JP5677014B2 - Rolling bearing, bearing device, information recording / reproducing device - Google Patents

Description

  The present invention relates to a rolling bearing with a shield plate, a bearing device having the rolling bearing, and an information recording / reproducing apparatus.

  2. Description of the Related Art Conventionally, an information recording / reproducing apparatus such as a hard disk for recording and reproducing various kinds of information magnetically or optically on a disk is known. In general, this type of information recording / reproducing apparatus includes an actuator having a swing arm provided with a head portion at the tip thereof for recording / reproducing a signal on a disk. This actuator is rotatably supported by a bearing device provided on the base end side of the swing arm. In other words, the swing arm can be rotated along a horizontal plane by rotating the bearing device, and the signal can be recorded and reproduced by moving the head portion at the tip of the swing arm to a predetermined position of the disk. Is possible.

  By the way, the bearing device for rotating the swing arm is generally composed of a shaft, a sleeve, and a rolling bearing interposed between the shaft and the sleeve. In particular, a rolling bearing used in this type of bearing device is required to operate stably for a long period of time, and conventionally, a rolling bearing with a shield plate has been often used.

In this rolling bearing with a shield plate, an annular shield plate (sealing plate) is attached to the inner peripheral surface of the outer ring, and the annular space defined between the shaft and the sleeve is closed with the shield plate. It is out.
Therefore, it is possible to prevent dust from the outside from adhering to the rolling elements, the rolling surfaces of the outer ring and the inner ring, and to prevent the internal grease from leaking to the outside. It is said that. Therefore, a rolling bearing with a shield plate is likely to operate stably over a long period of time compared to a rolling bearing without a shield plate.

  As shown in FIGS. 18 and 19, this kind of shield plate 100 is usually a metal member formed in an annular shape, and is formed on the inner peripheral surface of the outer ring 101 over the entire circumference. It is mounted by being fitted in the concave groove 102. The shield plate 100 is often a bent portion 100a that is bent so that the outer peripheral edge side is inclined over the entire circumference. The shield plate 100 is attached to the outer ring 101 using the elastic deformation of the bent portion 100a. Has been.

  As a mounting method, first, the shield plate 100 is pushed into an annular space defined between the outer ring 101 and the inner ring 103. Then, the bent portion 100 a is fitted into the locking groove 102 while being bent by contacting the holding surface 102 a that is the inner surface of the locking groove 102. When the shield plate 100 is completely pushed into contact with the abutting surface 102b of the locking groove 102, the bent portion 100a is elastically returned by the elastic restoring force in the locking groove 102, and the locking groove The holding surface 102a of 102 is pressed. As a result, the shield plate 100 is hooked into the locking groove 102 and locked. In this way, the shield plate 100 is attached to the outer ring 101.

  By the way, as described above, the bent portion 100a is often formed over the entire circumference of the shield plate 100. However, as shown in FIG. 20, the outer peripheral edge portion is notched at regular intervals along the circumferential direction. There is also known a shield plate 110 in which a portion 100b is formed and a portion located between adjacent cutout portions 100b functions as a bent portion 100a (locking protrusion) (see, for example, Patent Document 1).

  Further, as shown in FIG. 21, the bent groove 100 a is not provided, the shield plate 120 is simply formed in a flat plate shape, and the locking groove 102 is formed in a state where the C ring 104 as another member is overlapped on the shield plate 120. A method of attaching the shield plate 120 to the outer ring 101 by fitting into the outer ring 101 is also known.

JP 2002-89574 A

However, the following problems still remain in the conventional shield plate.
First, in the case of the shield plate 100 in which the bent portion 100a is formed over the entire circumference, the relationship between the outer diameter of the shield plate 100 and the inner diameter of the locking groove 102 (for example, the outer diameter of the shield plate 100 is locked). In some cases, such as when the inner diameter of the concave groove 102 is too large, or conversely, the inner diameter of the locking concave groove 102 is too smaller than the outer diameter of the shield plate 100, the shield plate 100 is connected via the bent portion 100 a. An excessive pressing force is transmitted, and the shield plate 100 may be buckled and deformed so that a portion located radially inward of the bent portion 100a falls down toward the inside of the bearing. In this case, there is a risk of inferior appearance or contact with a component that moves relative to the outer ring 101, such as a retainer, to cause rotation failure.

Further, since it is necessary to form the holding surface 102a and the abutting surface 102b of the locking groove 102 corresponding to the size of the bent portion 100a of the shield plate 100, the locking groove 102 is formed as shown in FIG. The thickness D of the outer ring 101 in the formed portion is easily reduced, and the distance Y between the opening edge and the abutting surface 102b is easily increased.
In particular, when the wall thickness D is reduced, the rigidity of the outer ring 101 is reduced, and irregular deformation due to adhesive distortion or the like occurs, or the roundness of the rolling surface of the outer ring 101 is impaired, and abnormal vibration occurs. And torque fluctuations such as waviness in the torque waveform were likely to occur. In addition, since the distance Y becomes longer, it is difficult to reduce the thickness of the entire rolling bearing.

  Next, in the case of the shield plate 110 in which the bent portion 100a is intermittently formed in the circumferential direction, a force acting on the outer ring 101 from the shield plate 110 (a force for expanding the outer ring 101 radially outward) is The direction was uneven. For this reason, the outer ring 101 is more likely to be illegally deformed, and the roundness of the rolling surface is impaired, and abnormal vibration and torque fluctuation are likely to occur. In addition, the above-described problem that the thickness D of the outer ring 101 becomes thin or the distance Y between the opening edge and the abutting surface 102b becomes long is also likely to occur.

Next, when the shield plate 120 is mounted using the C-ring 104, the thickness of the shield plate 120 and the C-ring 104 needs to be two parts, so as shown in FIG. The distance Y between the edge and the abutting surface 102b is long, and it is difficult to reduce the thickness of the entire rolling bearing.
Further, since the shield plate 120 is merely prevented from being removed by the C-ring 104, there is a possibility that the shield plate 120 may be displaced in the in-plane direction as indicated by an arrow due to an impact or the like. As a result, the inner ring 103 and the shield plate 120 come into contact with each other, causing abnormal vibration or rotation failure, or a gap is partially opened between the inner ring 103 and the shield plate 120, so that dust or the like is contained in the rolling bearing. May intrude or roll out and grease or the like may leak out of the bearing. Furthermore, two parts, the C ring 104 and the shield plate 120, are required, resulting in high costs.

  The present invention has been made in view of such circumstances, and its purpose is that the shield plate is less likely to be displaced and buckled, and that the outer ring is less likely to be improperly deformed. It is an object to provide a rolling bearing with a shield plate capable of suppressing an increase, a bearing device having the rolling bearing, and an information recording / reproducing device.

The present invention provides the following means in order to solve the above problems.
(1) A rolling bearing according to the present invention includes an inner ring and an outer ring arranged coaxially, a plurality of rolling elements held rotatably between the inner ring and the outer ring, and the inner ring in a radial direction. The outer ring is pressed radially outward with the outer peripheral edge side entering the annular groove formed on the inner peripheral surface of the outer ring over the entire circumference, and defined between the inner ring and the outer ring. An annular shield plate attached to the outer ring so as to close the annular space formed, and the shield plate is divided in the circumferential direction, and a first end portion located at both ends in the circumferential direction, and A portion in which the second end portion is slidably overlapped with each other and is formed in an annular shape so that the diameter can be reduced and expanded, and the first end portion and the second end portion that overlap each other enter at least the annular groove portion. The thickness of the sheet other than these both end portions is Together are less thickness of de plate, the outer peripheral edge of the shield plate is recessed radially inward, recess portion for diameter by applying an external force to the shield plate along the circumferential direction A plurality is formed .

According to the rolling bearing according to the present invention, the outer peripheral edge side of the shield plate enters the annular groove and presses the outer ring radially outward, so that the shield plate is engaged with the annular groove. It is attached to the outer ring and closes the annular space defined between the outer ring and the inner ring.
By the way, the shield plate is formed in an annular shape by slidably overlapping the first end and the second end located at both ends in the circumferential direction, respectively, so that the diameter can be reduced and the diameter can be increased. . Therefore, the outer diameter of the shield plate can be changed according to the inner diameter of the annular groove portion, and it is possible to suppress a strong pressing force from being transmitted from the outer ring side to the shield plate due to the difference in the diameter as in the prior art. Therefore, it is possible to make it difficult for the shield plate to cause buckling deformation that collapses toward the inside of the bearing, so that it is possible to eliminate poor appearance, rotation failure due to contact between the shield plate and other parts, abnormal vibration, etc. It is hard to cause.

Further, since the shield plate presses the outer ring radially outward as described above, unlike the conventional C-ring, the shield plate is unlikely to be displaced in the in-plane direction due to impact or the like. As a result, the shield plate and the inner ring come into contact with each other, resulting in poor rotation or abnormal vibration, or the gap between the inner ring and the shield plate is partially opened, resulting in internal entry of dust or external leakage such as grease. Can be suppressed.
Moreover, since the outer peripheral edge side of the shield plate presses the outer ring while entering the annular groove portion of the outer ring over the entire circumference, the pressing force acts uniformly on the outer ring in the circumferential direction. Therefore, the outer ring is not easily deformed illegally, and the roundness of the rolling surface can be maintained, so that occurrence of abnormal vibration and torque fluctuation (torque waveform undulation etc.) can be suppressed.

Furthermore, unlike the conventional bent portion or the one using a C-ring, the outer ring can be thickened by forming an annular groove on the outer ring so that the outer peripheral edge side of the shield plate can enter. In addition, it is possible to form the annular groove at a position as close as possible to the opening edge side of the outer ring. In particular, even if the first end portion and the second end portion overlap each other, the thickness of the portion that enters the annular groove is equal to or less than the plate thickness of the shield plate other than both ends, There is no need to partially increase the size of the annular groove. Therefore, it is possible to increase the rigidity of the outer ring so that it is difficult to cause unauthorized deformation, and it is easy to reduce the thickness of the entire bearing.
Furthermore, since no separate parts such as a C-ring are required, it is difficult to increase the cost.
And since an external force can be given to a shield board using a some hollow part and it can reduce in diameter, the operation | work which mounts a shield board with respect to an outer ring | wheel can be performed easily. Moreover, since it is not an opening part greatly cut out but a hollow, it can suppress as much as possible that the pressing force transmitted from a shield board to an outer ring | wheel becomes uneven in the circumferential direction. Therefore, it is difficult to cause adverse effects such as unauthorized deformation of the outer ring and deterioration of the roundness of the rolling surface.

(2) Further, in the rolling bearing according to the present invention, the first end portion and the second end portion are formed so as to be thinner than the thickness of the shield plate at portions other than the both end portions, and the shield. They may be overlapped with each other while maintaining the flatness of the plates.

  In this case, since the flatness of the shield plate is maintained, the first end portion and the second end portion, which are formed thin, are overlapped with each other. Can be a board. Therefore, it is possible to obtain a bearing having a more attractive appearance and excellent appearance. In addition, since the shield plate can be manufactured by simple processing by making both end portions thinner than other portions, it is easy to reduce the cost.

(3) Further, in the rolling bearing according to the present invention, the other end portion superimposed on one end portion of the first end portion and the second end portion has an outer diameter of the first end portion. It may be formed smaller than the outer diameter of the shield plate other than the end and the second end.

  In this case, even if the other end overlapped on one end of the first end and the second end overlapping each other is slightly raised on the opening edge side of the outer ring, the outer diameter Is difficult to contact the inner wall surface of the annular groove. If it comes into contact with the inner wall surface of the annular groove when it floats and is pressed radially inward by the contact, the other end may be displaced toward the inner ring and come into contact with the inner ring. . However, since the occurrence of such misalignment can be suppressed, it is possible to obtain a higher quality bearing that is less prone to rotation failure or abnormal vibration due to contact.

(4) Moreover, in the rolling bearing according to the present invention, one end portion of the first end portion and the second end portion is a portion located radially inside than a portion entering the annular groove portion. Moreover, you may have the bending part overlaid while riding on the other edge part.

In this case, the folded portion of one end portion of the first end portion and the second end portion is overlapped so as to ride on the other end portion. At this time, since it is not necessary to make the plate thickness at both ends thinner than the thickness of the other part of the shield plate (portion other than both ends), it is possible to suppress a decrease in strength at both ends and to prevent deformation such as bending. It is possible. Therefore, the shield plate can be easily handled, and the assembly work can be performed efficiently.
In addition, since the bending part is located in the radial inside rather than the part which penetrates in the annular groove part, this bending part does not affect the size of the annular groove part.

(5) In the rolling bearing according to the present invention, the annular groove is perpendicular to the axial direction of the outer ring and connected to the inner peripheral surface of the outer ring, and the abutting surface and the outer ring And an inclined edge formed in a tapered shape that gradually increases in diameter from the opening edge side toward the abutting surface side. It may be mounted in contact with the abutting surface and the slope.

  In this case, since the shield plate can be fixed in close contact with the abutting surface, the shield plate can be mounted more stably. In addition, since the slope has the largest diameter on the abutting surface side, it is possible to make the shield plate more difficult to drop out from the annular groove portion. Further, since the shield plate can be brought into close contact with the abutting surface, the seepage of oil or the like through the annular groove portion can be suppressed.

( 6 ) Further, in the rolling bearing according to the present invention, the number of the recessed portions and the number of the rolling elements may be relatively prime.

  In this case, since the number of rolling elements and the number of recesses can be in a relatively prime relationship, that is, a relationship that does not have a common divisor other than 1, the rolling bearing is viewed from the direction of the rotation axis. In addition, an arrangement pattern in which all rolling elements and all indentations overlap in the thickness direction of the rolling bearing, or an arrangement pattern in which all rolling elements and all indentations do not overlap in the thickness direction of the rolling bearing. There is no end.

  If the number of rolling elements and the number of depressions is the same, the two arrangement patterns appear alternately. In this case, although the presence of the recessed portion is unlikely to cause unauthorized deformation of the outer ring, a large pressure difference is easily exerted on the outer ring due to the appearance of the two arrangement patterns, and the possibility of causing unauthorized deformation is increased. End up. However, since the number of rolling elements and the number of recesses are in a relatively prime relationship, the two arrangement patterns do not appear alternately, and it is possible to prevent unauthorized deformation.

( 7 ) In the rolling bearing according to the present invention, the recess may be formed so that a recess is accommodated in the annular groove when the shield plate is mounted.

  In this case, since the hollow portion can be accommodated in the annular groove portion when the shield plate is attached, the hollow portion does not enter the annular space defined between the outer ring and the inner ring. Therefore, oil or the like does not bleed out through the recess.

( 8 ) A bearing device according to the present invention includes the rolling bearing according to the present invention, a shaft that is formed in a columnar shape and to which the inner ring is fixed, and is disposed coaxially with the shaft, and the outer ring is fixed. And a cylindrical sleeve.

  According to the bearing device of the present invention, since the rolling bearing described above is provided, the shaft and the sleeve can be smoothly and relatively rotated without causing abnormal vibration or torque fluctuation. Therefore, a high-performance bearing device can be obtained. Further, since the rolling bearing is provided which is easy to reduce the thickness and does not easily increase the cost, it is easy to make a thin and low-cost bearing device.

( 9 ) In the bearing device according to the present invention, a plurality of the rolling bearings are disposed between the shaft and the sleeve along the axial direction of the shaft, and the rolling bearings adjacent to each other in the axial direction are adjacent to each other. Between them, there may be disposed a spacer which is disposed coaxially with the shaft and holds the distance between the rolling bearings at a predetermined distance in the axial direction.

  In this case, since a plurality of rolling bearings are provided, the rigidity of the entire apparatus can be increased and the applicable range can be expanded. Moreover, it is possible to adjust easily the space | interval of rolling bearings with a spacer.

( 10 ) A bearing device according to the present invention includes the rolling bearing according to the present invention, and a shaft formed in a columnar shape and to which the inner ring is fixed, and the rolling bearing is along an axial direction of the shaft. A plurality of rolling bearings are arranged in a state of being spaced apart from each other, and are arranged coaxially with the shaft between the axially adjacent rolling bearings, and the spacing between the outer rings of both rolling bearings is predetermined in the axial direction. A spacer for holding at a distance is provided.

  According to the bearing device of the present invention, since the rolling bearing described above is provided, the shaft can be smoothly rotated without causing abnormal vibration or torque fluctuation. Therefore, a high-performance bearing device can be obtained. Further, since the rolling bearing is provided which is easy to reduce the thickness and does not easily increase the cost, it is easy to make a thin and low-cost bearing device. Moreover, since a plurality of rolling bearings are provided, the rigidity of the entire apparatus can be increased, and the application range can be expanded. Furthermore, the interval between the rolling bearings can be easily adjusted by the spacer.

( 11 ) An information recording / reproducing apparatus according to the present invention includes a bearing device according to the present invention, and is externally fitted to the sleeve so as to be rotatable about the axis of the shaft together with the sleeve to support the head gimbal assembly. A carriage having an arm part, a rotation driving part for rotating the magnetic recording medium, and an actuator for rotating the carriage and moving the head gimbal assembly in a direction parallel to the surface of the magnetic recording medium. It is characterized by.

  According to the information recording / reproducing apparatus of the present invention, since the shaft and the sleeve are provided with a high-performance bearing device in which the shaft and the sleeve rotate relatively smoothly, the arm portion is moved smoothly and at high speed, It is easy to accurately control the position of the head gimbal assembly with respect to the target track, and to improve performance. Further, since the thin and low-cost bearing device is provided, it is easy to make the device low-priced in the same way as it is thin and compact.

( 12 ) An information recording / reproducing apparatus according to the present invention includes a bearing device according to the present invention, and is fitted on the outer ring so as to be rotatable about the axis of the shaft together with the outer ring to support the head gimbal assembly. A carriage having an arm part, a rotation driving part for rotating the magnetic recording medium, and an actuator for rotating the carriage and moving the head gimbal assembly in a direction parallel to the surface of the magnetic recording medium. It is characterized by.

  According to the information recording / reproducing apparatus of the present invention, since the shaft is provided with a high-performance bearing device in which the shaft rotates smoothly and relatively, the arm portion is moved smoothly and at high speed to be a target track of the magnetic recording medium. On the other hand, it is easy to accurately control the position of the head gimbal assembly and to improve performance. Further, since the thin and low-cost bearing device is provided, it is easy to make the device low-priced in the same way as it is thin and compact.

According to the rolling bearing according to the present invention, it is difficult for positional deviation and buckling deformation of the shield plate to occur, and it is difficult to cause unauthorized deformation of the outer ring. Moreover, thickness reduction and cost increase can be suppressed.
Further, according to the bearing device and the information recording / reproducing device according to the present invention, since the rolling bearing is provided, high performance and low cost can be achieved.

1 is a perspective view showing an embodiment of an information recording / reproducing apparatus according to the present invention. It is a longitudinal cross-sectional view around the pivot shaft of the information recording / reproducing apparatus shown in FIG. It is a longitudinal cross-sectional view of the pivot shaft shown in FIG. It is a top view of the rolling bearing which comprises the pivot axis | shaft shown in FIG. It is sectional drawing of the rolling bearing along the AA line shown in FIG. It is sectional drawing of the shield board along the BB line shown in FIG. It is a top view of the shield board which comprises the rolling bearing shown in FIG. It is the side view which looked at the both ends of the shield board shown in FIG. 7 from the side. It is a top view which shows the modification of a shield board. It is a top view which shows another modification of a shield board. It is the side view which looked at the both ends of the shield board shown in FIG. 10 from the side. It is sectional drawing of the rolling bearing with which the shield board shown in FIG. 10 was mounted | worn. It is sectional drawing which shows a state when the 2nd end part which has overlapped with the 1st end part has floated in the shield board shown in FIG. It is a top view which shows another modification of a shield board. It is the side view which looked at the both ends of the shield board shown in FIG. 14 from the side. It is sectional drawing of the rolling bearing with which the shield board shown in FIG. 14 was mounted | worn. It is sectional drawing of the shield board along CC line shown in FIG. It is a figure of the conventional rolling bearing, Comprising: It is sectional drawing of a rolling bearing which has the shield board made into the bending part by which the outer peripheral edge side was bent over the perimeter. It is a top view of the rolling bearing shown in FIG. It is a figure of another conventional rolling bearing, Comprising: It is a top view of a rolling bearing which has the shield board in which the bending part was intermittently provided in the circumferential direction. It is a figure of another conventional rolling bearing, Comprising: It is sectional drawing of the rolling bearing which aimed at the removal of the shield board using C ring. It is a top view of the rolling bearing shown in FIG. It is a partial expanded sectional view of the rolling bearing shown in FIG. It is the elements on larger scale of the rolling bearing shown in FIG.

  Embodiments according to the present invention will be described below with reference to FIGS. In the present embodiment, the case where the bearing device is used for the pivot shaft of the information recording / reproducing apparatus will be described.

(Information recording / reproducing device)
As shown in FIG. 1, an information recording / reproducing apparatus 1 of the present embodiment is an apparatus for writing on a disk (magnetic recording medium) D having a vertical recording layer by a vertical recording method. 2, a laser light source 4 that supplies a light beam from the base end side through the optical waveguide 3, a head gimbal assembly (HGA) 5 supported on the tip end side of the carriage 2, and the head gimbal assembly 5 on the disk surface (disc D Surface) Actuator 6 that scans and moves in a horizontal plane parallel to D1, a spindle motor (rotation drive unit) 7 that rotates disk D around a rotation axis L1 in a fixed direction, and a current modulated according to information in the head A control unit 8 that supplies the slider 5b of the gimbal assembly 5 and a housing 9 that houses these components therein are provided. And are

The housing 9 has a box-like shape having a top opening made of a metal material such as aluminum, and has a rectangular bottom portion 9a as viewed from above, and a peripheral wall erected in the vertical direction with respect to the bottom portion 9a at the periphery of the bottom portion 9a. (Not shown). And the recessed part which accommodates each component mentioned above is formed in the inner side enclosed by the surrounding wall.
In FIG. 1, the peripheral wall surrounding the housing 9 is omitted for easy understanding.

  Further, a lid (not shown) is detachably fixed to the housing 9 so as to close the upper opening of the housing 9. 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.

The actuator 6 described above is attached to one corner of the bottom 9a outside the disk D. The actuator 6 is provided with a carriage 2 that can rotate around a rotation axis L2 in a horizontal plane around the pivot shaft 10.
The carriage 2 has an arm portion 2a extending from the base end portion toward the front end portion (in the direction of the disk D), and a base portion 2b supported in a cantilever manner via the arm portion 2a. It is integrally formed by processing or the like. The base 2b is formed in a substantially rectangular parallelepiped shape, and is supported so as to be rotatable around the pivot shaft 10. That is, the base portion 2 b is connected to the actuator 6 via the pivot shaft 10, and the pivot shaft 10 is the rotation center of the carriage 2.

The arm portion 2a extends in parallel to the surface direction (horizontal plane direction) of the upper surface of the base portion 2b on the side surface 2d opposite to the side surface 2c to which the actuator 6 is attached in the base portion 2b (side surface opposite to the corner portion). It has a flat plate shape and extends three along the height direction (vertical direction) of the base portion 2b.
Specifically, the arm portion 2a is formed in a tapered shape that tapers from the proximal end portion toward the distal end portion, and is arranged so that the disk D is sandwiched between the arm portions 2a. That is, the arm portion 2a and the disk D are configured to be alternately arranged, and the arm portion 2a can be moved in a direction parallel to the disk surface D1 (horizontal plane direction) by driving the actuator 6.
The carriage 2 and the head gimbal assembly 5 are retracted from the disk D by driving the actuator 6 when the rotation of the disk D is stopped.

The head gimbal assembly 5 is connected to the distal end of the arm portion 2a, and includes a suspension 5a and a slider 5b attached to the distal end of the suspension 5a. Further, the head gimbal assembly 5 guides a light beam from the laser light source 4 to a slider 5b having a near-field light generating element (not shown) to generate near-field light, and uses the near-field light to generate various information on the disk D. Is recorded and reproduced.
Note that the near-field light generating element includes, for example, an optical minute aperture, a protrusion formed in a nanometer size, and the like.

(Pivot axis)
As shown in FIGS. 2 and 3, the pivot shaft 10 includes a shaft 20 erected on the bottom 9 a of the housing 9, and surrounds the shaft 20 from the outside in the radial direction, and is disposed coaxially with the shaft 20. A substantially cylindrical sleeve 21 and two rolling bearings 22 interposed between the shaft 20 and the sleeve 21 are provided.

The shaft 20 is a cylindrical rod-shaped member extending along the rotation axis L2, and the bottom 9a side of the housing 9 is a base end, and the opposite side along the axial direction is a tip.
In the present embodiment, a direction orthogonal to the rotation axis L2 is referred to as a radial direction, and a direction around the rotation axis L2 is referred to as a circumferential direction.

At the base end portion of the shaft 20, a flange portion 20 a having a diameter larger than the diameter of the shaft 20 and a reduced diameter portion 20 b having a diameter smaller than the diameter of the shaft 20 are successively provided toward the end portion. ing. A male screw 20 c is formed on the reduced diameter portion 20 b and is screwed into a female screw 9 c formed on the bottom 9 a of the housing 9.
In this way, the shaft 20 is erected on the bottom 9 a of the housing 9. At this time, the shaft 20 is positioned in the height direction by the lower surface of the flange portion 20 a being in contact with the bottom portion 9 a of the housing 9.

The sleeve 21 is a member formed in a cylindrical shape having an inner peripheral surface spaced apart from the outer peripheral surface of the shaft 20 by a predetermined distance and having substantially the same diameter as the flange portion 20a. In addition, while the two rolling bearings 22 in the sleeve 21 are disposed, a spacer portion (spacer) 21a that holds the distance between the rolling bearings 22 at a predetermined distance in the axial direction protrudes radially inward. Has been.
The sleeve 21 is integrally combined with the carriage 2 by being press-fitted or adhesively fitted into an attachment hole 2 e formed in the base 2 b of the carriage 2.

  The two rolling bearings 22 described above are bearings with a shield plate and have the same configuration. As shown in FIGS. 3 to 6, the inner ring 30 fixed to the shaft 20 and the inner ring 30 are coaxial. An outer ring 31 disposed on the sleeve 21 and fixed to the sleeve 21, a plurality of rolling elements 32 rotatably held between the inner ring 30 and the outer ring 31, and an inner ring 30 and the outer ring 31. And an annular shield plate 33 for closing the annular space.

Note that the rolling bearing 22 of the present embodiment is a bearing to which preload is applied in the axial direction along the axial direction of the shaft 20. That is, preload is applied to one of the outer ring 31 and the inner ring 30 in the axial direction with respect to the other.
In the present embodiment, the rolling element 32 is described as a ball. Moreover, these rolling elements 32 are held so as to be able to roll by a retainer (not shown), and the number thereof is a prime number of seven.

Further, in the present embodiment, two shield plates 33 are mounted so as to be positioned on both sides in the axial direction of the rolling element 32 and block both sides of the annular space defined between the outer ring 31 and the inner ring 30. Take the case as an example.
Each shield plate 33 surrounds the inner ring 30 from the outer side in the radial direction, and presses the outer ring 31 in the radial direction in a state where the outer peripheral edge side enters the engaging annular groove 40 formed in the outer ring 31. . As a result, the shield plate 33 is engaged with the annular groove 40 and attached to the outer ring 31.

  Here, the shield plate 33 and the annular groove 40 will be described in detail.

  First, as shown in FIGS. 7 and 8, the shield plate 33 is divided in the circumferential direction, and in a state before being attached to the outer ring 31, for example, has a C shape in plan view. Further, portions of the shield plate 33 positioned at both ends in the circumferential direction are a first end portion 35 and a second end portion 36 that can be slidably overlapped with each other. These both end portions 35 and 36 are formed to be thinner than the plate thickness T of the shield plate 33 other than the both end portions 35 and 36, specifically, to have a half plate thickness t.

The first end portion 35 is formed thin so that a step appears on one surface of the shield plate 33 (upper side with respect to the paper surface in FIG. 8), and the formation range thereof is the entire shield width along the radial direction. Has been. On the other hand, the second end portion 36 is formed thin so that a step appears on the other surface of the shield plate 33 (lower side with respect to the paper surface in FIG. 8), and the formation range thereof is along the radial direction. The entire shield width.
In particular, since the first end portion 35 and the second end portion 36 are formed so that the respective steps in the thickness direction of the shield plate 33 face each other, the flatness of the shield plate 33 is maintained as shown in FIG. The first end 35 and the second end 36 can be overlapped as they are. That is, in the present embodiment, the total thickness of the first end portion 35 and the second end portion 36 that overlap each other is the same as the thickness T of the shield plate 33 other than the both end portions 35 and 36.

The shield plate 33 is formed in an annular shape by overlapping the first end portion 35 and the second end portion 36 with each other, and the diameter of the shield plate 33 is reduced by elastically deforming both end portions 35 and 36 so as to slide. The diameter can be increased. Therefore, the outer diameter size of the shield plate 33 can be changed according to the inner diameter of the annular groove portion 40 formed in the outer ring 31 and the outer peripheral edge side is inserted into the annular groove portion 40. The outer ring 31 can be pressed.
As a result, as shown in FIGS. 4 and 5, the shield plate 33 is reliably engaged in the annular groove 40, and as a result, is attached to the outer ring 31.

Subsequently, as shown in FIGS. 4 and 5, the annular groove portion 40 of the present embodiment is formed on the inner peripheral surface of the outer ring 31 over the entire circumference and is formed so as to open to the inner peripheral surface side. Yes. The annular groove portion 40 is parallel to the in-plane direction of the shield plate 33 (perpendicular to the axial direction of the outer ring 31) and is connected to the inner peripheral surface of the outer ring 31 (butting surface) 40a, And an inner wall (inclined surface) 40b connected to the wall 40a.
The inner wall portion 40 b is formed in a tapered shape that gradually increases in diameter from the opening edge side of the outer ring 31 toward the bottom wall portion 40 a, and functions as a guide surface that guides the shield plate 33 into the annular groove portion 40.

(How to attach the shield plate)
Next, a method for attaching the shield plate 33 to the outer ring 31 in the rolling bearing 22 configured as described above will be described.

First, as shown in FIG. 6, the first end portion 35 and the second end portion 36 of the shield plate 33 are overlapped with each other to make the shield plate 33 annular, and then between the outer ring 31 and the inner ring 30. The outer ring 31 is overlaid so as to close the defined annular space. Next, the shield plate 33 is tilted so that a part of the outer peripheral edge enters the annular groove 40, and then the remaining part of the outer peripheral edge is pushed into the annular space. At this time, the shield plate 33 is pushed in while being elastically deformed so that the outer diameter of the shield plate 33 is reduced.
Then, the remaining part of the outer peripheral edge portion of the shield plate 33 enters the annular groove portion 40 while being guided by the inner wall portion 40b of the annular groove portion 40 one after another, and is completely pushed into the bottom wall portion 40a of the annular groove portion 40. When in contact with the shield plate 33, the shield plate 33 elastically returns so as to expand its diameter by an elastic restoring force. As a result, as shown in FIGS. 4 and 5, the shield plate 33 enters the annular groove 40 with the outer peripheral edge in contact with the bottom wall 40a and the inner wall 40b, and the outer ring 31 is radially outward. Press.

As a result, the shield plate 33 can be reliably engaged in the annular groove 40, and the shield plate 33 can be attached to the outer ring 31 without being dropped. Moreover, since the shield plate 33 can be fixed in close contact with the bottom wall portion 40a of the annular groove portion 40, the shield plate 33 can be stabilized. Moreover, since the bottom wall part 40a has the largest diameter in the inner wall part 40b of the annular groove part 40, the shield plate 33 is hard to drop off.
By mounting the shield plate 33 in this manner, the annular space defined between the outer ring 31 and the inner ring 30 can be closed, and dust or the like can enter inside, or grease or the like can leak to the outside. Can be suppressed. As described above, since the shield plate 33 can be brought into close contact with the bottom wall portion 40a, the seepage of grease or oil through the annular groove portion 40 can be effectively suppressed.

In particular, according to the rolling bearing 22 of the present embodiment, the first end portion 35 and the second end portion 36 are slidably overlapped with each other to form an annular shape, and can be reduced in diameter and increased in diameter. Since the shield plate 33 is provided, the outer diameter of the shield plate 33 can be changed according to the inner diameter of the annular groove portion 40, and a strong pressing force from the outer ring 31 side is shielded from the outer ring 31 side due to the difference in diameter as in the prior art. Transmission to the plate 33 can be suppressed. Accordingly, it is possible to make it difficult for the shield plate 33 to cause buckling deformation that collapses toward the inside of the rolling bearing 22, thereby eliminating the appearance defect.
In addition, the first end portion 35 and the second end portion 36 of the shield plate 33 are overlapped with each other, but the flatness is maintained and the entire shield plate 33 is a flat annular member. Therefore, also in this respect, the rolling bearing 22 is excellent in appearance and excellent in appearance.

Further, since it is difficult for buckling deformation to occur in the shield plate 33, the possibility of contact between the shield plate 33 and other parts (for example, a cage) is low, and it is difficult to cause rotation failure or abnormal vibration due to the contact.
Further, since the shield plate 33 presses the outer ring 31 radially outward, unlike the conventional C-ring, the shield plate 33 is unlikely to be displaced in the in-plane direction due to impact or the like. Therefore, the shield plate 33 and the inner ring 30 come into contact with each other to cause rotation failure, abnormal vibration, etc., or the gap between the inner ring 30 and the shield plate 33 is partially opened so that dust or the like enters inside, or grease or the like It is possible to suppress leakage.

  Further, since the outer peripheral edge side of the shield plate 33 enters the annular groove portion 40 of the outer ring 31 over the entire circumference, the outer ring 31 is pressed, so that the pressing force is uniform in the circumferential direction with respect to the outer ring 31. Act on. Therefore, the outer ring 31 is not easily deformed illegally, and the roundness of the rolling surface can be maintained, so that occurrence of abnormal vibration and torque fluctuation (torque waveform undulation, etc.) can be suppressed.

  Furthermore, unlike the conventional bent portion or the one using a C-ring, the outer ring 31 may be formed with an annular groove portion 40 that can enter the outer peripheral edge of the shield plate 33. It is possible to easily increase the thickness (D shown in FIG. 5), and it is possible to form the annular groove 40 at a position as close as possible to the opening edge side of the outer ring 31. In particular, even if the first end portion 35 and the second end portion 36 overlap each other, the total thickness is the same as the plate thickness T of the shield plate 33 other than the both end portions 35, 36. There is no need to partially increase the size of 40. Therefore, the rigidity of the outer ring 31 against adhesion strain or the like can be increased, and it is possible to prevent unauthorized deformation and to make the entire rolling bearing 22 thinner.

  Furthermore, since no separate parts such as a C-ring are required, it is difficult to increase the cost. Further, since the shield plate 33 can be manufactured by a simple process in which both end portions 35 and 36 are made thinner than the other portions, it is easy to reduce the cost in this respect as well.

  Further, since the annular groove 40 is formed over the entire inner peripheral surface of the outer ring 31, the shield plate 33 can be mounted without worrying about the relative positional relationship between the outer ring 31 and the shield plate 33 in the circumferential direction. Since it can be easily attached to the outer ring 31, it is excellent in assemblability.

  Then, according to the pivot shaft 10 provided with the two rolling bearings 22 described above, the shaft 20 and the sleeve 21 can be rotated relatively smoothly without causing abnormal vibration or torque fluctuation. Therefore, a high-performance pivot shaft 10 can be obtained. Further, since the rolling bearing 22 is provided which is difficult to increase the cost, it is easy to reduce the price.

In particular, since the rolling bearing 22 that is easy to reduce in thickness is provided, when the thickness of the spacer portion 21a is the same as the conventional thickness, the total thickness can be reduced as compared with the pivot shaft having the conventional rolling bearing. It is possible to reduce the thickness.
Further, when the pivot shaft 10 of the present embodiment is made to have the same thickness as the total thickness of the conventional pivot shaft, the distance L between the ball centers of the two rolling bearings 22 separated in the axial direction (see FIG. 3) Can be longer. This is because the thickness of each rolling bearing 22 is thin, so that both rolling bearings 22 can be disposed closer to the opening end side of the sleeve 21 than in the prior art. Therefore, the pivot shaft 10 having high bending rigidity can be obtained.

In this regard, the slider 5b shown in FIG. 1 normally receives a force that rises from the disk D by a positive air pressure pad or the like (not shown), and is pressed against the disk D by a predetermined force by the arm 2a or the like. It has been. Therefore, the slider 5b is in a state of floating from the disk D due to the balance of both forces. Therefore, a force that approaches the disk D is likely to act on the arm portion 2a, and accordingly, a bending moment indicated by an arrow M in FIG.
Then, a force that causes the sleeve 21 to tilt with respect to the shaft 20 due to this bending moment acts on the pivot shaft 10, so that a radial load (arrow R) acts on the rolling bearings 22. At this time, as the distance L between the centers of the rolling bearings 22 is increased, the radial load can be stably supported, and the bending rigidity can be improved.
Therefore, the pivot shaft 10 according to the present embodiment is a bearing having higher bending rigidity than the conventional one.

Furthermore, according to the information recording / reproducing apparatus 1 provided with such a pivot shaft 10, the position of the head gimbal assembly 5 is accurately controlled with respect to the target track of the disk D by moving the arm portion 2a smoothly and at high speed. Easy to achieve, and high performance. Further, since the pivot shaft 10 can be reduced in thickness and is low in price, it is easy to make the apparatus low in cost in the same manner as it is compact.
In addition, since the bending rigidity of the pivot shaft 10 can be increased as described above, information can be read from and written to the disk D stably. In addition, since the pivot shaft 10 can reduce torque undulation and suppress torque fluctuation, information can be read and written stably in this respect. In addition, since the leakage of grease to the outside is suppressed by the shield plate 33 that is not easily displaced in the in-plane direction, it is difficult for information reading and writing failures due to the leakage of the grease to occur.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the case where the bearing device is applied to the pivot shaft 10 of the information recording / reproducing apparatus 1 having near-field light has been described as an example. However, the present invention is not limited to this. The present invention can be applied to a bearing device such as a device and a rotating shaft portion of various devices.

  In the above embodiment, two shield plates 33 are mounted so as to be positioned on both sides of the rolling element 32 in the axial direction, and both sides of the annular space defined between the outer ring 31 and the inner ring 30 are closed. However, a configuration may be adopted in which one shield plate 33 is attached to the outer ring 31 and one side of the annular space defined between the outer ring 31 and the inner ring 30 is closed.

  Further, although the rolling element 32 is a ball, it is not limited to the ball, and any rolling element such as a roller may be used. And although the number of the rolling elements 32 was set to seven, it is not limited to this number, You may set freely.

Moreover, in the said embodiment, the spacer part 21a protrudes from the inner peripheral surface of the sleeve 21 so that it may be inserted between the outer rings 31 of the two rolling bearings 22, and the spacer part 21a is used to Although the space | interval along the axial direction of the rolling bearings 22 was kept at the predetermined distance, it is not limited to this case.
For example, a spacer portion projecting radially outward is formed on the outer peripheral surface of the shaft 20, and the spacer portion is inserted between the inner rings 30 of the two rolling bearings 22, so that the two rolling bearings 22 The interval may be held at a predetermined distance.
Further, an annular spacer ring may be disposed between the two rolling bearings 22 to keep the spacing between the rolling bearings 22 at a predetermined distance. In this case, the spacer ring may be disposed between the inner rings 30 of the two rolling bearings 22 or may be disposed between the outer rings 31.

In the above embodiment, the pivot shaft 10 including the shaft 20 and the sleeve 21 is used. However, a bearing device that does not include the sleeve 21 may be used.
That is, the shaft 21, the two rolling bearings 22 arranged at intervals along the axial direction of the shaft 20, and the spacer that keeps the spacing between the outer rings 31 of the rolling bearings 22 at a predetermined distance in the axial direction. And a bearing device including the above. As the spacer, for example, the above-described annular spacer ring may be used.
Even in this case, the same effect can be obtained only in that the sleeve 21 is not provided.
In the case of an information recording / reproducing apparatus having this bearing device, the outer ring 31 may be press-fitted or adhesively fitted into the mounting hole 2e formed in the base 2b of the carriage 2.

In the above embodiment, when the shield plate 33 is attached to the outer ring 31, the attachment operation may be performed after the shield plate 33 is elastically deformed to reduce the diameter in advance using a dedicated tool.
In this case, as shown in FIG. 9, the outer peripheral edge of the shield plate 33 is recessed radially inward, and a recess 33a for reducing the diameter by applying an external force to the shield plate 33 is provided along the circumferential direction. It is good to form a plurality.

  The recesses 33a are, for example, recesses formed in a semicircular shape in accordance with the shape of the semi-columnar grip 45 that is the tool, and five recesses 33a are arranged at equal intervals along the circumferential direction. . Therefore, the number of rolling elements 32 (seven) and the number of depressions 33a (five) are in a prime relationship.

  With this configuration, when the shield plate 33 is attached to the outer ring 31, the shield plate 33 can be easily elasticized by applying an external force so as to grip the shield plate 33 while applying the grip 45 to each recess 33a. The diameter can be reduced by deformation. Then, after inserting the shield plate 33 gripped by the grip 45 into an annular space defined between the outer ring 31 and the inner ring 30, the grip 45 is pulled out. Then, since the shield plate 33 is elastically restored by the elastic restoring force and expands in diameter, the outer peripheral edge side smoothly enters the annular groove 40 and then presses the outer ring 31. As a result, the shield plate 33 can be reliably attached to the outer ring 31, and the attaching operation can be easily performed.

  In particular, the depression 33a is not a large cutout opening, but a depression to which the grip 45 is applied, so that the pressing force transmitted from the shield plate 33 to the outer ring 31 is uneven in the circumferential direction during mounting. Can be suppressed as much as possible. Therefore, it is difficult to cause adverse effects such as unauthorized deformation of the outer ring 31 and deterioration of the roundness of the rolling surface.

And since the number of the rolling elements 32 is seven and the number of the hollow parts 33a is a combination of five, both have a prime relationship. Therefore, when the rolling bearing 22 is viewed from the direction of the rotation axis L2, all the rolling elements 32 and all the recessed portions 33a overlap in the thickness direction of the rolling bearing 22 or do not overlap. There is no end.
If the number of the rolling elements 32 and the recesses 33a is the same number of five, the two arrangement patterns appear alternately during use. In this case, although the presence of the recessed portion 33a is unlikely to cause unauthorized deformation of the outer ring 31, a pressure difference applied to the outer ring 31 is likely to be large due to the appearance of the two arrangement patterns, which may cause unauthorized deformation. It will increase.

  However, since the number of the rolling elements 32 and the number of the recessed portions 33a are a prime combination, it is possible to prevent the two arrangement patterns from appearing alternately during use, thereby causing unauthorized deformation. Can be difficult.

In addition, when forming the recessed part 33a, it is preferable to form so that a recessed part may be settled in the annular groove part 40 formed in the outer ring | wheel 31 when the shield board 33 is mounted | worn. That is, it is preferable to form the recessed portion 33a within a range overlapping with the bottom wall portion 40a of the annular groove portion 40 in the axial direction.
In this way, when the shield plate 33 is mounted, the recessed portion 33a does not enter the annular space defined between the outer ring 31 and the inner ring 30, so that grease or oil through the recessed portion 33a can be prevented. It is possible to prevent exudation to the outside.

  Moreover, in the said embodiment, although the shield board 33 was formed so that all the shield widths might become uniform, as shown in FIG.10 and FIG.11, the outer diameter of the 1st end part 35 and the 2nd end part 36 is set. Further, it may be cut out so as to be smaller than the outer diameter of the shield plate 33 other than the both end portions 35 and 36. However, the cutout amount is set so that the outer diameters of both end portions 35 and 36 are larger than the inner diameter of the outer ring 31.

By doing so, as shown in FIG. 12, when the shield plate 33 is mounted, the first end 35 and the second end 36 that overlap each other and the inner wall 40 b of the annular groove 40 are interposed. A gap can be defined. Therefore, the first end portion 35 and the second end portion 36 having a small thickness are deformed due to stress concentration, for example, and as shown in FIG. 13, the second end portion 36 overlapping the first end portion 35 is the outer ring. Even if it slightly floats to the opening edge side of 31, since the outer diameter is small and the gap is secured, it is not immediately pressed radially inward by contact with the inner wall portion 40 b of the annular groove portion 40.
If it comes into contact with the inner wall 40b of the annular groove 40 when it floats and is pressed radially inward by the contact, the second end 36 is displaced to the inner ring 30 side (projected out). There is a risk of contact with the inner ring 30. However, since the occurrence of such misalignment can be suppressed, rotation failure, abnormal vibration, and the like due to contact are less likely to occur, and higher quality can be achieved.

  In this case, the outer diameter of both the first end portion 35 and the second end portion 36 is not reduced, but at least the outer diameter of the second end portion 36 that overlaps the first end portion 35 is reduced. It should be. Even in this case, the same effect can be obtained. However, it is preferable that the outer diameters of both end portions 35 and 36 are formed to be small, so that the mounting operation can be performed without worrying about the direction of the front and back of the shield plate 33, so that the mounting workability can be improved.

Moreover, in the said embodiment, it formed so that the thickness of the 1st end part 35 and the 2nd end part 36 which were mutually piled up might be half the board thickness T of the shield board 33 in each other than the both ends 35 and 36, respectively. However, the present invention is not limited to this case.
The first end portion 35 and the second end portion 36 are slidably overlapped with each other, and at least the thicknesses of the portions of the overlapping first end portion 35 and second end portion 36 that enter the annular groove portion 40 are these. It is sufficient that the thickness is equal to or less than the thickness T of the shield plate 33 except for the both end portions 35 and 36.

  For example, as shown in FIGS. 14 and 15, both the first end portion 35 and the second end portion 36 have the same thickness as the plate thickness T of the shield plate 33 except for the both end portions 35 and 36, and the second end portion 35 and 36. You may comprise so that the part 36 may have the bending part 36a piled up while riding on the 1st end part 35. FIG. The bent portion 36a is formed so as to be located radially inward from the outer peripheral edge portion of the shield plate 33 entering the annular groove portion 40. As shown in FIGS. 16 and 17, the shield plate 33 is attached. Sometimes it is located between the outer ring 31 and the inner ring 30.

Even if it is a case where it comprises in this way, the same effect can be show | played. In addition, since it is not necessary to make the thickness of both end portions 35 and 36 thinner than the plate thickness T of other portions of the shield plate 33 (portions other than both end portions 35 and 36), the strength of both end portions 35 and 36 is reduced. It is possible to suppress the deformation such as bending. Therefore, the shield plate 33 can be easily handled, and the assembly work can be performed efficiently.
The bent portion 36a is located on the radially inner side of the outer peripheral edge portion of the shield plate 33 entering the annular groove portion 40 as described above, and is located between the outer ring 31 and the inner ring 30 when the shield plate 33 is attached. Therefore, the bent portion 36a does not affect the size of the annular groove portion 40.

D ... Disk (magnetic recording medium)
DESCRIPTION OF SYMBOLS 1 ... Information recording / reproducing apparatus 2 ... Carriage 2a ... Arm part 5 ... Head gimbal assembly 6 ... Actuator 7 ... Spindle motor (rotation drive part)
10 ... Pivot shaft (bearing device)
20 ... Shaft 21 ... Sleeve 21a ... Spacer (Spacer)
DESCRIPTION OF SYMBOLS 22 ... Rolling bearing 30 ... Inner ring 31 ... Outer ring 32 ... Rolling element 33 ... Shield plate 33a ... Depression part 35 ... First end part 36 ... Second end part 36a ... Bending part 40 ... Annular groove part 40a ... Bottom wall of the annular groove part Part (butting surface)
40b ... Inner wall (slope) of the annular groove

Claims (12)

An inner ring and an outer ring arranged on the same axis;
A plurality of rolling elements movably held between the inner ring and the outer ring;
Surrounding the inner ring from the radially outer side, and pressing the outer ring radially outward in a state where the outer peripheral edge side enters the annular groove formed on the inner peripheral surface of the outer ring, the inner ring and the outer ring An annular shield plate attached to the outer ring so as to close the annular space defined between
The shield plate is divided in the circumferential direction, and the first end and the second end located respectively at both ends in the circumferential direction are slidably overlapped with each other so that the diameter can be reduced and expanded. Formed into
A rolling bearing characterized in that a thickness of at least a portion of the first end portion and the second end portion overlapping each other into the annular groove portion is equal to or less than a plate thickness of the shield plate other than the both end portions. Because
A rolling bearing characterized in that the outer peripheral edge of the shield plate is recessed inward in the radial direction, and a plurality of recesses are formed along the circumferential direction for applying an external force to the shield plate to reduce the diameter. . The rolling bearing according to claim 1,
The first end portion and the second end portion are formed to be thinner than the thickness of the shield plate except at both ends, and are overlapped with each other while maintaining the flatness of the shield plate. Rolling bearing characterized by The rolling bearing according to claim 2,
The other end overlapped on one end of the first end and the second end has an outer diameter outside the shield plate other than the first end and the second end. A rolling bearing characterized by being formed smaller than a diameter. The rolling bearing according to claim 1,
One end portion of the first end portion and the second end portion is overlapped with a portion positioned radially inward from the portion entering the annular groove portion while riding on the other end portion. A rolling bearing having a bent portion. In the rolling bearing according to any one of claims 1 to 4,
The annular groove is
An abutting surface that is perpendicular to the axial direction of the outer ring and is continuous with the inner peripheral surface of the outer ring;
The abutting surface and the opening end edge of the outer ring are connected to each other, and are defined by a tapered slope that gradually increases in diameter from the opening end side toward the abutting surface side,
The rolling bearing according to claim 1, wherein the shield plate is mounted in a state where an outer peripheral edge side is in contact with the abutting surface and the inclined surface. The rolling bearing according to claim 1 ,
The number of the said hollow parts and the number of the said rolling elements are mutually prime relations, The rolling bearing characterized by the above-mentioned. In the rolling bearing according to claim 1 or 6 ,
The rolling bearing according to claim 1, wherein the recess is formed so that a recess is accommodated in the annular groove when the shield plate is mounted. A rolling bearing according to any one of claims 1 to 7 ,
A shaft formed in a columnar shape and to which the inner ring is fixed;
And a cylindrical sleeve disposed coaxially with the shaft and to which the outer ring is fixed. The bearing device according to claim 8 , wherein
A plurality of the rolling bearings are disposed between the shaft and the sleeve along the axial direction of the shaft,
Between the rolling bearings adjacent to each other in the axial direction, a spacer is provided coaxially with the shaft, and a spacer is provided to maintain the distance between the rolling bearings at a predetermined distance in the axial direction. Bearing device. A rolling bearing according to any one of claims 1 to 7 ,
A shaft that is formed in a cylindrical shape and to which the inner ring is fixed;
A plurality of the rolling bearings are arranged in a state of being spaced along the axial direction of the shaft,
Between the rolling bearings adjacent to each other in the axial direction, a spacer is provided coaxially with the shaft and holds a distance between the outer rings of the rolling bearings at a predetermined distance in the axial direction. A bearing device. A bearing device according to claim 8 or 9 ,
A carriage that is externally fitted to the sleeve and is rotatable about the axis of the shaft together with the sleeve, and has an arm portion that supports the head gimbal assembly;
A rotation drive for rotating the magnetic recording medium;
An information recording / reproducing apparatus comprising: an actuator for rotating the carriage and moving the head gimbal assembly in a direction parallel to the surface of the magnetic recording medium. A bearing device according to claim 10 ,
A carriage that is externally fitted to the outer ring and is rotatable about the axis of the shaft together with the outer ring, and has an arm portion that supports a head gimbal assembly;
A rotation drive for rotating the magnetic recording medium;
An information recording / reproducing apparatus comprising: an actuator for rotating the carriage and moving the head gimbal assembly in a direction parallel to the surface of the magnetic recording medium.

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