JP5891071B2 - Rolling bearing, bearing device, information recording / reproducing device, and method of manufacturing rolling bearing - Google Patents

Description

  The present invention relates to a rolling bearing, a bearing device, an information recording / reproducing apparatus, and a method for manufacturing a rolling bearing.

  Some rolling bearings have an annular shield plate that closes an annular space between an inner ring and an outer ring. The shield plate includes an annular cover plate portion that is disposed along the radial direction and covers the annular space, and extends obliquely inward in the axial direction and outward in the radial direction from the outer peripheral edge portion of the cover plate portion. An intermediate plate portion that protrudes, a contact plate portion extending radially outward from the outer peripheral edge portion of the intermediate plate portion, and an axially outward and radial direction outer side from the outer peripheral edge portion of the contact plate portion. Those having locking projections extending obliquely in the direction are used. The shield plate is supported by the outer ring by contacting the stepped portion with the contact plate at the stepped portion and the contact surface with the locking projection formed in the locking groove formed in the outer ring. (For example, refer to Patent Document 1).

JP 2002-89574 A

  In the shield plate having the above shape, there may be a case where a sufficient annular space cannot be secured. In particular, when a reduction in size including a reduction in thickness of the rolling bearing in the thickness direction is attempted, the annular space cannot be secured, and there is a possibility of interfering with a cage or grease separated through the annular space.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a rolling bearing, a bearing device, an information recording / reproducing device, and a rolling bearing manufacturing method that can be downsized.

  A rolling bearing according to the present invention includes an inner ring, an outer ring surrounding the inner ring, a plurality of rolling elements that are rotatably held between the inner ring and the outer ring, and between the inner ring and the outer ring. An annular shield plate for closing the annular space, and the inner ring or the outer ring has a circumferential wall surface along the axial direction on the annular space side in the radial direction at an outer end in the axial direction, and an axial direction of the circumferential wall surface In a rolling bearing provided with a shield plate mounting portion having a step surface extending from the inner side to the annular space side along the radial direction, the shield plate is arranged along the radial direction to form the annular space. An annular cover plate portion that covers the outer peripheral surface of the cover plate portion, and a spring plate portion that extends inward in the axial direction from a peripheral portion on the peripheral wall surface side of the cover plate portion and presses and contacts the peripheral wall surface. .

  According to this rolling bearing, the spring plate portion extending inward in the axial direction from the peripheral edge portion on the peripheral wall surface side of the cover plate portion covering the annular space is pressed into contact with the peripheral wall surface along the axial direction of the shield plate mounting portion. By doing so, since the shield plate is supported by the shield plate attachment portion, the annular space between the shield plate and the step surface along the radial direction of the shield plate attachment portion can be enlarged. Therefore, a sufficient annular space can be secured. As a result, for example, even if a reduction in size including a reduction in thickness is achieved, the possibility that the shield plate and the cage or grease interfere with each other can be reduced, and thus the reduction in size can be achieved.

Further, in the rolling bearing according to the present invention, a plurality of the spring plate portions are provided at intervals, and each of the spring plate portions has leg plate portions at both ends having a long protruding length from the cover plate portion, and It has the connection board part with a short protrusion length from the said cover board part which connects these leg board parts .

  Thus, each of the spring plate portions forms leg plate portions having a long protruding length from the cover plate portion at both ends, and these leg plate portions are connected to each other by a connecting plate portion having a short protruding length from the cover plate portion. Since it is a structure, the circumferential direction length of the leg board part of both ends can be restrained. Therefore, it is easy to give these leg plate portions good spring properties. Moreover, although the protrusion length from a cover board part is shortened, the leakage of grease can be suppressed by connecting the leg board parts of both ends with a connection board part.

  The bearing device according to the present invention is characterized in that the inner ring of the rolling bearing is fitted on a shaft.

  According to this bearing device, since the rolling bearing can be reduced in size, the overall size can be reduced.

  In addition, the bearing device according to the present invention includes a first rolling bearing disposed on the shaft as the rolling bearing on one side in the axial direction and provided with the shield plate on the one side, and the other in the axial direction. It is preferable that the 2nd rolling bearing arrange | positioned by providing the said shield board in the other side is provided in this side.

  Thereby, since both a 1st rolling bearing and a 2nd rolling bearing can be reduced in size, the whole can be reduced in size effectively.

  An information recording / reproducing apparatus according to the present invention includes the bearing device, a carriage that is externally fitted to the outer ring, 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 unit that rotates the magnetic recording medium; and an actuator that rotates the carriage and moves the head gimbal assembly in a direction parallel to the surface of the magnetic recording medium. .

  According to this information recording / reproducing apparatus, since the bearing device can be reduced in size, the entire size can be reduced.

  A rolling bearing manufacturing method according to the present invention is a rolling bearing manufacturing method described above, using a mounting table having a circular mounting surface and a holding jig having a cylindrical holding wall, The step of placing the shield plate on the mounting surface by the cover plate portion while wrapping the spring plate portion on the mounting table in the axial direction, and the holding jig being wrapped on the mounting table in the axial direction The step of deforming the spring plate portion to the cover plate portion side in the radial direction by the holding wall surface and fitting the shield plate to the holding jig, and the holding wall surface and the peripheral wall surface are axial. A step of sliding the shield plate from the holding wall surface to the peripheral wall surface so as to be in contact with each other in the direction and pressing the spring plate portion against the peripheral wall surface.

  According to this manufacturing method, after the shield plate is placed on the placement surface of the mounting table at the cover plate portion, the holding jig is wrapped by the holding wall surface in the axial direction with respect to the mounting table. The shield plate is fitted and held by deforming the spring plate portion toward the cover plate portion side in the radial direction. Thereafter, the shield plate can be attached to the shield plate mounting portion by sliding the shield plate from the holding wall surface to the peripheral wall surface with the holding wall surface of the holding jig and the peripheral wall surface of the shield plate mounting portion adjacent to each other in the axial direction. Therefore, the shield plate can be easily and properly attached to the shield plate attachment portion.

  According to the rolling bearing, the bearing device, the information recording / reproducing apparatus, and the method for manufacturing the rolling bearing according to the present invention, the size can be reduced.

1 is a perspective view showing a first embodiment of an information recording / reproducing apparatus according to the present invention. It is a longitudinal section showing a pivot shaft which is a first embodiment of a bearing device according to the present invention. It is a longitudinal section showing a 1st embodiment of a rolling bearing concerning the present invention. It is a perspective view which shows the shield board of the rolling bearing shown in FIG. It is a top view which shows the shield board of the rolling bearing shown in FIG. 3 shows a shield plate of the rolling bearing shown in FIG. 3, wherein (a) is a sectional view taken along the line X1-X1 shown in FIG. 5, and (b) is a sectional view taken along the line X2-X2 shown in FIG. FIGS. 3A and 3B show a manufacturing method of the rolling bearing shown in FIG. 3, wherein (a) is a longitudinal sectional view showing a shield plate placing step and (b) is a shield plate holding step. FIGS. 3A and 3B show a method for manufacturing the rolling bearing shown in FIG. 3, wherein FIG. 3A is a longitudinal sectional view showing a front stage of a shield plate attaching step, and FIG. It is a longitudinal cross-sectional view which shows the modification of 1st Embodiment of the rolling bearing which concerns on this invention. The manufacturing method of 2nd Embodiment of the rolling bearing which concerns on this invention is shown, (a) is a shield board mounting process, (b) is a shield board holding process, (c) is a shield board attachment process, It is a longitudinal cross-sectional view shown, respectively. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the rolling bearing which concerns on this invention. It is a longitudinal cross-sectional view which shows the shield board mounting process of 3rd Embodiment of the rolling bearing which concerns on this invention. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the rolling bearing which concerns on this invention. It is a longitudinal cross-sectional view which shows the shield board mounting process of 4th Embodiment of the rolling bearing which concerns on this invention. It is a longitudinal cross-sectional view which shows 4th Embodiment of the rolling bearing which concerns on this invention. It is a longitudinal cross-sectional view which shows 5th Embodiment of the rolling bearing which concerns on this invention. The manufacturing method of 5th Embodiment of the rolling bearing which concerns on this invention is shown, (a) is a shield board mounting process, (b) is a shield board holding process, (c) is a shield board attachment process, It is a longitudinal cross-sectional view shown, respectively. It is a longitudinal cross-sectional view which shows 6th Embodiment of the rolling bearing which concerns on this invention. It is a perspective view which shows the shield board of the rolling bearing shown in FIG.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following embodiment, a case will be described in which the bearing device constitutes the pivot shaft of the information recording / reproducing device, and the rolling bearing is used for the pivot shaft.

  As shown in FIG. 1, an information recording / reproducing apparatus 1 according to the first embodiment is an apparatus for writing on a disk (magnetic recording medium) D having a vertical recording layer by a vertical recording method. A laser light source 4 for supplying a light beam from the base end side of the carriage 2 through the optical waveguide 3, a head gimbal assembly (HGA) 5 supported on the tip end side of the carriage 2, and the carriage 2 are rotated to make a head gimbal assembly. 5 for scanning and moving the disk 5 in a horizontal plane parallel to the disk surface (the surface of the disk D) D1, a spindle motor (rotation drive unit) 7 for rotating the disk D in a fixed direction around the rotation axis L1, and information And a control unit 8 for supplying a current modulated according to the above to the slider 5b of the head gimbal assembly 5, Includes a housing 9 which, a.

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 supported in a connected state at 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.

(First embodiment of bearing device and rolling bearing)
Next, the configuration of the pivot shaft which is the first embodiment of the bearing device according to the present invention and the rolling bearing used therefor will be described with reference to FIGS.

As shown in FIG. 1, the pivot shaft 10 is a bearing device that supports the carriage 2 so as to be rotatable about the rotation axis L <b> 2. As a schematic configuration, the pivot shaft 10 is shown in FIG. 2 erected on the bottom portion 9 a of the housing 9. A substantially cylindrical shaft 20 shown in the figure, a sleeve 21 provided around the radial direction of the shaft 20 and arranged coaxially with the shaft 20 with the rotation axis L2 as a common axis, and the shaft 20 and the sleeve 21 And a pair of rolling bearings (first rolling bearing, second rolling bearing) 22A and 22B interposed therebetween. The carriage 2 described above is rotatable around the axis of the shaft 20.
In the first embodiment, the direction along the rotation axis L2, that is, the axial direction is referred to as “axial direction”, the direction orthogonal to the rotation axis L2, that is, the radial direction is referred to as “radial direction”, and the rotation axis L2 is the center. The direction of circulation is referred to as “circumferential direction”. Further, one side in the axial direction (upper side in FIG. 2) is “upper”, and the other side, that is, the other side in the axial direction (lower side in FIG. 2) is “lower”.

  The shaft 20 is a shaft member that extends in the axial direction about the rotation axis L2. The shaft 20 includes a substantially cylindrical shaft core portion 20a, a flange portion 20b projecting radially outward from a lower end portion of the shaft core portion 20a, and a male screw portion 20c provided vertically on the lower end surface of the shaft core portion 20a. It is equipped with. The flange portion 20b is a ring-shaped flange portion in plan view formed on the outer periphery of the shaft core portion 20a, and the upper surface of the flange portion 20b is such that the inner peripheral portion is higher than the outer peripheral portion. It is formed in a step shape. The male screw portion 20c is a screwed portion having a male screw (not shown) formed on the outer peripheral surface. The male screw portion 20c is screwed into a female screw hole (not shown) formed in the bottom portion 9a (shown in FIG. 1) of the housing 9, so that the shaft 20 is erected on the bottom portion 9a 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 b being in contact with the bottom portion 9 a of the housing 9.

The sleeve 21 is a substantially cylindrical member that is fitted onto outer rings 31A and 31B of rolling bearings 22A and 22B, which will be described later, and the rolling bearing 22A is fitted inside the upper end portion of the sleeve 21 so that the sleeve 21 A rolling bearing 22B is fitted inside the lower end. In addition, on the inner peripheral surface of the axially intermediate portion of the sleeve 21 (the portion between the upper and lower two rolling bearings 22A and 22B), a spacer portion that holds the axial interval between the rolling bearing 22A and the rolling bearing 22B at a predetermined distance. 21a is formed. The spacer portion 21a is an annular convex portion projecting radially inward over the entire circumference, and outer rings 31A and 31B of first and second rolling bearings 22A and 22B, which will be described later, respectively. It is locked. That is, the outer edge of the lower end portion of the outer ring 31A of the upper rolling bearing 22A is locked to the upper end surface of the spacer portion 21a, and the outer edge of the upper end portion of the outer ring 31B of the lower rolling bearing 22B is locked to the lower end surface of the spacer portion 21a. Is locked.
The sleeve 21 is integrally assembled with the carriage 2 by being press-fitted or adhesively fitted inside a mounting hole (not shown) formed in the base 2b of the carriage 2 shown in FIG.

Each of the rolling bearing 22A and the rolling bearing 22B is a bearing with a shield plate that is pivotally supported by the shaft 20, and is mounted on the shaft 20 and arranged side by side in the axial direction. Further, the rolling bearing 22A positioned on the upper side in the axial direction and the rolling bearing 22B positioned on the lower side in the axial direction have the same configuration, and are arranged in directions that are vertically reversed.
Hereinafter, when the description overlaps, only the rolling bearing 22A will be described, and for the rolling bearing 22B having the same configuration, the reference numerals corresponding to the respective reference numerals of the rolling bearing 22A are written in parentheses and the description is omitted.

  As a schematic configuration of the rolling bearing 22A (22B), a plan view annular inner ring 30A (30B) and a plan view annular ring arranged coaxially with the inner ring 30A (30B) with the rotation axis L2 as a common axis. The outer ring 31A (31B), a plurality of rolling elements 32A (32B) held rotatably between the inner ring 30A (30B) and the outer ring 31A (31B), the inner ring 30A (30B) and the outer ring 31A (31B) And an annular shield plate 33A (33B) that closes the annular annular space 34A (34B) in a plan view on one side in the axial direction.

  The inner ring 30A (30B) is a cylindrical cylindrical body that extends in the axial direction around the rotation axis L2, and is externally fitted to the shaft core portion 20a of the shaft 20 shown in FIG.

  A curved groove-shaped rolling surface 40A (40B) into which a plurality of rolling elements 32A (32B) are fitted so as to be capable of rolling is formed on the outer peripheral surface of the central portion in the axial direction of the inner ring 30A (30B). The rolling surface 40A (40B) is an arc-shaped groove portion extending in the circumferential direction along the vertical surface of the rotation axis L2, and extends over the entire circumference of the outer circumferential surface of the inner ring 30A (30B). It is installed.

  In the rolling bearing 22B, which has the same structure as the rolling bearing 22A and is disposed on the lower side, the lower end surface of the inner ring 30B contacts the upper surface 20d of the flange portion 20b of the shaft 20 (the upper surface of the inner peripheral portion of the flange portion 20b). Therefore, the lower end surface of the inner ring 30B of the rolling bearing 22B is locked by the flange portion 20b.

  The outer ring 31A (31B) of the rolling bearing 22A (22B) is a cylindrical cylindrical body that surrounds the inner ring 30A (30B) and extends in the axial direction about the rotation axis L2, and the inner ring 30A (30B). Circumferentially provided radially outward.

  The outer ring 31A (31B) has a radially outer space 34A (34B) side at one outer end (the upper end in FIG. 2 for the outer ring 31A and the lower end in FIG. 2 for the outer ring 31B). A shield plate attachment portion 39A (39B) to which the shield plate 33A (33B) is attached is formed at a certain inner edge portion. The shield plate mounting portion 39A (39B) has a shape in which the inner edge portion of the outer ring 31A (31B) is cut out in a substantially L shape (stepped shape) in cross section, and extends over the entire circumference of the outer ring 31A (31B). Is formed.

  As shown in FIG. 3, the peripheral wall surface 39a (rising surface) along the axial direction of the shield plate mounting portion 39A (39B) is an undercut portion for locking a spring plate portion 36 of a shield plate 33A (33B) described later. The outer cylindrical surface portion 39aa extending from the end surface of the outer ring 31A (31B) toward the axially central side (inner side) with a constant diameter, and the axially central portion from the axially central end of the outer cylindrical surface portion 39aa. A taper-shaped taper surface portion 39ab that is gradually expanded in diameter toward the side, and an inner cylindrical surface portion 39ac that extends from the end of the taper surface portion 39ab in the axial direction center side toward the axial direction center side with a constant diameter. doing. The step surface 39b along the radial direction of the shield plate mounting portion 39A (39B) is formed in the radial direction from the axially central end (inside) end of the peripheral wall surface 39a, that is, the axially central end of the inner cylindrical surface 39ac. Along the annular space 34A (34B) side, that is, radially inward.

  As shown in FIG. 2, on the inner peripheral surface of the axially central portion of the outer ring 31A (31B), the rolling element 32A (32B) faces the rolling surface 40A (40B) of the inner ring 30A (30B). Is formed in a curved groove-shaped rolling surface 41A (41B) that is fitted to be capable of rolling. The rolling surface 41A (41B) is an arc-shaped groove portion extending in the circumferential direction along the vertical surface of the rotation axis L2, and extends over the entire circumference of the inner circumferential surface of the outer ring 31A (31B). It is extended. Further, the rolling surface 41A (41B) of the outer ring 31A (31B) is formed in a shape obtained by inverting the rolling surface 40A (40B) of the inner ring 30A (30B) described above in a longitudinal sectional view.

  Note that the lower end surface of the outer ring 31B of the rolling bearing 22B having the same structure as that of the rolling bearing 22A is separated from the flange portion 20b of the shaft 20, so that the lower surface of the outer ring 31B of the rolling bearing 22B is below the outer ring 31B. The end face is not locked.

The rolling element 32A (32B) is a sphere (ball), and is interposed between the rolling surface 40A (40B) of the inner ring 30A (30B) and the rolling surface 41A (41B) of the outer ring 31A (31B). These rolling surfaces 40A and 41A (40B and 41B) are sandwiched so as to be rotatable from both radial sides. The radius of the rolling element 32A (32B) is slightly smaller than the radius of curvature of the above-described rolling surfaces 40A, 41A (40B, 41B) in the longitudinal sectional view.
Further, a plurality of rolling elements 32A (32B) are arranged in parallel in the circumferential direction, and these rolling elements 32A (32B) are held so as to be able to roll by a retainer 42 shown in FIG. The number is 7 which is a prime number of 2 or more.

  The shield plate 33A (33B) is provided only on one side in the axial direction of the rolling bearing 22A (22B). The shield plate 33A (33B) is press-formed from a stainless steel plate, and the annular space 34A (34B) is formed from the outer end side (opening side of the sleeve 21) of the inner ring 30A (30B) and the outer ring 31A (31B). The sealing plate is a ring-shaped blocking plate that is closed in a plan view, and is attached to the outer ring 31A (31B) by fitting the outer peripheral portion thereof to the shield plate mounting portion 39A (39B) described above. Further, the inner peripheral portion of the shield plate 33A (33B) is separated from the inner ring 30A (30B), thereby allowing relative axial displacement between the inner ring 30A (30B) and the outer ring 31A (31B). Yes.

  As a schematic configuration of the shield plate 33A (33B), an annular flat cover plate portion 35 arranged along a plane orthogonal to the rotation axis L2 and the peripheral wall surface 39a side of the cover plate portion 35 are provided. A plurality of spring plate portions 36 projecting from the outer peripheral edge portion. The cover plate portion 35 is disposed along the radial direction to cover the annular space 34A (34B), and the spring plate portion 36 is bent from the outer peripheral edge portion of the cover plate portion 35 to the cover plate portion 35. It extends inward in the axial direction and presses and contacts the peripheral wall surface 39a of the shield plate mounting portion 39A (39B). The spring plate portion 36 does not have a portion facing outward in the axial direction in the direction away from the cover plate portion 35, and is all directed inward in the axial direction.

  When the shield plate 33A (33B) is attached to the shield plate attachment portion 39A (39B), that is, in a natural state, the whole of the plurality of spring plate portions 36 is pivoted from the cover plate portion 35 as shown in FIG. The taper shape is gradually increased in diameter as it is separated in the direction. A notch portion 37 is formed between the spring plate portions 36 adjacent to each other in the circumferential direction. In other words, a plurality of spring plate portions 36 are intermittently disposed along the outer peripheral edge portion of the cover plate portion 35 in the shield plate 33A (33B). As shown in FIG. 5, the plurality of spring plate portions 36 have an equal length in the circumferential direction of the cover plate portion 35, and are arranged at equal intervals in the circumferential direction.

  Each of the plurality of spring plate portions 36 has leg plate portions 36a having a long projecting length from the cover plate portion 35 shown in FIG. 6A at both ends in the circumferential direction as shown in FIG. The connecting plate portion 36b having a short protrusion length from the cover plate portion 35 shown in FIG. 6B is provided in the middle in the circumferential direction so as to connect the leg plate portions 36a at both ends and the leg plate portions 36a as shown in FIG. doing. Note that the number of the spring plate portions 36 is, for example, five, and the number of the rolling elements 32A (32B) (seven) and the number of the spring plate portions 36 (five) are relatively prime.

  As shown in FIG. 3, in a state where the shield plate 33A (33B) is attached to the shield plate attachment portion 39A (39B), the spring plate portion 36 follows the tapered surface portion 39ab and the inner cylindrical surface portion 39ac of the peripheral wall surface 39a. Become a shape. That is, the spring plate portion 36 has a tapered shape in which the cover plate portion 35 side gradually increases in diameter from the outer peripheral edge portion of the cover plate portion 35 toward the axial center, and the side opposite to the cover plate portion 35 has a constant diameter. It has a cylindrical shape. As a result, when in a natural state, the spring plate portion 36 that has been tapered as a whole presses and contacts the inner cylindrical surface portion 39ac of the peripheral wall surface 39a in the radial direction.

  The spring plate portion 36 is also in pressure contact with the tapered surface portion 39ab of the peripheral wall surface 39a, and is thereby pressed inward in the axial direction, so that the end portion opposite to the cover plate portion 35, that is, the cover plate of the leg plate portion 36a. The end opposite to the portion 35 is in press contact with the step surface 39b of the shield plate mounting portion 39A (39B). In other words, the spring plate portion 36 is undercut fitted to the peripheral wall surface 39a having the tapered surface portion 39ab of the shield plate attachment portion 39A (39B).

  In this manner, the spring plate portion 36 is pressed and brought into contact with the tapered surface portion 39ab and the inner cylindrical surface portion 39ac of the peripheral wall surface 39a of the shield plate attachment portion 39A (39B), and the end opposite to the cover plate portion 35 is shielded. The shield plate 33A (33B) is fitted to the outer ring 31A (31B) by being placed on the stepped surface 39b of the plate attachment portion 39A (39B). Note that the spring plate portion 36 of the shield plate 33A (33B) is wrapped with the cage 42 in the axial direction while being attached to the outer ring 31A (31B).

  As shown in FIG. 2, the shaft 20 includes a rolling bearing 22 </ b> A that is disposed on one side in the axial direction of the shaft 20 as a rolling bearing and provided with a shield plate 33 </ b> A on one side, and the other side in the axial direction. A rolling bearing 22B, which is located on the other side and is provided with a shield plate 33B, is mounted.

  Preload is applied in the axial direction of the shaft 20 to the inner ring 30A of the rolling bearing 22A and the inner ring 30B of the rolling bearing 22B. As a result, the rolling surface 40A of the inner ring 30A of the rolling bearing 22A and the rolling bearing 22B are applied. The axial distance T1 between the inner ring 30B and the rolling surface 40B in the axial direction is smaller than the axial distance T2 between the rolling surface 41A of the outer ring 31A of the rolling bearing 22A and the rolling surface 41B of the outer ring 31B of the rolling bearing 22B. ing.

  In other words, the axial interval T1 between the rolling surface 40A of the inner ring 30A of the rolling bearing 22A and the rolling surface 40B of the inner ring 30B of the rolling bearing 22B is equal to the rolling surface 41A of the outer ring 31A of the rolling bearing 22A and the rolling bearing 22B. Preload is applied to the rolling bearing 22A and the rolling bearing 22B in a prescribed direction so as to be smaller than the interval T2 in the axial direction between the outer ring 31B and the rolling surface 41B. Specifically, as indicated by an arrow in FIG. 2, in the rolling bearing 22A, the shield plate 33A in the axial direction of the inner ring 30A is moved in the direction opposite to the shield plate 33A in the axial direction of the outer ring 31A through the rolling elements 32A. Preload is applied, and also in the rolling bearing 22B, preload is applied in the direction opposite to the axial shield plate 33B of the outer ring 31B from the axial shield plate 33B side of the inner ring 30B via the rolling elements 32B. ing.

  When preload is applied, the contact point 60A (60B) between the rolling surface 40A (40B) of the inner ring 30A (30B) of the rolling bearing 22A (22B) and the rolling element 32A (32B) is the inner ring 30A of the rolling bearing 22A (22B). It is located on the shield plate 33A (33B) side in the axial direction from the axial center part 40a (40b) of the rolling surface 40A (40B) of (30B). Further, a contact point 61A (61B) between the rolling surface 41A (41B) of the outer ring 31A (31B) of the rolling bearing 22A (22B) and the rolling element 32A (32B) is an outer ring 31A (31B) of the rolling bearing 22A (22B). ) Of the rolling surface 41A (41B) is located on the opposite side of the shield plate 33A (33B) from the axial central portion 41a (41b).

(1st Embodiment of the manufacturing method of a rolling bearing)
Next, a method for manufacturing the rolling bearing 22A (22B) having the above structure will be described.

"Shield plate placement process"
As shown in FIG. 7A, a columnar mounting table 50 having a flat circular mounting surface 50a at one end in the axial direction is prepared, and a shield plate 33A (33B) is mounted on the mounting table 50. A shield plate placing step is performed. Here, the outer diameter of the mounting surface 50 a of the mounting table 50 is larger than the inner diameter of the cover plate portion 35 and smaller than the outer diameter of the cover plate portion 35. In the shield plate mounting step, the mounting table 50 is arranged with the mounting surface 50a facing horizontally upward, the shield plate 33A (33B) is placed on the mounting table 50, and the spring plate 36 is faced down to cover the cover plate. The portion 35 is placed on the placement surface 50a. As a result, the spring plate portion 36 is in a state of being wrapped on the mounting table 50 in the axial direction of the shield plate 33A (33B).

"Shield plate holding process"
Next, a cylindrical holding jig 51 having a cylindrical holding wall surface 51a on the inner peripheral side is prepared, and a shield plate holding step is performed in which the holding jig 51 holds the shield plate 33A (33B). Here, the inner diameter of the holding wall surface 51a is smaller than the maximum outer diameter at the position of the spring plate portion 36 of the shield plate 33A (33B) in the natural state and the outer diameter of the cover plate portion 35 of the shield plate 33A (33B). The diameter is larger than the outer diameter of the mounting surface 50a of the mounting table 50. In the shield plate holding step, as shown in FIG. 7 (b), the mounting surface 50a and the holding wall surface 51a are placed on the mounting table 50 in which the shield plate 33A (33B) is placed in the mounting step. Are held coaxially, the holding jig 51 with the lower end surface 51b facing downward is moved from the upper side to the lower side to wrap a predetermined amount in the axial direction. Then, the holding wall surface 51a of the holding jig 51 elastically deforms the spring plate portion 36 toward the radial cover plate portion 35 side, that is, the reduced diameter side, and the shield plate 33A is caused by the spring force generated by the elastic deformation of the spring plate portion 36. (33B) is fitted to the holding wall surface 51a and held by the holding jig 51.

"Main body assembly process"
Separately from the shield plate placing step and the shield plate holding step described above, as shown in FIG. 8A, a plurality of rolling elements 32A are provided between the inner ring 30A (30B) and the outer ring 31A (31B) that have been processed. (32B) is arranged, and a plurality of rolling elements 32A (32B) are arranged at equal intervals by the cage. In this way, the main body 22Aa (22Ba) excluding the shield plate 33A (33B) of the rolling bearing 22A (22B) is assembled.

"Shield plate installation process"
As shown in FIG. 8A, the main body 22Aa (22Ba) assembled in the main body assembling process is arranged with the shield plate attachment portion 39A (39B) on the upper side. Then, the holding jig 51 in a state where the shield plate 33A (33B) is held on the flat upper end surface 31a along the axis orthogonal direction of the outer ring 31A (31B) of the main body 22Aa (22Ba) in the shield plate holding step described above. Is placed on a flat lower end surface 51b along the direction perpendicular to the axis. Accordingly, the holding wall surface 51a of the holding jig 51 and the peripheral wall surface 39a of the shield plate mounting portion 39A (39B) of the outer ring 31A (31B) are arranged adjacent to each other in the axial direction. At this time, the holding wall surface 51a of the holding jig 51 and the shield plate mounting portion 39A (39B) of the outer ring 31A (31B) are arranged coaxially. The inner diameter of the holding wall surface 51a is equal to or smaller than the inner diameter of the outer cylindrical surface portion 39aa which is the outermost axial direction of the shield plate mounting portion 39A (39B).

  Next, as shown in FIGS. 8A to 8B, a cylindrical pressing jig 55 having a flat circular pressing surface 55 a along the axial orthogonal direction at one end in the axial direction is provided in the holding jig 51. Insert into the top from above. Here, the outer diameter of the pressing jig 55 is smaller than the inner diameter of the holding wall surface 51a and larger than the inner diameter of the cover plate portion 35 of the shield plate 33A (33B). In the shield plate attaching step, the pressing jig 55 with the pressing surface 55a facing downward is moved from the upper side to the lower side with respect to the holding jig 51 and the main body 22Aa (22Ba). Then, the pressing surface 55a of the pressing jig 55 comes into contact with the cover plate portion 35 of the shield plate 33A (33B) held on the holding wall surface 51a of the holding jig 51 and presses it downward. As a result, the shield plate 33A (33B) slides on the holding wall surface 51a of the holding jig 51, and then slides on the peripheral wall surface 39a of the shield plate mounting portion 39A (39B) of the outer ring 31A (31B). It spreads in the radial direction and comes into a state of pressing and contacting the tapered surface portion 39ab and the inner cylindrical surface portion 39ac. Thereby, shield board 33A (33B) will be supported by main part 22Aa (22Ba).

(Pivot shaft manufacturing method)
Next, a manufacturing method of the pivot shaft 10 configured as described above will be described.
First, an adhesive (for example, anaerobic adhesive) (not shown) is applied to the outer peripheral surface of the lower end portion of the shaft core portion 20a of the shaft 20 shown in FIG. Then, the rolling bearing 22B is inserted into the shaft core portion 20a of the shaft 20 with the shield plate 33B on the lower side, and the rolling bearing 22B is pushed in until the lower end surface of the inner ring 30B contacts the upper stage surface 20d of the flange portion 20b.

  Next, after applying an adhesive (not shown) to the inner peripheral surfaces of the upper end portion and the lower end portion of the sleeve 21, the sleeve 21 is inserted into the shaft core portion 20a of the shaft 20, and the lower end surface of the spacer portion 21a is a rolling bearing. The sleeve 21 is pushed in until it contacts the upper end surface of the outer ring 31B of 22B.

  Next, the rolling bearing 22A is inserted into the annular space defined between the shaft core portion 20a of the shaft 20 and the sleeve 21 while being inserted into the shaft core portion 20a of the shaft 20 with the shield plate 33A facing upward. The bearing 22A is inserted, and the rolling bearing 22A is pushed in until the lower end surface of the outer ring 31A contacts the upper end surface of the spacer portion 21a.

Next, a preload is applied in the axial direction to the rolling bearing 22A and the rolling bearing 22B.
That is, the rolling bearing 22A and the rolling bearing 22B are fixed to the shaft 20 and the sleeve 21 while pressing the inner ring 30A of the rolling bearing 22A toward the rolling bearing 22B with a predetermined pressure with a pressing jig (not shown).

  As described above, when the inner ring 30A is pressed by the pressing jig, the rolling surface 40A of the inner ring 30A and the rolling element 32A of the rolling bearing 22A are opposite to the rolling bearing 22B from the axial center portion 40a of the rolling surface 40A. Point contact is made at the contact point 60A on the side (upper side). Further, the rolling contact surface 41A of the outer ring 31A and the rolling element 32A make point contact at a contact point 61A on the rolling bearing 22B side (lower side) with respect to the axial center portion 41a of the rolling contact surface 41A. Therefore, the preload direction is the arrow direction shown in FIG.

On the other hand, since the inner ring 30B of the rolling bearing 22B is pressed from the flange portion 20b side, the rolling surface 40B and the rolling element 32B of the inner ring 30B of the rolling bearing 22B are from the axial central portion 40b of the rolling surface 40B. Point contact at the contact point 60B on the flange portion 20b side (lower side). Further, the rolling contact surface 41B of the outer ring 31B and the rolling element 32B are in point contact at a contact point 61B on the rolling bearing 22A side (upper side) with respect to the axial center portion 41b of the rolling contact surface 41B. Therefore, the preload direction is the arrow direction shown in FIG.
Thus, preload is applied to the rolling bearing 22A and the rolling bearing 22B, and the pivot shaft 10 is completed.

  According to the rolling bearing 22A (22B) described above, the annular space 34A (34B) is formed on the circumferential wall surface 39a along the axial direction of the shield plate mounting portion 39A (39B) provided on the radially inner side of the outer ring 31A (31B). The shield plate 33A (33B) is brought into contact with the outer ring 31A (31B) by pressing and contacting the spring plate portion 36 extending inward in the axial direction from the outer peripheral edge portion of the cover plate portion 35 covering the peripheral wall surface 39a. Since the structure is supported, the annular space 34A (34B) between the step surface 39b along the radial direction of the shield plate attachment portion 39A (39B) and the shield plate 33A (33B) can be enlarged. Therefore, the annular space 34A (34B) can be sufficiently secured. As a result, for example, even if a reduction in size including a reduction in thickness is achieved, the possibility of interference between the shield plate 33A (33B) and the retainer 42 or grease (not shown) can be reduced, thus enabling a reduction in size.

  The spring plate portion 36 of the shield plate 33A (33B) is formed with leg plate portions 36a having a long protruding length from the cover plate portion 35 at both ends, and these are connecting plates having a short protruding length from the cover plate portion 35. Since it is the structure connected with the part 36b, the circumferential direction length of the leg board part 36a of both ends can be restrained. Therefore, it is easy to give these leg plate portions 36a good spring properties. Moreover, although the protrusion length from the cover board part 35 is shortened, leakage of grease can be suppressed by connecting the leg board parts 36a of both ends with the connection board part 36b.

  According to the pivot shaft 10 described above, since the rolling bearing 22A (22B) can be reduced in size, the overall size can be reduced.

  In addition, since the pivot shaft 10 can reduce both the rolling bearing 22A and the rolling bearing 22B, the entire shaft can be effectively reduced in size.

  According to the information recording / reproducing apparatus 1 described above, since the pivot shaft 10 can be reduced in size, the overall size can be reduced.

  According to the manufacturing method of the rolling bearing 22A (22B) described above, after the shield plate 33A (33B) is placed on the placement surface 50a of the placement table 50 by the cover plate portion 35, the holding jig 51 is placed on the placement table. When it is wrapped in the axial direction with respect to 50, the holding jig 51 deforms the spring plate portion 36 toward the radial cover plate portion 35 by the holding wall surface 51a to fit and hold the shield plate 33A (33B). Thereafter, the holding wall 51a of the holding jig 51 and the peripheral wall 39a of the shield plate mounting portion 39A (39B) are adjacent to each other in the axial direction, and the shield plate 33A (33B) is slid from the holding wall 51a to the peripheral wall 39a. The shield plate 33A (33B) can be attached to the shield plate attachment portion 39A (39B). Therefore, the shield plate 33A (33B) can be easily and properly attached to the shield plate attachment portion 39A (39B).

  In the above description, the single-sided shield type in which the shield plate 33A (33B) is provided only on one axial side of the rolling bearing 22A (22B) has been described as an example. However, as shown in FIG. The present invention is also applicable to a double-sided shield type in which the portion 39A (39B) and the shield plate 33A (33B) are provided. Further, the shield plate mounting portion 39A (39B) and the shield plate 33A (33A) can be changed as in the following second to fourth embodiments.

(Second Embodiment of Rolling Bearing)
As shown in FIG. 10A, the spring plate portion 36 of the shield plate 33A (33B) in the natural state extends so as to gradually increase in diameter as it is bent from the cover plate portion 35 and separated in the axial direction. A taper-shaped taper plate portion 36c and a taper-shaped taper plate portion 36d that bends from the opposite side of the taper plate portion 36c to the cover plate portion 35 and extends so as to gradually increase in diameter as it is separated in the axial direction. Have. Here, the taper plate portion 36d has a smaller taper than the taper plate portion 36c.

  Such a shield plate 33A (33B) is a shield plate placement step similar to that of the first embodiment, as shown in FIG. 10 (a), with respect to the placement table 50 having the placement surface 50a horizontally upward. With the spring plate portion 36 facing downward, the cover plate portion 35 is placed on the placement surface 50a. Thereafter, in the same shield plate holding process as in the first embodiment, the spring plate portion 36 is elastically deformed toward the cover plate portion 35 in the radial direction by the holding wall surface 51a of the holding jig 51 as shown in FIG. Then, the shield plate 33A (33B) is fitted to the holding wall surface 51a.

  Next, as shown in FIG. 10C, the holding jig 51 holding the shield plate 33A (33B) in this way is subjected to the same shield plate attachment process as in the first embodiment, and the main body 22Aa (22Ba). The outer ring 31A (31B) is placed on the upper end surface 31a at the lower end surface 51b, and the pressing jig 55 is inserted into the holding jig 51 to press the shield plate 33A (33B). As a result, the pressing jig 55 slides the shield plate 33A (33B) on the holding wall surface 51a of the holding jig 51, and then contacts the peripheral wall surface 39a of the shield plate mounting portion 39A (39B) of the outer ring 31A (31B). Slide. As a result, the spring plate portion 36 of the shield plate 33A (33B) expands in diameter and comes into pressure contact with the peripheral wall surface 39a and is supported by the main body 22Aa (22Ba).

  At this time, as shown in FIG. 11, the spring plate portion 36 has a taper shape in which the taper plate portion 36 c is gradually expanded from the outer peripheral edge portion of the cover plate portion 35 toward the axial center side. The tapered surface portion 39ab is pressed into contact with the tapered surface portion 39ab, and the tapered plate portion 36d is pressed into contact with the inner cylindrical surface portion 39ac and the step surface 39b of the peripheral wall surface 39a in a cylindrical shape with a constant diameter.

(Third embodiment of rolling bearing)
As shown in FIG. 12, the longitudinal section of the spring plate 36 of the shield plate 33 </ b> A (33 </ b> B) in the natural state is gradually increased in diameter and extended as it is bent from the cover plate 35 and separated in the axial direction. And a taper-shaped taper plate portion 36f that is bent from the side opposite to the cover plate portion 35 of the curve plate portion 36e and gradually increases in diameter as it is separated in the axial direction. Have. As shown in FIG. 13, the peripheral wall surface 39a of the shield plate mounting portion 39A (39B) of the outer ring 31A (31B) has a cylindrical surface shape with a constant diameter.

  After the shield plate 33A (33B) is held on the holding wall surface 51a of the holding jig 51 by performing the same shield plate placement step and shield plate holding step as in the first embodiment, the first embodiment By performing the same shield plate attachment process as in Fig. 5, the shield plate is attached to the shield plate attachment portion 39A (39B).

  As a result, as shown in FIG. 13, the spring plate portion 36 has a shape in which the curved plate portion 36e is more curved than in the natural state, and the tapered plate portion 36f has a cylindrical shape with a constant diameter, and the peripheral wall surface 39a. Press contact.

(Fourth embodiment of rolling bearing)
As shown in FIG. 14, the spring plate portion 36 of the shield plate 33A (33B) in the natural state is a tapered shape extending so as to gradually increase in diameter as it is bent from the cover plate portion 35 and separated in the axial direction. A taper plate portion 36g, and a taper-shaped taper plate portion 36h extending from the side opposite to the cover plate portion 35 of the taper plate portion 36g so as to gradually increase in diameter as it is separated in the axial direction. Yes. Here, the taper plate portion 36g has a smaller taper than the taper plate portion 36h.

  After the shield plate 33A (33B) is held on the holding wall surface 51a of the holding jig 51 by performing the same shield plate placement step and shield plate holding step as in the first embodiment, the first embodiment By performing the same shield plate attachment process as in Fig. 5, the shield plate is attached to the shield plate attachment portion 39A (39B).

  As a result, as shown in FIG. 15, the spring plate portion 36 has a taper plate portion 36g and a taper plate portion 36h that each have a smaller taper than the natural state, and the taper plate portion 36h is opposite to the taper plate portion 36g. Are pressed and contacted with the inner cylindrical surface portion 39ac and the stepped surface 39b of the peripheral wall surface 39a.

(Fifth embodiment of rolling bearing)
In the fifth embodiment, as shown in FIG. 16, the shield plate 33A ′ (33B) is formed on the outer edge of the inner ring 30A (30B) in the axial direction and on the radial annular space 34A (34B) side. A shield plate attachment portion 39A ′ (39B ′) to which “) is attached is formed. The shield plate mounting portion 39A ′ (39B ′) has a shape in which the outer edge portion of the inner ring 30A (30B) is cut out in a substantially L shape (stepped shape) when viewed in cross section, and around the entire circumference of the inner ring 30A (30B). It is formed over.

  The peripheral wall surface 39a ′ (rising surface) along the axial direction of the shield plate mounting portion 39A ′ (39B ′) is an undercut portion that locks the spring plate portion 36 ′ of the shield plate 33A ′ (33B ′). An outer cylindrical surface portion 39aa ′ extending with a constant diameter from the end surface of the inner ring 30A (30B) toward the axially central side (inner side), and the axially central side from the axially central end portion of the outer cylindrical surface portion 39aa ′ A taper-shaped taper surface portion 39ab ′ gradually reduced in diameter toward the inner side, and an inner cylindrical surface portion 39ac ′ extending from the end portion of the taper surface portion 39ab ′ on the axially central side toward the axially central side with a constant diameter, have. The step surface 39b ′ along the radial direction of the shield plate mounting portion 39A ′ (39B ′) is an end on the axially central side (inside) of the peripheral wall surface 39a ′, that is, an end on the axially central side of the inner cylindrical surface portion 39ac ′. It extends from the portion to the annular space 34A (34B) side along the radial direction.

  The shield plate 33A '(33B') is attached to the inner ring 30A (30B) by fitting the inner peripheral portion thereof to the shield plate mounting portion 39A '(39B') described above. The outer peripheral portion of the shield plate 33A '(33B') is separated from the outer ring 31A (31B).

  The shield plate 33A ′ (33B ′) includes an annular flat cover plate portion 35 ′ formed along a plane orthogonal to the rotation axis L2, and a peripheral wall surface 39a ′ side of the cover plate portion 35 ′. And a plurality of spring plate portions 36 ′ protruding from the inner peripheral edge portion. The cover plate portion 35 ′ is disposed along the radial direction to cover the annular space 34 A (34 B), and the spring plate portion 36 ′ extends inward in the axial direction from the inner peripheral edge portion of the cover plate portion 35 to shield it. It press-contacts with peripheral wall surface 39a 'of board attachment part 39A' (39B ').

  When the shield plate 33A ′ (33B ′) is in a natural state, the spring plate portion 36 ′ is bent with respect to the cover plate portion 35 ′ as shown in FIG. The whole has a tapered shape in which the diameter gradually decreases as the distance from the cover plate portion 35 ′ increases in the axial direction.

  As shown in FIG. 16, in a state where the shield plate 33A ′ (33B ′) is attached to the shield plate attachment portion 39A ′ (39B ′), the spring plate portion 36 ′ has the tapered surface portion 39ab ′ of the peripheral wall surface 39a ′ and The shape follows the inner cylindrical surface portion 39ac ′. That is, the spring plate portion 36 ′ has a tapered shape in which the cover plate portion 35 ′ side is gradually expanded in diameter from the inner peripheral edge portion of the cover plate portion 35 ′ toward the axial center, and is opposite to the cover plate portion 35. The side has a cylindrical shape with a constant diameter. Thereby, when in a natural state, the spring plate portion 36 ′ that has been tapered as a whole comes into pressure contact with the inner cylindrical surface portion 39 ac ′ of the peripheral wall surface 39 a in the radial direction.

  The spring plate portion 36 ′ is also in press contact with the tapered surface portion 39ab ′ of the peripheral wall surface 39a ′, thereby being pressed inward in the axial direction, and the end opposite to the cover plate portion 35 ′ is shielded. The plate mounting portion 39A ′ (39B ′) is in pressure contact with the step surface 39b ′. In other words, the spring plate portion 36 'is undercut fitted to the peripheral wall surface 39a' having the tapered surface portion 39ab 'of the shield plate mounting portion 39A' (39B ').

  As described above, the spring plate portion 36 ′ is pressed into contact with the tapered surface portion 39ab ′ and the inner cylindrical surface portion 39ac ′ of the peripheral wall surface 39a ′ of the shield plate attachment portion 39A ′ (39B ′) and the cover plate portion 35 ′. The opposite end is placed on the stepped surface 39b ′ of the shield plate mounting portion 39A ′ (39B ′), whereby the shield plate 33A ′ (33B ′) is fitted to the inner ring 30A (30B). Is done. Note that the spring plate portion 36 ′ of the shield plate 33 </ b> A ′ (33 </ b> B ′) is wrapped with the cage 42 in the axial direction while being attached to the inner ring 30 </ b> A (30 </ b> B).

(Fifth embodiment of manufacturing method of rolling bearing)
Next, a method for manufacturing the rolling bearing 22A (22B) of the fifth embodiment having the above structure will be described.

"Shield plate placement process"
As shown in FIG. 17A, a cylindrical mounting table 50 ′ having a flat circular mounting surface 50a ′ at one end in the axial direction is prepared, and a shield plate 33A ′ (33B ′) is provided on the mounting table 50 ′. ) Is carried out. Here, the inner diameter of the mounting surface 50a ′ of the mounting table 50 ′ is larger than the inner diameter of the cover plate portion 35 ′ and smaller than the outer diameter of the cover plate portion 35 ′. In the shield plate mounting step, the mounting table 50 'is disposed with the mounting surface 50a' facing horizontally upward, and the shield plate 33A '(33B') is placed on the mounting table 50 'with the spring plate portion 36' disposed thereon. It is made to face downward and is placed on the placement surface 50a ′ by the cover plate portion 35 ′. As a result, the spring plate portion 36 ′ is in a state of being wrapped on the mounting table 50 ′ in the axial direction of the shield plate 33A ′ (33B ′).

"Shield plate holding process"
Next, a cylindrical holding jig 51 ′ having a cylindrical holding wall surface 51a ′ on the outer peripheral side is prepared, and a shield plate holding step for holding the shield plate 33A ′ (33B ′) on the holding jig 51 ′. I do. Here, the outer diameter of the holding wall surface 51a ′ is larger than the minimum inner diameter at the position of the spring plate portion 36 ′ of the shield plate 33A ′ (33B ′) in a natural state and the shield plate 33A ′ (33B ′). The diameter is smaller than the inner diameter of the cover plate portion 35 'and smaller than the inner diameter of the mounting surface 50a' of the mounting table 50 '. In the shield plate holding step, the placement surface 50a ′ and the holding wall surface 51a ′ are arranged coaxially with respect to the placement table 50 ′ in which the shield plate 33A ′ (33B ′) is placed in the placement step. In this state, the holding jig 51 ′ with the lower end surface 51 b ′ facing downward is moved from the upper side to the lower side to wrap a predetermined amount in the axial direction. Then, the holding wall surface 51a ′ of the holding jig 51 ′ elastically deforms the spring plate portion 36 ′ to the radial cover plate portion 35 ′ side, that is, the enlarged diameter side, as shown in FIG. The shield plate 33A ′ (33B ′) is fitted to the holding wall surface 51a ′ by the spring force generated by the elastic deformation of the spring plate portion 36 ′ and is held by the holding jig 51 ′.

"Shield plate installation process"
As shown in FIG. 17B, the main body 22Aa (22Ba) assembled in the main body assembling process is arranged with the shield plate mounting portion 39A ′ (39B ′) on the upper side. A holding jig 51 ′ holding the shield plate 33A ′ (33B ′) is placed on the upper end surface 30a of the inner ring 30A (30B) of the main body 22Aa (22Ba), and a flat lower end surface 51b along the axis orthogonal direction. Place in '. Thereby, the holding wall surface 51a ′ of the holding jig 51 ′ and the peripheral wall surface 39a ′ of the shield plate mounting portion 39A ′ (39B ′) of the inner ring 30A (30B) are arranged adjacent to each other in the axial direction. . At this time, the holding wall surface 51a ′ of the holding jig 51 ′ and the shield plate mounting portion 39A ′ (39B ′) of the inner ring 30A (30B) are arranged coaxially. The outer diameter of the holding wall surface 51a ′ is equal to or greater than the outer diameter of the outer cylindrical surface portion 39aa ′ on the outermost axial direction of the shield plate mounting portion 39A ′ (39B ′).

  Next, a cylindrical pressing jig 55 ′ having a flat circular pressing surface 55 a ′ at one end in the axial direction is placed on the holding jig 51 ′ from above. Here, the inner diameter of the pressing jig 55 ′ is larger than the outer diameter of the holding wall surface 51a ′, and smaller than the outer diameter of the cover plate portion 35 ′ of the shield plate 33A ′ (33B ′). ing. In the shield plate attaching step, the pressing jig 55 'with the pressing surface 55a' facing downward is moved from the upper side to the lower side with respect to the holding jig 51 'and the main body 22Aa (22Ba). Then, as shown in FIG. 17C, the cover plate of the shield plate 33A ′ (33B ′) in which the pressing surface 55a ′ of the pressing jig 55 ′ is held by the holding wall surface 51a ′ of the holding jig 51 ′. It abuts against the part 35 'and presses it downward. As a result, after the shield plate 33A ′ (33B ′) slides on the holding wall surface 51a ′ of the holding jig 51 ′, it slides on the peripheral wall surface 39a ′ of the shield plate mounting portion 39A ′ (39B ′) of the inner ring 30A (30B). Then, the spring plate portion 36 ′ is narrowed in the radial direction and brought into a state of being pressed and contacted with the tapered surface portion 39 ab ′ and the inner cylindrical surface portion 39 ac ′. As a result, the shield plate 33A '(33B') is supported by the main body 22Aa (22Ba).

(Sixth embodiment of rolling bearing)
In the sixth embodiment shown in FIG. 18, the shield plate 33A (33B) shown in FIG. 19 is used. The shield plate 33A (33B) has a claw shape in which a plurality of spring plate portions 36 have a narrow width in the circumferential direction. When in the natural state, the plurality of spring plate portions 36 have a tapered shape that is gradually expanded in diameter toward the outside in the axial direction.

  As shown in FIG. 18, in a state where the shield plate 33A (33B) is attached to the shield plate attachment portion 39A (39B), the spring plate portion 36 is curved while the tapered surface portion 39ab and the inner cylindrical surface portion of the peripheral wall surface 39a are curved. Contact 39ac. That is, the spring plate portion 36 has a shape in which the diameter is gradually increased from the outer peripheral edge portion of the flat cover plate portion 35 toward the center in the axial direction, and has an arc shape in which the axial cross section is curved.

  After the shield plate 33A (33B) is held on the holding wall surface 51a of the holding jig 51 by performing the same shield plate placement step and shield plate holding step as in the first embodiment, the first embodiment By performing the same shield plate attachment process as in Fig. 5, the shield plate is attached to the shield plate attachment portion 39A (39B). Thereby, as shown in FIG. 18, the spring plate part 36 is curved and press-contacts the peripheral wall surface 39a.

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 22A Rolling bearing (one of the first and second rolling bearings)
22B Rolling bearing (the other of the first and second rolling bearings)
30A Inner ring 30B Inner ring 31A Outer ring 31B Outer ring 32A Rolling body 32B Rolling body 33A Shield plate 33A 'Shield plate 33B Shield plate 33B' Shield plate 34A Annular space 34B Annular space 35 Cover plate portion 35 'Cover plate portion 36 Spring plate portion 36' Spring plate portion 36 'Spring Plate part 36a Leg plate part 36b Connecting plate part 39A Shield plate attachment part 39B Shield plate attachment part 39a Peripheral wall surface 39a 'Peripheral wall surface 39b Stepped surface 39b' Stepped surface 40A Rolling surface 40B Rolling surface 41A Rolling surface 41B Rolling surface 50 Mounting table 50 'Mounting table 50a Mounting surface 50a' Mounting surface 51 Holding jig 51 'Holding jig 51a Holding wall 51a' Holding wall

Claims (5)

An inner ring, an outer ring surrounding the inner ring, a plurality of rolling elements rotatably held between the inner ring and the outer ring, and an annular shield for closing an annular space between the inner ring and the outer ring With a board,
The inner ring or the outer ring has a radial wall surface in the radial direction at the outer end in the axial direction, a circumferential wall surface along the axial direction, and a radial wall from the inner side in the axial direction toward the annular space side. In a rolling bearing provided with a shield plate mounting portion having an extended step surface,
The shield plate is disposed along a radial direction and covers an annular cover plate portion that covers the annular space, and extends inward in the axial direction from a peripheral portion on the peripheral wall surface side of the cover plate portion. have a spring plate portion for pressing contact with the wall surface, the is spring plate portion is provided with a plurality at intervals, each of these spring plate section, leg plates at both ends is longer projecting length from the cover plate portion and parts, the rolling bearing, characterized in that the projecting length from the cover plate portion for connecting the leg plate portions to have a short connecting plate. The bearing device according to claim 1, wherein the inner ring of the rolling bearing is fitted on a shaft . The bearing device according to claim 2 ,
A first rolling bearing located on one side in the axial direction as the rolling bearing on the shaft and disposed with the shield plate on the one side, and the shield on the other side located on the other side in the axial direction A bearing device comprising a second rolling bearing arranged with a plate. A bearing device according to claim 2 ,
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 actuator for rotating the carriage and moving the head gimbal assembly in a direction parallel to the surface of the magnetic recording medium;
Information recording and reproducing apparatus characterized in that it comprises. It is a manufacturing method of the rolling bearing according to claim 1,
  Using a mounting table having a circular mounting surface and a holding jig having a cylindrical holding wall,
  Placing the shield plate on the placement surface at the cover plate portion while wrapping the spring plate portion on the placement table in the axial direction;
  By wrapping the holding jig in the axial direction with respect to the mounting table, the spring plate portion is deformed to the cover plate portion side in the radial direction by the holding wall surface, and the shield plate is fitted to the holding jig. A process of
  And a step of sliding the shield plate from the holding wall surface to the peripheral wall surface so that the holding wall surface and the peripheral wall surface are adjacent to each other in the axial direction and pressing the spring plate portion against the peripheral wall surface. A method of manufacturing a rolling bearing.

Images