JP2015113907A - Bearing device and information recording reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device capable of suppressing enlargement.SOLUTION: A bearing device is equipped with a shaft, a pair of rolling bearings disposed so as to align in an axial direction of the shaft, and a hub cap joined with the shaft, and covering the rolling bearings from the outside in the axial direction. The rolling bearing has an inner ring fixed to the shaft, and an outer ring surrounding the inner ring from the outside in a diametrical direction of the shaft. The hub cap has a stepped portion projecting inward in the axial direction. The stepped portion has thickness corresponding to difference between the height of an outside end portion in the axial direction of the inner ring which is a distance from an end surface in the inner side in the axial direction of the outer ring to an end surface on the outer side in the axial direction of the inner ring, and the height of an outside end portion in the axial direction of the outer ring which is a distance from the end surface on the inner side in the axial direction of the outer ring to the end surface on the outer side in the axial direction of the outer ring.

Description

  The present invention relates to a bearing device and an information recording / reproducing device.

  2. Description of the Related Art Conventionally, an information recording / reproducing apparatus such as a hard disk for storing and reproducing various kinds of information on a disk (magnetic recording medium) is known. In general, an information recording / reproducing apparatus includes a head gimbal assembly having a slider for recording / reproducing a signal on / from a disk, and an arm (rotating member) having the head gimbal assembly mounted on the distal end side. This arm is rotatable by a bearing device provided on the base end side. By rotating the arm, the slider can be moved to a predetermined position on the disk to record and reproduce signals.

  By the way, the structure described in the following patent document 1 is known as this kind of bearing device, for example. The bearing device includes a shaft, a pair of rolling bearings that are extrapolated to the shaft and arranged side by side in the axial direction of the shaft, a sleeve that interpolates the pair of rolling bearings, and covers the rolling bearing from the outside in the axial direction. And a hub cap. For example, the hub cap is fixed to the outer periphery of the shaft and the inner periphery of the sleeve, and is cut into a narrow width over the entire periphery at the radial intermediate portion.

JP 2004-92870 A

  However, when the rolling bearing portion rotates, there is a risk that the grease scatters to the outside through a gap in a portion that is narrowly cut over the entire circumference in the radial intermediate portion of the hub cap. Further, a large amount of outgas generated from the grease may be released to the outside from the gap. In particular, when a bearing device is used in an information recording / reproducing apparatus such as a hard disk, grease or outgas adheres to the disk, etc., which causes disc recording failure and reproduction failure, and component deterioration. There is a fear. In particular, in recent years, information recording / reproducing apparatuses have been increasing in density, and there is an increasing demand for dealing with such defects. Therefore, a problem remains in terms of suppressing the scattering of grease and the release of outgas.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a bearing device and an information recording / reproducing device capable of suppressing the scattering of grease and the release of outgas.

  In order to achieve the above object, the present invention employs the following means.

  (1) That is, the bearing device according to the first aspect of the present invention is joined to the shaft, a pair of rolling bearings that are extrapolated to the shaft and arranged in the axial direction of the shaft, and the shaft. A hub cap that covers the rolling bearing from the outside in the axial direction, and the rolling bearing includes an inner ring that is fixed to the shaft, and an outer ring that surrounds the inner ring from the outside in the radial direction of the shaft. The hub cap has a stepped portion protruding inward in the axial direction, and the stepped portion is a distance from the inner end surface in the axial direction of the outer ring to the end surface in the axial direction of the inner ring. The axially outer end of the outer ring, which is the height of the axially outer end of the inner ring and the distance from the axially inner end surface of the outer ring to the axially outer end surface of the outer ring. The difference from the height of the part And having a thickness sized to respond.

  According to this configuration, the gap between the hub cap and the rolling bearing can be formed in a complicated labyrinth shape by the step portion of the hub cap. Therefore, scattering of grease to the outside of the bearing device and release of outgas can be suppressed.

  (2) In the bearing device according to (1) above, a shield that seals the rolling bearing is disposed inside the hub cap in the axial direction, and the hub cap projects inward in the axial direction. The second stepped portion has a height of the outer end portion in the axial direction of the inner ring or the outer ring, and the axial direction of the shield from the inner end surface of the outer ring in the axial direction. The shield may have a thickness corresponding to a difference with the height of the outer end portion in the axial direction of the shield, which is a distance to the outer end surface of the shield.

  According to this structure, the clearance gap between a hub cap and a shield can be made into a more complicated labyrinth shape by the second step portion of the hub cap. Therefore, splashing of grease to the outside of the bearing device and release of outgas can be reliably suppressed.

  (3) In the bearing device according to (2), the shield includes a bent portion that is bent inward in the axial direction, and a convex portion that protrudes toward the bent portion is formed in the hub cap. May be.

  According to this configuration, the gap between the hub cap and the shield can be made into a more complicated labyrinth shape by the convex portion of the hub cap and the bent portion of the shield. Therefore, splashing of grease to the outside of the bearing device and release of outgas can be reliably suppressed.

  (4) In the bearing device according to any one of (1) to (3), a shield that seals the rolling bearing is disposed inside the hub cap in the axial direction, The outer end portion in the axial direction is formed with a shield holding portion that is recessed inward in the axial direction and holds the shield, and the hub cap has a radially inner end portion of the shield holding portion and the You may have the 2nd bending part bent along the outer side edge part of the said axial direction of an outer ring | wheel.

  According to this configuration, the gap between the hub cap and the outer ring can be made a more complicated labyrinth shape by the second bent part of the hub cap and the shield holding part of the outer ring. Therefore, splashing of grease to the outside of the bearing device and release of outgas can be reliably suppressed.

  (5) In the bearing device according to any one of (1) to (4), the hub cap includes an outer side in the axial direction of one rolling bearing of the pair of rolling bearings and the other rolling bearing. You may arrange | position at the both sides of the outer side of the said axial direction.

  According to this configuration, since the pair of rolling bearings are covered from both sides in the axial direction, it is possible to suppress the grease inside the bearing device from being scattered and the dust from entering the inside of the bearing device. Thereby, the smooth rotation of the rolling bearing is not hindered, and the performance of the rolling bearing can be ensured.

  (6) In the bearing device according to any one of (1) to (5), the inner end portion in the radial direction of the hub cap may be in contact with the outer end portion in the axial direction of the inner ring. Good.

According to this structure, since the space | interval of a hub cap and each member becomes small, the labyrinth effect improves. For this reason, it is possible to suppress the grease inside the bearing device from being scattered and the dust from entering the bearing device without affecting the preload management, and to ensure the performance of the rolling bearing.
Furthermore, since the space | interval of a hub cap and each member becomes small, thickness reduction of a bearing apparatus is also attained.

  (7) An information recording / reproducing apparatus according to a second aspect of the present invention provides the bearing device according to any one of (1) to (6), a housing connected to the shaft, and the outer ring. A rotating member that is externally fitted and rotates around a central axis of the shaft, and a slider that is attached to the rotating member and records and reproduces information on a magnetic recording medium.

According to this configuration, since the bearing device is provided, it is possible to suppress the scattering of grease and the release of outgas.
Furthermore, according to this configuration, contamination inside the information recording / reproducing apparatus due to the grease can be suppressed, and writing and reading of the disc can be surely executed. An information recording / reproducing apparatus can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the bearing apparatus and information recording / reproducing apparatus which can suppress scattering of grease and discharge | release of outgas can be provided.

1 is a perspective view of an information recording / reproducing apparatus according to an embodiment. It is side surface sectional drawing in the AA of FIG. It is an expanded sectional view of the important section of the bearing device concerning a first embodiment. It is an expanded sectional view of the important section of the bearing device concerning a second embodiment. It is an expanded sectional view of the important section of the bearing device concerning a third embodiment. It is an expanded sectional view of the important section of the bearing device concerning a 4th embodiment. It is an expanded sectional view of the important section of the bearing device concerning a 5th embodiment. It is side surface sectional drawing of the bearing apparatus which concerns on the 1st modification of 1st embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
(Information recording / reproducing device)
FIG. 1 is a perspective view of an information recording / reproducing apparatus 1 according to the embodiment, and FIG. 2 is a side sectional view taken along line AA of FIG.
As shown in FIG. 1, the information recording / reproducing apparatus 1 is an apparatus that performs writing and reading on a disk D (magnetic recording medium) having a recording layer. The information recording / reproducing apparatus 1 is externally fitted to an outer ring 40 (see FIG. 2), and an arm 8 (rotating member) that rotates around the central axis L1 of the shaft 20 and a head gimbal supported on the distal end side of the arm 8. The assembly 4, the slider 2 attached to the tip of the head gimbal assembly 4, an actuator 6 (VCM: voice coil motor) that scans and moves the head gimbal assembly 4, a spindle motor 7 that rotates the disk D, and according to information A control unit 5 for supplying the modulated current to the slider 2 and a housing 9 for housing these components therein.

  The housing 9 is made of a metal material such as aluminum and has a box-like shape having an opening at the top, and has a rectangular bottom 9a in plan view and a peripheral wall that stands vertically from the peripheral edge of the bottom 9a ( (Not shown). On the inner side of the housing 9 surrounded by the peripheral wall, a recess for accommodating the above-described components is formed. The spindle motor 7 is attached to substantially the center of the bottom portion 9a, and the disc D is detachably fixed by fitting a center hole into the spindle motor 7.

  A bearing device 10 is disposed on the side of the disk D. As shown in FIG. 2, the bearing device 10 is inserted into the sleeve 8a, and the arm 8 is fixed to the outer peripheral surface of the sleeve 8a. As shown in FIG. 1, one side of the arm 8 across the bearing device 10 is connected to the actuator 6 described above. The other side of the arm 8 extends in parallel with the surface of the disk D, and the head gimbal assembly 4 is connected to the tip thereof. The head gimbal assembly 4 includes a suspension 3 and a slider 2 that is attached to the tip of the suspension 3 and is disposed to face the surface of the disk D. The slider 2 includes a recording element for writing (recording) information on the disk D and a reproducing element for reading (reproducing) information from the disk D.

  In the information recording / reproducing apparatus 1 configured as described above, in order to record or reproduce information, first, the spindle motor 7 is driven to rotate the disk D around the central axis L2. Further, the actuator 6 is driven to rotate the arm 8 around the central axis L1 of the bearing device 10. As a result, the slider 2 disposed at the tip of the head gimbal assembly 4 can be scanned and moved to each part of the surface of the disk D. Then, by driving the recording element or reproducing element of the slider 2, information can be recorded or reproduced on the disk D.

(First embodiment, bearing device)
FIG. 3 is an enlarged cross-sectional view of a main part of the bearing device 10 according to the first embodiment.
As shown in FIGS. 2 and 3, the bearing device 10 according to the first embodiment includes a shaft 20 and a pair of rolling bearings 30 (firstly attached to the shaft 20 and arranged side by side in the axial direction of the shaft 20. The first rolling bearing 31 and the second rolling bearing 32) are arranged coaxially with the shaft 20, and are joined to the shaft 20 and the disc-like spacer 70 arranged inside the pair of rolling bearings 31, 32 in the axial direction. And a hub cap 80 that covers the rolling bearing 30 from the outside in the axial direction.

  In the present application, a direction along the central axis (that is, the central axis of the shaft 20) L1 of the bearing device 10 is referred to as an “axial direction”. In the present application, the axially inner sides of the pair of rolling bearings 31 and 32 (the other rolling bearing side of the pair of rolling bearings 31 and 32 as viewed from one rolling bearing and the spacer 70 side of each rolling bearing 31 and 32). Is called the “inner side in the axial direction”, and the outer side in the axial direction of the pair of rolling bearings 31, 32 (the other side of the pair of rolling bearings 31, 32, the opposite side of the other rolling bearing, each rolling bearing The opposite side of the spacers 31 and 32 from the spacer 70 is referred to as “the outside in the axial direction”. Further, a direction orthogonal to the central axis L1 is referred to as a “radial direction”, and a direction around the central axis L1 is referred to as a “circumferential direction”.

  The shaft 20 is formed in a cylindrical shape from a metal material such as aluminum or stainless steel, and is connected to the housing 9. A flange 25 is formed on one axial side of the shaft 20. The shaft 20 is formed with a recess 27 that opens on an end surface of the shaft 20 in the axial direction. The concave portion 27 penetrates the shaft 20 in the axial direction, and opens individually on both end surfaces of the shaft 20 in the axial direction. The recess 27 is arranged coaxially with the central axis L1. The concave portion 27 is partially flared on one axial side of the shaft 20 (the side on which the flange 25 is formed).

  As shown in FIG. 2, the bearing device 10 includes, as the rolling bearing 30, a first rolling bearing 31 disposed on one side in the axial direction of the shaft 20 and a second rolling bearing disposed on the other side in the axial direction of the shaft 20. And a rolling bearing 32. In addition, the 1st rolling bearing 31 and the 2nd rolling bearing 32 are the same shapes, and are arrange | positioned plane-symmetrically.

  As shown in FIG. 3, the rolling bearing 30 includes an inner ring 36 fixed to the shaft 20, an outer ring 40 that surrounds the inner ring 36 from the outside in the radial direction of the shaft 20 and abuts against an axial end surface of the spacer 70, A plurality of rolling elements 35 disposed between the outer ring 40 and the outer ring 40, a retainer 50 that holds the rolling element 35 in a freely rotatable manner, and an inner ring 36 and an outer ring 40 that are disposed outside the rolling element 35 in the axial direction. And a shield 60 (inner shield 60a and outer shield 60b) for sealing the gap.

The inner ring 36 and the outer ring 40 are formed in a substantially cylindrical shape from a metal material.
An inner diameter of the inner ring 36 is formed to a size that can be inserted into the shaft 20. In the present embodiment, the inner diameter of the inner ring 36 is formed to be slightly larger than the outer diameter of the shaft 20. The inner ring 36 is inserted into the shaft 20 and fixed with, for example, an adhesive or the like with a preload applied thereto. The inner diameter of the inner ring 36 may be the same as or slightly smaller than the outer diameter of the shaft 20. In this case, the inner ring 36 is inserted into the shaft 20 and is press-fitted and fixed.
A rolling groove 38 is formed at the axial center of the outer peripheral surface of the inner ring 36. The rolling groove 38 is formed over the entire circumference of the inner ring 36.

An outer ring main body 45 is formed near the center of the outer ring 40 in the axial direction. A rolling groove 48 is formed at the center in the axial direction of the outer ring 40 on the inner peripheral surface of the outer ring main body 45. The rolling groove 48 is formed over the entire circumference of the outer ring main body 45.
The rolling element 35 is formed in a spherical shape from a metal material. The rolling element 35 is disposed inside each rolling groove 38, 48 and rolls along each rolling groove 38, 48.

  A shield holding portion 41 (an outer shield holding portion 41 b and an inner shield holding portion 41 a) that is recessed inward in the axial direction and holds the shield 60 is formed at the outer end portion in the axial direction of the outer ring 40. The shield holding portion 41 is formed by cutting out the radially inner edge of the outer end of the outer ring 40 in the axial direction over the entire circumference.

An outer shield holding portion 41b that holds the outer shield 60b is formed on the outer side of the outer ring main body portion 45 in the axial direction. On the other hand, an inner shield holding portion 41a that holds the inner shield 60a is formed inside the outer ring main body portion 45 in the axial direction. The inner shield holding part 41a also functions as a spacer holding part that holds the spacer.
The outer shield holding part 41b and the inner shield holding part 41a have the same shape and are arranged in plane symmetry.

  The outer diameter of the outer ring 40 is the same over the entire axial direction of the outer ring 40. On the other hand, the inner diameter of the outer ring 40 is the smallest inner diameter of the outer ring main body 45. The inner diameter of the inner shield holding part 41a and the inner diameter of the outer shield holding part 41b are equal and larger than the inner diameter of the outer ring main body part 45.

  As shown in FIG. 2, the spacer 70 has a predetermined thickness in the axial direction. The spacer 70 is a ring-shaped member made of a metal material such as aluminum, iron, or stainless steel, and is formed by forging or machining. The inner diameter of the spacer 70 is slightly smaller than the inner diameter of the outer ring 40 of the rolling bearing 30 (the inner diameter of the outer ring main body 45). The outer diameter of the spacer 70 is slightly smaller than the outer diameter of the outer ring 40 of the rolling bearing 30.

  The spacer 70 is disposed between the first rolling bearing 31 and the second rolling bearing 32. Thereby, the 1st rolling bearing 31 and the 2nd rolling bearing 32 can be arrange | positioned only a predetermined space | interval at intervals in the axial direction.

  Furthermore, the inner ring 36 of the first rolling bearing 31 and the inner ring 36 of the second rolling bearing 32 are pivoted while the distance between the outer ring 40 of the first rolling bearing 31 and the outer ring 40 of the second rolling bearing 32 is held by the spacer 70. Preload can be applied to the inner ring 36 of the first rolling bearing 31 and the inner ring 36 of the second rolling bearing 32 by fixing to the shaft 20 while being relatively pressed along the direction. The inner ring 36 of the first rolling bearing 31 and the inner ring 36 of the second rolling bearing 32 are fixed to the shaft 20 with an adhesive, for example, with a preload applied thereto. Therefore, the bearing device 10 can be formed by so-called inner ring preload. The outer end portion in the axial direction of the inner ring 36 of the rolling bearing 30 is disposed slightly inward in the axial direction with respect to the outer end portion in the axial direction of the outer ring 40 of the rolling bearing 30.

  By forming the bearing device 10 by so-called inner ring preload, it is possible to increase the rigidity of the pair of rolling bearings 31 and 32 and to increase the resonance frequency (resonance point) of the bearing device 10. Therefore, it can be set as the bearing apparatus 10 which can respond to high-speed rotation.

  The inner ring preload according to the present embodiment is, for example, in a state where the inner ring 36 of the first rolling bearing 31 and the inner ring 36 of the second rolling bearing 32 are relatively pressed along the axial direction, and the inner ring 36 of the first rolling bearing 31 is pressed. And what is called a fixed position preload which applies preload by fixing the inner ring | wheel 36 of the 2nd rolling bearing 32 to the shaft 20 is employ | adopted. In addition to the fixed position preload, for example, an urging member is provided, and the inner ring 36 of the first rolling bearing 31 and the inner ring 36 of the second rolling bearing 32 are held in a relatively pressed state along the axial direction. A so-called constant pressure preload may be employed in which a preload is applied.

  The method for fixing the inner ring 36 and the shaft 20 and the method for fixing the outer ring 40 and the sleeve 8a are not limited to the adhesive. Therefore, for example, the inner ring 36 may be fixed to the shaft 20 and the outer ring 40 may be fixed to the sleeve 8a by press-fitting or laser welding. Thereby, the inner ring | wheel 36 can be fixed to the shaft 20 and an outer ring | wheel 40 can be fixed to the sleeve 8a, without using an adhesive agent. Therefore, generation of outgas from the adhesive can be prevented, and a defect in the information recording / reproducing apparatus 1 (see FIG. 1) due to outgas can be prevented.

  As shown in FIG. 3, a holding portion 42 that holds the shield 60 is formed on the side surface in the axial direction of the outer ring main body portion 45. The holding portion 42 is disposed on the inner side in the axial direction from the outer end portion in the axial direction of the inner ring 36.

  From the viewpoint of suppressing an increase in the size of the bearing device 10, it is preferable that the holding portion 42 is disposed more inside in the axial direction. In the present embodiment, the outer end portion in the axial direction of the inner ring 36 of the rolling bearing 30 is arranged slightly inward in the axial direction than the outer end portion in the axial direction of the outer ring 40 of the rolling bearing 30 by so-called inner ring preload. . Therefore, the holding portion 42 is disposed on the inner side in the axial direction from the outer end portion in the axial direction of the inner ring 36 of the rolling bearing 30.

  On the inner side in the radial direction of the shield holding portion 41, a standing portion 43 that rises along the axial direction from the outer periphery of the holding portion 42 to the outer side in the axial direction from the holding portion 42 is formed. A flange portion 44 is formed at the outer end portion in the axial direction of the shield holding portion 41 so as to protrude toward the inner side in the radial direction of the outer ring 40. The holding portion 42 and the flange portion 44 are connected by a standing portion 43. The standing portion 43 is a radially inner portion located on the inner side in the axial direction of the shield holding portion 41.

  A portion of the flange portion 44 that protrudes most inward in the radial direction (hereinafter, referred to as a top portion 44p) is outside in the axial direction from the outer end portion in the axial direction of the inner ring 36 of the rolling bearing 30 and in the axial direction of the shaft 20. It arrange | positions inside an axial direction rather than an outer side edge part. The flange portion 44 is formed over the entire circumference on the radially inner side of the outer end portion of the outer ring 40 in the axial direction, and is formed so that the outer diameter gradually decreases from the standing portion 43 to the top portion 44p. ing. The flange portion 44 is a radially inner portion located on the outer side in the axial direction of the shield holding portion 41.

  The outer shield 60b (shield) includes a sealing portion 61 that seals a gap between the inner ring 36 and the outer ring 40, and a bending portion 62 that is disposed on the radially outer side of the sealing portion 61 and bends inward in the axial direction. The claw portion 65 is disposed outside the bending portion 62 in the radial direction and protrudes in the opposite direction to the rolling element 35. The bent portion 62 is disposed on the inner side in the radial direction of the contact portion 64 and the contact portion 64 that contacts the axial side surface (holding portion 42) of the outer ring main body 45. And a connecting portion 63 that connects between the two. The claw portion 65 is formed along the outer periphery of the contact portion 64. For example, a plurality of claw portions 65 are formed at equal angular intervals in the circumferential direction of the outer shield 60b. In addition, the structure of the nail | claw part 65 is not restricted to this, For example, you may form over the perimeter of the contact part 64. FIG.

  The inner shield 60a has the same configuration as the outer shield 60b. The bent portion 62 of the inner shield 60a is bent outward in the axial direction (on the side of the rolling element 35).

Here, the holding of the shield 60 will be described using the outer shield 60b as an example. Since the same holds for the inner shield 60a, the description thereof is omitted.
When the outer shield 60b is press-fitted between the inner ring 36 and the outer ring 40, the claw portion 65 comes into contact with the inner peripheral surface (the flange portion 44) of the outer shield holding portion 41b of the outer ring 40, and the outer shield 60b is radially inward. The claw portion 65 is elastically deformed. Thereby, the outer shield 60b is held on the inner peripheral surface of the outer shield holding portion 41b (the portion of the flange portion 44 on the side of the standing portion 43).

  By forming the flange portion 44, it is possible to suppress the outer shield 60b from being greatly displaced outward in the axial direction or coming out to the outside.

In the present embodiment, both the outer shield 60b and the inner shield 60a are provided as the shield 60. Thereby, since the clearance gap between the inner ring | wheel 36 and the outer ring | wheel 40 is obstruct | occluded, it can suppress that the grease with which the clearance gap was scattered. Accordingly, the rolling bearing 30 can be smoothly rotated without being seized, so that the performance of the rolling bearing 30 can be ensured. In addition, it is possible to suppress the occurrence of writing errors and reading errors due to the scattered grease adhering to the surface of the disk D. Furthermore, since the gap between the inner ring 36 and the outer ring 40 is closed, it is possible to suppress dust from entering the gap. Thereby, since the rolling bearing 30 can be smoothly rotated, the performance of the rolling bearing 30 can be ensured.
The outer shield 60b and the inner shield 60a have the same shape and are arranged symmetrically.

  As shown in FIG. 2, the hub cap 80 is extrapolated to the shaft 20 and covers the rolling bearing 30 from the outside in the axial direction. The hub cap 80 is formed along the axial outer end of the rolling bearing 30. The hub caps 80 are disposed on both sides of the first rolling bearing 31 in the axial direction and the second rolling bearing 32 in the axial direction. The hub cap 80 on the outer side in the axial direction of the first rolling bearing 31 has a plane-symmetrical shape with respect to the hub cap 80 on the outer side in the axial direction of the second rolling bearing 32. Hereinafter, the hub cap 80 on the outer side in the axial direction of the second rolling bearing 32 will be described with reference to FIG. 3.

  As shown in FIG. 3, the hub cap 80 is disposed between the rolling bearing 30 and the virtual plane F <b> 1 including the end surface of the shaft 20 in the axial direction, and the outer end of the second rolling bearing 32 in the axial direction of the outer ring 40. Are spaced apart from each other by a predetermined distance in the axial direction.

  The hub cap 80 includes a main body portion 81 extending in the radial direction, a step portion 82 (second step portion) that is disposed on the outer side in the radial direction of the main body portion 81 and protrudes toward the inner side in the axial direction, and the step portion 82. A convex portion 83 that is arranged on the outer side in the radial direction and protrudes toward the bent portion 62 of the shield 60, and is arranged on the outer side in the radial direction of the main body portion 81, and the inner end portion in the radial direction of the outer shield holding portion 41b And a bent portion 84 (second bent portion) bent along the outer end portion in the axial direction of 40.

  The main body 81 is formed so that the radially inner portion covers the outer end of the inner ring 36 in the axial direction. The radially inner peripheral surface of the main body 81 is in contact with the outer peripheral surface 21 of the shaft 20. The axially inner surface of the radially inner portion of the main body 81 is in contact with the axially outer end portion of the inner ring 36. For example, the main body 81 of the hub cap 80 is fixed to each of the shaft 20 and the inner ring 36 with an adhesive.

  The method for fixing the hub cap 80 to the shaft 20 and the inner ring 36 is not limited to an adhesive. Therefore, for example, the hub cap 80 may be fixed to the shaft 20 and the inner ring 36 by press fitting, laser welding, or the like. Thereby, the hub cap 80 can be fixed to the shaft 20 and the inner ring 36 without using an adhesive. Therefore, generation of outgas from the adhesive can be prevented, and a defect in the information recording / reproducing apparatus 1 (see FIG. 1) due to outgas can be prevented.

  In the present embodiment, the hub cap 80 is manufactured by press working, and the radially inner end of the hub cap 80 is brought into contact with the axially outer end of the inner ring 36. By the way, when the hub cap is press-fitted and fixed for the inner ring preload, it is general that the hub cap does not contact the inner ring from the viewpoint of managing the amount of preload. However, if a fixing method such as welding or adhesion is used, the hub cap may be brought into contact with the inner ring. By bringing the hub cap into contact with the inner ring, the distance between the hub cap and each member is reduced, so that the labyrinth effect is improved and the bearing device can be made thinner. And when using fixing methods, such as welding and adhesion | attachment, since the thickness of a hub cap can be made thin, it can press-work easily.

  The step portion 82 is disposed inside the main body portion 81 in the axial direction, and has a thickness corresponding to the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the shield 60. Have Here, the height of the outer end portion in the axial direction of the inner ring 36 refers to the distance from the inner end surface in the axial direction of the outer ring 40 to the outer end surface in the axial direction of the inner ring 36. The height of the outer end portion in the axial direction of the shield 60 refers to the distance from the inner end surface in the axial direction of the outer ring 40 to the outer surface in the axial direction of the sealing portion 61 of the shield 60. The thickness of the stepped portion 82 refers to the axial thickness of the stepped portion 82, that is, the distance from the inner surface in the axial direction of the main body 81 to the inner surface in the axial direction of the stepped portion 82.

  The thickness of the stepped portion 82 is slightly smaller than the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the shield 60. Therefore, the axially inner surface of the radially inner portion of the main body 81 abuts against the outer end of the inner ring 36 in the axial direction, so that there is a gap between the stepped portion 82 and the sealing portion 61 of the shield 60. A gap in the axial direction is provided.

  The convex portion 83 is disposed inside the stepped portion 82 in the axial direction, and is formed over the entire circumference of the stepped portion 82. The convex portion 83 has a height corresponding to the axial height of the bent portion 62. Here, the axial height of the bent portion 62 refers to a distance from a reference (for example, the holding portion 42 (side surface in the axial direction of the outer ring main body portion 45)) to the outer end portion in the axial direction of the connecting portion 63. The height of the convex portion 83 means the height in the axial direction of the convex portion 83, that is, the distance from the inner surface in the axial direction of the step portion 82 to the inner surface in the axial direction of the convex portion 83.

  The height of the convex portion 83 is slightly smaller than the height of the bent portion 62 in the axial direction. Therefore, the axially inner surface of the radially inner portion of the main body 81 abuts against the outer end of the inner ring 36 in the axial direction. A radial gap is provided.

  The bent portion 84 includes an outer extending portion 86 that extends in the radial direction, and a connecting portion 85 that connects the outer extending portion 86 and the main body portion 81. The connecting portion 85 is formed over the entire circumference of the main body portion 81 so as to cover the radially inner end portion of the outer shield holding portion 41b. The connecting portion 85 is spaced from the radially inner end of the outer shield holding portion 41b by a predetermined distance in the radial direction.

  The extended portion 86 is formed over the entire circumference of the connecting portion 85 so as to cover the outer end of the outer shield holding portion 41b in the axial direction. The extended portion 86 is spaced apart from the axially outer end of the outer shield holding portion 41b by a predetermined interval in the axial direction. The outer surface in the axial direction of the extended portion 86 is disposed on the inner side in the axial direction with respect to the virtual surface F1.

  The outer diameter of the hub cap 80 (extended portion 86) is slightly smaller than the outer diameter of the outer ring 40. As a result, the hub cap 80 does not contact the inner peripheral surface of the sleeve 8a (see FIG. 2), and the smooth rotation of the rolling bearing 30 is not hindered, so that the performance of the rolling bearing 30 can be ensured. it can.

  As described above, a predetermined interval is provided between the stepped portion 82 and the sealing portion 61 of the shield 60, between the convex portion 83 and the bent portion 62, and between the bent portion 84 and the outer shield holding portion 41b. A gap is formed. Thereby, the clearance gap between the hub cap 80 and the shield 60 and the clearance gap between the hub cap 80 and the outer ring | wheel 40 are labyrinth-like. The gap between the stepped portion 82 and the sealing portion 61 of the shield 60, the gap between the convex portion 83 and the bent portion 62, and the gap between the bent portion 84 and the outer shield holding portion 41b are substantially the same. Have an interval.

  As described above, according to the bearing device 10 according to the present embodiment, the hub cap 80 has the stepped portion 82 that protrudes inward in the axial direction, and the stepped portion 82 is the outer end portion in the axial direction of the inner ring 36. By having a thickness corresponding to the difference between the height and the height of the outer end portion of the shield 60 in the axial direction, the stepped portion 82 of the hub cap 80 creates a complicated labyrinth between the hub cap 80 and the shield 60. Can be used. Therefore, scattering of grease to the outside of the bearing device 10 and release of outgas can be suppressed.

  The shield 60 has a bent portion 62 that is bent inward in the axial direction, and the hub cap 80 is formed with a convex portion 83 that protrudes toward the bent portion 62, so that the convex portion 83 of the hub cap 80 is formed. And the bent portion 62 of the shield 60 allow the gap between the hub cap 80 and the shield 60 to have a more complex labyrinth shape. Therefore, scattering of grease to the outside of the bearing device 10 and release of outgas can be reliably suppressed.

  The hub cap 80 has a bent portion 84 that bends along the radially inner end portion of the outer shield holding portion 41b and the axially outer end portion of the outer ring 40, so that the bent portion 84 of the hub cap 80 The outer shield holding portion 41b of the outer ring 40 allows the gap between the hub cap 80 and the outer ring 40 to have a more complicated labyrinth shape. Therefore, scattering of grease to the outside of the bearing device 10 and release of outgas can be reliably suppressed.

  Further, the hub caps 80 are arranged on both sides of the first rolling bearing 31 in the axial direction of the pair of rolling bearings 30 and the outer side of the second rolling bearing 32 in the axial direction, so that the pair of rolling bearings 30 are axially arranged. Therefore, it is possible to prevent the grease inside the bearing device 10 from being scattered and the dust from entering the inside of the bearing device 10. Thereby, the smooth rotation of the rolling bearing 30 is not hindered, and the performance of the rolling bearing 30 can be ensured.

Moreover, since the space | interval of the hub cap 80 and each member becomes small because the inner end part of the hub cap 80 in the radial direction contacts the outer end part of the inner ring 36 in the axial direction, the labyrinth effect is improved. Therefore, it is possible to suppress the grease inside the bearing device 10 from being scattered and the dust from entering the bearing device 10 without affecting the preload management, and the performance of the rolling bearing 30 can be ensured.
Furthermore, since the space | interval of the hub cap 80 and each member becomes small, the thickness reduction of the bearing apparatus 10 is also attained.

According to the information recording / reproducing apparatus 1 according to the present embodiment, since the bearing device 10 is provided, it is possible to suppress scattering of grease and release of outgas.
Furthermore, according to this configuration, contamination inside the information recording / reproducing apparatus 1 due to the grease can be suppressed, and writing and reading of the disc can be surely executed. The information recording / reproducing apparatus 1 can be realized.

  In the present embodiment, the shield 60 includes both the outer shield 60b and the inner shield 60a. However, the present invention is not limited to this. For example, only the outer shield 60b may be provided. However, from the viewpoint of ensuring the performance of the rolling bearing 30, it is preferable to include both the outer shield 60b and the inner shield 60a.

  In the present embodiment, an example in which preload (so-called inner ring preload) is applied to the inner ring 36 of the first rolling bearing 31 and the inner ring 36 of the second rolling bearing 32 has been described. However, the present invention is not limited thereto. For example, preload (so-called outer ring preload) may be applied to the outer ring 40 of the first rolling bearing 31 and the outer ring 40 of the second rolling bearing 32.

  Further, in the present embodiment, an example in which the outer end portion in the axial direction of the inner ring 36 of the rolling bearing 30 is disposed slightly inward in the axial direction than the outer end portion in the axial direction of the outer ring 40 of the rolling bearing 30 is given. However, this is not restrictive. For example, the axially outer end portion of the outer ring 40 of the rolling bearing 30 may be disposed slightly inward in the axial direction relative to the axially outer end portion of the inner ring 36 of the rolling bearing 30.

  In the present embodiment, the step portion 82 (second step portion) of the hub cap 80 corresponds to the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the shield 60. However, the present invention is not limited to this example. For example, the step portion 82 of the hub cap 80 may have a thickness corresponding to the difference between the height of the outer end portion in the axial direction of the outer ring 40 and the height of the outer end portion in the axial direction of the shield 60. Good. Here, the height of the outer end portion in the axial direction of the outer ring 40 refers to the distance from the inner end surface in the axial direction of the outer ring 40 to the outer end surface in the axial direction of the outer ring 40. The configuration in which the stepped portion 82 of the hub cap 80 has a thickness corresponding to the difference between the height of the outer end portion in the axial direction of the outer ring 40 and the height of the outer end portion in the axial direction of the shield 60 is, for example, rolling. This can be adopted when the outer end portion in the axial direction of the outer ring 40 of the bearing 30 is arranged slightly inward in the axial direction with respect to the outer end portion in the axial direction of the inner ring 36 of the rolling bearing 30.

  In the present embodiment, the example in which the hub cap 80 is brought into contact with the shaft 20 has been described. However, the present invention is not limited to this. For example, a collar part integrated with the shaft may be provided, and a hub cap may be brought into contact with the collar part.

In the present embodiment, the bent portion 62 of the shield 60 is provided in a structure for holding the shield 60 on the shield holding portion 41 of the outer ring 40, but is not limited thereto. For example, the position and size of the bent portion in the shield may be freely set.
Further, a plurality of concave portions may be provided on the shield, and the convex portions may be provided on the hub cap at positions corresponding thereto. Thereby, the labyrinth effect can be improved.

(Second embodiment)
FIG. 4 is an enlarged cross-sectional view of a main part of the bearing device 100 according to the second embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  As shown in FIG. 4, the hub cap 180 includes a main body portion 181 extending in the radial direction, a convex portion 183 that is disposed on the outer side in the radial direction of the main body portion 181, and protrudes toward the bent portion 62 of the shield 60. A bending portion 184 (second bending portion) that is disposed on the outer side in the radial direction of the portion 181 and bends along the inner end portion in the radial direction of the outer shield holding portion 41b and the outer end portion in the axial direction of the outer ring 40; It has. That is, the hub cap 180 according to this embodiment does not have a stepped portion (second stepped portion) that protrudes inward in the axial direction.

  A gap in the axial direction is provided between the main body portion 181 (outer portion in the radial direction) and the sealing portion 61 of the shield 60. The gap between the main body 181 and the sealing part 61 of the shield 60 is larger than the gap between the convex part 183 and the bent part 62 and the gap between the bent part 184 and the outer shield holding part 41b. Since there is no step portion, the gap is slightly larger.

  A gap is formed between the main body portion 181 and the sealing portion 61 of the shield 60, between the convex portion 183 and the bent portion 62, and between the bent portion 184 and the outer shield holding portion 41b by a predetermined interval. ing. Thereby, the clearance gap between the hub cap 180 and the shield 60 and the clearance gap between the hub cap 180 and the outer ring | wheel 40 are labyrinth-like.

  As described above, according to the bearing device 100 according to the present embodiment, since the hub cap 180 does not have the stepped portion (second stepped portion) protruding toward the inner side in the axial direction, the first embodiment With a simpler structure than that according to the above, it is possible to suppress the scattering of grease and the release of outgas to the outside of the bearing device 100.

(Third embodiment)
FIG. 5 is an enlarged cross-sectional view of a main part of the bearing device 200 according to the third embodiment. In the third embodiment, the same components as those in the second embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  As shown in FIG. 5, the hub cap 280 is spaced from the outer end portion of the rolling bearing 30 in the axial direction by a predetermined interval in the axial direction. The hub cap 280 is disposed on the radially inner side of the main body part 281, on the radially inner side of the main body part 281, projecting toward the inner side in the axial direction, and on the radially outer side of the step part 282. And a convex portion 283 that protrudes toward the bent portion 62 of the shield 60. That is, the hub cap 280 according to the present embodiment has a bent portion (second bent portion) that bends along the radially inner end portion of the outer shield holding portion 41b and the outer end portion of the outer ring 40 in the axial direction. Not done.

  The radially inner peripheral surfaces of the main body portion 281 and the stepped portion 282 are in contact with the outer peripheral surface 21 of the shaft 20. The inner surface of the stepped portion 282 in the axial direction is separated from the outer end portion of the inner ring 36 in the axial direction by a predetermined distance. For example, the main body portion 281 and the step portion 282 of the hub cap 280 are fixed to the shaft 20 with an adhesive.

  In addition, the fixing method of the hub cap 280 and the shaft 20 is not limited to an adhesive agent. Therefore, for example, the hub cap 280 may be fixed to the shaft 20 by press fitting, laser welding, or the like. Thereby, the hub cap 280 can be fixed to the shaft 20 without using an adhesive. Therefore, generation of outgas from the adhesive can be prevented, and a defect in the information recording / reproducing apparatus 1 (see FIG. 1) due to outgas can be prevented.

  The step portion 282 is disposed inside the main body portion 281 in the axial direction, and has a thickness corresponding to the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the outer ring 40. Have Here, the height of the outer end portion in the axial direction of the inner ring 36 refers to the distance from the inner end surface in the axial direction of the outer ring 40 to the outer end surface in the axial direction of the inner ring 36. The height of the outer end portion in the axial direction of the outer ring 40 refers to the distance from the inner end surface in the axial direction of the outer ring 40 to the outer end surface in the axial direction of the outer ring 40. The thickness of the stepped portion 282 refers to the axial thickness of the stepped portion 282, that is, the distance from the axially inner surface of the main body 281 to the axially inner surface of the stepped portion 282.

  The thickness of the stepped portion 282 is substantially the same as the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the outer ring 40. Therefore, the inner surface in the axial direction of the radially inner portion of the step portion 282 is separated from the outer end portion in the axial direction of the inner ring 36 by a predetermined distance, whereby the radially inner portion of the step portion 282 and the inner ring 36 are separated. In the meantime, an axial gap is provided between the radially outer portion of the main body 281 and the outer ring 40 so that the distance between them is the same.

  The convex portion 283 is disposed inside the stepped portion 282 in the axial direction, and is formed over the entire circumference of the stepped portion 282. The height of the convex portion 283 is slightly larger than the height of the bent portion 62 in the axial direction by the distance between the stepped portion 282 and the inner ring 36. Thus, an axial or radial gap is provided between the convex portion 283 and the bent portion 62 to the same extent as the distance between the step portion 282 and the inner ring 36.

  The radially outer portion of the main body 281 is spaced apart from the axially outer end of the outer shield holding portion 41b by a predetermined distance in the axial direction. The radially outer end of the stepped portion 282 is spaced from the radially inner end of the outer shield holding portion 41b by a predetermined distance in the radial direction.

  Between the step portion 282 and the inner ring 36, between the step portion 282 and the sealing portion 61 of the shield 60, between the convex portion 283 and the bent portion 62, between the step portion 282 and the outer shield holding portion 41b, and the main body A gap is formed between the portion 281 and the outer shield holding portion 41b by a predetermined interval. As a result, the gap between the hub cap 280 and the rolling bearing 30 and the gap between the hub cap 280 and the shield 60 are in a labyrinth shape.

  As described above, according to the bearing device 200 according to the present embodiment, the hub cap 280 has the stepped portion 282 that protrudes inward in the axial direction, and the stepped portion 282 is at the outer end portion in the axial direction of the inner ring 36. By having a thickness corresponding to the difference between the height and the height of the outer end of the outer ring 40 in the axial direction, the gap between the hub cap 280 and the rolling bearing 30 is further complicated by the step 282 of the hub cap 280. It can be a labyrinth. Therefore, scattering of grease to the outside of the bearing device 200 and release of outgas can be reliably suppressed.

  Further, since the hub cap 280 does not have a bent portion (second bent portion) that bends along the radially inner end portion of the outer shield holding portion 41b and the outer end portion of the outer ring 40 in the axial direction, With a simpler structure than the structure according to the second embodiment, it is possible to suppress the scattering of grease and the release of outgas to the outside of the bearing device 200.

(Fourth embodiment)
FIG. 6 is an enlarged cross-sectional view of a main part of the bearing device 300 according to the fourth embodiment. Note that in the fourth embodiment, the same components as those in the third embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  As shown in FIG. 6, the hub cap 380 includes a main body portion 381 extending in the radial direction, a step portion 382 that is disposed on the inner side in the radial direction of the main body portion 381, and protrudes toward the inner side in the axial direction, and a step portion 382. The step part 383 (2nd step part) which is arrange | positioned in the radial direction outer side and protrudes toward the inner side of an axial direction is provided. That is, the hub cap 380 according to the present embodiment does not have a convex portion that protrudes toward the bent portion 62 of the shield 60.

  The step portion 382 is disposed inside the main body portion 381 in the axial direction, and has a thickness corresponding to the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the outer ring 40. Have The thickness of the stepped portion 382 is substantially the same as the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the outer ring 40. Therefore, the inner surface in the axial direction in the radially inner portion of the stepped portion 382 is separated from the outer end portion in the axial direction of the inner ring 36 by a predetermined distance, whereby the radially inner portion of the stepped portion 382 and the inner ring 36 are separated. In the meantime, axial gaps are provided between the radially outer portion of the main body 381 and the outer ring 40 so that the distance between them is the same.

  The step portion 383 is disposed inside the step portion 382 in the axial direction, and has a thickness corresponding to the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the shield 60. Have The thickness of the stepped portion 383 is substantially the same as the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the shield 60. Therefore, the axially inner surface of the radially inner portion of the stepped portion 382 is separated from the outer end portion of the inner ring 36 in the axial direction by a predetermined distance, so that there is a step between the stepped portion 383 and the shield 60. An axial gap is provided to the same extent as the distance between the portion 382 and the inner ring 36.

  Note that the gap between the stepped portion 383 and the bent portion 62 of the shield 60 is slightly larger than the gap between the stepped portion 383 and the sealing portion 61 of the shield 60 because there is no convex portion. doing.

  Between the step portion 382 and the inner ring 36, between the step portion 383 and the shield 60, between the step portion 383 and the outer shield holding portion 41b, between the step portion 382 and the outer shield holding portion 41b, and the main body portion 381. A gap is formed between the outer shield holding portion 41b and a predetermined gap. Thereby, the gap between the hub cap 380 and the rolling bearing 30 and the gap between the hub cap 380 and the shield 60 are in a labyrinth shape.

  As described above, according to the bearing device 300 according to the present embodiment, since the hub cap 380 does not have the convex portion protruding toward the bent portion 62 of the shield 60, the structure according to the third embodiment. However, with a simple structure, it is possible to suppress the scattering of grease to the outside of the bearing device 300 and the release of outgas.

(Fifth embodiment)
FIG. 7 is an enlarged cross-sectional view of a main part of the bearing device 400 according to the fifth embodiment. Note that in the fifth embodiment, the same components as those in the fourth embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  As shown in FIG. 7, the hub cap 480 includes a main body portion 481 extending in the radial direction, and a step portion 482 that is disposed inside the main body portion 481 in the radial direction and protrudes toward the inner side in the axial direction. Yes. That is, the hub cap 480 according to the present embodiment does not have a stepped portion (second stepped portion) that protrudes inward in the axial direction.

  The step portion 482 is disposed inside the main body portion 481 in the axial direction, and has a thickness corresponding to the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the outer ring 40. Have The thickness of the stepped portion 482 is substantially the same as the difference between the height of the outer end portion in the axial direction of the inner ring 36 and the height of the outer end portion in the axial direction of the outer ring 40. Therefore, the axially inner surface of the radially inner portion of the stepped portion 482 is separated from the axially outer end portion of the inner ring 36 by a predetermined distance, whereby the radially inner portion of the stepped portion 482 and the inner ring 36 are separated. In the meantime, axial gaps are provided between the radially outer portion of the main body 481 and the outer ring 40 so that the distance between them is the same.

  The gap between the stepped portion 482 and the shield 60 is slightly larger than the gap between the stepped portion 482 and the inner ring 36 because the stepped portion (second stepped portion) is not provided. .

  Between the stepped portion 482 and the inner ring 36, between the stepped portion 482 and the shield 60, between the stepped portion 482 and the outer shield holding portion 41b, and between the main body portion 481 and the outer shield holding portion 41b, A gap is formed at a predetermined interval. As a result, the gap between the hub cap 480 and the rolling bearing 30 and the gap between the hub cap 480 and the shield 60 are in a labyrinth shape.

  As described above, according to the bearing device 400 according to the present embodiment, the hub cap 480 does not have a stepped portion (second stepped portion) that protrudes inward in the axial direction. With a simpler structure than the structure according to the above, it is possible to suppress the scattering of grease to the outside of the bearing device 400 and the release of outgas.

  In the above-described embodiment, the hub caps have been described with reference to the example in which the hub caps are arranged on both sides of the first rolling bearing 31 in the axial direction and the second rolling bearing 32 in the axial direction. Not limited to this.

(First modification of the first embodiment)
FIG. 8 is a side cross-sectional view of a bearing device 500 according to a first modification of the first embodiment. For example, as shown in FIG. 8, the hub cap 80 may be disposed only on the outer side in the axial direction of the second rolling bearing 32 of the pair of rolling bearings 30.

The hub cap 80 covers the second rolling bearing 32 from the outside in the axial direction. The hub cap 80 is formed along the outer end of the second rolling bearing 32 in the axial direction.
The first rolling bearing 31 is disposed in a state where the outer side surface in the axial direction of the inner ring 36 is in contact with the flange 525 of the shaft 520. The first rolling bearing 31 is covered from the outside in the axial direction by a flange 525.

  In the above-described embodiment, the height reference is described as the end surface on the inner side in the axial direction of the outer ring 40, but is not limited thereto. For example, when the spacer 70 is provided, the height reference may be one surface of the spacer 70 in the axial direction. If the spacer 70 is not provided, the height reference may be the center of the rolling element 35.

It should be noted that the technical scope of the present invention is not limited to the above-described embodiment, and includes those in which various modifications are made to the above-described embodiment without departing from the spirit of the present invention. That is, the specific materials and structures described in the embodiments are merely examples, and can be changed as appropriate.
For example, the specific configuration of the information recording / reproducing apparatus is not limited to the configuration of the embodiment. Further, the specific shape of the shaft of the bearing device is not limited to the shape of the embodiment. In the embodiment, the outer shield of the rolling bearing is fixed to the outer ring, but may be fixed to the inner ring. Further, in the embodiment, the recess penetrates the shaft in the axial direction, but it does not have to penetrate. Moreover, you may combine the structure of the 1st modification of 1st embodiment, and the structure of 2nd-5th embodiment.

DESCRIPTION OF SYMBOLS 1 ... Information recording / reproducing apparatus, 2 ... Slider, 8 ... Arm (rotating member), 9 ... Housing, 10, 100, 200, 300, 400, 500 ... Bearing apparatus, 20,520 ... Shaft, 30, 31, 32 ... rolling bearing, 36 ... inner ring, 40 ... outer ring, 41 ... shield holding part, 60b ... outer shield (shield), 62 ... bent part, 82, 383 ... step part (second step part), 83, 183, 283 ... Convex part, 84, 184 ... bent part (second bent part), 282, 382, 482 ... step part, 80, 180, 280, 380, 480 ... hub cap, D ... disk (magnetic recording medium)

Claims (7)

A shaft,
A pair of rolling bearings extrapolated to the shaft and arranged side by side in the axial direction of the shaft;
A hub cap joined to the shaft and covering the rolling bearing from the outside in the axial direction,
The rolling bearing includes an inner ring fixed to the shaft, and an outer ring surrounding the inner ring from the outside in the radial direction of the shaft,
The hub cap has a stepped portion protruding inward in the axial direction,
The stepped portion is a distance from an inner end surface of the outer ring in the axial direction to an outer end surface of the inner ring in the axial direction, and a height of the outer end portion in the axial direction of the inner ring, and the shaft of the outer ring. A thickness corresponding to a difference between a height of the outer end of the outer ring in the axial direction, which is a distance from an end face on the inner side of the outer ring to the end face of the outer ring in the axial direction. Bearing device. A shield that seals the rolling bearing is disposed inside the hub cap in the axial direction,
The hub cap has a second stepped portion protruding inward in the axial direction,
The second step portion is the height of the outer end portion in the axial direction of the inner ring or the outer ring, and the distance from the inner end surface in the axial direction of the outer ring to the outer end surface in the axial direction of the shield. The bearing device according to claim 1, wherein the bearing device has a thickness corresponding to a difference from a height of an outer end portion in the axial direction of the shield. The shield has a bent portion that bends inward in the axial direction;
The bearing device according to claim 2, wherein the hub cap is formed with a protruding portion that protrudes toward the bent portion. A shield that seals the rolling bearing is disposed inside the hub cap in the axial direction,
On the outer end portion in the axial direction of the outer ring, a shield holding portion that is recessed inward in the axial direction and holds the shield is formed.
The said hub cap has a 2nd bending part bent along the inner end part of the radial direction of the said shield holding | maintenance part, and the outer side edge part of the said axial direction of the said outer ring | wheel. The bearing device according to any one of the above.   5. The hub cap according to claim 1, wherein the hub caps are arranged on both outer sides in the axial direction of one rolling bearing of the pair of rolling bearings and on an outer side in the axial direction of the other rolling bearing. The bearing device according to any one of the above.   The bearing device according to claim 1, wherein an inner end portion of the hub cap in a radial direction is in contact with an outer end portion of the inner ring in the axial direction. A bearing device according to any one of claims 1 to 6,
A housing connected to the shaft;
A rotation member that is externally fitted to the outer ring and rotates about the central axis of the shaft;
A slider mounted on the rotating member, for recording and reproducing information on a magnetic recording medium;
An information recording / reproducing apparatus comprising:

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