JP2014101922A - Holder, rolling bearing, bearing device and information recording and reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a holder whose thickness can be reduced in the axial direction while maintaining its rigidity, a roller bearing including this holder, a bearing device and an information recording and reproducing apparatus.SOLUTION: A retainer 60 (holder) holding rolling elements 35 between an outer ring 31 and an inner ring 36, includes: an annular base part 61 arranged coaxially with the outer ring 31 and the inner ring 36, pocket parts P which are concavely formed in the radial direction on the outer circumferential face of the base part 61 and in which the rolling elements 35 are disposed; and a plurality of pairs of claw parts 63 and 63 capable of rotatably holding the rolling elements 35. The plurality of pairs of claw parts 63 and 63 include base end parts 63b and 63b connected to the outer circumferential face having the pocket parts P formed therein, respectively, and are erected toward one side in the axial direction.

Description

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

  Generally, a rolling bearing includes an outer ring and an inner ring arranged on the same axis, a plurality of rolling elements disposed between the outer ring and the inner ring, and a cage that holds the rolling elements in a freely rolling manner. I have. Various types of cages of this type are known. For example, as one of them, an annular rim portion (corresponding to a “base portion” in the claims, hereinafter referred to as “base portion”), and this There is known a device including a pocket portion formed at a radial position of the base portion and individually holding each rolling element. (For example, refer to Patent Document 1).

  The pocket portion is formed as a recess in one axial end surface of the base portion. In addition, a pair of claw portions are erected at positions corresponding to the pocket portions so as to face each other. The pair of claw portions face each other in the circumferential direction with the pocket portion therebetween, and are raised in a state of being curved in an arc shape so that the distance from each other approaches from the proximal end portion toward the distal end portion.

  By the way, recently, in order to cope with further downsizing and thinning of the information recording / reproducing apparatus, rolling bearings and bearing devices incorporated in the information recording / reproducing apparatus are also shortened in the axial direction (hereinafter referred to as “thinning”). Is required.

As a technique for meeting the demand for thin rolling bearings and bearing devices, for example, it is conceivable to reduce the diameter of rolling elements. However, reducing the diameter of the rolling element is not preferable because it leads to an increase in cost due to an increase in the number of processing steps of the rolling element and the number of assembly steps of the rolling bearing. Moreover, since the rigidity of a rolling element and a rolling bearing falls by diameter reduction of a rolling element, there exists a limit in diameter reduction of a rolling element.
Therefore, as another method corresponding to the demand for thinning of the rolling bearing and the bearing device, it is conceivable to thin the cage for holding the rolling elements. In the cage of the prior art, since the base portion and the claw portion are continuously provided along the axial direction, the cage can be thinned by thinning the base portion.

JP 2003-329044 A

  However, in the cage of the prior art, since the base portion and the claw portion are continuously provided along the axial direction, there is a limit to reducing the thickness of the cage by thinning the base portion. Moreover, there is a possibility that the rigidity of the cage is lowered by making the base portion thin. Therefore, the conventional cage cannot be thinned effectively.

  Therefore, the present invention has been made in view of the above-described circumstances, and a cage that can be thinned in the axial direction while ensuring rigidity, a rolling bearing, a bearing device, and an information recording / reproducing device including the cage. The issue is to provide

  In order to solve the above-described problems, the cage of the present invention rolls in a state where a plurality of rolling elements arranged between the outer ring and the inner ring arranged on the same axis are evenly arranged in the circumferential direction. A retainer that can be freely held, and is formed with an annular base portion disposed coaxially with the outer ring and the inner ring, and a dent formed in a radial direction on any of an inner peripheral surface and an outer peripheral surface of the base portion, A spherical pocket portion into which a rolling element is inserted, and a plurality of pairs of claw portions capable of holding the rolling element inserted into the pocket portion in a freely rollable manner. Each portion is characterized in that a base end portion is connected to either the inner peripheral surface or the outer peripheral surface where the pocket portion is formed, and is erected toward one side in the axial direction.

  According to the present invention, the plurality of pairs of claw portions are respectively connected to either the inner peripheral surface or the outer peripheral surface of the base portion where the pocket portions are formed, and are directed toward one side in the axial direction. Therefore, the cage can be made thinner in the axial direction than in the prior art in which the base portion and the claw portion are continuously provided along the axial direction. Further, the base end portion of a plurality of pairs of claw portions is connected to either the inner peripheral surface or the outer peripheral surface of the base portion, so that the base portion is located on either the inner side or the outer side in the radial direction from the claw portion. Therefore, even if the thickness of the base portion is ensured, the influence on the thickness of the cage can be suppressed. Therefore, the cage can be thinned in the axial direction while ensuring the rigidity of the cage.

  The pocket portion is formed so as to penetrate the base portion in the axial direction, and when the rolling element is inserted into the pocket portion and held by the pair of claws, the axial direction of the base portion The outer surface of the said rolling element is exposed from the end surface in the other side of this.

  According to the present invention, when the rolling element is inserted into the pocket part and held by the pair of claws, the outer surface of the rolling element is set to be exposed from the end face on the other side in the axial direction of the base part. The base part can be made thinner. Therefore, the cage can be further thinned in the axial direction.

  In addition, a connection portion that connects the pair of claws is provided between the plurality of pairs of claws.

  According to the present invention, it is possible to improve the rigidity between the pair of claws by providing the connection portion that connects the pair of claws. Therefore, it is possible to further reduce the thickness of the cage in the axial direction while ensuring the rigidity of the cage.

  In addition, a concave portion that is recessed in the axial direction is formed on a surface of the connection portion on the one side in the axial direction.

  According to the present invention, the recess can be filled with grease by forming the recess on the surface on one side in the axial direction of the connecting portion. That is, since the concave portion of the connection portion functions as a grease pocket, the cage can be thinned in the axial direction while ensuring the rigidity of the cage, and the grease pocket can be provided.

  The rolling bearing according to the present invention includes the above-described cage, and prevents any interference between the outer ring and the inner ring at a position corresponding to the base portion of the cage. It is characterized in that a relief portion is formed.

  According to the present invention, since the escape portion for preventing interference with the base portion of the cage is formed in either the outer ring or the inner ring, the holding that is reduced in thickness without interfering with the outer ring and the inner ring. A vessel can be arranged. Therefore, it is possible to reduce the thickness, weight and cost of the rolling bearing while maintaining the performance of the rolling bearing equivalent to that of the prior art.

  The information recording / reproducing apparatus according to the present invention includes a bearing device described above, a housing that supports an end of one side of the bearing device, and an outer ring that rotates around the central axis of the shaft. A moving member and a slider mounted on the rotating member and recording and reproducing information with a magnetic recording medium are provided.

  According to the present invention, since the bearing device that can be thinned is provided, the information recording / reproducing device can be thinned, lightened, and reduced in cost.

  According to the present invention, the plurality of pairs of claw portions are respectively connected to either the inner peripheral surface or the outer peripheral surface of the base portion where the pocket portions are formed, and are directed toward one side in the axial direction. Therefore, the cage can be made thinner in the axial direction than in the prior art in which the base portion and the claw portion are continuously provided along the axial direction. Further, the base end portion of a plurality of pairs of claw portions is connected to either the inner peripheral surface or the outer peripheral surface of the base portion, so that the base portion is located on either the inner side or the outer side in the radial direction from the claw portion. Since it arrange | positions, even if it secures the thickness of a base part, the influence with respect to the thickness of a holder | retainer can be suppressed. Therefore, the cage can be thinned in the axial direction while ensuring the rigidity of the cage.

1 is a perspective view of an information recording / reproducing apparatus according to an embodiment. It is side surface sectional drawing of the rolling bearing which concerns on 1st embodiment. It is a perspective view of the retainer of the first embodiment when viewed from one side in the axial direction. It is a perspective view of the retainer of 1st embodiment when it sees from the other side of an axial direction. It is side surface sectional drawing of the bearing apparatus which concerns on 1st embodiment. It is side surface sectional drawing of the rolling bearing and bearing apparatus which concern on the 1st modification of 1st embodiment. It is side surface sectional drawing of the rolling bearing and bearing apparatus which concern on the 2nd modification of 1st embodiment. It is side surface sectional drawing of the rolling bearing and bearing apparatus which concern on the 3rd modification of 1st embodiment. It is side surface sectional drawing of the rolling bearing which concerns on 2nd embodiment. It is a perspective view of the retainer of 2nd embodiment when it sees from one side of an axial direction. It is a perspective view of the retainer of 2nd embodiment when it sees from the other side of an axial direction. It is side surface sectional drawing of the bearing apparatus which concerns on 2nd embodiment.

  Hereinafter, a retainer according to the first embodiment (corresponding to a “retainer” in claims), a rolling bearing including the retainer, a bearing device, and an information recording / reproducing device will be described. In the following, the information recording / reproducing apparatus according to the embodiment will be described, and then the rolling bearing, the retainer, and the bearing apparatus according to the first embodiment will be described in this order.

(Information recording / reproducing device)
FIG. 1 is a perspective view of an information recording / reproducing apparatus 1 according to the embodiment.
As shown in FIG. 1, the information recording / reproducing apparatus 1 is an apparatus that writes and reads data on a disk (magnetic recording medium) D having a recording layer. The information recording / reproducing apparatus 1 includes an arm (rotating member) 8, a head gimbal assembly 4 supported on the tip side of the arm 8, a slider 2 attached to the tip of the head gimbal assembly 4, and a head gimbal assembly 4. An actuator (VCM: voice coil motor) 6 for moving the scan, a spindle motor 7 for rotating the disk D, a control unit 5 for supplying a current modulated in accordance with information to the slider 2, and these components are housed inside. And a housing 9 to be provided.

  The housing 9 is made of a metal material such as aluminum, iron, or stainless steel, and has a box shape with an opening at the top. The housing 9 stands vertically from the rectangular bottom 9a and the peripheral edge of the bottom 9a. It is comprised with the surrounding wall (not shown) provided. A housing recess for housing each of the above-described components is formed inside the housing 9 surrounded by the peripheral wall. A spindle motor 7 is attached to substantially the center of the bottom portion 9a, and the disc D is detachably fixed by fitting a center hole into the spindle motor 7.

A bearing device 10 is disposed on the side of the disk D. The end of the bearing device 10 is supported by the bottom 9 a of the housing 9. An arm 8 is fitted and fixed to the outer peripheral surface of the bearing device 10. The base end portion of the arm 8 is connected to the actuator 6 described above. Further, the arm 8 extends in parallel with the surface of the disk D from the proximal end side toward the distal end side.
A head gimbal assembly 4 is connected to the tip of the arm 8. The head gimbal assembly 4 includes a suspension 3 and a slider 2 that is attached to the tip of the suspension 3 and is disposed to face the surface of the disk D. The slider 2 includes a recording element for writing (recording) information on the disk D and a reproducing element for reading (reproducing) information from the disk D.

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

(Rolling bearing of the first embodiment)
FIG. 2 is a side sectional view of the rolling bearing 30 according to the first embodiment. Hereinafter, a direction along the axis of the rolling bearing 30 (hereinafter referred to as “center axis L1”) is referred to as “axial direction”. Moreover, the upper side in FIG. 2 is defined as one side in the axial direction, and the lower side in FIG. 2 is defined as the other side in the axial direction. Further, a direction orthogonal to the central axis L1 is referred to as a “radial direction”, and a direction around the central axis L1 is referred to as a “circumferential direction”.

  As shown in FIG. 2, the rolling bearing 30 is a cylindrical member having a thickness T in the axial direction, and an outer ring 31 and an inner ring arranged coaxially with the outer ring 31 on the inner side in the radial direction of the outer ring 31. 36, a plurality of rolling elements 35 that are rotatably held between the outer ring 31 and the inner ring 36, and a retainer 60 that holds the plurality of rolling elements 35 so as to be freely rotatable in a circumferentially arranged state. It is equipped with.

(Outer ring)
The outer ring 31 is a cylindrical member made of a metal material such as stainless steel, and is formed by, for example, forging or machining. The outer ring 31 has a thickness T in the axial direction, and the one end face 31a and the other end face 31b in the axial direction of the outer ring 31 are the one end face 30a and the other end face 30b in the axial direction of the rolling bearing 30, respectively. It is the same plane.

An outer ring rolling surface 34 is formed on the inner peripheral surface 32 of the outer ring 31. The outer ring rolling surface 34 is formed in an arc shape in a side cross section so as to follow the outer surface of the rolling element 35 at the axial intermediate portion of the outer ring 31. The curvature radius in the side cross section of the outer ring rolling surface 34 is formed to be substantially the same as or slightly larger than the curvature radius of the outer surface of the rolling element 35. The outer ring rolling surface 34 is formed over the entire circumference of the inner circumferential surface 32 of the outer ring 31, and the outer surfaces of a plurality of rolling elements 35 arranged in an annular shape can come into contact with each other.
The radially inner edges of the one end face 31a and the other end face 31b of the outer ring 31 are stepped portions 33a and 33b that are recessed by one step, respectively. The shield member 25 is fitted to the step portion 33 a formed on the one end surface 31 a of the outer ring 31.

  The shield member 25 is a ring-shaped member made of a metal material such as iron or aluminum. The shield member 25 closes the annular space formed between the outer ring 31 and the inner ring 36 from one side in the axial direction, and the grease applied between the outer ring 31 and the inner ring 36 and the rolling element 35 is It prevents scattering from one side in the axial direction to the outside.

The outer diameter of the shield member 25 is formed to be slightly larger than the inner diameter of the side surface of the stepped portion 33a on one side. The outer end portion 26 in the radial direction of the shield member 25 is a bent portion 26a that is bent so as to protrude toward the other side in the axial direction. The shield member 25 is fitted and fixed to the inner side in the radial direction of the stepped portion 33a on the one end surface 31a of the outer ring 31 in a state where the bent portion 26a is elastically deformed inward in the radial direction.
The inner diameter of the shield member 25 is formed to be slightly smaller than the outer diameter of the inner ring 36.

(Inner ring)
The inner ring 36 is a substantially cylindrical member made of a metal material such as stainless steel having a predetermined thickness in the axial direction, and is formed by forging or machining, for example. The axial thickness of the inner ring 36 in this embodiment is, for example, about ½ of the thickness T of the outer ring 31 and is formed to be thinner than the thickness of the rolling bearing 30.

  An inner ring rolling surface 39 is formed on the outer peripheral surface 37 of the inner ring 36. The inner ring rolling surface 39 has a side section formed in an arc shape so that the outer diameter of the inner ring 36 gradually decreases from one side in the axial direction of the inner ring 36 to the other side. The curvature radius in the side cross section of the inner ring rolling surface 39 is formed to be substantially the same as or slightly larger than the curvature radius of the outer surface of the rolling element 35. The inner ring rolling surface 39 is formed over the entire circumference of the outer circumferential surface 37 of the inner ring 36, and the outer surfaces of the plurality of rolling elements 35 arranged in an annular shape can come into contact with each other.

The one end surface 36 a in the axial direction of the inner ring 36 is disposed so as to be substantially flush with the one end surface 31 a of the outer ring 31, and is flush with the one end surface 30 a in the axial direction of the rolling bearing 30. .
A radially outer edge of one end surface 36a of the inner ring 36 is a stepped portion 38 that is recessed toward the other side in the axial direction. On the one side in the axial direction with respect to the stepped portion 38, the radially inner end portion 27 of the shield member 25 is disposed at a predetermined distance from the stepped portion 38. By providing the stepped portion 38, the inner ring 36 and the inner end portion 27 of the shield member 25 are prevented from interfering with each other. Further, since the gap between the stepped portion 38 and the inner end portion 27 of the shield member 25 has a labyrinth shape, the grease applied between the outer ring 31 and the inner ring 36 and the rolling element 35 is externally applied from one side in the axial direction. To prevent splashing.

  Here, the inner ring 36 is formed to be thinner than the rolling bearing 30, and the other end face 36 b of the inner ring 36 is more axial than the other end face 31 b of the outer ring 31 (that is, the other end face 30 b of the rolling bearing 30). It is arranged on one side. Thereby, a space is formed over the entire circumference between the other end surface 30 b of the rolling bearing 30 and the other end surface 36 b of the inner ring 36. In this space, a base portion 61 of a retainer 60 described later is disposed. In this way, the other end surface 36b of the inner ring 36 is arranged on one side in the axial direction with respect to the other end surface 30b of the rolling bearing 30, thereby preventing interference between the inner ring 36 and the base portion 61 of the retainer 60. The escape portion 40 is formed.

(Rolling body)
The rolling element 35 is formed in a spherical shape from a metal material. A plurality of rolling elements 35 (13 in this embodiment) are arranged between the outer ring rolling surface 34 of the outer ring 31 and the inner ring rolling surface 39 of the inner ring 36, and the outer ring rolling surface 34 and the inner ring rolling surface are arranged. It rolls along 39. The plurality of rolling elements 35 are equally arranged in an annular shape along the circumferential direction so as to be freely rollable by a retainer 60.

(Retainer of the first embodiment)
FIG. 3 is a perspective view of the retainer 60 when viewed from one side in the axial direction.
FIG. 4 is a perspective view of the retainer 60 when viewed from the other side in the axial direction.
The retainer 60 is a member made of, for example, resin or the like that holds the rolling elements 35 in a rollable manner while rotating around the central axis L1 by the guidance of the outer ring 31, the inner ring 36 and the rolling elements 35. As shown in FIG. 3, the retainer 60 includes a base portion 61, a pocket portion P, a plurality of pairs of claw portions 63, 63, and a connection portion 65 that connects the pair of claw portions 63, 63 together. ing.

As shown in FIG. 2, the base portion 61 is disposed coaxially with the outer ring 31 and the inner ring 36 and is formed in an annular shape. The inner diameter of the base portion 61 is formed to be smaller than the outer diameter of the inner ring 36.
The thickness of the base portion 61 in the axial direction is formed to be thinner than the separation distance along the axial direction between the other end surface 30 b of the rolling bearing 30 and the other end surface 36 b of the inner ring 36. As a result, the base portion 61 can be disposed in the space between the other end surface 30 b of the rolling bearing 30 and the other end surface 36 b of the inner ring 36 without interfering with the inner ring 36.

As shown in FIG. 3, the pocket part P is formed in the outer peripheral surface 61a of the base part 61 so as to be recessed toward the inside in the radial direction. The pocket portion P is formed in a spherical shape whose diameter is slightly larger than that of the rolling element 35 (see FIG. 2), and the rolling element 35 can be inserted therein. For example, 13 pocket portions P are formed at equal intervals in the circumferential direction.
As shown in FIG. 4, the pocket portion P is formed so as to penetrate the base portion 61 in the axial direction. As a result, the retainer 60 can be reduced in weight and the material cost can be reduced. The pocket portion P may be formed so as to close the other side in the axial direction without penetrating the base portion 61 in the axial direction. In this case, the rigidity of the base portion 61 (that is, the retainer 60) can be improved.

As shown in FIG. 3, a plurality of sets (13 sets in this embodiment) of the pair of claw portions 63 and 63 are provided so as to correspond to the 13 pocket portions P, respectively, and are inserted into the pocket portions P. The rolling elements (see FIG. 2) are formed so as to be able to roll freely.
The pair of claw portions 63 and 63 has a base end portion 63b connected to the outer peripheral surface 61a of the base portion 61 in which the pocket portion P is formed. And a pair of nail | claw parts 63 and 63 are along the axial direction in the state which curved in the circular arc shape so that the distance of each other front-end | tip part 63a may approach from the other side of an axial direction to one side, respectively. It is erected. The inner surfaces of the pair of claw portions 63 and 63 are connected to the pocket portion P and have the same curvature as the pocket portion P. The opening diameter between the tip parts 63 a and 63 a of the pair of claw parts 63 and 63 is smaller than the diameter of the rolling element 35. Therefore, the pair of claw parts 63 and 63 can reliably hold the rolling element 35 without falling off from the pocket part P.

  Here, as shown in FIG. 2, when the rolling element 35 is inserted into the pocket portion P and held by the pair of claw portions 63, 63, the retainer 60 has the other axial direction of the base portion 61 in a side sectional view. The side end face 62 b is formed so as to contact the outer surface of the rolling element 35. Therefore, the outer surface of the rolling element 35 is exposed from the other end surface 62b of the base portion 61 to the other side through the pocket portion P penetrating in the axial direction. Thus, the base part 61 of the retainer 60 is formed as thin as possible.

As shown in FIG. 3, a connecting portion 65 that connects the pair of claw portions 63, 63 is provided between each pair of adjacent claw portions 63, 63. The connecting portion 65 is formed in a plate shape that closes the gap between the pair of adjacent claw portions 63 and 63 in each adjacent group. The other end surface in the axial direction of the connecting portion 65 is formed to be flush with the other end surface 62 b of the base portion 61.
The connecting portion 65 is formed with a recess 66 that is recessed by one step on the other side in the axial direction from the one end surface 62 a of the base portion 61. The recess 66 functions as a grease pocket that can be filled with grease (not shown). Therefore, the retainer 60 can be thinned in the axial direction while ensuring the rigidity of the retainer 60, and the retainer 60 can be provided with a grease pocket.

(Bearing device of the first embodiment)
FIG. 5 is a side sectional view of the bearing device 10 according to the first embodiment.
As shown in FIG. 5, the bearing device 10 according to the first embodiment has the above-described rolling bearing 30 with respect to the shaft 20 erected on the bottom portion 9 a of the housing 9 of the information recording / reproducing apparatus 1 (see FIG. 1). Is formed by arranging a pair in the axial direction of the shaft 20 with the outer ring spacer 55 interposed therebetween. The shaft 20, the pair of rolling bearings 30 and 30, and the outer ring spacer 55 are arranged coaxially and have a common central axis L1. In the following description, the outer ring spacer 55 side is referred to as the inner side in the axial direction when viewed from the pair of rolling bearings 30, 30, and the opposite side from the outer ring spacer 55 as viewed from the pair of rolling bearings 30, 30. Is called the outside in the axial direction.

The shaft 20 is a substantially cylindrical member extending along the central axis L1, and is formed of a metal material such as aluminum, iron, or stainless steel.
The diameter of the shaft 20 is formed to be smaller than the inner diameter of the inner ring 36 so that the shaft 20 can be inserted into the inner rings 36 of the pair of rolling bearings 30. In this case, the inner rings 36 and 36 of the pair of rolling bearings 30 and 30 are fixed to the shaft 20 by an adhesive, welding, or the like. In addition, the diameter of the shaft 20 is formed to be the same as the inner diameter of the inner ring 36 or slightly larger than the inner diameter of the inner ring 36 so that it can be press-fitted into the inner rings 36 of the pair of rolling bearings 30, 30. Also good. In this case, the inner rings 36 and 36 of the pair of rolling bearings 30 and 30 are press-fitted and fixed to 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 connected to the base end portion of the shaft 20. The reduced diameter portion 20 b is formed with a male screw (not shown) that is screwed into a female screw (not shown) formed on the bottom 9 a of the housing 9. The shaft 20 is erected on the bottom portion 9a of the housing 9 by the screwing. At this time, the flange portion 20 a is in contact with the bottom portion 9 a of the housing 9, whereby the shaft 20 is positioned in the height direction.

The pair of rolling bearings 30, 30 are arranged such that the tip 63 a of the claw 63 of the retainer 60 faces the outside in the axial direction of the shaft 20 (that is, the one side surfaces 30 a, 30 a of the pair of rolling bearings 30, 30 are respectively It is extrapolated to the shaft 20 (facing the outside in the axial direction).
The rolling bearing 30 on the base end side of the shaft 20 is fixed by, for example, an adhesive or the like in a state where the one end surface 36a of the inner ring 36 is in contact with the flange portion 20a of the shaft 20 and is positioned in the axial direction.

The outer ring spacer 55 is an annular member having a predetermined thickness in the axial direction, and is formed of a metal material such as aluminum, iron, or stainless steel.
The outer diameter of the outer ring spacer 55 is formed so as to be substantially the same as the outer diameter of the outer rings 31, 31 of the pair of rolling bearings 30, 30.
By providing the outer ring spacer 55 between the outer rings 31 and 31 of the pair of rolling bearings 30 and 30, a gap is provided between the other side end surfaces 36b and 36b of the inner ring 36 of the pair of rolling bearings 30 and 30. it can. Thus, the inner rings 36, 36 of the pair of rolling bearings 30, 30 can be relatively pressed, and the distance between the inner rings 36, 36 of the pair of rolling bearings 30, 30 can be shortened. Preload can be added.

(First modification of the first embodiment)
FIG. 6 is a side sectional view of the rolling bearing 30 and the bearing device 10 according to a first modification of the first embodiment.
Then, the rolling bearing 30 and the bearing apparatus 10 which concern on the 1st modification of 1st embodiment are demonstrated.
In the bearing device 10 according to the first embodiment, the rolling bearing 30 is arranged in the axial direction of the shaft 20 with the outer ring spacer 55 interposed with respect to the shaft 20 erected on the bottom 9 a of the housing 9. It was formed by arrange | positioning a pair by (for example, refer FIG. 5).
On the other hand, as shown in FIG. 6, the bearing device 10 according to the first modification of the first embodiment is aligned in the axial direction of the shaft 20 without interposing the outer ring spacer 55 (see FIG. 5). This is different from the first embodiment in that a pair is arranged. Detailed description of the same components as those in the first embodiment will be omitted, and only different portions will be described.

As shown in FIG. 6, in the bearing device 10 according to the first modification of the first embodiment, the other side end surfaces 31 b and 31 b of the outer rings 31 and 31 of the pair of rolling bearings 30 and 30 are abutted against each other. In the state, they are arranged side by side in the axial direction.
Here, the other end surface 36 b of the inner ring 36 of the rolling bearing 30 is arranged on one side in the axial direction with respect to the other end surface 31 b of the outer ring 31. Therefore, when the other end surfaces 31b, 31b of the outer rings 31, 31 of the pair of rolling bearings 30, 30 are abutted against each other, the other end surfaces 36b, 36b of the inner rings 36, 36 of the pair of rolling bearings 30, 30 are between. A gap is formed. Thus, the escape portion 40 for preventing the interference between the inner ring 36 and the base portion 61 of the retainer 60 is formed without interposing the outer ring spacer 55 (see FIG. 5), and the pair of rolling bearings 30, 30 inner rings 36 and 36 can be pressed relatively, and the distance between the inner rings 36 and 36 of the pair of rolling bearings 30 and 30 can be shortened. Therefore, preload can be applied to the pair of rolling bearings 30 and 30 without interposing the outer ring spacer 55 (see FIG. 5).

(Effect of the first modification of the first embodiment)
According to the first modification of the first embodiment, since the outer ring spacer 55 (see FIG. 5) is not provided, the bearing device 10 can be further reduced in thickness and cost can be reduced as compared with the first embodiment. Can do.

(Second modification of the first embodiment)
FIG. 7 is a side sectional view of the rolling bearing 30 and the bearing device 10 according to a second modification of the first embodiment.
Then, the rolling bearing 30 and the bearing apparatus 10 which concern on the 2nd modification of 1st embodiment are demonstrated.
In the bearing device 10 according to the first embodiment, the other end face 36b of the inner ring 36 is disposed on one side in the axial direction with respect to the other end face 31b of the outer ring 31, thereby reducing the axial thickness of the inner ring 36. The relief portion 40 of the base portion 61 of the retainer 60 was formed (see FIG. 5).
On the other hand, as shown in FIG. 7, the bearing device 10 according to the second modification of the first embodiment cuts off a part of the inner ring 36 corresponding to the base portion 61 of the retainer 60, thereby 40 is different from the first embodiment in that 40 is formed. Detailed description of the same components as those in the first embodiment will be omitted, and only different portions will be described.

(Inner ring)
As shown in FIG. 7, the other end surface 36 b of the inner ring 36 is disposed so as to be substantially flush with the other end surface 31 b of the outer ring 31. That is, the axial thickness of the inner ring 36 is substantially the same as the axial thickness of the outer ring 31.
Further, a portion of the inner ring 36 corresponding to the base portion 61 of the retainer 60 is cut away to form a relief portion 40. In the second modification of the present embodiment, the outer peripheral edge of the other end surface 36b of the inner ring 36 is cut away to form a relief portion 40.
The depth of cut along the axial direction of the escape portion 40 is formed to be deeper than the thickness of the base portion 61 in the axial direction. The outer diameter of the escape portion 40 is formed to be smaller than the inner diameter of the base portion 61. Thereby, the base part 61 does not interfere with the inner ring 36.

(Effect of the second modification of the first embodiment)
According to the second modification of the first embodiment, the escape portion 40 can be formed in a state where the axial thickness of the inner ring 36 is substantially the same as the axial thickness of the outer ring 31. Thereby, since the contact area of the shaft 20 and the inner ring | wheel 36 can be increased compared with 1st embodiment, the inner ring | wheel 36 can be firmly fixed with respect to the shaft 20. FIG.

(Third modification of the first embodiment)
FIG. 8 is a side cross-sectional view of the rolling bearing 30 and the bearing device 10 according to a third modification of the first embodiment.
Subsequently, the rolling bearing 30 and the bearing device 10 according to a third modification of the first embodiment will be described.
In the rolling bearing 30 according to the first embodiment, the shield member 25 is fitted in the stepped portion 33a of the one end surface 31a of the outer ring 31, and is arranged on one side in the axial direction. Further, the bearing device 10 according to the first embodiment applies a preload by relatively pressing the inner rings 36, 36 of the pair of rolling bearings 30, 30 (see FIG. 5 for both).
On the other hand, as shown in FIG. 8, in the rolling bearing 30 according to the third modification of the first embodiment, the shield member 25 is disposed on the other side in the axial direction of the rolling bearing 30, and The second embodiment is different from the first embodiment in that a preload is applied by relatively pressing the outer rings 31 and 31 of the pair of rolling bearings 30 and 30. Detailed description of the same components as those in the first embodiment will be omitted, and only different portions will be described.

(Rolling bearing according to a third modification of the first embodiment)
In the rolling bearing 30 according to the third modification of the first embodiment, the shield member 25 is fitted to a stepped portion 33b formed on the other end surface 31b of the outer ring 31. The radially inner end 27 of the shield member 25 is disposed away from the shaft 20 by a predetermined distance.
The shield member 25 closes the annular space formed between the outer ring 31 and the inner ring 36 from the other side in the axial direction, and the grease applied between the outer ring 31 and the inner ring 36 and the rolling element 35 is It is prevented from scattering from the other side in the axial direction to the outside.

(Bearing device according to a third modification of the first embodiment)
The bearing device 10 according to the third modification of the first embodiment includes an inner ring spacer 59 interposed between the inner rings 36 and 36 of the pair of rolling bearings 30 and 30, and the radial direction of the pair of rolling bearings 30 and 30. It is formed by providing a sleeve 57 on the outside. In the following description, the inner ring spacer 59 side is referred to as the inner side in the axial direction when viewed from the pair of rolling bearings 30 and 30, and the opposite side to the inner ring spacer 59 when viewed from the pair of rolling bearings 30 and 30. Is called the outside in the axial direction.

The inner ring spacer 59 is an annular member having a predetermined thickness in the axial direction, and is formed of a metal material such as aluminum, iron, or stainless steel. The inner ring spacer 59 is arranged coaxially with the shaft 20 and the central axis L1 of the pair of rolling bearings 30 and 30.
The inner diameter and outer diameter of the inner ring spacer 59 are formed to be substantially the same as the inner diameter and outer diameter of the inner rings 36 and 36 of the pair of rolling bearings 30 and 30.

Similarly to the inner ring spacer 59, the sleeve 57 is a substantially cylindrical member made of a metal material such as aluminum, iron, or stainless steel, and is formed by forging or machining.
The inner diameter of the sleeve 57 is formed to be larger than the outer diameter of the pair of rolling bearings 30, 30 so that the sleeve 57 can be extrapolated to the pair of rolling bearings 30, 30.

The pair of rolling bearings 30 and 30 are arranged such that the tip 63a of the claw portion 63 of the retainer 60 faces inward in the axial direction (that is, the one side surfaces 30a and 30a of the pair of rolling bearings 30 and 30 are in the axial direction, respectively. It is extrapolated to the shaft 20 (facing the inside).
By interposing the inner ring spacer 59 between the inner rings 36, 36 of the pair of rolling bearings 30, 30, a gap is provided between the one end surfaces 31a, 31a of the outer rings 31, 31 of the pair of rolling bearings 30, 30. be able to. Accordingly, the outer rings 31 and 31 of the pair of rolling bearings 30 and 30 can be relatively pressed, and the distance between the outer rings 31 and 31 of the pair of rolling bearings 30 and 30 can be shortened. Preload can be added. At this time, preload can be applied to the pair of rolling bearings 30 and 30 by fixing the outer rings 31 and 31 of the pair of rolling bearings 30 and 30 to the sleeve 57 with an adhesive or the like while relatively pressing.

(Effects of the first embodiment and the third modification of the first embodiment)
According to the retainer 60 which concerns on 1st embodiment and the 3rd modification of 1st embodiment, several pairs of nail | claw parts 63 and 63 are each on the outer peripheral surface 61a of the base part 61 in which the pocket part P was formed. Since the base end portions 63b and 63b are connected and are erected toward the one side in the axial direction, the retainer 60 is provided more than the conventional technology in which the base portion and the claw portion are continuously provided along the axial direction. Thinner in the axial direction. Further, the base portion 61 is disposed radially inward of the claw portion 63 by connecting the base end portions 63 b and 63 b of the plurality of pairs of claw portions 63 and 63 to the outer peripheral surface 61 a of the base portion 61. Therefore, even if the thickness of the base portion 61 is ensured, the influence on the thickness of the retainer 60 can be suppressed. Therefore, the retainer 60 can be thinned in the axial direction while ensuring the rigidity of the retainer 60.

  Further, when the rolling element 35 is inserted into the pocket portion P and held by the pair of claws 63, 63, the outer surface of the rolling element 35 is exposed from the other end face 62b in the axial direction of the base portion 61. Thus, the base portion 61 can be further reduced in thickness. Therefore, the retainer 60 can be further thinned in the axial direction.

  Moreover, the rigidity between a pair of nail | claw parts 63 and 63 can be improved by providing the connection part 65 which connects a pair of nail | claw parts 63 and 63. Therefore, it is possible to further reduce the thickness of the retainer 60 in the axial direction while ensuring the rigidity of the retainer 60.

  In addition, the recess 66 can be filled with grease by forming the recess 66 on one surface of the connecting portion 65 in the axial direction. That is, since the recess 66 of the connecting portion 65 functions as a grease pocket, the retainer 60 can be thinned in the axial direction while ensuring the rigidity of the retainer 60, and a grease pocket can be provided.

  Further, since the escape portion 40 for preventing interference with the base portion 61 of the retainer 60 is formed in the inner ring 36, the thin retainer 60 can be disposed without interfering with the inner ring 36. Therefore, the rolling bearing 30 can be reduced in thickness, weight, and cost while maintaining the performance of the rolling bearing 30 at the same level as the prior art.

  Further, since the above-described bearing device 10 that can be thinned is provided, the information recording / reproducing apparatus 1 can be thinned, lightened, and reduced in cost.

(Second embodiment)
FIG. 9 is a side sectional view of the rolling bearing 230 according to the second embodiment.
FIG. 10 is a perspective view of the retainer 260 of the second embodiment when viewed from one side in the axial direction.
FIG. 11 is a perspective view of the retainer 260 of the second embodiment when viewed from the other side in the axial direction.
FIG. 12 is a side sectional view of the bearing device 210 according to the second embodiment.
Next, the rolling bearing 230 and the bearing device 210 according to the second embodiment will be described.
The rolling bearing 30 according to the first embodiment shown in FIG. 2 has a pocket portion P that is recessed toward the inside in the radial direction on the outer peripheral surface 61a of the base portion 61 of the retainer 60 shown in FIG. Base end portions 63 b and 63 b of the portions 63 and 63 were connected to the outer peripheral surface 61 a of the base portion 61.
On the other hand, in the rolling bearing 230 according to the second embodiment shown in FIG. 9, the pocket portion P is formed to be recessed outward in the radial direction on the inner peripheral surface 261b of the base portion 261 of the retainer 260 shown in FIG. The base end portions 263b and 263b of the pair of claw portions 263 and 263 are different from the first embodiment in that they are connected to the inner peripheral surface 261b of the base portion 261. Detailed description of the same components as those in the first embodiment will be omitted, and only different portions will be described.

(Rolling bearing of the second embodiment)
As shown in FIG. 9, the inner ring 36 has a thickness T in the axial direction, and the one end face 36 a and the other end face 36 b in the axial direction of the inner ring 36 are respectively on one side in the axial direction of the rolling bearing 230. It is flush with the end face 230a and the other end face 230b.
An inner ring rolling surface 39 is formed on the outer peripheral surface 37 of the inner ring 36. The inner ring rolling surface 39 has an arcuate side surface cross section along the outer surface of the rolling element 35 at the axial intermediate portion of the inner ring 36. The inner ring rolling surface 39 is formed over the entire circumference of the outer circumferential surface 37 of the inner ring 36.
The radially outer edges of the one end face 36a and the other end face 36b of the inner ring 36 are stepped portions 38a and 38b that are recessed by one step, respectively. A shield member 225 is fitted to the stepped portion 38b formed on the other end surface 36b of the inner ring 36.

The inner diameter of the shield member 225 is formed to be slightly smaller than the inner diameter of the side surface of the other stepped portion 38b. An inner end 227 in the radial direction of the shield member 225 is a bent portion 227a that is bent so as to protrude toward one side in the axial direction. The shield member 225 is fitted and fixed to the outer side in the radial direction of the stepped portion 38b on the other end surface 36b of the inner ring 36 in a state where the bent portion 227a is elastically deformed to the outer side in the radial direction.
The outer diameter of the shield member 225 is formed to be slightly smaller than the outer diameter of the outer ring 31.

  The outer ring 31 is a substantially cylindrical member made of a metal material such as stainless steel having a predetermined thickness in the axial direction, and is formed by forging or machining, for example. The axial thickness of the outer ring 31 in the present embodiment is, for example, about ½ of the thickness T of the inner ring 36 and is formed to be thinner than the thickness of the rolling bearing 230.

An outer ring rolling surface 34 is formed on the inner peripheral surface 32 of the outer ring 31. The outer ring rolling surface 34 has an arcuate side cross section so that the inner diameter of the outer ring 31 gradually increases from one axial side of the outer ring 31 toward the other side.
The one end surface 31 a in the axial direction of the outer ring 31 is arranged so as to be substantially flush with the one end surface 36 a of the inner ring 36, and is flush with the one end surface 230 a in the axial direction of the rolling bearing 230. .

  Here, the outer ring 31 is formed to be thinner than the rolling bearing 230, and the other end face 31b of the outer ring 31 is more axial than the other end face 36b of the inner ring 36 (that is, the other end face 230b of the rolling bearing 230). It is arranged on one side. Thereby, a space is formed over the entire circumference between the other end surface 230 b of the rolling bearing 230 and the other end surface 31 b of the outer ring 31. A base portion 261 of a retainer 260 described later is disposed in this space. Thus, the other end surface 31b of the outer ring 31 is disposed on one side in the axial direction with respect to the other end surface 230b of the rolling bearing 230, thereby preventing interference between the outer ring 31 and the base portion 261 of the retainer 260. An escape portion 240 is formed.

(Retainer of the second embodiment)
The thickness of the base portion 261 in the axial direction is formed so as to be thinner than the separation distance along the axial direction between the other end surface 230 b of the rolling bearing 230 and the other end surface 31 b of the outer ring 31. As a result, the base portion 261 can be disposed in the space between the other end surface 230 b of the rolling bearing 230 and the other end surface 31 b of the outer ring 31 without interfering with the outer ring 31.

As shown in FIG. 10, a pocket portion P is formed in the inner peripheral surface 261 b of the base portion 261 so as to be recessed outward in the radial direction.
As shown in FIG. 11, the pocket portion P is formed so as to penetrate the base portion 261 in the axial direction.
As shown in FIG. 10, the pair of claw portions 263 and 263 has a base end portion 263b connected to an inner peripheral surface 261b of a base portion 261 in which a pocket portion P is formed.
A connecting portion 265 for connecting the pair of claw portions 263 and 263 to each other is provided between each pair of adjacent claw portions 263 and 263. The connecting portion 265 is formed in a plate shape that closes a gap between a pair of adjacent claw portions 263 and 263 in each pair. The connection portion 265 has a recess 266 that is recessed by one step on the other side in the axial direction from the one end surface 262a of the base portion 261. The recess 266 functions as a grease pocket that can be filled with grease (not shown).

As shown in FIG. 12, the bearing device 210 according to the second embodiment is provided with a sleeve 51 on the radially outer side of the pair of rolling bearings 230 and 230.
The sleeve 51 fixes the outer rings 31 and 31 of the pair of rolling bearings 230 and 230 so as not to move relative to each other. The sleeve 51 is a member made of a metal material such as aluminum, iron, or stainless steel, forging, machining, or the like. It is formed by. The sleeve 51 includes a cylindrical main body cylinder portion 52, and a spacer portion 53 that protrudes inward in the radial direction at an axial intermediate portion of the main body cylinder portion 52. In the following description, when viewed from the pair of rolling bearings 230, 230, the spacer part 53 side interposed between the pair of rolling bearings 230, 230 is referred to as the inner side in the axial direction, and the pair of rolling bearings 230, 230. When viewed from the side, the side opposite to the spacer portion 53 is referred to as the axially outer side.

The inner diameter of the sleeve 51 is larger than the outer diameter of the outer rings 31, 31 so that the outer rings 31, 31 of the pair of rolling bearings 230, 230 can be inserted and arranged inside the main body cylinder part 52 except for the spacer portion 53. It is formed as follows. The axial length of the sleeve 51 is appropriately set according to the number of arms 8 (see FIG. 1).
The pair of rolling bearings 230 and 230 are arranged such that the front end portion 263a of the claw portion 263 of the retainer 260 faces the inner side in the axial direction (that is, the one side surfaces 230a and 230a of the pair of rolling bearings 230 and 230 are in the axial direction. It is extrapolated to the shaft 20 and fixed to the sleeve 51 (facing inward).
By interposing the spacer portion 53 between the outer rings 31 and 31 of the pair of rolling bearings 230 and 230, a gap can be provided between the one end surfaces 36a and 36a of the inner ring 36 of the pair of rolling bearings 230 and 230. . Thus, as in the first embodiment, the inner rings 36, 36 of the pair of rolling bearings 230, 230 can be relatively pressed, and the distance between the inner rings 36, 36 of the pair of rolling bearings 230, 230 can be shortened. A preload can be applied to the pair of rolling bearings 230, 230.

(Effect of the second embodiment)
According to the retainer 260 according to the second embodiment, the plurality of pairs of claw portions 263 and 263 are connected to the base end portions 263b and 263b on the inner peripheral surface 261b of the base portion 261 in which the pocket portions P are formed, respectively. Thus, the retainer 260 can be made thinner in the axial direction than in the prior art in which the base portion and the claw portion are continuously provided along the axial direction. Further, the base end portions 263b and 263b of the plurality of pairs of claw portions 263 and 263 are connected to the inner peripheral surface 261b of the base portion 261, so that the base portion 261 is disposed on the outer side in the radial direction from the claw portion 263. Therefore, even if the thickness of the base portion 261 is ensured, the influence on the thickness of the retainer 260 can be suppressed. Therefore, the retainer 260 can be thinned in the axial direction while ensuring the rigidity of the retainer 260.

  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.

  In the first embodiment, the case where the bearing device 10 is applied as the rotation shaft of the arm 8 of the information recording / reproducing apparatus 1 has been described as an example. However, the application is limited to the rotation shaft of the arm 8 of the information recording / reproducing apparatus 1. Not. For example, the bearing devices 10 and 210 may be applied as the rotating shaft of the spindle motor 7 that rotates the disk D of the information recording / reproducing apparatus 1, and each embodiment is used as the rotating shaft of a polygon mirror for scanning a laser light source. Also, the bearing devices 10 and 210 of the modified examples may be applied.

The shape of the shaft 20 is not limited to each embodiment and each modification. For example, although the flange part 20a was formed in the base end part of the shaft 20 of each embodiment, the flange part 20a does not need to be formed.
Moreover, the number of sets of the pair of claw portions 63, 63, 263, 263 of the retainers 60, 260 of each embodiment is not limited to each embodiment. Furthermore, the arrangement number of the rolling elements 35 is not limited to each embodiment.

  In each embodiment, the connection portions 65 and 265 are provided between the pair of adjacent claw portions 63, 63, 263, and 263 of the retainers 60 and 260, but the connection portions 65 and 265 may not be provided. . Moreover, you may provide the connection parts 65 and 265 partially.

In each embodiment, although the pocket part P of the retainers 60 and 260 penetrates the base parts 61 and 261 of the retainers 60 and 260 in the axial direction, they may not penetrate in the axial direction.
In each embodiment, the outer surface of the rolling element 35 is exposed to the other side from the other end surfaces 62b and 262b of the base parts 61 and 261 via the pocket portion P. However, the outer surface of the rolling element 35 is the base. It does not need to be exposed from the other side end surfaces 62b and 262b of the parts 61 and 261.

  In the second embodiment, the escape portion 240 is formed by shortening (that is, thinning) the axial length of the outer ring 31 corresponding to the base portion 261 of the retainer 260. The embodiments are not limited. For example, the escape portion may be formed by cutting out a part of the outer ring 31 corresponding to the base portion 261 of the retainer 260.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Information recording / reproducing apparatus 2 ... Slider 8 ... Arm (rotating member) 9 ... Housing 10, 210 ... Bearing apparatus 20 ... Shaft 30, 230 ... Rolling bearing 31 ... Outer ring 35 ... Rolling element 36 ... Inner ring 40, 240 ... Relief part 60, 260 ... Retainer (retainer) 61, 261 ... Base part 61a ... Outer surface 261b .... Inner peripheral surfaces 63, 263 ... Claw parts 63b, 263b ... Base end parts 62b, 262b ... End face on the other side (end face on the other side) 65, 265 ... Connection parts 66, 266 ...・ Recess

Claims (7)

A plurality of rolling elements disposed between an outer ring and an inner ring arranged on the same axis are held in a state of being uniformly arranged in the circumferential direction so as to be freely rollable,
An annular base portion disposed coaxially with the outer ring and the inner ring;
A spherical pocket portion that is recessed in the radial direction on either the inner peripheral surface or the outer peripheral surface of the base portion, and into which the rolling elements are inserted;
A plurality of sets of claw portions capable of rolling the rolling elements inserted into the pocket portions; and
With
A plurality of sets of the pair of claw portions are respectively erected toward one side in the axial direction with a base end portion connected to either the inner peripheral surface or the outer peripheral surface where the pocket portion is formed. A cage characterized by having The cage according to claim 1,
The pocket portion is formed through the base portion in the axial direction,
When the rolling element is inserted into the pocket portion and held by the pair of claws, the outer surface of the rolling element is exposed from the end surface of the base portion on the other axial side. vessel. The cage according to claim 1 or 2,
A retainer for connecting the pair of claw parts to each other is provided between the plurality of pairs of claw parts. The cage according to claim 3, wherein
The retainer is characterized in that a concave portion recessed in the axial direction is formed on a surface of the connection portion on the one side in the axial direction. A cage according to claim 1,
One of the outer ring and the inner ring is provided with a relief portion for preventing interference with the base portion at a position corresponding to the base portion of the cage. A rolling bearing according to claim 5;
A shaft on which the rolling bearing is extrapolated;
A bearing device comprising: A bearing device according to claim 6,
A housing that supports one end of the bearing device;
A rotating member that is extrapolated to the outer ring and rotates around the central axis of the shaft;
A slider mounted on the rotating member for recording and reproducing information with a magnetic recording medium;
An information recording / reproducing apparatus comprising:

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