JP5580664B2 - 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 raceways of the outer ring and the inner ring, and to prevent leakage of internal grease or lubricating oil to the outside. Is possible. 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 such a rolling bearing with a shield plate, for example, one using a shield plate in which a plurality of locking projections are provided on the outer peripheral edge (see Patent Document 1) is known.
The shield plate in the rolling bearing is formed by forming a metal plate in an annular shape, and a plurality of locking projections are provided on the outer peripheral edge portion at regular intervals along the circumferential direction. The plurality of locking projections are provided so as to incline obliquely from the outer peripheral edge toward the radially outer side, and can be bent and deformed in an orthogonal direction substantially orthogonal to the in-plane direction of the shield plate. Has been.

The shield plate configured in this manner is attached to the outer ring by locking the locking projection in the locking groove formed in the outer ring.
Specifically, the shield plate is pushed into an annular space defined between the outer ring and the inner ring so that the locking projection is fitted in the locking groove. Then, the locking protrusion is fitted into the locking groove while being bent in the orthogonal direction with the base side as a base point. Then, when the shield plate is completely pushed, the locking projections are elastically returned by the elastic restoring force in the locking grooves and press the inner surface of the locking grooves. As a result, the locking projection is caught in the locking groove and locked. In this way, the shield plate is attached to the outer ring.

JP 2002-89574 A

By the way, in the conventional shield plate, since the locking projection that is bent and deformed in the orthogonal direction substantially orthogonal to the in-plane direction of the shield plate is used, the locking projection is the inner surface of the locking groove. Is pressed toward the outer side in the radial direction of the outer ring.
In particular, it is difficult to lengthen the protruding amount (length) of the locking protrusion in consideration of the entire thickness of the rolling bearing. In addition, if the length of the shield plate is excessively long, too much load is applied to the base point, leading to a decrease in rigidity. Therefore, it is necessary to shorten the protruding amount of the locking projection, and the distance between the tip portion, which is the point of action of the bending moment of the locking projection, and the root serving as the base point tends to be close. Therefore, it is difficult to elastically deform the locking projection, and in order to realize a reliable locking state, it is necessary to increase the rigidity of the locking projection and increase the pressing force accordingly. In particular, in the case of a bearing device such as a very small miniature ball bearing, it becomes more prominent.

Therefore, in the conventional rolling bearing with a shield plate, there is a high possibility that the outer ring is illegally deformed so as to expand radially outward due to the pressing force of the locking projection. For this reason, the roundness of the outer ring may be impaired, and harmful vibrations and load torque fluctuations may occur.
Furthermore, due to the strong pressing force of the locking projection, the central part of the shield plate may be distorted so as to buckle, causing a defective appearance or a component that moves relative to the outer ring, such as a retainer. There was also a risk of contact with the like.

  For example, a method of attaching the shield plate to the outer ring using another member such as a C-ring without providing a locking projection on the shield plate is conceivable. Two parts are required, resulting in high costs.

  The present invention has been made in view of such circumstances, and its purpose is to provide a rolling bearing with a shield plate that does not easily cause unauthorized deformation of the outer ring without incurring high costs, and a bearing device having the same, and information It is to provide a recording / reproducing apparatus.

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 that are coaxially disposed, a plurality of rolling elements that are rotatably held between the inner ring and the outer ring, and an inner circumference of the outer ring. An annular shield plate that is formed along the circumferential direction on the surface and is engaged with an engaging groove that opens to the inner peripheral surface side, and closes an annular space defined between the inner ring and the outer ring; The shield plate includes an annular shield body whose inner peripheral edge surrounds the inner ring from the outer side in the radial direction and whose outer peripheral edge faces the outer ring, and a plurality of circumferentially extending outer peripheral edges of the shield body along the circumferential direction. An elastically deformable portion that is disposed and projects from the outer peripheral edge portion toward the outer ring along the in-plane direction of the shield body, and is elastically deformable in the in-plane direction;
An engagement protrusion formed at a part of the elastic deformation portion, formed at a distal end portion of the elastic deformation portion, and engaged with the engagement groove portion,
The elastic deformation portion is formed in a cantilever shape having a base end portion connected to the outer peripheral edge portion of the shield body and extending along the outer peripheral edge portion of the shield body and having a distal end portion as a free end. The engaging projection is urged toward the engaging groove along the in-plane direction.

According to the rolling bearing of the present invention, the shield plate is mounted on the outer ring by the engagement protrusion formed on the elastically deforming portion entering and engaging with the engagement groove. At this time, since the engaging protrusion is urged toward the engaging groove by the elastic deformation portion, the engagement is reliably maintained, and there is no fear of the shield plate falling off.
As a result, the annular space defined between the outer ring and the inner ring can be closed with a shield plate, dust and the like can be mixed inside, and grease and lubricating oil can leak to the outside. Can be suppressed.
And since the elastic deformation part is formed in the cantilever shape, it can be made to be easily elastically deformed in the in-plane direction of a shield main body. Therefore, it is possible to weaken the pressing force by which the engaging protrusions press the outer ring radially outward, and to make it difficult to cause unauthorized deformation of the outer ring.

  By the way, the elastic deformation part protrudes toward the outer ring along the in-plane direction of the shield body from the outer peripheral edge part of the shield body, and an engagement protrusion is formed on a part thereof. Therefore, unlike conventional ones, it is possible to freely and easily design the size and shape of the engaging protrusion in the surface without being restricted by the thickness of the rolling bearing or the thickness of the shield plate. It is possible to reduce the deformation amount of the elastic deformation portion.

Therefore, the urging force of the elastic deformation portion can be suppressed, and the pressing force that the engaging projection presses the outer ring radially outward can be weakened. Therefore, it is possible to make the outer ring difficult to cause unauthorized deformation that swells radially outward. Therefore, it is easy to maintain the roundness of the outer ring, and harmful vibrations and load torque fluctuations hardly occur.
Further, no separate parts such as a C-ring are required, and the shield plate can be securely attached to the outer ring with one part of the shield plate, so that the cost is not increased.

(2) In the rolling bearing of the present invention, the engaging groove is formed to open to the opening edge side of the outer ring, and is parallel to the in-plane direction of the shield plate and the inner circumference of the outer ring. A bottom wall portion continuous to the surface and an inner wall portion connecting the bottom wall portion and the opening edge, and a portion of the inner wall portion connected to the opening edge is It is formed in a tapered shape that gradually decreases in diameter from the opening edge toward the bottom wall portion, and elastically deforms the elastic deformation portion toward the shield body while guiding the engagement protrusion into the engagement groove portion. It may be a guide surface.

In this case, since the engaging groove is opened on the opening edge side of the outer ring, the shield plate can be easily attached to the outer ring, for example, with one touch.
That is, when the shield plate is overlapped with the outer ring so as to close the annular space defined between the outer ring and the inner ring, the engagement protrusion of the shield plate is formed at the inlet side portion of the inner wall portion of the engagement groove. Touch a certain guide surface. When the shield plate is pushed into the annular space, the engaging projection is guided into the engaging groove while contacting the guide surface, and then comes into contact with the bottom wall.

In particular, since the inlet side portion of the inner wall portion serves as a guide surface, the elastic deformation portion can be naturally elastically deformed toward the shield body along the in-plane direction of the shield body as the shield plate is pushed. . Then, at the same time, the elastically deforming portion is elastically returned by the elastic restoring force, and urges the engaging protrusion to be pressed against the inner wall portion side. Thereby, a shield board can be engaged in the groove part for engagement, and it can be made to mount with respect to an outer ring | wheel.
As described above, since the engaging groove is open on the opening edge side of the outer ring, the mounting operation to the outer ring can be performed by a simple operation by simply pushing the shield plate.

(3) Further, in the rolling bearing according to the present invention, a portion of the inner wall portion that is continuously provided on the bottom wall portion side gradually increases in diameter from the opening edge toward the bottom wall portion. It may be a lead-in surface formed on the surface.

  In this case, when the shield plate is pushed in and the engagement protrusion is brought into contact with the bottom wall portion, the engagement protrusion can be hooked on the pull-in surface of the inner wall portion, and the engagement state in the engagement groove portion can be further increased. You can be sure.

(4) In the rolling bearing of the present invention, the engagement groove may be formed in an annular shape over the entire inner peripheral surface of the outer ring.

  In this case, since the shield plate can be attached to the outer ring without worrying about the relative positional relationship between the outer ring and the shield plate in the circumferential direction, the assembly is excellent.

(6) In the rolling bearing of the present invention, the elastically deformable portion is bent at least once in the middle from the base end portion toward the tip end portion, and extends along the outer peripheral edge portion of the shield body. The existing portions may be formed so as to be arranged in parallel toward the radially outer side of the shield body.

  In this case, it is possible to prevent the elastically deforming portion from extending long in the circumferential direction of the shield body. Therefore, it is easy to arrange the elastically deforming portions at multiple points on the outer peripheral edge of the shield body. Therefore, stability when the shield plate is attached can be improved. Further, by increasing the number of elastic deformation portions, it is possible to weaken the pressing force that one engaging projection acts on the outer ring, so that the outer ring is hardly deformed and contributes to the maintenance of roundness. easy.

(7) In the rolling bearing of the present invention, the elastically deforming portions are arranged at equal intervals along the circumferential direction on the outer peripheral edge of the shield body, and the number thereof is a prime number of 3 or more. May be.

  In this case, the elastically deformable portions can be arranged at equal intervals along the circumferential direction without facing the radial direction across the rotation axis of the outer ring. Therefore, the pressing force is not transmitted simultaneously from the engaging protrusion to the portion of the outer ring facing the radial direction across the rotation axis. Therefore, it is easy to contribute to maintaining the roundness of the outer ring.

(8) In the rolling bearing of the present invention described above, the number of the elastically deformable 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 elastic deformation portions can be in a relatively prime relationship, that is, a relationship having no common divisor other than 1, the rolling bearing can be arranged in the direction of the rotation axis. Arrangement pattern in which all rolling elements and all elastic deformation parts overlap in the thickness direction of the rolling bearing when viewed from the above, or arrangement pattern in which all rolling elements and all elastic deformation parts do not overlap in the thickness direction It will not become.
If the number of rolling elements and the number of elastically deforming parts are the same, the two arrangement patterns appear alternately during use. In this case, the pressure difference applied to the outer ring by the two arrangement patterns becomes large, and an adverse effect that causes unauthorized deformation of the outer ring is likely to occur.
However, since the number of rolling elements and the number of elastic deformation portions can be made relatively prime to each other, the two arrangement patterns can be prevented from appearing alternately during use.

(9) Further, a bearing device according to the present invention includes the rolling bearing according to the present invention, a shaft formed in a columnar shape to which the inner ring is fixed, and 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 rotated relatively without causing harmful vibrations and fluctuations in load torque. Therefore, a high-performance bearing device can be obtained. Moreover, since the rolling bearing which is difficult to raise cost is provided, it is easy to make a low-cost bearing device.

(9) Further, an information recording / reproducing apparatus according to the present invention supports the head gimbal assembly by being externally fitted to the bearing device of the present invention and capable of rotating around the shaft together with the sleeve. A carriage having an arm part, a rotation driving part for rotating the magnetic recording medium in a fixed direction, 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 having.

  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. In addition, since a low-cost bearing device is provided, it is easy to reduce the price as well.

According to the rolling bearing of the present invention, the cost is not increased, and it is possible to prevent the outer ring from being illegally deformed. The roundness of the outer ring is maintained, and harmful vibration and load torque fluctuation occur. Can be difficult.
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 of the pivot axis | shaft of the information recording / reproducing apparatus 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 a top view of the shield board which comprises the rolling bearing shown in FIG. It is sectional drawing of the shield board along the BB line shown in FIG. It is a figure which shows 1 process at the time of mounting | wearing the outer ring with the shield board shown in FIG. 5, Comprising: (a) is the fragmentary top view which piled up the shield board on the outer ring, (b) is C shown to (a). It is sectional drawing along the -C line. It is a figure which shows the state which pushed in the shield board from the state shown in FIG. 7, Comprising: (a) is a fragmentary top view, (b) is sectional drawing along the DD line | wire shown to (a). It is a figure which shows the state which pushed the shield board further from the state shown in FIG. 8, Comprising: (a) is a partial top view, (b) is sectional drawing along the EE line shown to (a). . It is a top view which shows the modification of the elastic deformation part of a shield board. It is a top view which shows another modification of the elastic deformation part of a shield board. It is a top view which shows the state which elastically deformed the elastic deformation part shown in FIG. 11 using the exclusive tool. It is a top view which shows the state which inserted the shield board in the annular space defined between the outer ring | wheel and the inner ring | wheel after the state shown in FIG. It is a top view which shows the state which pulled out the exclusive tool after the state shown in FIG. 13, and attached the shield board to the outer ring | wheel. It is a top view which shows another modification of the elastic deformation part of a shield board.

  Hereinafter, embodiments according to the present invention will be described with reference to FIGS. 1 to 15. 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 FIG. 2, the pivot shaft 10 includes a substantially cylindrical shaft 20 erected on the bottom portion 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.

The shaft 20 is a substantially cylindrical rod-shaped member extending along the rotation axis L2, and the bottom 9a side of the housing 9 is a base end portion, and the opposite side along the axial direction is a tip end portion.
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 (not shown) is formed on the reduced diameter portion 20 b and is screwed to a female screw (not shown) 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 substantially 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. Further, while the two rolling bearings 22 in the sleeve 21 are disposed, a spacer portion 21a that holds the distance between the rolling bearings 22 at a predetermined distance in the axial direction protrudes radially inward. .
The sleeve 21 is integrally combined with the carriage 2 by being press-fitted or adhesively fitted into a mounting hole (not shown) formed in the base portion 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 and 4, 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. Further, these rolling elements 32 are held so as to be able to roll by a retainer (not shown), and the number thereof is 7 which is a prime number of 2 or more.

  Further, the shield plate 33 of the present embodiment is attached to the outer ring 31 so as to close the annular space defined between the inner ring 30 and the outer ring 31 from the opening side of the sleeve 21 (see FIG. 2). ). Specifically, the shield plate 33 is attached to the outer ring 31 by engaging a plurality of engaging projections 37 with the engaging groove portion 40 formed in the outer ring 31.

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

  First, as shown in FIGS. 5 and 6, the shield plate 33 includes an annular shield body 35 extending along a plane orthogonal to the rotation axis L <b> 2, and an outer peripheral edge portion of the shield body 35 in the circumferential direction. A plurality of elastic deformation portions 36 arranged along the elastic deformation portions 36 and engagement protrusions 37 formed on each of the elastic deformation portions 36 are configured.

  The shield body 35 is formed so that the inner peripheral edge surrounds the inner ring 30 from the outer side in the radial direction and the outer peripheral edge faces the outer ring 31 (see FIGS. 3 and 4). The step is formed to become.

A plurality of elastic deformation portions 36 are arranged at equal intervals along the circumferential direction on the outer peripheral edge portion of the shield body 35. In the present embodiment, five are arranged. Therefore, the number of rolling elements 32 (seven) and the number of elastic deformation portions 36 (five) have a prime relationship with each other.
These elastic deformation portions 36 project from the outer peripheral edge of the shield main body 35 toward the outer ring 31 along the in-plane direction of the shield main body 35, and in the in-plane direction as indicated by arrows in FIGS. It can be elastically deformed. Specifically, the elastic deformation portion 36 extends along the outer peripheral edge portion of the shield body 35, the base end portion 36a is connected to the outer peripheral edge portion of the shield main body 35, and the distal end portion 36b is a free end. It is cantilevered. As a result, the entire elastic deformation portion 36 is elastically deformed in the in-plane direction with the base end portion 36a as a base point. At this time, in particular, the tip portion 36b is positively elastically deformed.

An engagement protrusion 37 that is engaged with the engagement groove 40 is formed at the distal end portion 36 b of the elastic deformation portion 36. The engagement protrusion 37 is formed so as to protrude outward in the radial direction.
As shown in FIGS. 3 and 4, the engagement protrusion 37 is fitted in the engagement groove portion 40 of the outer ring 31 and is inserted into the engagement groove portion 40 along the in-plane direction by the elastic deformation portion 36. It is energized. As a result, the engagement protrusion 37 is reliably engaged in the engagement groove 40, and as a result, the shield plate 33 is attached to the outer ring 31.

  As shown in FIG. 5, the elastically deforming portion 36 is formed in a tapered shape that gradually increases in width from the substantially intermediate portion toward the tip portion 36b, and the engagement protrusion 37 is formed by the taper portion 36c. This prevents it from protruding locally.

Subsequently, as shown in FIG. 3 and FIG. 4, the engaging groove portion 40 of the present embodiment is formed in an annular shape over the entire inner peripheral surface of the outer ring 31, opens to the inner peripheral surface side, and opens to the outer ring. It is formed in a stepped shape so as to open to the opening edge side of 31.
That is, the engaging groove portion 40 includes a bottom wall portion 41 that is parallel to the in-plane direction of the shield plate 33 and that is connected to the inner peripheral surface of the outer ring 31, and the bottom wall portion 41 and the opening edge of the outer ring 31. It is defined by the inner wall 42 that is continuously provided.

A portion of the inner wall portion 42 that is connected to the opening edge is formed in a tapered shape that gradually decreases in diameter from the opening edge toward the bottom wall portion 41, and the engagement protrusion 37 is formed in the engagement groove portion 40. The guide surface 42a is configured to elastically deform the elastic deformation portion 36 toward the shield main body 35 while guiding to the side.
Further, a portion of the inner wall portion 42 that is connected to the bottom wall portion 41 side is a drawing surface 42 b that is formed in a reverse tapered shape that gradually increases in diameter from the opening edge toward the bottom wall portion 41.

(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.
In the case of the present embodiment, since the engaging groove portion 40 is also opened on the opening edge side of the outer ring 31, the shield plate 33 can be easily mounted by one touch, for example.

  First, when the shield plate 33 is overlaid on the outer ring 31 so as to close the annular space defined between the outer ring 31 and the inner ring 30, as shown in FIGS. 7 (a) and 7 (b). The engagement protrusion 37 of the shield plate 33 contacts the guide surface 42 a that is the inlet side portion of the inner wall portion 42 of the engagement groove portion 40. Then, when the shield plate 33 is pushed into the annular space from this state, the engaging protrusion 37 is guided into the engaging groove portion 40 while being in contact with the guide surface 42a, and then comes into contact with the bottom wall portion 41.

Particularly, since the inlet side portion of the inner wall portion 42 is a guide surface 42a, as shown in FIGS. 8 (a) and 8 (b), the elastic deformation portion 36 is moved to the shield body as the shield plate 33 is pushed. It can be naturally elastically deformed toward the shield main body 35 along the in-plane direction of 35. In particular, since the tapered portion 36c of the elastic deformation portion 36 and the guide surface 42a are in contact with each other, the elastic deformation portion 36 can be elastically deformed by light pushing.
Then, at the same time, the elastic deformation portion 36 is elastically returned by the elastic restoring force, and urges the engagement protrusion 37 to be pressed against the inner wall portion 42 side. As a result, the shield plate 33 can be reliably engaged in the engaging groove portion 40, and can be attached to the outer ring 31 without fear of the shield plate 33 falling off.
Moreover, when the shield plate 33 is pushed in and the engagement protrusion 37 is brought into contact with the bottom wall portion 41, the engagement protrusion 37 is pulled into the drawing surface of the inner wall portion 42 as shown in FIGS. 9 (a) and 9 (b). 42b can be hooked, and the engagement state in the engaging groove 40 can be made more reliable.

As described above, since the engaging groove portion 40 is open on the opening edge side to the outer ring 31, the mounting operation to the outer ring 31 can be performed by a simple operation by simply pushing the shield plate 33.
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 and the like can be mixed inside, and grease and lubricating oil can be removed from the outside. It is possible to suppress the leakage.

In particular, according to the rolling bearing 22 of the present embodiment, unlike the conventional one, the size and shape of the engagement protrusion 37 can be reduced without being limited by the thickness of the rolling bearing 22 or the thickness of the shield plate 33. In addition to being able to design freely and easily in the plane of 35, the amount of deformation of the elastic deformation portion 36 can be reduced.
Therefore, the urging force of the elastic deformation portion 36 can be suppressed, and the pressing force that the engaging projection 37 presses the outer ring 31 radially outward via the inner wall portion 42 can be weakened. Therefore, it is possible to make it difficult to cause the outer ring 31 to be illegitimately deformed so as to bulge outward in the radial direction. In addition, since the elastic deformation portion 36 of the present embodiment is formed in a cantilever shape, it can be easily elastically deformed in the in-plane direction of the shield body 35. Therefore, it is possible to weaken the pressing force with which the engaging protrusion 37 presses the outer ring 31 radially outward, and it is possible to make it more difficult to cause the outer ring 31 to be illegally deformed.

  For these reasons, according to the rolling bearing 22 of the present embodiment, the roundness of the outer ring 31 can be easily maintained, and harmful vibrations and fluctuations in load torque are unlikely to occur. Further, since the pressing force can be weakened, it is difficult to cause an appearance defect such as distortion in the shield plate 33 and the possibility of contact with other parts (for example, a cage) is small. Furthermore, since a separate component such as a C-ring is not required and the shield plate 33 can be securely attached to the outer ring 31 with one component of the shield plate 33, the cost is not increased.

Further, since the engaging groove portion 40 is formed in an annular shape over the entire inner peripheral surface of the outer ring 31, the shield can be used without worrying about the relative positional relationship between the outer ring 31 and the shield plate 33 in the circumferential direction. Since the plate 33 can be easily attached to the outer ring 31, it is excellent in assemblability.
Further, five elastically deforming portions 36 are formed at equal intervals along the outer peripheral edge portion of the shield plate 33, so that they do not face each other across the rotation axis L2 as shown in FIG. Therefore, the pressing force is not transmitted simultaneously from the engagement protrusion 37 to the portion of the outer ring 31 that faces the radial direction across the rotation axis L2. Therefore, it is easy to contribute to maintaining the roundness of the outer ring 31.

Furthermore, since the number of the rolling elements 32 is seven and the number of the elastically deforming portions 36 is five, both are in 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 elastic deformation portions 36 do not have an arrangement pattern that does not overlap in the thickness direction of the rolling bearing 22.
If the number of the rolling elements 32 and the elastic deformation portions 36 is the same number of five, the two arrangement patterns appear alternately during use. In this case, the pressure difference applied to the outer ring 31 by the two arrangement patterns becomes large, and an adverse effect that causes unauthorized deformation of the outer ring 31 is likely to occur. However, since the number of the rolling elements 32 and the number of the elastic deformation portions 36 are a prime combination, it is possible to prevent the two arrangement patterns from appearing alternately during use.

  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 smoothly and relatively rotated without causing harmful vibrations and fluctuations in load torque. . Therefore, a high-performance pivot shaft 10 can be obtained. Moreover, since it is also the rolling bearing 22 which is hard to invite high cost, it is easy to achieve cost reduction.

  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. In addition, since the pivot shaft 10 is inexpensive, it is easy to reduce the price.

  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 having near-field light has been described as an example. The present invention can be applied to a bearing device and a rotating shaft portion of various devices.

  In the above embodiment, 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. Alternatively, two shield plates 33 may be mounted so as to be positioned on both sides of 32, and both sides of the annular space defined between the outer ring 31 and the inner ring 30 may be closed.

  Moreover, although the number of the elastic deformation parts 36 of the shield plate 33 is five, it is not limited to this number and may be set freely. However, it is preferable to use a prime number of 3 or more from the viewpoint of being able to be arranged without facing the radial direction across the rotation axis L2 and easily contributing to the roundness of the outer ring 31.

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.
However, it is preferable that the number of the elastic deformation portions 36 and the number of the rolling elements 32 are combined so as to have a relatively prime relationship. For example, as described above, not only is the combination of prime numbers such that the number of elastic deformation portions 36 is 5 and the number of rolling elements 32 is 7, but the number of elastic engagement protrusions 36 is 5 and the number of rolling elements 32 is Combinations of prime numbers and odd numbers such as 9 are possible, combinations of odd numbers such that the number of elastic deformation portions 36 is 9 and the number of rolling elements 32 is 25 are possible, and elastic deformation portions 36 are also possible. A combination of an odd number and an even number such that the number of rolling elements 32 is 16 is possible.

Moreover, although the engaging groove portion 40 is formed in an annular shape over the entire inner peripheral surface of the outer ring 31, a plurality of engaging groove portions 40 may be formed at intervals along the circumferential direction instead of the annular shape. In this case, there is an advantage that it is easy to restrict the shield plate 33 from rotating in the circumferential direction with respect to the outer ring 31 after the shield plate 33 is attached to the outer ring 31.
However, since the shield plate 33 can be attached to the outer ring 31 without worrying about the relative positional relationship between the outer ring 31 and the shield plate 33 in the circumferential direction, it is preferable to form the engaging groove 40 in an annular shape.

Moreover, in the said embodiment, although the case where the elastic deformation part 36 was formed in the cantilever shape extended along the outer-periphery edge part of the shield main body 35 toward the front-end | tip part 36b from the base end part 36a was illustrated as an example, As shown in FIG. 10, the portion that is bent approximately 180 degrees once along the direction from the base end portion 36 a to the tip end portion 36 b and extends along the outer peripheral edge of the shield main body 35 is radially outside the shield main body 35. You may form so that it may line up in parallel toward the direction.
By doing so, it is possible to prevent the elastic deformation portion 36 from extending long in the circumferential direction of the shield body 35, so that the elastic deformation portions 36 can be easily arranged at multiple points on the outer peripheral edge portion of the shield body 35. Therefore, the stability when the shield plate 33 is attached can be improved. Further, by increasing the number of elastic deformation portions 36, it is possible to weaken the pressing force that one engaging projection 37 acts on the outer ring 31, so that the outer ring 31 is less likely to be improperly deformed, and the roundness is reduced. Easy to contribute to maintenance.
The bending of the elastic deformation portion 36 is not limited to one time, and may be bent two or more times to form a bellows shape.

  In addition, as shown in FIG. 11, the two elastically deformable portions 36 may be arranged so that the base end portions 36 a are common, and may extend in opposite directions in the circumferential direction. In this case, since the two engaging projections 37 can be brought close to each other, the shield plate 33 can be easily mounted stably.

  By the way, in the above embodiment, when the shield plate 33 is attached to the outer ring 31, the engagement projection 37 is engaged by pushing the shield plate 33 into an annular space formed between the outer ring 31 and the inner ring 30. Although engaged with the groove portion 40, the elastic deformation portion 36 may be deformed in advance using a dedicated tool, and the engagement protrusion 37 may be engaged with the engagement groove portion 40.

  For example, taking the shield plate 33 having the elastic deformation portion 36 shown in FIG. 11 as an example, first, as shown in FIG. 12, while applying a semi-cylindrical grip G to the base end portion 36a of each elastic deformation portion 36, The shield body 35 is sandwiched and gripped from the outside in the radial direction. By this gripping, the elastic deformation portion 36 is elastically deformed toward the outer peripheral edge side of the shield body 35 along the in-plane direction of the shield body 35.

  Next, as shown in FIG. 13, the grip G is pulled out after the gripped shield plate 33 is inserted into an annular space defined between the outer ring 31 and the inner ring 30. Then, since the elastic deformation part 36 is elastically returned by the elastic restoring force, the engagement protrusion 37 is urged radially outward. As a result, as shown in FIG. 14, the engagement protrusion 37 can be engaged with the engagement groove 40, and the shield plate 33 can be securely attached to the outer ring 31.

  In particular, when a dedicated tool such as the grip G is used, the engaging groove 40 does not have to be opened on the opening edge side of the outer ring 31. That is, the engaging groove 40 may be formed so as to open only on the inner peripheral surface side of the outer ring 31. However, it is preferable that the engaging groove portion 40 is opened on the opening edge side of the outer ring 31 because the shield plate 33 can be attached with one touch without using a dedicated tool.

In the above embodiment, the elastically deforming portion 36 is formed in a cantilever shape. However, the present invention is not limited to this case, and the outer ring 31 extends from the outer peripheral edge portion of the shield body 35 along the in-plane direction of the shield body 35. As long as it projects toward the surface and can be elastically deformed in the in-plane direction, it may be designed freely.
For example, as shown in FIG. 15, both ends may be connected to the outer peripheral edge of the shield body 35, and the elastic deformation portion 36 may be formed so as to define a through hole 38 between the shield body 35. . In this case, the engagement protrusion 37 may be formed on a part of the elastic deformation portion 36.
Even in this case, it is possible to elastically deform the elastic deformation portion 36 toward the shield main body 35 using the space of the through hole 38, and the same effects can be obtained.

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)
DESCRIPTION OF SYMBOLS 20 ... Shaft 21 ... Sleeve 22 ... Rolling bearing 30 ... Inner ring 31 ... Outer ring 32 ... Rolling body 33 ... Shield plate 35 ... Shield main body 36 ... Elastic deformation part 37 ... Engagement protrusion 40 ... Engaging groove part 41 ... Bottom of engaging groove part Wall 42 ... Inner wall 42a of the engaging groove 42a ... Guide surface 42b ... Retracting surface

Claims (9)

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;
An annular ring formed on the inner circumferential surface of the outer ring along the circumferential direction and engaged with an engaging groove that opens to the inner circumferential surface side to block the annular space defined between the inner ring and the outer ring. And a shield plate,
The shield plate is
An annular shield body whose inner peripheral edge surrounds the inner ring from the radially outer side and whose outer peripheral edge faces the outer ring;
A plurality of outer peripheral edges of the shield body are disposed along the circumferential direction, projecting from the outer peripheral edge along the in-plane direction of the shield body toward the outer ring and elastically deformable in the in-plane direction. An elastically deformable part,
An engagement protrusion formed at a part of the elastic deformation portion, formed at a distal end portion of the elastic deformation portion, and engaged with the engagement groove portion,
The elastic deformation portion is formed in a cantilever shape having a base end portion connected to the outer peripheral edge portion of the shield body and extending along the outer peripheral edge portion of the shield body and having a distal end portion as a free end. , the rolling bearing, characterized in that said engaging projection along the plane direction and urges the groove side for the engagement. The rolling bearing according to claim 1,
The engaging groove is formed so as to open to the opening edge side of the outer ring, is parallel to the in-plane direction of the shield plate, and is connected to the inner peripheral surface of the outer ring, and the bottom And an inner wall portion connecting the wall portion and the opening edge,
A portion of the inner wall portion that is continuous with the opening edge is formed in a tapered shape that gradually decreases in diameter from the opening edge toward the bottom wall portion, and the engagement protrusion is formed in the engagement groove portion. A rolling bearing characterized by being a guide surface that elastically deforms the elastic deformation portion toward the shield body while guiding. The rolling bearing according to claim 2,
A portion of the inner wall portion that is continuously provided on the bottom wall portion side is a pull-in surface formed in a reverse taper shape that gradually increases in diameter from the opening edge toward the bottom wall portion. Rolling bearing. In the rolling bearing according to any one of claims 1 to 3,
The rolling bearing according to claim 1, wherein the engaging groove is formed in an annular shape over the entire inner peripheral surface of the outer ring. In the rolling bearing according to any one of claims 1 to 4,
The elastically deforming portion is bent at least once in the middle from the base end portion to the tip end portion, and a portion extending along the outer peripheral edge portion of the shield body is directed radially outward of the shield body. Rolling bearings characterized by being arranged in parallel. In the rolling bearing according to any one of claims 1 to 5 ,
The rolling bearing according to claim 1, wherein the elastically deforming portions are arranged at equal intervals along the circumferential direction on the outer peripheral edge of the shield body, and the number thereof is a prime number of 3 or more . In the rolling bearing according to any one of claims 1 to 6,
The rolling bearing according to claim 1, wherein the number of the elastically deforming portions and the number of the rolling elements are in a prime relationship . 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. A bearing device according to claim 8,
  A carriage externally fitted to the sleeve and rotatable around the shaft together with the sleeve, and having an arm portion for supporting a head gimbal assembly;
  A rotation drive unit that rotates the magnetic recording medium in a certain direction;
  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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