a direction that moves away from the bearing 43 in the axial direction, similar to the example where the seal 44 is provided on the sleeve 42, and the direction of extension and shape of the first extended portion 44a are not particularly limited.

[0164] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to these embodiments. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention.

[0165] The configuration of the disk drive unit 1 has been described above with reference to Figures 1 and 2. However, the configuration of the disk drive unit 1 is not limited to the examples in Figures 1 and 2. For example, the shape of each component of the disk drive unit 1 is not limited to the examples in Figures 1 and 2. For example, the positional relationship between the components of the disk drive unit 1 is not limited to the examples in Figures 1 and 2. For example, some components of the disk drive unit 1 may be deleted, modified, or added compared to the examples in Figures 1 and 2.

[0166] In the above, the configuration of the bearing device 40 was described with reference to Figure 3. However, the configuration of the bearing device 40 is not limited to the example in Figure 3. For example, the shape of each component of the bearing device 40 is not limited to the example in Figure 3. For example, the positional relationship between the components of the bearing device 40 is not limited to the example in Figure 3. For example, some components of the bearing device 40 may be deleted, changed, or added compared to the example in Figure 3. For example, the first member according to the present invention only needs to have at least an outer circumferential surface and does not need to have a cylindrical shape like the shaft 41. Also, the second member according to the present invention only needs to have at least an inner circumferential surface and does not need to have a cylindrical shape like the sleeve 42.

[0167] The above describes an example in which the bearing devices 40, 40B, 40C, 40D, 40E, 40F, 40G, 40H, 40I, 40J, 40K, and 40L are used as components of the disk drive device 1. However, the bearing devices 40, 40B, 40C, 40D, 40E, 40F, 40G, 40H, 40I, 40J, 40K, and 40L may also be used as components of devices other than the disk drive device 1.

[0168] 1. Disk drive unit 10. Base plate 40. Bearing unit (bearing unit for disk drive unit) 40A. Bearing unit (bearing unit for disk drive unit) 40B. Bearing unit (bearing unit for disk drive unit) 40C. Bearing unit (bearing unit for disk drive unit) 40D. Bearing unit (bearing unit for disk drive unit) 40E. Bearing unit (bearing unit for disk drive unit) 40F. Bearing unit (bearing unit for disk drive unit) 40G. Bearing unit (bearing unit for disk drive unit) 40H. Bearing unit (bearing unit for disk drive unit) 40I. Bearing unit (bearing unit for disk drive unit) 40J. Bearing unit (bearing unit for disk drive unit) 40K. Bearing unit (bearing unit for disk drive unit) 40L. Bearing unit (bearing unit for disk drive unit) 41. Shaft (first member) 41d. Upper end (end) 42. Sleeve (second member) 42c. Upper end (end) 43 Bearing 43a Inner ring 43b Outer ring 44 Seal (first seal) 44a First extension part 44a1 Upper end part (end part) 44b Second extension part 45 Seal (second seal) 45a Third extension part 45b Fourth extension part 80 Cover 81 Projection part 81a Lower surface (surface) F2 Inclined surface

Claims

1. A bearing device for a disk drive device, comprising: a bearing having an inner ring and an outer ring; a first member to which the inner ring is attached; a second member to which the outer ring is attached; and an annular first seal arranged in the axial direction of the bearing with respect to the bearing, extending in the circumferential direction of the bearing, and provided on the first member or the second member, wherein the first seal has a first extending portion that extends in a direction away from the bearing in the axial direction.

2. The bearing device for a disk drive device according to claim 1, wherein the first seal is provided on the second member, and the first seal has a second extending portion that extends radially from the second member toward the first member toward the bearing, and the first extending portion extends along the outer circumferential surface of the first member from the radially inner end of the second extending portion.

3. The bearing device for a disk drive device according to claim 2, wherein the radial length of the first extension is longer than the maximum radial length of the inner ring.

4. The bearing device for a disk drive device according to claim 2, wherein the radial length of the first extension is longer than the axial length of the second extension.

5. The bearing device for a disk drive device according to claim 2, wherein the axial length of the second extension is longer than the radial length of the first extension.

6. The bearing device for a disk drive device according to claim 1, wherein the first seal is provided on the second member, positioned between the bearing and the first seal, extends in the circumferential direction of the bearing, and comprises an annular second seal provided on the first member.

7. The bearing device for a disk drive device according to claim 6, wherein the second seal has a third extending portion that extends in a direction away from the bearing in the axial direction.

8. The bearing device for a disk drive device according to claim 7, wherein the second seal has a fourth extending portion that extends radially from the first member toward the second member, and the third extending portion extends toward the second member from the radially outer end of the fourth extending portion.

9. The bearing device for a disk drive device according to claim 1, wherein the first seal is provided on the second member, and the end of the first member on the side of the first seal relative to the bearing is further from the bearing than the end of the first seal on the side of the bearing.

10. The end of the second member on the side of the first seal with respect to the bearing is further from the bearing than the end of the first member on the side of the first seal with respect to the bearing, the bearing device for a disk drive device according to claim 1.

11. The bearing device for a disk drive device according to claim 1, wherein the first seal is provided on the first member, and the first seal has a second extending portion that extends radially from the first member toward the second member toward the second member, and the first extending portion extends along the inner circumferential surface of the second member from the radially outer end of the second extending portion.

12. The bearing device for a disk drive device according to claim 1, wherein the first seal is provided on the first member, and the first extended portion faces away from the bearing and has an inclined surface that is inclined in a direction that moves away from the bearing in the axial direction as it extends radially outward from the bearing.

13. A disk drive device comprising the bearing device for a disk drive device described in claim 1.

14. The disk drive device according to claim 13, comprising: a base plate; and a cover attached to the base plate, wherein the first member is sandwiched in the axial direction by the base plate and the cover, the cover is provided with a projection that protrudes toward the first member relative to the surrounding portion, and the first seal is provided on the second member, and a gap is formed between the projection and the first seal.

15. A disk drive device according to claim 13, comprising: a base plate; and a cover attached to the base plate, wherein the first member is sandwiched in the axial direction by the base plate and the cover, the cover is provided with a projection that protrudes toward the first member relative to the surrounding portion, and the end of the second member on the first seal side with respect to the bearing is located on the opposite side from the first member with respect to the surface of the projection that is on the first member side.

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